Merge branch 'master' into blender2.8

[blender.git] / source / blender / editors / animation / anim_filter.c

/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version. 
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2008 Blender Foundation, Joshua Leung
 * All rights reserved.
 *
 * 
 * Contributor(s): Joshua Leung (original author)
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/editors/animation/anim_filter.c
 *  \ingroup edanimation
 */


/* This file contains a system used to provide a layer of abstraction between sources
 * of animation data and tools in Animation Editors. The method used here involves 
 * generating a list of edit structures which enable tools to naively perform the actions 
 * they require without all the boiler-plate associated with loops within loops and checking 
 * for cases to ignore. 
 *
 * While this is primarily used for the Action/Dopesheet Editor (and its accessory modes),
 * the Graph Editor also uses this for its channel list and for determining which curves
 * are being edited. Likewise, the NLA Editor also uses this for its channel list and in
 * its operators.
 *
 * Note: much of the original system this was based on was built before the creation of the RNA
 * system. In future, it would be interesting to replace some parts of this code with RNA queries,
 * however, RNA does not eliminate some of the boiler-plate reduction benefits presented by this 
 * system, so if any such work does occur, it should only be used for the internals used here...
 *
 * -- Joshua Leung, Dec 2008 (Last revision July 2009)
 */

#include <string.h>

#include "DNA_anim_types.h"
#include "DNA_armature_types.h"
#include "DNA_camera_types.h"
#include "DNA_cachefile_types.h"
#include "DNA_lamp_types.h"
#include "DNA_lattice_types.h"
#include "DNA_linestyle_types.h"
#include "DNA_key_types.h"
#include "DNA_mask_types.h"
#include "DNA_material_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meta_types.h"
#include "DNA_movieclip_types.h"
#include "DNA_node_types.h"
#include "DNA_particle_types.h"
#include "DNA_space_types.h"
#include "DNA_sequence_types.h"
#include "DNA_scene_types.h"
#include "DNA_screen_types.h"
#include "DNA_speaker_types.h"
#include "DNA_world_types.h"
#include "DNA_gpencil_types.h"
#include "DNA_object_types.h"
#include "DNA_userdef_types.h"
#include "DNA_layer_types.h"

#include "MEM_guardedalloc.h"

#include "BLI_blenlib.h"
#include "BLI_utildefines.h"
#include "BLI_alloca.h"
#include "BLI_ghash.h"
#include "BLI_string.h"

#include "BKE_animsys.h"
#include "BKE_action.h"
#include "BKE_fcurve.h"
#include "BKE_context.h"
#include "BKE_global.h"
#include "BKE_group.h"
#include "BKE_key.h"
#include "BKE_layer.h"
#include "BKE_main.h"
#include "BKE_material.h"
#include "BKE_modifier.h"
#include "BKE_node.h"
#include "BKE_mask.h"
#include "BKE_sequencer.h"

#include "ED_anim_api.h"
#include "ED_markers.h"

#include "UI_resources.h"  /* for TH_KEYFRAME_SCALE lookup */

/* ************************************************************ */
/* Blender Context <-> Animation Context mapping */

/* ----------- Private Stuff - General -------------------- */

/* Get vertical scaling factor (i.e. typically used for keyframe size) */
static void animedit_get_yscale_factor(bAnimContext *ac)
{
        bTheme *btheme = UI_GetTheme();
        
        /* grab scale factor directly from action editor setting
         * NOTE: This theme setting doesn't have an ID, as it cannot be accessed normally
         *       since it is a float, and the theem settings methods can only handle chars.
         */
        ac->yscale_fac = btheme->tact.keyframe_scale_fac;
        
        /* clamp to avoid problems with uninitialised values... */
        if (ac->yscale_fac < 0.1f)
                ac->yscale_fac = 1.0f;
        //printf("yscale_fac = %f\n", ac->yscale_fac);
}

/* ----------- Private Stuff - Action Editor ------------- */

/* Get shapekey data being edited (for Action Editor -> ShapeKey mode) */
/* Note: there's a similar function in key.c (BKE_key_from_object) */
static Key *actedit_get_shapekeys(bAnimContext *ac)
{
        SceneLayer *sl = ac->scene_layer;
        Object *ob;
        Key *key;
        
        ob = OBACT_NEW(sl);
        if (ob == NULL) 
                return NULL;
        
        /* XXX pinning is not available in 'ShapeKey' mode... */
        //if (saction->pin) return NULL;
        
        /* shapekey data is stored with geometry data */
        key = BKE_key_from_object(ob);
        
        if (key) {
                if (key->type == KEY_RELATIVE)
                        return key;
        }
        
        return NULL;
}

/* Get data being edited in Action Editor (depending on current 'mode') */
static bool actedit_get_context(bAnimContext *ac, SpaceAction *saction)
{
        /* get dopesheet */
        ac->ads = &saction->ads;
        
        /* sync settings with current view status, then return appropriate data */
        switch (saction->mode) {
                case SACTCONT_ACTION: /* 'Action Editor' */
                        /* if not pinned, sync with active object */
                        if (/*saction->pin == 0*/ true) {
                                if (ac->obact && ac->obact->adt)
                                        saction->action = ac->obact->adt->action;
                                else
                                        saction->action = NULL;
                        }
                        
                        ac->datatype = ANIMCONT_ACTION;
                        ac->data = saction->action;
                        
                        ac->mode = saction->mode;
                        return true;
                        
                case SACTCONT_SHAPEKEY: /* 'ShapeKey Editor' */
                        ac->datatype = ANIMCONT_SHAPEKEY;
                        ac->data = actedit_get_shapekeys(ac);
                        
                        /* if not pinned, sync with active object */
                        if (/*saction->pin == 0*/ true) {
                                Key *key = (Key *)ac->data;
                                
                                if (key && key->adt)
                                        saction->action = key->adt->action;
                                else
                                        saction->action = NULL;
                        }
                        
                        ac->mode = saction->mode;
                        return true;
                
                case SACTCONT_GPENCIL: /* Grease Pencil */ /* XXX review how this mode is handled... */
                        /* update scene-pointer (no need to check for pinning yet, as not implemented) */
                        saction->ads.source = (ID *)ac->scene;
                        
                        ac->datatype = ANIMCONT_GPENCIL;
                        ac->data = &saction->ads;
                        
                        ac->mode = saction->mode;
                        return true;

                case SACTCONT_CACHEFILE: /* Cache File */ /* XXX review how this mode is handled... */
                        /* update scene-pointer (no need to check for pinning yet, as not implemented) */
                        saction->ads.source = (ID *)ac->scene;

                        ac->datatype = ANIMCONT_CHANNEL;
                        ac->data = &saction->ads;

                        ac->mode = saction->mode;
                        return true;
                        
                case SACTCONT_MASK: /* Mask */ /* XXX review how this mode is handled... */
                {
                        /* TODO, other methods to get the mask */
                        // Sequence *seq = BKE_sequencer_active_get(ac->scene);
                        //MovieClip *clip = ac->scene->clip;
//                      struct Mask *mask = seq ? seq->mask : NULL;
                        
                        /* update scene-pointer (no need to check for pinning yet, as not implemented) */
                        saction->ads.source = (ID *)ac->scene;
                        
                        ac->datatype = ANIMCONT_MASK;
                        ac->data = &saction->ads;
                        
                        ac->mode = saction->mode;
                        return true;
                }
                case SACTCONT_DOPESHEET: /* DopeSheet */
                        /* update scene-pointer (no need to check for pinning yet, as not implemented) */
                        saction->ads.source = (ID *)ac->scene;
                        
                        ac->datatype = ANIMCONT_DOPESHEET;
                        ac->data = &saction->ads;
                        
                        ac->mode = saction->mode;
                        return true;
                
                default: /* unhandled yet */
                        ac->datatype = ANIMCONT_NONE;
                        ac->data = NULL;
                        
                        ac->mode = -1;
                        return false;
        }
}

/* ----------- Private Stuff - Graph Editor ------------- */

/* Get data being edited in Graph Editor (depending on current 'mode') */
static bool graphedit_get_context(bAnimContext *ac, SpaceIpo *sipo)
{
        /* init dopesheet data if non-existent (i.e. for old files) */
        if (sipo->ads == NULL) {
                sipo->ads = MEM_callocN(sizeof(bDopeSheet), "GraphEdit DopeSheet");
                sipo->ads->source = (ID *)ac->scene;
        }
        ac->ads = sipo->ads;
        
        /* set settings for Graph Editor - "Selected = Editable" */
        if (sipo->flag & SIPO_SELCUVERTSONLY)
                sipo->ads->filterflag |= ADS_FILTER_SELEDIT;
        else
                sipo->ads->filterflag &= ~ADS_FILTER_SELEDIT;
        
        /* sync settings with current view status, then return appropriate data */
        switch (sipo->mode) {
                case SIPO_MODE_ANIMATION:  /* Animation F-Curve Editor */
                        /* update scene-pointer (no need to check for pinning yet, as not implemented) */
                        sipo->ads->source = (ID *)ac->scene;
                        sipo->ads->filterflag &= ~ADS_FILTER_ONLYDRIVERS;
                        
                        ac->datatype = ANIMCONT_FCURVES;
                        ac->data = sipo->ads;
                        
                        ac->mode = sipo->mode;
                        return true;
                
                case SIPO_MODE_DRIVERS:  /* Driver F-Curve Editor */
                        /* update scene-pointer (no need to check for pinning yet, as not implemented) */
                        sipo->ads->source = (ID *)ac->scene;
                        sipo->ads->filterflag |= ADS_FILTER_ONLYDRIVERS;
                        
                        ac->datatype = ANIMCONT_DRIVERS;
                        ac->data = sipo->ads;
                        
                        ac->mode = sipo->mode;
                        return true;
                
                default: /* unhandled yet */
                        ac->datatype = ANIMCONT_NONE;
                        ac->data = NULL;
                        
                        ac->mode = -1;
                        return false;
        }
}

/* ----------- Private Stuff - NLA Editor ------------- */

/* Get data being edited in Graph Editor (depending on current 'mode') */
static bool nlaedit_get_context(bAnimContext *ac, SpaceNla *snla)
{
        /* init dopesheet data if non-existent (i.e. for old files) */
        if (snla->ads == NULL)
                snla->ads = MEM_callocN(sizeof(bDopeSheet), "NlaEdit DopeSheet");
        ac->ads = snla->ads;
        
        /* sync settings with current view status, then return appropriate data */
        /* update scene-pointer (no need to check for pinning yet, as not implemented) */
        snla->ads->source = (ID *)ac->scene;
        snla->ads->filterflag |= ADS_FILTER_ONLYNLA;
        
        ac->datatype = ANIMCONT_NLA;
        ac->data = snla->ads;
        
        return true;
}

/* ----------- Public API --------------- */

/* Obtain current anim-data context, given that context info from Blender context has already been set 
 *      - AnimContext to write to is provided as pointer to var on stack so that we don't have
 *        allocation/freeing costs (which are not that avoidable with channels).
 */
bool ANIM_animdata_context_getdata(bAnimContext *ac)
{
        SpaceLink *sl = ac->sl;
        bool ok = false;
        
        /* context depends on editor we are currently in */
        if (sl) {
                switch (ac->spacetype) {
                        case SPACE_ACTION:
                        {
                                SpaceAction *saction = (SpaceAction *)sl;
                                ok = actedit_get_context(ac, saction);
                                break;
                        }
                        case SPACE_IPO:
                        {
                                SpaceIpo *sipo = (SpaceIpo *)sl;
                                ok = graphedit_get_context(ac, sipo);
                                break;
                        }
                        case SPACE_NLA:
                        {
                                SpaceNla *snla = (SpaceNla *)sl;
                                ok = nlaedit_get_context(ac, snla);
                                break;
                        }
                }
        }
        
        /* check if there's any valid data */
        return (ok && ac->data);
}

/* Obtain current anim-data context from Blender Context info 
 *      - AnimContext to write to is provided as pointer to var on stack so that we don't have
 *        allocation/freeing costs (which are not that avoidable with channels).
 *      - Clears data and sets the information from Blender Context which is useful
 */
bool ANIM_animdata_get_context(const bContext *C, bAnimContext *ac)
{
        ScrArea *sa = CTX_wm_area(C);
        ARegion *ar = CTX_wm_region(C);
        SpaceLink *sl = CTX_wm_space_data(C);
        Scene *scene = CTX_data_scene(C);
        
        /* clear old context info */
        if (ac == NULL) return false;
        memset(ac, 0, sizeof(bAnimContext));
        
        /* get useful default context settings from context */
        ac->scene = scene;
        if (scene) {
                ac->markers = ED_context_get_markers(C);
        }
        ac->scene_layer = CTX_data_scene_layer(C);
        ac->obact = (ac->scene_layer->basact) ? ac->scene_layer->basact->object : NULL;
        ac->sa = sa;
        ac->ar = ar;
        ac->sl = sl;
        ac->spacetype = (sa) ? sa->spacetype : 0;
        ac->regiontype = (ar) ? ar->regiontype : 0;
        
        /* initialise default y-scale factor */
        animedit_get_yscale_factor(ac);
        
        /* get data context info */
        // XXX: if the below fails, try to grab this info from context instead... (to allow for scripting)
        return ANIM_animdata_context_getdata(ac);
}

/* ************************************************************ */
/* Blender Data <-- Filter --> Channels to be operated on */

/* macros to use before/after getting the sub-channels of some channel,
 * to abstract away some of the tricky logic involved
 *
 * cases:
 *      1) Graph Edit main area (just data) OR channels visible in Channel List
 *      2) If not showing channels, we're only interested in the data (Action Editor's editing)
 *      3) We don't care what data, we just care there is some (so that a collapsed 
 *         channel can be kept around). No need to clear channels-flag in order to 
 *         keep expander channels with no sub-data out, as those cases should get
 *         dealt with by the recursive detection idiom in place.
 *
 * Implementation Note:
 *  YES the _doSubChannels variable is NOT read anywhere. BUT, this is NOT an excuse
 *  to go steamrolling the logic into a single-line expression as from experience,
 *  those are notoriously difficult to read + debug when extending later on. The code
 *  below is purposefully laid out so that each case noted above corresponds clearly to
 *  one case below.
 */
#define BEGIN_ANIMFILTER_SUBCHANNELS(expanded_check) \
        { \
                int _filter = filter_mode; \
                short _doSubChannels = 0; \
                if (!(filter_mode & ANIMFILTER_LIST_VISIBLE) || (expanded_check)) \
                        _doSubChannels = 1; \
                else if (!(filter_mode & ANIMFILTER_LIST_CHANNELS)) \
                        _doSubChannels = 2; \
                else { \
                        filter_mode |= ANIMFILTER_TMP_PEEK; \
                } \
                 \
                { \
                        (void) _doSubChannels; \
                }
/* ... standard sub-channel filtering can go on here now ... */
#define END_ANIMFILTER_SUBCHANNELS \
                filter_mode = _filter; \
        } (void)0

/* ............................... */

/* quick macro to test if AnimData is usable */
#define ANIMDATA_HAS_KEYS(id) ((id)->adt && (id)->adt->action)

/* quick macro to test if AnimData is usable for drivers */
#define ANIMDATA_HAS_DRIVERS(id) ((id)->adt && (id)->adt->drivers.first)

/* quick macro to test if AnimData is usable for NLA */
#define ANIMDATA_HAS_NLA(id) ((id)->adt && (id)->adt->nla_tracks.first)

/* Quick macro to test for all three above usability tests, performing the appropriate provided 
 * action for each when the AnimData context is appropriate. 
 *
 * Priority order for this goes (most important, to least): AnimData blocks, NLA, Drivers, Keyframes.
 *
 * For this to work correctly, a standard set of data needs to be available within the scope that this
 * gets called in: 
 *  - ListBase anim_data;
 *  - bDopeSheet *ads;
 *  - bAnimListElem *ale;
 *  - size_t items;
 *
 *  - id: ID block which should have an AnimData pointer following it immediately, to use
 *  - adtOk: line or block of code to execute for AnimData-blocks case (usually ANIMDATA_ADD_ANIMDATA)
 *  - nlaOk: line or block of code to execute for NLA tracks+strips case
 *  - driversOk: line or block of code to execute for Drivers case
 *  - nlaKeysOk: line or block of code for NLA Strip Keyframes case
 *  - keysOk: line or block of code for Keyframes case
 *
 * The checks for the various cases are as follows:
 *      0) top level: checks for animdata and also that all the F-Curves for the block will be visible
 *      1) animdata check: for filtering animdata blocks only
 *      2A) nla tracks: include animdata block's data as there are NLA tracks+strips there
 *      2B) actions to convert to nla: include animdata block's data as there is an action that can be 
 *              converted to a new NLA strip, and the filtering options allow this
 *      2C) allow non-animated datablocks to be included so that datablocks can be added
 *      3) drivers: include drivers from animdata block (for Drivers mode in Graph Editor)
 *  4A) nla strip keyframes: these are the per-strip controls for time and influence
 *      4B) normal keyframes: only when there is an active action
 */
#define ANIMDATA_FILTER_CASES(id, adtOk, nlaOk, driversOk, nlaKeysOk, keysOk) \
        { \
                if ((id)->adt) { \
                        if (!(filter_mode & ANIMFILTER_CURVE_VISIBLE) || !((id)->adt->flag & ADT_CURVES_NOT_VISIBLE)) { \
                                if (filter_mode & ANIMFILTER_ANIMDATA) { \
                                        adtOk \
                                } \
                                else if (ads->filterflag & ADS_FILTER_ONLYNLA) { \
                                        if (ANIMDATA_HAS_NLA(id)) { \
                                                nlaOk \
                                        } \
                                        else if (!(ads->filterflag & ADS_FILTER_NLA_NOACT) || ANIMDATA_HAS_KEYS(id)) { \
                                                nlaOk \
                                        } \
                                } \
                                else if (ads->filterflag & ADS_FILTER_ONLYDRIVERS) { \
                                        if (ANIMDATA_HAS_DRIVERS(id)) { \
                                                driversOk \
                                        } \
                                } \
                                else { \
                                        if (ANIMDATA_HAS_NLA(id)) { \
                                                nlaKeysOk \
                                        } \
                                        if (ANIMDATA_HAS_KEYS(id)) { \
                                                keysOk \
                                        } \
                                } \
                        } \
                } \
        } (void)0

/* ............................... */

/* Add a new animation channel, taking into account the "peek" flag, which is used to just check 
 * whether any channels will be added (but without needing them to actually get created).
 *
 * ! This causes the calling function to return early if we're only "peeking" for channels
 */
// XXX: ale_statement stuff is really a hack for one special case. It shouldn't really be needed...
#define ANIMCHANNEL_NEW_CHANNEL_FULL(channel_data, channel_type, owner_id, ale_statement) \
        if (filter_mode & ANIMFILTER_TMP_PEEK) \
                return 1; \
        else { \
                bAnimListElem *ale = make_new_animlistelem(channel_data, channel_type, (ID *)owner_id); \
                if (ale) { \
                        BLI_addtail(anim_data, ale); \
                        items ++; \
                        ale_statement \
                } \
        } (void)0
        
#define ANIMCHANNEL_NEW_CHANNEL(channel_data, channel_type, owner_id) \
        ANIMCHANNEL_NEW_CHANNEL_FULL(channel_data, channel_type, owner_id, {})
        
/* ............................... */
        
/* quick macro to test if an anim-channel representing an AnimData block is suitably active */
#define ANIMCHANNEL_ACTIVEOK(ale) \
        (!(filter_mode & ANIMFILTER_ACTIVE) || !(ale->adt) || (ale->adt->flag & ADT_UI_ACTIVE) )

/* quick macro to test if an anim-channel (F-Curve, Group, etc.) is selected in an acceptable way */
#define ANIMCHANNEL_SELOK(test_func) \
        (!(filter_mode & (ANIMFILTER_SEL | ANIMFILTER_UNSEL)) || \
         ((filter_mode & ANIMFILTER_SEL) && test_func) || \
         ((filter_mode & ANIMFILTER_UNSEL) && test_func == 0) )
                  
/* quick macro to test if an anim-channel (F-Curve) is selected ok for editing purposes 
 *      - _SELEDIT means that only selected curves will have visible+editable keyframes
 *
 * checks here work as follows:
 *      1) seledit off - don't need to consider the implications of this option
 *      2) foredit off - we're not considering editing, so channel is ok still
 *      3) test_func (i.e. selection test) - only if selected, this test will pass
 */
#define ANIMCHANNEL_SELEDITOK(test_func) \
        (!(filter_mode & ANIMFILTER_SELEDIT) || \
         !(filter_mode & ANIMFILTER_FOREDIT) || \
         (test_func) )

/* ----------- 'Private' Stuff --------------- */

/* this function allocates memory for a new bAnimListElem struct for the 
 * provided animation channel-data. 
 */
static bAnimListElem *make_new_animlistelem(void *data, short datatype, ID *owner_id)
{
        bAnimListElem *ale = NULL;
        
        /* only allocate memory if there is data to convert */
        if (data) {
                /* allocate and set generic data */
                ale = MEM_callocN(sizeof(bAnimListElem), "bAnimListElem");
                
                ale->data = data;
                ale->type = datatype;
                
                ale->id = owner_id;
                ale->adt = BKE_animdata_from_id(owner_id);
                
                /* do specifics */
                switch (datatype) {
                        case ANIMTYPE_SUMMARY:
                        {
                                /* nothing to include for now... this is just a dummy wrappy around all the other channels 
                                 * in the DopeSheet, and gets included at the start of the list
                                 */
                                ale->key_data = NULL;
                                ale->datatype = ALE_ALL;
                                break;
                        }
                        case ANIMTYPE_SCENE:
                        {
                                Scene *sce = (Scene *)data;
                                
                                ale->flag = sce->flag;
                                
                                ale->key_data = sce;
                                ale->datatype = ALE_SCE;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_OBJECT:
                        {
                                Base *base = (Base *)data;
                                Object *ob = base->object;
                                
                                ale->flag = ob->flag;
                                
                                ale->key_data = ob;
                                ale->datatype = ALE_OB;
                                
                                ale->adt = BKE_animdata_from_id(&ob->id);
                                break;
                        }
                        case ANIMTYPE_FILLACTD:
                        {
                                bAction *act = (bAction *)data;
                                
                                ale->flag = act->flag;
                                
                                ale->key_data = act;
                                ale->datatype = ALE_ACT;
                                break;
                        }
                        case ANIMTYPE_FILLDRIVERS:
                        {
                                AnimData *adt = (AnimData *)data;
                                
                                ale->flag = adt->flag;
                                
                                // XXX... drivers don't show summary for now
                                ale->key_data = NULL;
                                ale->datatype = ALE_NONE;
                                break;
                        }
                        case ANIMTYPE_DSMAT:
                        {
                                Material *ma = (Material *)data;
                                AnimData *adt = ma->adt;
                                
                                ale->flag = FILTER_MAT_OBJD(ma);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSLAM:
                        {
                                Lamp *la = (Lamp *)data;
                                AnimData *adt = la->adt;
                                
                                ale->flag = FILTER_LAM_OBJD(la);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSCAM:
                        {
                                Camera *ca = (Camera *)data;
                                AnimData *adt = ca->adt;
                                
                                ale->flag = FILTER_CAM_OBJD(ca);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSCACHEFILE:
                        {
                                CacheFile *cache_file = (CacheFile *)data;
                                AnimData *adt = cache_file->adt;

                                ale->flag = FILTER_CACHEFILE_OBJD(cache_file);

                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;

                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSCUR:
                        {
                                Curve *cu = (Curve *)data;
                                AnimData *adt = cu->adt;
                                
                                ale->flag = FILTER_CUR_OBJD(cu);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSARM:
                        {
                                bArmature *arm = (bArmature *)data;
                                AnimData *adt = arm->adt;
                                
                                ale->flag = FILTER_ARM_OBJD(arm);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSMESH:
                        {
                                Mesh *me = (Mesh *)data;
                                AnimData *adt = me->adt;
                                
                                ale->flag = FILTER_MESH_OBJD(me);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSLAT:
                        {
                                Lattice *lt = (Lattice *)data;
                                AnimData *adt = lt->adt;
                                
                                ale->flag = FILTER_LATTICE_OBJD(lt);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSSPK:
                        {
                                Speaker *spk = (Speaker *)data;
                                AnimData *adt = spk->adt;
                                
                                ale->flag = FILTER_SPK_OBJD(spk);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSSKEY:
                        {
                                Key *key = (Key *)data;
                                AnimData *adt = key->adt;
                                
                                ale->flag = FILTER_SKE_OBJD(key);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSWOR:
                        {
                                World *wo = (World *)data;
                                AnimData *adt = wo->adt;
                                
                                ale->flag = FILTER_WOR_SCED(wo);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSNTREE:
                        {
                                bNodeTree *ntree = (bNodeTree *)data;
                                AnimData *adt = ntree->adt;
                                
                                ale->flag = FILTER_NTREE_DATA(ntree);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSLINESTYLE:
                        {
                                FreestyleLineStyle *linestyle = (FreestyleLineStyle *)data;
                                AnimData *adt = linestyle->adt;
                                
                                ale->flag = FILTER_LS_SCED(linestyle); 
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSPART:
                        {
                                ParticleSettings *part = (ParticleSettings *)ale->data;
                                AnimData *adt = part->adt;
                                
                                ale->flag = FILTER_PART_OBJD(part);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSTEX:
                        {
                                Tex *tex = (Tex *)data;
                                AnimData *adt = tex->adt;
                                
                                ale->flag = FILTER_TEX_DATA(tex);
                                
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSGPENCIL:
                        {
                                bGPdata *gpd = (bGPdata *)data;
                                AnimData *adt = gpd->adt;
                                
                                /* NOTE: we just reuse the same expand filter for this case */
                                ale->flag = EXPANDED_GPD(gpd);
                                
                                // XXX: currently, this is only used for access to its animation data
                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;
                                
                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_DSMCLIP:
                        {
                                MovieClip *clip = (MovieClip *)data;
                                AnimData *adt = clip->adt;

                                ale->flag = EXPANDED_MCLIP(clip);

                                ale->key_data = (adt) ? adt->action : NULL;
                                ale->datatype = ALE_ACT;

                                ale->adt = BKE_animdata_from_id(data);
                                break;
                        }
                        case ANIMTYPE_NLACONTROLS:
                        {
                                AnimData *adt = (AnimData *)data;
                                
                                ale->flag = adt->flag;
                                
                                ale->key_data = NULL;
                                ale->datatype = ALE_NONE;
                                break;
                        }
                        case ANIMTYPE_GROUP:
                        {
                                bActionGroup *agrp = (bActionGroup *)data;
                                
                                ale->flag = agrp->flag;
                                
                                ale->key_data = NULL;
                                ale->datatype = ALE_GROUP;
                                break;
                        }
                        case ANIMTYPE_FCURVE:
                        {
                                FCurve *fcu = (FCurve *)data;
                                
                                ale->flag = fcu->flag;
                                
                                ale->key_data = fcu;
                                ale->datatype = ALE_FCURVE;
                                break;
                        }
                        case ANIMTYPE_SHAPEKEY:
                        {
                                KeyBlock *kb = (KeyBlock *)data;
                                Key *key = (Key *)ale->id;
                                
                                ale->flag = kb->flag;
                                
                                /* whether we have keyframes depends on whether there is a Key block to find it from */
                                if (key) {
                                        /* index of shapekey is defined by place in key's list */
                                        ale->index = BLI_findindex(&key->block, kb);
                                        
                                        /* the corresponding keyframes are from the animdata */
                                        if (ale->adt && ale->adt->action) {
                                                bAction *act = ale->adt->action;
                                                char *rna_path = BKE_keyblock_curval_rnapath_get(key, kb);
                                                
                                                /* try to find the F-Curve which corresponds to this exactly,
                                                 * then free the MEM_alloc'd string
                                                 */
                                                if (rna_path) {
                                                        ale->key_data = (void *)list_find_fcurve(&act->curves, rna_path, 0);
                                                        MEM_freeN(rna_path);
                                                }
                                        }
                                        ale->datatype = (ale->key_data) ? ALE_FCURVE : ALE_NONE;
                                }
                                break;
                        }
                        case ANIMTYPE_GPLAYER:
                        {
                                bGPDlayer *gpl = (bGPDlayer *)data;
                                
                                ale->flag = gpl->flag;
                                
                                ale->key_data = NULL;
                                ale->datatype = ALE_GPFRAME;
                                break;
                        }
                        case ANIMTYPE_MASKLAYER:
                        {
                                MaskLayer *masklay = (MaskLayer *)data;
                                
                                ale->flag = masklay->flag;
                                
                                ale->key_data = NULL;
                                ale->datatype = ALE_MASKLAY;
                                break;
                        }
                        case ANIMTYPE_NLATRACK:
                        {
                                NlaTrack *nlt = (NlaTrack *)data;
                                
                                ale->flag = nlt->flag;
                                
                                ale->key_data = &nlt->strips;
                                ale->datatype = ALE_NLASTRIP;
                                break;
                        }
                        case ANIMTYPE_NLAACTION:
                        {
                                /* nothing to include for now... nothing editable from NLA-perspective here */
                                ale->key_data = NULL;
                                ale->datatype = ALE_NONE;
                                break;
                        }
                }
        }
        
        /* return created datatype */
        return ale;
}
 
/* ----------------------------------------- */

/* 'Only Selected' selected data and/or 'Include Hidden' filtering
 * NOTE: when this function returns true, the F-Curve is to be skipped 
 */
static bool skip_fcurve_selected_data(bDopeSheet *ads, FCurve *fcu, ID *owner_id, int filter_mode)
{
        if (fcu->grp != NULL && fcu->grp->flag & ADT_CURVES_ALWAYS_VISIBLE) {
                return false;
        }
        /* hidden items should be skipped if we only care about visible data, but we aren't interested in hidden stuff */
        const bool skip_hidden = (filter_mode & ANIMFILTER_DATA_VISIBLE) && !(ads->filterflag & ADS_FILTER_INCL_HIDDEN);
        
        if (GS(owner_id->name) == ID_OB) {
                Object *ob = (Object *)owner_id;
                
                /* only consider if F-Curve involves pose.bones */
                if ((fcu->rna_path) && strstr(fcu->rna_path, "pose.bones")) {
                        bPoseChannel *pchan;
                        char *bone_name;
                        
                        /* get bone-name, and check if this bone is selected */
                        bone_name = BLI_str_quoted_substrN(fcu->rna_path, "pose.bones[");
                        pchan = BKE_pose_channel_find_name(ob->pose, bone_name);
                        if (bone_name) MEM_freeN(bone_name);
                        
                        /* check whether to continue or skip */
                        if ((pchan) && (pchan->bone)) {
                                /* if only visible channels, skip if bone not visible unless user wants channels from hidden data too */
                                if (skip_hidden) {
                                        bArmature *arm = (bArmature *)ob->data;
                                        
                                        /* skipping - not visible on currently visible layers */
                                        if ((arm->layer & pchan->bone->layer) == 0)
                                                return true;
                                        /* skipping - is currently hidden */
                                        if (pchan->bone->flag & BONE_HIDDEN_P)
                                                return true;
                                }
                                
                                /* can only add this F-Curve if it is selected */
                                if (ads->filterflag & ADS_FILTER_ONLYSEL) {
                                        if ((pchan->bone->flag & BONE_SELECTED) == 0)
                                                return true;
                                }
                        }
                }
        }
        else if (GS(owner_id->name) == ID_SCE) {
                Scene *scene = (Scene *)owner_id;
                
                /* only consider if F-Curve involves sequence_editor.sequences */
                if ((fcu->rna_path) && strstr(fcu->rna_path, "sequences_all")) {
                        Editing *ed = BKE_sequencer_editing_get(scene, false);
                        Sequence *seq = NULL;
                        char *seq_name;
                        
                        if (ed) {
                                /* get strip name, and check if this strip is selected */
                                seq_name = BLI_str_quoted_substrN(fcu->rna_path, "sequences_all[");
                                seq = BKE_sequence_get_by_name(ed->seqbasep, seq_name, false);
                                if (seq_name) MEM_freeN(seq_name);
                        }
                        
                        /* can only add this F-Curve if it is selected */
                        if (ads->filterflag & ADS_FILTER_ONLYSEL) {
                                if ((seq == NULL) || (seq->flag & SELECT) == 0)
                                        return true;
                        }
                }
        }
        else if (GS(owner_id->name) == ID_NT) {
                bNodeTree *ntree = (bNodeTree *)owner_id;
                
                /* check for selected nodes */
                if ((fcu->rna_path) && strstr(fcu->rna_path, "nodes")) {
                        bNode *node;
                        char *node_name;
                        
                        /* get strip name, and check if this strip is selected */
                        node_name = BLI_str_quoted_substrN(fcu->rna_path, "nodes[");
                        node = nodeFindNodebyName(ntree, node_name);
                        if (node_name) MEM_freeN(node_name);
                        
                        /* can only add this F-Curve if it is selected */
                        if (ads->filterflag & ADS_FILTER_ONLYSEL) {
                                if ((node) && (node->flag & NODE_SELECT) == 0)
                                        return true;
                        }
                }
        }
        
        return false;
}

/* Helper for name-based filtering - Perform "partial/fuzzy matches" (as in 80a7efd) */
static bool name_matches_dopesheet_filter(bDopeSheet *ads, char *name)
{
        if (ads->flag & ADS_FLAG_FUZZY_NAMES) {
                /* full fuzzy, multi-word, case insensitive matches */
                const size_t str_len = strlen(ads->searchstr);
                const int words_max = (str_len / 2) + 1;
                
                int (*words)[2] = BLI_array_alloca(words, words_max);
                const int words_len = BLI_string_find_split_words(ads->searchstr, str_len, ' ', words, words_max);
                bool found = false;
                
                /* match name against all search words */
                for (int index = 0; index < words_len; index++) {
                        if (BLI_strncasestr(name, ads->searchstr + words[index][0], words[index][1])) {
                                found = true;
                                break;
                        }
                }
                
                /* if we have a match somewhere, this returns true */
                return found;
        }
        else {
                /* fallback/default - just case insensitive, but starts from start of word */
                return BLI_strcasestr(name, ads->searchstr) != NULL;
        }
}

/* (Display-)Name-based F-Curve filtering
 * NOTE: when this function returns true, the F-Curve is to be skipped 
 */
static bool skip_fcurve_with_name(bDopeSheet *ads, FCurve *fcu, ID *owner_id)
{
        bAnimListElem ale_dummy = {NULL};
        const bAnimChannelType *acf;
        
        /* create a dummy wrapper for the F-Curve */
        ale_dummy.type = ANIMTYPE_FCURVE;
        ale_dummy.id = owner_id;
        ale_dummy.data = fcu;
        
        /* get type info for channel */
        acf = ANIM_channel_get_typeinfo(&ale_dummy);
        if (acf && acf->name) {
                char name[256]; /* hopefully this will be enough! */
                
                /* get name */
                acf->name(&ale_dummy, name);
                
                /* check for partial match with the match string, assuming case insensitive filtering 
                 * if match, this channel shouldn't be ignored!
                 */
                return !name_matches_dopesheet_filter(ads, name);
        }
        
        /* just let this go... */
        return true;
}

/**
 * Check if F-Curve has errors and/or is disabled
 *
 * \return true if F-Curve has errors/is disabled
 */
static bool fcurve_has_errors(FCurve *fcu)
{
        /* F-Curve disabled - path eval error */
        if (fcu->flag & FCURVE_DISABLED) {
                return true;
        }
        
        /* driver? */
        if (fcu->driver) {
                ChannelDriver *driver = fcu->driver;
                DriverVar *dvar;
                
                /* error flag on driver usually means that there is an error
                 * BUT this may not hold with PyDrivers as this flag gets cleared
                 *     if no critical errors prevent the driver from working...
                 */
                if (driver->flag & DRIVER_FLAG_INVALID)
                        return true;
                        
                /* check variables for other things that need linting... */
                // TODO: maybe it would be more efficient just to have a quick flag for this?
                for (dvar = driver->variables.first; dvar; dvar = dvar->next) {
                        DRIVER_TARGETS_USED_LOOPER(dvar)
                        {
                                if (dtar->flag & DTAR_FLAG_INVALID)
                                        return true;
                        }
                        DRIVER_TARGETS_LOOPER_END
                }
        }
        
        /* no errors found */
        return false;
}

/* find the next F-Curve that is usable for inclusion */
static FCurve *animfilter_fcurve_next(bDopeSheet *ads, FCurve *first, bActionGroup *grp, int filter_mode, ID *owner_id)
{
        FCurve *fcu = NULL;
        
        /* loop over F-Curves - assume that the caller of this has already checked that these should be included 
         * NOTE: we need to check if the F-Curves belong to the same group, as this gets called for groups too...
         */
        for (fcu = first; ((fcu) && (fcu->grp == grp)); fcu = fcu->next) {
                /* special exception for Pose-Channel/Sequence-Strip/Node Based F-Curves:
                 *      - the 'Only Selected' and 'Include Hidden' data filters should be applied to sub-ID data which
                 *        can be independently selected/hidden, such as Pose-Channels, Sequence Strips, and Nodes.
                 *        Since these checks were traditionally done as first check for objects, we do the same here
                 *      - we currently use an 'approximate' method for getting these F-Curves that doesn't require
                 *        carefully checking the entire path
                 *      - this will also affect things like Drivers, and also works for Bone Constraints
                 */
                if (ads && owner_id) {
                        if ((filter_mode & ANIMFILTER_TMP_IGNORE_ONLYSEL) == 0) {
                                if ((ads->filterflag & ADS_FILTER_ONLYSEL) || (ads->filterflag & ADS_FILTER_INCL_HIDDEN) == 0) {
                                        if (skip_fcurve_selected_data(ads, fcu, owner_id, filter_mode))
                                                continue;
                                }
                        }
                }
                
                /* only include if visible (Graph Editor check, not channels check) */
                if (!(filter_mode & ANIMFILTER_CURVE_VISIBLE) || (fcu->flag & FCURVE_VISIBLE)) {
                        /* only work with this channel and its subchannels if it is editable */
                        if (!(filter_mode & ANIMFILTER_FOREDIT) || EDITABLE_FCU(fcu)) {
                                /* only include this curve if selected in a way consistent with the filtering requirements */
                                if (ANIMCHANNEL_SELOK(SEL_FCU(fcu)) && ANIMCHANNEL_SELEDITOK(SEL_FCU(fcu))) {
                                        /* only include if this curve is active */
                                        if (!(filter_mode & ANIMFILTER_ACTIVE) || (fcu->flag & FCURVE_ACTIVE)) {
                                                /* name based filtering... */
                                                if ( ((ads) && (ads->filterflag & ADS_FILTER_BY_FCU_NAME)) && (owner_id) ) {
                                                        if (skip_fcurve_with_name(ads, fcu, owner_id))
                                                                continue;
                                                }
                                                
                                                /* error-based filtering... */
                                                if ((ads) && (ads->filterflag & ADS_FILTER_ONLY_ERRORS)) {
                                                        /* skip if no errors... */
                                                        if (fcurve_has_errors(fcu) == false)
                                                                continue;
                                                }
                                                
                                                /* this F-Curve can be used, so return it */
                                                return fcu;
                                        }
                                }
                        }
                }
        }
        
        /* no (more) F-Curves from the list are suitable... */
        return NULL;
}

static size_t animfilter_fcurves(ListBase *anim_data, bDopeSheet *ads, FCurve *first, bActionGroup *grp, int filter_mode, ID *owner_id)
{
        FCurve *fcu;
        size_t items = 0;
        
        /* loop over every F-Curve able to be included 
         *      - this for-loop works like this: 
         *              1) the starting F-Curve is assigned to the fcu pointer so that we have a starting point to search from
         *              2) the first valid F-Curve to start from (which may include the one given as 'first') in the remaining 
         *                 list of F-Curves is found, and verified to be non-null
         *              3) the F-Curve referenced by fcu pointer is added to the list
         *              4) the fcu pointer is set to the F-Curve after the one we just added, so that we can keep going through 
         *                 the rest of the F-Curve list without an eternal loop. Back to step 2 :)
         */
        for (fcu = first; ( (fcu = animfilter_fcurve_next(ads, fcu, grp, filter_mode, owner_id)) ); fcu = fcu->next) {
                ANIMCHANNEL_NEW_CHANNEL(fcu, ANIMTYPE_FCURVE, owner_id);
        }
        
        /* return the number of items added to the list */
        return items;
}

static size_t animfilter_act_group(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, bAction *UNUSED(act), bActionGroup *agrp, int filter_mode, ID *owner_id)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        //int ofilter = filter_mode;
        
        /* if we care about the selection status of the channels, 
         * but the group isn't expanded (1)...
         *  (1) this only matters if we actually care about the hierarchy though.
         *              - Hierarchy matters: this hack should be applied
         *              - Hierarchy ignored: cases like [#21276] won't work properly, unless we skip this hack
         */
        if ( ((filter_mode & ANIMFILTER_LIST_VISIBLE) && EXPANDED_AGRP(ac, agrp) == 0) &&     /* care about hierarchy but group isn't expanded */
             (filter_mode & (ANIMFILTER_SEL | ANIMFILTER_UNSEL)) )                          /* care about selection status */
        {
                /* if the group itself isn't selected appropriately, we shouldn't consider it's children either */
                if (ANIMCHANNEL_SELOK(SEL_AGRP(agrp)) == 0)
                        return 0;
                
                /* if we're still here, then the selection status of the curves within this group should not matter,
                 * since this creates too much overhead for animators (i.e. making a slow workflow)
                 *
                 * Tools affected by this at time of coding (2010 Feb 09):
                 *      - inserting keyframes on selected channels only
                 *      - pasting keyframes
                 *      - creating ghost curves in Graph Editor
                 */
                filter_mode &= ~(ANIMFILTER_SEL | ANIMFILTER_UNSEL | ANIMFILTER_LIST_VISIBLE);
        }
        
        /* add grouped F-Curves */
        BEGIN_ANIMFILTER_SUBCHANNELS(EXPANDED_AGRP(ac, agrp))
        {
                /* special filter so that we can get just the F-Curves within the active group */
                if (!(filter_mode & ANIMFILTER_ACTGROUPED) || (agrp->flag & AGRP_ACTIVE)) {
                        /* for the Graph Editor, curves may be set to not be visible in the view to lessen clutter,
                         * but to do this, we need to check that the group doesn't have it's not-visible flag set preventing 
                         * all its sub-curves to be shown
                         */
                        if (!(filter_mode & ANIMFILTER_CURVE_VISIBLE) || !(agrp->flag & AGRP_NOTVISIBLE)) {
                                /* group must be editable for its children to be editable (if we care about this) */
                                if (!(filter_mode & ANIMFILTER_FOREDIT) || EDITABLE_AGRP(agrp)) {
                                        /* get first F-Curve which can be used here */
                                        FCurve *first_fcu = animfilter_fcurve_next(ads, agrp->channels.first, agrp, filter_mode, owner_id);
                                        
                                        /* filter list, starting from this F-Curve */
                                        tmp_items += animfilter_fcurves(&tmp_data, ads, first_fcu, agrp, filter_mode, owner_id);
                                }
                        }
                }
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* add this group as a channel first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* restore original filter mode so that this next step works ok... */
                        //filter_mode = ofilter;
                        
                        /* filter selection of channel specially here again, since may be open and not subject to previous test */
                        if (ANIMCHANNEL_SELOK(SEL_AGRP(agrp)) ) {
                                ANIMCHANNEL_NEW_CHANNEL(agrp, ANIMTYPE_GROUP, owner_id);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added to the list */
        return items;
}

static size_t animfilter_action(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, bAction *act, int filter_mode, ID *owner_id)
{
        bActionGroup *agrp;
        FCurve *lastchan = NULL;
        size_t items = 0;
        
        /* don't include anything from this action if it is linked in from another file,
         * and we're getting stuff for editing...
         */
        if ((filter_mode & ANIMFILTER_FOREDIT) && ID_IS_LINKED_DATABLOCK(act))
                return 0;
                
        /* do groups */
        // TODO: do nested groups?
        for (agrp = act->groups.first; agrp; agrp = agrp->next) {
                /* store reference to last channel of group */
                if (agrp->channels.last) 
                        lastchan = agrp->channels.last;
                        
                /* action group's channels */
                items += animfilter_act_group(ac, anim_data, ads, act, agrp, filter_mode, owner_id);
        }
        
        /* un-grouped F-Curves (only if we're not only considering those channels in the active group) */
        if (!(filter_mode & ANIMFILTER_ACTGROUPED)) {
                FCurve *firstfcu = (lastchan) ? (lastchan->next) : (act->curves.first);
                items += animfilter_fcurves(anim_data, ads, firstfcu, NULL, filter_mode, owner_id);
        }
        
        /* return the number of items added to the list */
        return items;
}

/* Include NLA-Data for NLA-Editor:
 *      - when ANIMFILTER_LIST_CHANNELS is used, that means we should be filtering the list for display
 *        Although the evaluation order is from the first track to the last and then apply the Action on top,
 *        we present this in the UI as the Active Action followed by the last track to the first so that we 
 *        get the evaluation order presented as per a stack.
 *      - for normal filtering (i.e. for editing), we only need the NLA-tracks but they can be in 'normal' evaluation
 *        order, i.e. first to last. Otherwise, some tools may get screwed up.
 */
static size_t animfilter_nla(bAnimContext *UNUSED(ac), ListBase *anim_data, bDopeSheet *ads, AnimData *adt, int filter_mode, ID *owner_id)
{
        NlaTrack *nlt;
        NlaTrack *first = NULL, *next = NULL;
        size_t items = 0;
        
        /* if showing channels, include active action */
        if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                /* if NLA action-line filtering is off, don't show unless there are keyframes, 
                 * in order to keep things more compact for doing transforms
                 */
                if (!(ads->filterflag & ADS_FILTER_NLA_NOACT) || (adt->action)) {
                        /* there isn't really anything editable here, so skip if need editable */
                        if ((filter_mode & ANIMFILTER_FOREDIT) == 0) {
                                /* just add the action track now (this MUST appear for drawing)
                                 *      - as AnimData may not have an action, we pass a dummy pointer just to get the list elem created, then
                                 *        overwrite this with the real value - REVIEW THIS...
                                 */
                                ANIMCHANNEL_NEW_CHANNEL_FULL((void *)(&adt->action), ANIMTYPE_NLAACTION, owner_id, 
                                        {
                                                ale->data = adt->action ? adt->action : NULL; 
                                        });
                        }
                }
                
                /* first track to include will be the last one if we're filtering by channels */
                first = adt->nla_tracks.last;
        }
        else {
                /* first track to include will the first one (as per normal) */
                first = adt->nla_tracks.first;
        }
        
        /* loop over NLA Tracks - assume that the caller of this has already checked that these should be included */
        for (nlt = first; nlt; nlt = next) {
                /* 'next' NLA-Track to use depends on whether we're filtering for drawing or not */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) 
                        next = nlt->prev;
                else
                        next = nlt->next;
                
                /* if we're in NLA-tweakmode, don't show this track if it was disabled (due to tweaking) for now 
                 *      - active track should still get shown though (even though it has disabled flag set)
                 */
                // FIXME: the channels after should still get drawn, just 'differently', and after an active-action channel
                if ((adt->flag & ADT_NLA_EDIT_ON) && (nlt->flag & NLATRACK_DISABLED) && (adt->act_track != nlt))
                        continue;
                
                /* only work with this channel and its subchannels if it is editable */
                if (!(filter_mode & ANIMFILTER_FOREDIT) || EDITABLE_NLT(nlt)) {
                        /* only include this track if selected in a way consistent with the filtering requirements */
                        if (ANIMCHANNEL_SELOK(SEL_NLT(nlt))) {
                                /* only include if this track is active */
                                if (!(filter_mode & ANIMFILTER_ACTIVE) || (nlt->flag & NLATRACK_ACTIVE)) {
                                        /* name based filtering... */
                                        if (((ads) && (ads->filterflag & ADS_FILTER_BY_FCU_NAME)) && (owner_id)) {
                                                bool track_ok = false, strip_ok = false;
                                                
                                                /* check if the name of the track, or the strips it has are ok... */
                                                track_ok = name_matches_dopesheet_filter(ads, nlt->name);
                                                
                                                if (track_ok == false) {
                                                        NlaStrip *strip;
                                                        for (strip = nlt->strips.first; strip; strip = strip->next) {
                                                                if (name_matches_dopesheet_filter(ads, strip->name)) {
                                                                        strip_ok = true;
                                                                        break;
                                                                }
                                                        }
                                                }
                                                
                                                /* skip if both fail this test... */
                                                if (!track_ok && !strip_ok) {
                                                        continue;
                                                }
                                        }
                                        
                                        /* add the track now that it has passed all our tests */
                                        ANIMCHANNEL_NEW_CHANNEL(nlt, ANIMTYPE_NLATRACK, owner_id);
                                }
                        }
                }
        }
        
        /* return the number of items added to the list */
        return items;
}

/* Include the control FCurves per NLA Strip in the channel list
 * NOTE: This is includes the expander too...
 */
static size_t animfilter_nla_controls(ListBase *anim_data, bDopeSheet *ads, AnimData *adt, int filter_mode, ID *owner_id)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        /* add control curves from each NLA strip... */
        /* NOTE: ANIMTYPE_FCURVES are created here, to avoid duplicating the code needed */
        BEGIN_ANIMFILTER_SUBCHANNELS(((adt->flag & ADT_NLA_SKEYS_COLLAPSED) == 0))
        {
                NlaTrack *nlt;
                NlaStrip *strip;
                
                /* for now, we only go one level deep - so controls on grouped FCurves are not handled */
                for (nlt = adt->nla_tracks.first; nlt; nlt = nlt->next) {
                        for (strip = nlt->strips.first; strip; strip = strip->next) {
                                ListBase strip_curves = {NULL, NULL};
                                size_t strip_items = 0;
                                
                                /* create the raw items */
                                strip_items += animfilter_fcurves(&strip_curves, ads, strip->fcurves.first, NULL, filter_mode, owner_id);
                                
                                /* change their types and add extra data
                                 * - There is no point making a separate copy of animfilter_fcurves for this now/yet,
                                 *   unless we later get per-element control curves for other stuff too
                                 */
                                if (strip_items) {
                                        bAnimListElem *ale, *ale_n = NULL;
                                        
                                        for (ale = strip_curves.first; ale; ale = ale_n) {
                                                ale_n = ale->next;
                                                
                                                /* change the type to being a FCurve for editing NLA strip controls */
                                                BLI_assert(ale->type == ANIMTYPE_FCURVE);
                                                
                                                ale->type = ANIMTYPE_NLACURVE;
                                                ale->owner = strip;
                                                
                                                ale->adt  = NULL; /* XXX: This way, there are no problems with time mapping errors */
                                        }
                                }
                                
                                /* add strip curves to the set of channels inside the group being collected */
                                BLI_movelisttolist(&tmp_data, &strip_curves);
                                BLI_assert(BLI_listbase_is_empty(&strip_curves));
                                tmp_items += strip_items;
                        }
                }
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* add the expander as a channel first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* currently these channels cannot be selected, so they should be skipped */
                        if ((filter_mode & (ANIMFILTER_SEL | ANIMFILTER_UNSEL)) == 0) {
                                ANIMCHANNEL_NEW_CHANNEL(adt, ANIMTYPE_NLACONTROLS, owner_id);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the numebr of items added to the list */
        return items;
}

/* determine what animation data from AnimData block should get displayed */
static size_t animfilter_block_data(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, ID *id, int filter_mode)
{
        AnimData *adt = BKE_animdata_from_id(id);
        size_t items = 0;
        
        /* image object datablocks have no anim-data so check for NULL */
        if (adt) {
                IdAdtTemplate *iat = (IdAdtTemplate *)id;
                
                /* NOTE: this macro is used instead of inlining the logic here, since this sort of filtering is still needed
                 * in a few places in the rest of the code still - notably for the few cases where special mode-based
                 * different types of data expanders are required.
                 */
                ANIMDATA_FILTER_CASES(iat,
                        { /* AnimData */
                                /* specifically filter animdata block */
                                if (ANIMCHANNEL_SELOK(SEL_ANIMDATA(adt)) ) {
                                        ANIMCHANNEL_NEW_CHANNEL(adt, ANIMTYPE_ANIMDATA, id);
                                }
                        },
                        { /* NLA */
                                items += animfilter_nla(ac, anim_data, ads, adt, filter_mode, id);
                        },
                        { /* Drivers */
                                items += animfilter_fcurves(anim_data, ads, adt->drivers.first, NULL, filter_mode, id);
                        },
                        { /* NLA Control Keyframes */
                                items += animfilter_nla_controls(anim_data, ads, adt, filter_mode, id);
                        },
                        { /* Keyframes */
                                items += animfilter_action(ac, anim_data, ads, adt->action, filter_mode, id);
                        }
                );
        }
        
        return items;
}



/* Include ShapeKey Data for ShapeKey Editor */
static size_t animdata_filter_shapekey(bAnimContext *ac, ListBase *anim_data, Key *key, int filter_mode)
{
        size_t items = 0;
        
        /* check if channels or only F-Curves */
        if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                KeyBlock *kb;
                
                /* loop through the channels adding ShapeKeys as appropriate */
                for (kb = key->block.first; kb; kb = kb->next) {
                        /* skip the first one, since that's the non-animatable basis */
                        if (kb == key->block.first) continue;
                        
                        /* only work with this channel and its subchannels if it is editable */
                        if (!(filter_mode & ANIMFILTER_FOREDIT) || EDITABLE_SHAPEKEY(kb)) {
                                /* only include this track if selected in a way consistent with the filtering requirements */
                                if (ANIMCHANNEL_SELOK(SEL_SHAPEKEY(kb)) ) {
                                        // TODO: consider 'active' too?
                                        
                                        /* owner-id here must be key so that the F-Curve can be resolved... */
                                        ANIMCHANNEL_NEW_CHANNEL(kb, ANIMTYPE_SHAPEKEY, key);
                                }
                        }
                }
        }
        else {
                /* just use the action associated with the shapekey */
                // TODO: somehow manage to pass dopesheet info down here too?
                if (key->adt) {
                        if (filter_mode & ANIMFILTER_ANIMDATA) {
                                if (ANIMCHANNEL_SELOK(SEL_ANIMDATA(key->adt)) ) {
                                        ANIMCHANNEL_NEW_CHANNEL(key->adt, ANIMTYPE_ANIMDATA, key);
                                }
                        }
                        else if (key->adt->action) {
                                items = animfilter_action(ac, anim_data, NULL, key->adt->action, filter_mode, (ID *)key);
                        }
                }
        }
        
        /* return the number of items added to the list */
        return items;
}

/* Helper for Grease Pencil - layers within a datablock */
static size_t animdata_filter_gpencil_layers_data(ListBase *anim_data, bDopeSheet *ads, bGPdata *gpd, int filter_mode)
{
        bGPDlayer *gpl;
        size_t items = 0;
        
        /* loop over layers as the conditions are acceptable */
        for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
                /* only if selected */
                if (ANIMCHANNEL_SELOK(SEL_GPL(gpl)) ) {
                        /* only if editable */
                        if (!(filter_mode & ANIMFILTER_FOREDIT) || EDITABLE_GPL(gpl)) {
                                /* active... */
                                if (!(filter_mode & ANIMFILTER_ACTIVE) || (gpl->flag & GP_LAYER_ACTIVE)) {
                                        /* skip layer if the name doesn't match the filter string */
                                        if ((ads) && (ads->filterflag & ADS_FILTER_BY_FCU_NAME)) {
                                                if (name_matches_dopesheet_filter(ads, gpl->info) == false)
                                                        continue;
                                        }
                                        
                                        
                                        /* add to list */
                                        ANIMCHANNEL_NEW_CHANNEL(gpl, ANIMTYPE_GPLAYER, gpd);
                                }
                        }
                }
        }
        
        return items;
}

/* Helper for Grease Pencil - Grease Pencil datablock - GP Frames */
static size_t animdata_filter_gpencil_data(ListBase *anim_data, bDopeSheet *ads, bGPdata *gpd, int filter_mode)
{
        size_t items = 0;
        
        /* When asked from "AnimData" blocks (i.e. the top-level containers for normal animation),
         * for convenience, this will return GP Datablocks instead. This may cause issues down
         * the track, but for now, this will do...
         */
        if (filter_mode & ANIMFILTER_ANIMDATA) {
                /* just add GPD as a channel - this will add everything needed */
                ANIMCHANNEL_NEW_CHANNEL(gpd, ANIMTYPE_GPDATABLOCK, NULL);
        }
        else {
                ListBase tmp_data = {NULL, NULL};
                size_t tmp_items = 0;
                
                /* add gpencil animation channels */
                BEGIN_ANIMFILTER_SUBCHANNELS(EXPANDED_GPD(gpd))
                {
                        tmp_items += animdata_filter_gpencil_layers_data(&tmp_data, ads, gpd, filter_mode);
                }
                END_ANIMFILTER_SUBCHANNELS;
                
                /* did we find anything? */
                if (tmp_items) {
                        /* include data-expand widget first */
                        if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                                /* add gpd as channel too (if for drawing, and it has layers) */
                                ANIMCHANNEL_NEW_CHANNEL(gpd, ANIMTYPE_GPDATABLOCK, NULL);
                        }
                        
                        /* now add the list of collected channels */
                        BLI_movelisttolist(anim_data, &tmp_data);
                        BLI_assert(BLI_listbase_is_empty(&tmp_data));
                        items += tmp_items;
                }
        }
        
        return items;
}

/* Grab all Grease Pencil datablocks in file */
// TODO: should this be amalgamated with the dopesheet filtering code?
static size_t animdata_filter_gpencil(bAnimContext *ac, ListBase *anim_data, void *UNUSED(data), int filter_mode)
{
        bDopeSheet *ads = ac->ads;
        size_t items = 0;
        
        if (ads->filterflag & ADS_FILTER_GP_3DONLY) {
                Scene *scene = (Scene *)ads->source;
                SceneLayer *sl = (SceneLayer *)ac->scene_layer;
                Base *base;

                /* Active scene's GPencil block first - No parent item needed... */
                if (scene->gpd) {
                        items += animdata_filter_gpencil_data(anim_data, ads, scene->gpd, filter_mode);
                }
                
                /* Objects in the scene */
                for (base = sl->object_bases.first; base; base = base->next) {
                        /* Only consider this object if it has got some GP data (saving on all the other tests) */
                        if (base->object && base->object->gpd) {
                                Object *ob = base->object;
                                
                                /* firstly, check if object can be included, by the following factors:
                                 *      - if only visible, must check for layer and also viewport visibility
                                 *              --> while tools may demand only visible, user setting takes priority
                                 *                      as user option controls whether sets of channels get included while
                                 *                      tool-flag takes into account collapsed/open channels too
                                 *      - if only selected, must check if object is selected 
                                 *      - there must be animation data to edit (this is done recursively as we 
                                 *        try to add the channels)
                                 */
                                if ((filter_mode & ANIMFILTER_DATA_VISIBLE) && !(ads->filterflag & ADS_FILTER_INCL_HIDDEN)) {
                                        /* layer visibility - we check both object and base, since these may not be in sync yet */
                                        if ((base->flag & BASE_VISIBLED) == 0) continue;
                                        
                                        /* outliner restrict-flag */
                                        if (ob->restrictflag & OB_RESTRICT_VIEW) continue;
                                }
                                
                                /* check selection and object type filters */
                                if ( (ads->filterflag & ADS_FILTER_ONLYSEL) && !((base->flag & BASE_SELECTED) /*|| (base == scene->basact)*/) ) {
                                        /* only selected should be shown */
                                        continue;
                                }
                                
                                /* check if object belongs to the filtering group if option to filter 
                                 * objects by the grouped status is on
                                 *      - used to ease the process of doing multiple-character choreographies
                                 */
                                if (ads->filterflag & ADS_FILTER_ONLYOBGROUP) {
                                        if (BKE_group_object_exists(ads->filter_grp, ob) == 0)
                                                continue;
                                }
                                
                                /* finally, include this object's grease pencil datablock */
                                /* XXX: Should we store these under expanders per item? */
                                items += animdata_filter_gpencil_data(anim_data, ads, ob->gpd, filter_mode);
                        }
                }
        }
        else {
                bGPdata *gpd;
                
                /* Grab all Grease Pencil datablocks directly from main, but only those that seem to be useful somewhere */
                for (gpd = G.main->gpencil.first; gpd; gpd = gpd->id.next) {
                        /* only show if gpd is used by something... */
                        if (ID_REAL_USERS(gpd) < 1)
                                continue;
                        
                        /* add GP frames from this datablock */
                        items += animdata_filter_gpencil_data(anim_data, ads, gpd, filter_mode);
                }
        }
        
        /* return the number of items added to the list */
        return items;
}

/* Helper for Grease Pencil data integrated with main DopeSheet */
static size_t animdata_filter_ds_gpencil(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, bGPdata *gpd, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        /* add relevant animation channels for Grease Pencil */
        BEGIN_ANIMFILTER_SUBCHANNELS(EXPANDED_GPD(gpd))
        {
                /* add animation channels */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, &gpd->id, filter_mode);
                
                /* add Grease Pencil layers */
                // TODO: do these need a separate expander?
                // XXX:  what order should these go in?
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* include data-expand widget first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* check if filtering by active status */
                        // XXX: active check here needs checking
                        if (ANIMCHANNEL_ACTIVEOK(gpd)) {
                                ANIMCHANNEL_NEW_CHANNEL(gpd, ANIMTYPE_DSGPENCIL, gpd);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added to the list */
        return items;
}

/* Helper for Cache File data integrated with main DopeSheet */
static size_t animdata_filter_ds_cachefile(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, CacheFile *cache_file, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;

        /* add relevant animation channels for Cache File */
        BEGIN_ANIMFILTER_SUBCHANNELS(FILTER_CACHEFILE_OBJD(cache_file))
        {
                /* add animation channels */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, &cache_file->id, filter_mode);
        }
        END_ANIMFILTER_SUBCHANNELS;

        /* did we find anything? */
        if (tmp_items) {
                /* include data-expand widget first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* check if filtering by active status */
                        // XXX: active check here needs checking
                        if (ANIMCHANNEL_ACTIVEOK(cache_file)) {
                                ANIMCHANNEL_NEW_CHANNEL(cache_file, ANIMTYPE_DSCACHEFILE, cache_file);
                        }
                }

                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }

        /* return the number of items added to the list */
        return items;
}

/* Helper for Mask Editing - mask layers */
static size_t animdata_filter_mask_data(ListBase *anim_data, Mask *mask, const int filter_mode)
{
        MaskLayer *masklay_act = BKE_mask_layer_active(mask);
        MaskLayer *masklay;
        size_t items = 0;

        /* loop over layers as the conditions are acceptable */
        for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
                /* only if selected */
                if (ANIMCHANNEL_SELOK(SEL_MASKLAY(masklay)) ) {
                        /* only if editable */
                        if (!(filter_mode & ANIMFILTER_FOREDIT) || EDITABLE_MASK(masklay)) {
                                /* active... */
                                if (!(filter_mode & ANIMFILTER_ACTIVE) || (masklay_act == masklay)) {
                                        /* add to list */
                                        ANIMCHANNEL_NEW_CHANNEL(masklay, ANIMTYPE_MASKLAYER, mask);
                                }
                        }
                }
        }

        return items;
}

/* Grab all mask data */
static size_t animdata_filter_mask(ListBase *anim_data, void *UNUSED(data), int filter_mode)
{
        Mask *mask;
        size_t items = 0;
        
        /* for now, grab mask datablocks directly from main */
        // XXX: this is not good...
        for (mask = G.main->mask.first; mask; mask = mask->id.next) {
                ListBase tmp_data = {NULL, NULL};
                size_t tmp_items = 0;
                
                /* only show if mask is used by something... */
                if (ID_REAL_USERS(mask) < 1)
                        continue;
                
                /* add mask animation channels */
                BEGIN_ANIMFILTER_SUBCHANNELS(EXPANDED_MASK(mask))
                {
                        tmp_items += animdata_filter_mask_data(&tmp_data, mask, filter_mode);
                }
                END_ANIMFILTER_SUBCHANNELS;
                
                /* did we find anything? */
                if (tmp_items) {
                        /* include data-expand widget first */
                        if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                                /* add gpd as channel too (if for drawing, and it has layers) */
                                ANIMCHANNEL_NEW_CHANNEL(mask, ANIMTYPE_MASKDATABLOCK, NULL);
                        }
                        
                        /* now add the list of collected channels */
                        BLI_movelisttolist(anim_data, &tmp_data);
                        BLI_assert(BLI_listbase_is_empty(&tmp_data));
                        items += tmp_items;
                }
        }
        
        /* return the number of items added to the list */
        return items;
}

/* NOTE: owner_id is scene, material, or texture block, which is the direct owner of the node tree in question */
static size_t animdata_filter_ds_nodetree_group(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, ID *owner_id, bNodeTree *ntree, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        /* add nodetree animation channels */
        BEGIN_ANIMFILTER_SUBCHANNELS(FILTER_NTREE_DATA(ntree))
        {
                /* animation data filtering */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)ntree, filter_mode);
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* include data-expand widget first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* check if filtering by active status */
                        if (ANIMCHANNEL_ACTIVEOK(ntree)) {
                                ANIMCHANNEL_NEW_CHANNEL(ntree, ANIMTYPE_DSNTREE, owner_id);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added to the list */
        return items;
}

static size_t animdata_filter_ds_nodetree(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, ID *owner_id, bNodeTree *ntree, int filter_mode)
{
        bNode *node;
        size_t items = 0;
        
        items += animdata_filter_ds_nodetree_group(ac, anim_data, ads, owner_id, ntree, filter_mode);
        
        for (node = ntree->nodes.first; node; node = node->next) {
                if (node->type == NODE_GROUP) {
                        if (node->id) {
                                if ((ads->filterflag & ADS_FILTER_ONLYSEL) && (node->flag & NODE_SELECT) == 0) {
                                        continue;
                                }
                                items += animdata_filter_ds_nodetree_group(ac, anim_data, ads, owner_id, (bNodeTree *) node->id,
                                                                           filter_mode | ANIMFILTER_TMP_IGNORE_ONLYSEL);
                        }
                }
        }

        return items;
}

static size_t animdata_filter_ds_linestyle(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Scene *sce, int filter_mode)
{
        SceneRenderLayer *srl;
        FreestyleLineSet *lineset;
        size_t items = 0;
        
        for (srl = sce->r.layers.first; srl; srl = srl->next) {
                for (lineset = srl->freestyleConfig.linesets.first; lineset; lineset = lineset->next) {
                        if (lineset->linestyle) {
                                lineset->linestyle->id.tag |= LIB_TAG_DOIT;
                        }
                }
        }
        
        for (srl = sce->r.layers.first; srl; srl = srl->next) {
                /* skip render layers without Freestyle enabled */
                if (!(srl->layflag & SCE_LAY_FRS))
                        continue;
                
                /* loop over linesets defined in the render layer */
                for (lineset = srl->freestyleConfig.linesets.first; lineset; lineset = lineset->next) {
                        FreestyleLineStyle *linestyle = lineset->linestyle;
                        ListBase tmp_data = {NULL, NULL};
                        size_t tmp_items = 0;

                        if ((linestyle == NULL) ||
                            !(linestyle->id.tag & LIB_TAG_DOIT))
                        {
                                continue;
                        }
                        linestyle->id.tag &= ~LIB_TAG_DOIT;
                        
                        /* add scene-level animation channels */
                        BEGIN_ANIMFILTER_SUBCHANNELS(FILTER_LS_SCED(linestyle))
                        {
                                /* animation data filtering */
                                tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)linestyle, filter_mode);
                        }
                        END_ANIMFILTER_SUBCHANNELS;
                        
                        /* did we find anything? */
                        if (tmp_items) {
                                /* include anim-expand widget first */
                                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                                        /* check if filtering by active status */
                                        if (ANIMCHANNEL_ACTIVEOK(linestyle)) {
                                                ANIMCHANNEL_NEW_CHANNEL(linestyle, ANIMTYPE_DSLINESTYLE, sce);
                                        }
                                }
                                
                                /* now add the list of collected channels */
                                BLI_movelisttolist(anim_data, &tmp_data);
                                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                                items += tmp_items;
                        }
                }
        }
        
        /* return the number of items added to the list */
        return items;
}

static size_t animdata_filter_ds_texture(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, 
                                         Tex *tex, ID *owner_id, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        /* add texture's animation data to temp collection */
        BEGIN_ANIMFILTER_SUBCHANNELS(FILTER_TEX_DATA(tex)) 
        {
                /* texture animdata */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)tex, filter_mode);
                
                /* nodes */
                if ((tex->nodetree) && !(ads->filterflag & ADS_FILTER_NONTREE)) {
                        /* owner_id as id instead of texture, since it'll otherwise be impossible to track the depth */
                        // FIXME: perhaps as a result, textures should NOT be included under materials, but under their own section instead
                        // so that free-floating textures can also be animated
                        tmp_items += animdata_filter_ds_nodetree(ac, &tmp_data, ads, (ID *)tex, tex->nodetree, filter_mode);
                }
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* include texture-expand widget? */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* check if filtering by active status */
                        if (ANIMCHANNEL_ACTIVEOK(tex)) {
                                ANIMCHANNEL_NEW_CHANNEL(tex, ANIMTYPE_DSTEX, owner_id);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added to the list */
        return items;
}

/* NOTE: owner_id is either material, lamp, or world block, which is the direct owner of the texture stack in question */
static size_t animdata_filter_ds_textures(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, ID *owner_id, int filter_mode)
{
        MTex **mtex = NULL;
        size_t items = 0;
        int a = 0;
        
        /* get datatype specific data first */
        if (owner_id == NULL)
                return 0;
        
        switch (GS(owner_id->name)) {
                case ID_MA:
                {
                        Material *ma = (Material *)owner_id;
                        mtex = (MTex **)(&ma->mtex);
                        break;
                }
                case ID_LA:
                {
                        Lamp *la = (Lamp *)owner_id;
                        mtex = (MTex **)(&la->mtex);
                        break;
                }
                case ID_WO:
                {
                        World *wo = (World *)owner_id;
                        mtex = (MTex **)(&wo->mtex);
                        break;
                }
                case ID_PA:
                {
                        ParticleSettings *part = (ParticleSettings *)owner_id;
                        mtex = (MTex **)(&part->mtex);
                        break;
                }
                default: 
                {
                        /* invalid/unsupported option */
                        if (G.debug & G_DEBUG)
                                printf("ERROR: Unsupported owner_id (i.e. texture stack) for filter textures - %s\n", owner_id->name);
                        return 0;
                }
        }
        
        /* firstly check that we actuallly have some textures, by gathering all textures in a temp list */
        for (a = 0; a < MAX_MTEX; a++) {
                Tex *tex = (mtex[a]) ? mtex[a]->tex : NULL;
                
                /* for now, if no texture returned, skip (this shouldn't confuse the user I hope) */
                if (tex == NULL) 
                        continue;
                
                /* add texture's anim channels */
                items += animdata_filter_ds_texture(ac, anim_data, ads, tex, owner_id, filter_mode);
        }
        
        /* return the number of items added to the list */
        return items;
}


static size_t animdata_filter_ds_material(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Material *ma, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        /* add material's animation data to temp collection */
        BEGIN_ANIMFILTER_SUBCHANNELS(FILTER_MAT_OBJD(ma))
        {
                /* material's animation data */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)ma, filter_mode);
                        
                /* textures */
                if (!(ads->filterflag & ADS_FILTER_NOTEX))
                        tmp_items += animdata_filter_ds_textures(ac, &tmp_data, ads, (ID *)ma, filter_mode);
                        
                /* nodes */
                if ((ma->nodetree) && !(ads->filterflag & ADS_FILTER_NONTREE)) 
                        tmp_items += animdata_filter_ds_nodetree(ac, &tmp_data, ads, (ID *)ma, ma->nodetree, filter_mode);
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* include material-expand widget first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* check if filtering by active status */
                        if (ANIMCHANNEL_ACTIVEOK(ma)) {
                                ANIMCHANNEL_NEW_CHANNEL(ma, ANIMTYPE_DSMAT, ma);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        return items;
}

static size_t animdata_filter_ds_materials(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Object *ob, int filter_mode)
{
        bool has_nested = false;
        size_t items = 0;
        int a = 0;
        
        /* first pass: take the materials referenced via the Material slots of the object */
        for (a = 1; a <= ob->totcol; a++) {
                Material *ma = give_current_material(ob, a);
                
                /* if material is valid, try to add relevant contents from here */
                if (ma) {
                        /* add channels */
                        items += animdata_filter_ds_material(ac, anim_data, ads, ma, filter_mode);
                        
                        /* for optimising second pass - check if there's a nested material here to come back for */
                        if (has_nested == false) {
                                has_nested = (give_node_material(ma) != NULL);
                        }
                }
        }
        
        /* second pass: go through a second time looking for "nested" materials (material.material references)
         *
         * NOTE: here we ignore the expanded status of the parent, as it could be too confusing as to why these are
         *       disappearing/not available, since the relationships between these is not that clear
         */
        if (has_nested) {
                for (a = 1; a <= ob->totcol; a++) {
                        Material *base = give_current_material(ob, a);
                        Material *ma   = give_node_material(base);
                        
                        /* add channels from the nested material if it exists
                         *   - skip if the same material is referenced in its node tree
                         *     (which is common for BI materials) as that results in
                         *     confusing duplicates
                         */
                        if ((ma) && (ma != base)) {
                                items += animdata_filter_ds_material(ac, anim_data, ads, ma, filter_mode);
                        }
                }
        }
        
        /* return the number of items added to the list */
        return items;
}


/* ............ */

/* Temporary context for modifier linked-data channel extraction */
typedef struct tAnimFilterModifiersContext {
        bAnimContext *ac;       /* anim editor context */
        bDopeSheet *ads;    /* dopesheet filtering settings */
        
        ListBase tmp_data;  /* list of channels created (but not yet added to the main list) */
        size_t items;       /* number of channels created */
        
        int filter_mode;    /* flags for stuff we want to filter */
} tAnimFilterModifiersContext;


/* dependency walker callback for modifier dependencies */
static void animfilter_modifier_idpoin_cb(void *afm_ptr, Object *ob, ID **idpoin, int UNUSED(cb_flag))
{
        tAnimFilterModifiersContext *afm = (tAnimFilterModifiersContext *)afm_ptr;
        ID *owner_id = &ob->id;
        ID *id = *idpoin;
        
        /* NOTE: the walker only guarantees to give us all the ID-ptr *slots*, 
         * not just the ones which are actually used, so be careful!
         */
        if (id == NULL)
                return;
                
        /* check if this is something we're interested in... */
        switch (GS(id->name)) {
                case ID_TE: /* Textures */
                {
                        Tex *tex = (Tex *)id;
                        if (!(afm->ads->filterflag & ADS_FILTER_NOTEX)) {       
                                afm->items += animdata_filter_ds_texture(afm->ac, &afm->tmp_data, afm->ads, tex, owner_id, afm->filter_mode);
                        }
                        break;
                }
                
                /* TODO: images? */
                default:
                        break;
        }
}

/* animation linked to data used by modifiers 
 * NOTE: strictly speaking, modifier animation is already included under Object level
 *       but for some modifiers (e.g. Displace), there can be linked data that has settings
 *       which would be nice to animate (i.e. texture parameters) but which are not actually
 *       attached to any other objects/materials/etc. in the scene
 */
// TODO: do we want an expander for this?
static size_t animdata_filter_ds_modifiers(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Object *ob, int filter_mode)
{
        tAnimFilterModifiersContext afm = {NULL};
        size_t items = 0;
        
        /* 1) create a temporary "context" containing all the info we have here to pass to the callback 
         *    use to walk through the dependencies of the modifiers
         *
         * ! Assumes that all other unspecified values (i.e. accumulation buffers) are zero'd out properly
         */
        afm.ac          = ac;
        afm.ads         = ads;
        afm.filter_mode = filter_mode;
        
        /* 2) walk over dependencies */
        modifiers_foreachIDLink(ob, animfilter_modifier_idpoin_cb, &afm);
        
        /* 3) extract data from the context, merging it back into the standard list */
        if (afm.items) {
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &afm.tmp_data);
                BLI_assert(BLI_listbase_is_empty(&afm.tmp_data));
                items += afm.items;
        }
        
        return items;
}

/* ............ */


static size_t animdata_filter_ds_particles(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Object *ob, int filter_mode)
{
        ParticleSystem *psys;
        size_t items = 0;

        for (psys = ob->particlesystem.first; psys; psys = psys->next) {
                ListBase tmp_data = {NULL, NULL};
                size_t tmp_items = 0;
                
                /* if no material returned, skip - so that we don't get weird blank entries... */
                if (ELEM(NULL, psys->part, psys->part->adt))
                        continue;
                
                /* add particle-system's animation data to temp collection */
                BEGIN_ANIMFILTER_SUBCHANNELS(FILTER_PART_OBJD(psys->part))
                {
                        /* particle system's animation data */
                        tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)psys->part, filter_mode);
                        
                        /* textures */
                        if (!(ads->filterflag & ADS_FILTER_NOTEX))
                                tmp_items += animdata_filter_ds_textures(ac, &tmp_data, ads, (ID *)psys->part, filter_mode);
                }
                END_ANIMFILTER_SUBCHANNELS;
                
                /* did we find anything? */
                if (tmp_items) {
                        /* include particle-expand widget first */
                        if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                                /* check if filtering by active status */
                                if (ANIMCHANNEL_ACTIVEOK(psys->part)) {
                                        ANIMCHANNEL_NEW_CHANNEL(psys->part, ANIMTYPE_DSPART, psys->part);
                                }
                        }
                        
                        /* now add the list of collected channels */
                        BLI_movelisttolist(anim_data, &tmp_data);
                        BLI_assert(BLI_listbase_is_empty(&tmp_data));
                        items += tmp_items;
                }
        }
        
        /* return the number of items added to the list */
        return items;
}


static size_t animdata_filter_ds_obdata(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Object *ob, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        IdAdtTemplate *iat = ob->data;
        short type = 0, expanded = 0;
        
        /* get settings based on data type */
        switch (ob->type) {
                case OB_CAMERA: /* ------- Camera ------------ */
                {
                        Camera *ca = (Camera *)ob->data;
                        
                        if (ads->filterflag & ADS_FILTER_NOCAM)
                                return 0;
                        
                        type = ANIMTYPE_DSCAM;
                        expanded = FILTER_CAM_OBJD(ca);
                        break;
                }
                case OB_LAMP: /* ---------- Lamp ----------- */
                {
                        Lamp *la = (Lamp *)ob->data;
                        
                        if (ads->filterflag & ADS_FILTER_NOLAM)
                                return 0;
                        
                        type = ANIMTYPE_DSLAM;
                        expanded = FILTER_LAM_OBJD(la);
                        break;
                }
                case OB_CURVE: /* ------- Curve ---------- */
                case OB_SURF: /* ------- Nurbs Surface ---------- */
                case OB_FONT: /* ------- Text Curve ---------- */
                {
                        Curve *cu = (Curve *)ob->data;
                        
                        if (ads->filterflag & ADS_FILTER_NOCUR)
                                return 0;
                        
                        type = ANIMTYPE_DSCUR;
                        expanded = FILTER_CUR_OBJD(cu);
                        break;
                }
                case OB_MBALL: /* ------- MetaBall ---------- */
                {
                        MetaBall *mb = (MetaBall *)ob->data;
                        
                        if (ads->filterflag & ADS_FILTER_NOMBA)
                                return 0;
                        
                        type = ANIMTYPE_DSMBALL;
                        expanded = FILTER_MBALL_OBJD(mb);
                        break;
                }
                case OB_ARMATURE: /* ------- Armature ---------- */
                {
                        bArmature *arm = (bArmature *)ob->data;
                        
                        if (ads->filterflag & ADS_FILTER_NOARM)
                                return 0;
                        
                        type = ANIMTYPE_DSARM;
                        expanded = FILTER_ARM_OBJD(arm);
                        break;
                }
                case OB_MESH: /* ------- Mesh ---------- */
                {
                        Mesh *me = (Mesh *)ob->data;
                        
                        if (ads->filterflag & ADS_FILTER_NOMESH)
                                return 0;
                        
                        type = ANIMTYPE_DSMESH;
                        expanded = FILTER_MESH_OBJD(me);
                        break;
                }
                case OB_LATTICE: /* ---- Lattice ---- */
                {
                        Lattice *lt = (Lattice *)ob->data;
                        
                        if (ads->filterflag & ADS_FILTER_NOLAT)
                                return 0;
                        
                        type = ANIMTYPE_DSLAT;
                        expanded = FILTER_LATTICE_OBJD(lt);
                        break;
                }
                case OB_SPEAKER: /* ---------- Speaker ----------- */
                {
                        Speaker *spk = (Speaker *)ob->data;
                        
                        type = ANIMTYPE_DSSPK;
                        expanded = FILTER_SPK_OBJD(spk);
                        break;
                }
        }
        
        /* add object data animation channels */
        BEGIN_ANIMFILTER_SUBCHANNELS(expanded)
        {
                /* animation data filtering */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)iat, filter_mode);
                
                /* sub-data filtering... */
                switch (ob->type) {
                        case OB_LAMP:  /* lamp - textures + nodetree */
                        {
                                Lamp *la = ob->data;
                                bNodeTree *ntree = la->nodetree;
                                
                                /* nodetree */
                                if ((ntree) && !(ads->filterflag & ADS_FILTER_NONTREE))
                                        tmp_items += animdata_filter_ds_nodetree(ac, &tmp_data, ads, &la->id, ntree, filter_mode);
                                
                                /* textures */
                                if (!(ads->filterflag & ADS_FILTER_NOTEX))
                                        tmp_items += animdata_filter_ds_textures(ac, &tmp_data, ads, &la->id, filter_mode);
                                break;
                        }
                }
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* include data-expand widget first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* check if filtering by active status */
                        if (ANIMCHANNEL_ACTIVEOK(iat)) {
                                ANIMCHANNEL_NEW_CHANNEL(iat, type, iat);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added to the list */
        return items;
}

/* shapekey-level animation */
static size_t animdata_filter_ds_keyanim(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Object *ob, Key *key, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        /* add shapekey-level animation channels */
        BEGIN_ANIMFILTER_SUBCHANNELS(FILTER_SKE_OBJD(key))
        {
                /* animation data filtering */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)key, filter_mode);
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* include key-expand widget first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        if (ANIMCHANNEL_ACTIVEOK(key)) {
                                ANIMCHANNEL_NEW_CHANNEL(key, ANIMTYPE_DSSKEY, ob);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added to the list */
        return items;
}


/* object-level animation */
static size_t animdata_filter_ds_obanim(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Object *ob, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        AnimData *adt = ob->adt;
        short type = 0, expanded = 1;
        void *cdata = NULL;

        /* determine the type of expander channels to use */
        /* this is the best way to do this for now... */
        ANIMDATA_FILTER_CASES(ob,
                { /* AnimData - no channel, but consider data */ },
                { /* NLA - no channel, but consider data */ },
                { /* Drivers */
                        type = ANIMTYPE_FILLDRIVERS;
                        cdata = adt;
                        expanded = EXPANDED_DRVD(adt);
                },
                { /* NLA Strip Controls - no dedicated channel for now (XXX) */ },
                { /* Keyframes */
                        type = ANIMTYPE_FILLACTD;
                        cdata = adt->action;
                        expanded = EXPANDED_ACTC(adt->action);
                });
                
        /* add object-level animation channels */
        BEGIN_ANIMFILTER_SUBCHANNELS(expanded)
        {
                /* animation data filtering */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)ob, filter_mode);
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* include anim-expand widget first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        if (type != ANIMTYPE_NONE) {
                                /* NOTE: active-status (and the associated checks) don't apply here... */
                                ANIMCHANNEL_NEW_CHANNEL(cdata, type, ob);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added to the list */
        return items;
}

/* get animation channels from object2 */
static size_t animdata_filter_dopesheet_ob(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Base *base, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        Object *ob = base->object;
        size_t tmp_items = 0;
        size_t items = 0;
        
        /* filter data contained under object first */
        BEGIN_ANIMFILTER_SUBCHANNELS(EXPANDED_OBJC(ob))
        {
                Key *key = BKE_key_from_object(ob);
                
                /* object-level animation */
                if ((ob->adt) && !(ads->filterflag & ADS_FILTER_NOOBJ)) {
                        tmp_items += animdata_filter_ds_obanim(ac, &tmp_data, ads, ob, filter_mode);
                }
                
                /* shape-key */
                if ((key && key->adt) && !(ads->filterflag & ADS_FILTER_NOSHAPEKEYS)) {
                        tmp_items += animdata_filter_ds_keyanim(ac, &tmp_data, ads, ob, key, filter_mode);
                }
                
                /* modifiers */
                if ((ob->modifiers.first) && !(ads->filterflag & ADS_FILTER_NOMODIFIERS)) {
                        tmp_items += animdata_filter_ds_modifiers(ac, &tmp_data, ads, ob, filter_mode);
                }
                
                /* materials */
                if ((ob->totcol) && !(ads->filterflag & ADS_FILTER_NOMAT)) {
                        tmp_items += animdata_filter_ds_materials(ac, &tmp_data, ads, ob, filter_mode);
                }
                
                /* object data */
                if (ob->data) {
                        tmp_items += animdata_filter_ds_obdata(ac, &tmp_data, ads, ob, filter_mode);
                }
                
                /* particles */
                if ((ob->particlesystem.first) && !(ads->filterflag & ADS_FILTER_NOPART)) {
                        tmp_items += animdata_filter_ds_particles(ac, &tmp_data, ads, ob, filter_mode);
                }
                
                /* grease pencil */
                if ((ob->gpd) && !(ads->filterflag & ADS_FILTER_NOGPENCIL)) {
                        tmp_items += animdata_filter_ds_gpencil(ac, &tmp_data, ads, ob->gpd, filter_mode);
                }
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        
        /* if we collected some channels, add these to the new list... */
        if (tmp_items) {
                /* firstly add object expander if required */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* check if filtering by selection */
                        // XXX: double-check on this - most of the time, a lot of tools need to filter out these channels!
                        if (ANIMCHANNEL_SELOK((base->flag & BASE_SELECTED))) {
                                /* check if filtering by active status */
                                if (ANIMCHANNEL_ACTIVEOK(ob)) {
                                        ANIMCHANNEL_NEW_CHANNEL(base, ANIMTYPE_OBJECT, ob);
                                }
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added */
        return items;
}

static size_t animdata_filter_ds_world(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Scene *sce, World *wo, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        /* add world animation channels */
        BEGIN_ANIMFILTER_SUBCHANNELS(FILTER_WOR_SCED(wo))
        {
                /* animation data filtering */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)wo, filter_mode);
                
                /* textures for world */
                if (!(ads->filterflag & ADS_FILTER_NOTEX))
                        tmp_items += animdata_filter_ds_textures(ac, &tmp_data, ads, (ID *)wo, filter_mode);
                        
                /* nodes */
                if ((wo->nodetree) && !(ads->filterflag & ADS_FILTER_NONTREE)) 
                        tmp_items += animdata_filter_ds_nodetree(ac, &tmp_data, ads, (ID *)wo, wo->nodetree, filter_mode);
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* include data-expand widget first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* check if filtering by active status */
                        if (ANIMCHANNEL_ACTIVEOK(wo)) {
                                ANIMCHANNEL_NEW_CHANNEL(wo, ANIMTYPE_DSWOR, sce);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added to the list */
        return items;
}

static size_t animdata_filter_ds_scene(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Scene *sce, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        AnimData *adt = sce->adt;
        short type = 0, expanded = 1;
        void *cdata = NULL;
        
        /* determine the type of expander channels to use */
        // this is the best way to do this for now...
        ANIMDATA_FILTER_CASES(sce,
                { /* AnimData - no channel, but consider data */},
                { /* NLA - no channel, but consider data */},
                { /* Drivers */
                        type = ANIMTYPE_FILLDRIVERS;
                        cdata = adt;
                        expanded = EXPANDED_DRVD(adt);
                },
                { /* NLA Strip Controls - no dedicated channel for now (XXX) */ },
                { /* Keyframes */
                        type = ANIMTYPE_FILLACTD;
                        cdata = adt->action;
                        expanded = EXPANDED_ACTC(adt->action);
                });
                
        /* add scene-level animation channels */
        BEGIN_ANIMFILTER_SUBCHANNELS(expanded)
        {
                /* animation data filtering */
                tmp_items += animfilter_block_data(ac, &tmp_data, ads, (ID *)sce, filter_mode);
        }
        END_ANIMFILTER_SUBCHANNELS;
        
        /* did we find anything? */
        if (tmp_items) {
                /* include anim-expand widget first */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        if (type != ANIMTYPE_NONE) {
                                /* NOTE: active-status (and the associated checks) don't apply here... */
                                ANIMCHANNEL_NEW_CHANNEL(cdata, type, sce);
                        }
                }
                
                /* now add the list of collected channels */
                BLI_movelisttolist(anim_data, &tmp_data);
                BLI_assert(BLI_listbase_is_empty(&tmp_data));
                items += tmp_items;
        }
        
        /* return the number of items added to the list */
        return items;
}

static size_t animdata_filter_dopesheet_scene(bAnimContext *ac, ListBase *anim_data, bDopeSheet *ads, Scene *sce, int filter_mode)
{
        ListBase tmp_data = {NULL, NULL};
        size_t tmp_items = 0;
        size_t items = 0;
        
        /* filter data contained under object first */
        BEGIN_ANIMFILTER_SUBCHANNELS(EXPANDED_SCEC(sce))
        {
                bNodeTree *ntree = sce->nodetree;
                bGPdata *gpd = sce->gpd;
                World *wo = sce->world;
                
                /* Action, Drivers, or NLA for Scene */
                if ((ads->filterflag & ADS_FILTER_NOSCE) == 0) {
                        tmp_items += animdata_filter_ds_scene(ac, &tmp_data, ads, sce, filter_mode);
                }
                
                /* world */
                if ((wo) && !(ads->filterflag & ADS_FILTER_NOWOR)) {
                        tmp_items += animdata_filter_ds_world(ac, &tmp_data, ads, sce, wo, filter_mode);
                }
                
                /* nodetree */
                if ((ntree) && !(ads->filterflag & ADS_FILTER_NONTREE)) {
                        tmp_items += animdata_filter_ds_nodetree(ac, &tmp_data, ads, (ID *)sce, ntree, filter_mode);
                }
                
                /* line styles */
                if ((ads->filterflag & ADS_FILTER_NOLINESTYLE) == 0) {
                        tmp_items += animdata_filter_ds_linestyle(ac, &tmp_data, ads, sce, filter_mode);
                }
                
                /* grease pencil */
                if ((gpd) && !(ads->filterflag & ADS_FILTER_NOGPENCIL)) {
                        tmp_items += animdata_filter_ds_gpencil(ac, &tmp_data, ads, gpd, filter_mode);
                }
                
                /* TODO: one day, when sequencer becomes its own datatype, perhaps it should be included here */
        }
        END_ANIMFILTER_SUBCHANNELS;

        /* if we collected some channels, add these to the new list... */
        if (tmp_items) {
                /* firstly add object expander if required */
                if (filter_mode & ANIMFILTER_LIST_CHANNELS) {
                        /* check if filtering by selection */
                        if (ANIMCHANNEL_SELOK((sce->flag & SCE_DS_SELECTED))) {
                                /* NOTE: active-status doesn't matter for this! */
                                ANIMCHANNEL_NEW_CHANNEL(sce, ANIMTYPE_SCENE, sce);
                        }
                }
                
                /* now add the list of