static short paste_action_keys(bAnimContext *ac,
                               const eKeyPasteOffset offset_mode, const eKeyMergeMode merge_mode, bool flip)
{	
	ListBase anim_data = {NULL, NULL};
	int filter, ok = 0;
	
	/* filter data 
	 * - First time we try to filter more strictly, allowing only selected channels 
	 *   to allow copying animation between channels
	 * - Second time, we loosen things up if nothing was found the first time, allowing
	 *   users to just paste keyframes back into the original curve again [#31670]
	 */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT /*| ANIMFILTER_CURVESONLY*/ | ANIMFILTER_NODUPLIS);
	
	if (ANIM_animdata_filter(ac, &anim_data, filter | ANIMFILTER_SEL, ac->data, ac->datatype) == 0)
		ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* paste keyframes */
	ok = paste_animedit_keys(ac, &anim_data, offset_mode, merge_mode, flip);

	/* clean up */
	ANIM_animdata_freelist(&anim_data);

	return ok;
}

void ob_to_keylist(bDopeSheet *ads, Object *ob, DLRBT_Tree *keys, DLRBT_Tree *blocks)
{	
	bAnimContext ac = {NULL};
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	bAnimListElem dummychan = {NULL};
	Base dummybase = {NULL};
	
	if (ob == NULL)
		return;
	
	/* create a dummy wrapper data to work with */
	dummybase.object = ob;
	
	dummychan.type = ANIMTYPE_OBJECT;
	dummychan.data = &dummybase;
	dummychan.id = &ob->id;
	dummychan.adt = ob->adt;
	
	ac.ads = ads;
	ac.data = &dummychan;
	ac.datatype = ANIMCONT_CHANNEL;
	
	/* get F-Curves to take keyframes from */
	filter = ANIMFILTER_DATA_VISIBLE; // curves only
	ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
	
	/* loop through each F-Curve, grabbing the keyframes */
	for (ale = anim_data.first; ale; ale = ale->next)
		fcurve_to_keylist(ale->adt, ale->data, keys, blocks);
	
	ANIM_animdata_freelist(&anim_data);
}

/* helper - add NLA Tracks to empty (and selected) AnimData blocks */
bool nlaedit_add_tracks_empty(bAnimContext *ac)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	bool added = false;
	
	/* get a list of the selected AnimData blocks in the NLA */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_ANIMDATA | ANIMFILTER_SEL | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* check if selected AnimData blocks are empty, and add tracks if so... */
	for (ale = anim_data.first; ale; ale = ale->next) {
		AnimData *adt = ale->adt;
		
		/* sanity check */
		BLI_assert(adt->flag & ADT_UI_SELECTED);
		
		/* ensure it is empty */
		if (BLI_listbase_is_empty(&adt->nla_tracks)) {
			/* add new track to this AnimData block then */
			add_nlatrack(adt, NULL);
			added = true;
		}
	}
	
	/* cleanup */
	ANIM_animdata_freelist(&anim_data);
	
	return added;
}

/* This function is used to loop over the keyframe data in a DopeSheet summary */
static short summary_keyframes_loop(KeyframeEditData *ked, bAnimContext *ac, KeyframeEditFunc key_ok, KeyframeEditFunc key_cb, FcuEditFunc fcu_cb)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter, ret_code = 0;
	
	/* sanity check */
	if (ac == NULL)
		return 0;
	
	/* get F-Curves to take keyframes from */
	filter = ANIMFILTER_DATA_VISIBLE;
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* loop through each F-Curve, working on the keyframes until the first curve aborts */
	for (ale = anim_data.first; ale; ale = ale->next) {
		switch (ale->datatype) {
			case ALE_MASKLAY:
			case ALE_GPFRAME:
				break;
			default:
				ret_code = ANIM_fcurve_keyframes_loop(ked, ale->data, key_ok, key_cb, fcu_cb);
				break;
		}
		
		if (ret_code)
			break;
	}
	
	ANIM_animdata_freelist(&anim_data);
	
	return ret_code;
}

void cachefile_to_keylist(bDopeSheet *ads, CacheFile *cache_file, DLRBT_Tree *keys, DLRBT_Tree *blocks)
{
	if (cache_file == NULL) {
		return;
	}

	/* create a dummy wrapper data to work with */
	bAnimListElem dummychan = {NULL};
	dummychan.type = ANIMTYPE_DSCACHEFILE;
	dummychan.data = cache_file;
	dummychan.id = &cache_file->id;
	dummychan.adt = cache_file->adt;

	bAnimContext ac = {NULL};
	ac.ads = ads;
	ac.data = &dummychan;
	ac.datatype = ANIMCONT_CHANNEL;

	/* get F-Curves to take keyframes from */
	ListBase anim_data = { NULL, NULL };
	int filter = ANIMFILTER_DATA_VISIBLE; // curves only
	ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);

	/* loop through each F-Curve, grabbing the keyframes */
	for (bAnimListElem *ale = anim_data.first; ale; ale = ale->next) {
		fcurve_to_keylist(ale->adt, ale->data, keys, blocks);
	}

	ANIM_animdata_freelist(&anim_data);
}

/* Deselects keyframes in the Graph Editor
 *	- This is called by the deselect all operator, as well as other ones!
 *
 *  - test: check if select or deselect all
 *	- sel: how to select keyframes 
 *		0 = deselect
 *		1 = select
 *		2 = invert
 *	- do_channels: whether to affect selection status of channels
 */
static void deselect_graph_keys(bAnimContext *ac, short test, short sel, short do_channels)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	SpaceIpo *sipo = (SpaceIpo *)ac->sl;
	KeyframeEditData ked = {{NULL}};
	KeyframeEditFunc test_cb, sel_cb;
	
	/* determine type-based settings */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_CURVE_VISIBLE | ANIMFILTER_NODUPLIS);
	
	/* filter data */
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* init BezTriple looping data */
	test_cb = ANIM_editkeyframes_ok(BEZT_OK_SELECTED);
	
	/* See if we should be selecting or deselecting */
	if (test) {
		for (ale = anim_data.first; ale; ale = ale->next) {
			if (ANIM_fcurve_keyframes_loop(&ked, ale->key_data, NULL, test_cb, NULL)) {
				sel = SELECT_SUBTRACT;
				break;
			}
		}
	}
	
	/* convert sel to selectmode, and use that to get editor */
	sel_cb = ANIM_editkeyframes_select(sel);
	
	/* Now set the flags */
	for (ale = anim_data.first; ale; ale = ale->next) {
		FCurve *fcu = (FCurve *)ale->key_data;
		
		/* Keyframes First */
		ANIM_fcurve_keyframes_loop(&ked, ale->key_data, NULL, sel_cb, NULL);
		
		/* affect channel selection status? */
		if (do_channels) {
			/* only change selection of channel when the visibility of keyframes doesn't depend on this */
			if ((sipo->flag & SIPO_SELCUVERTSONLY) == 0) {
				/* deactivate the F-Curve, and deselect if deselecting keyframes.
				 * otherwise select the F-Curve too since we've selected all the keyframes
				 */
				if (sel == SELECT_SUBTRACT) 
					fcu->flag &= ~FCURVE_SELECTED;
				else
					fcu->flag |= FCURVE_SELECTED;
			}
			
			/* always deactivate all F-Curves if we perform batch ops for selection */
			fcu->flag &= ~FCURVE_ACTIVE;
		}
	}
	
	/* Cleanup */
	ANIM_animdata_freelist(&anim_data);
}

/* this function is responsible for setting handle-type of selected keyframes */
static void sethandles_action_keys(bAnimContext *ac, short mode) 
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	KeyframeEditFunc edit_cb = ANIM_editkeyframes_handles(mode);
	KeyframeEditFunc sel_cb = ANIM_editkeyframes_ok(BEZT_OK_SELECTED);
	
	/* filter data */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT /*| ANIMFILTER_CURVESONLY*/ | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* loop through setting flags for handles 
	 * Note: we do not supply KeyframeEditData to the looper yet. Currently that's not necessary here...
	 */
	for (ale = anim_data.first; ale; ale = ale->next) {
		FCurve *fcu = (FCurve *)ale->key_data;
		
		/* any selected keyframes for editing? */
		if (ANIM_fcurve_keyframes_loop(NULL, fcu, NULL, sel_cb, NULL)) {
			/* change type of selected handles */
			ANIM_fcurve_keyframes_loop(NULL, fcu, NULL, edit_cb, calchandles_fcurve);

			ale->update |= ANIM_UPDATE_DEFAULT;
		}
	}

	ANIM_animdata_update(ac, &anim_data);
	ANIM_animdata_freelist(&anim_data);
}

static void duplicate_action_keys(bAnimContext *ac)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	/* filter data */
	if (ELEM(ac->datatype, ANIMCONT_GPENCIL, ANIMCONT_MASK))
		filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT | ANIMFILTER_NODUPLIS);
	else
		filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT /*| ANIMFILTER_CURVESONLY*/ | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* loop through filtered data and delete selected keys */
	for (ale = anim_data.first; ale; ale = ale->next) {
		if (ELEM(ale->type, ANIMTYPE_FCURVE, ANIMTYPE_NLACURVE))
			duplicate_fcurve_keys((FCurve *)ale->key_data);
		else if (ale->type == ANIMTYPE_GPLAYER)
			ED_gplayer_frames_duplicate((bGPDlayer *)ale->data);
		else if (ale->type == ANIMTYPE_MASKLAYER)
			ED_masklayer_frames_duplicate((MaskLayer *)ale->data);
		else
			BLI_assert(0);

		ale->update |= ANIM_UPDATE_DEFAULT;
	}

	ANIM_animdata_update(ac, &anim_data);
	ANIM_animdata_freelist(&anim_data);
}

static void borderselect_nla_strips(bAnimContext *ac, rcti rect, short mode, short selectmode)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	SpaceNla *snla = (SpaceNla *)ac->sl;
	View2D *v2d = &ac->ar->v2d;
	rctf rectf;
	float ymin /* =(float)(-NLACHANNEL_HEIGHT(snla)) */ /* UNUSED */, ymax = 0;
	
	/* convert border-region to view coordinates */
	UI_view2d_region_to_view(v2d, rect.xmin, rect.ymin + 2, &rectf.xmin, &rectf.ymin);
	UI_view2d_region_to_view(v2d, rect.xmax, rect.ymax - 2, &rectf.xmax, &rectf.ymax);
	
	/* filter data */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_LIST_CHANNELS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* convert selection modes to selection modes */
	selectmode = selmodes_to_flagmodes(selectmode);
	
	/* loop over data, doing border select */
	for (ale = anim_data.first; ale; ale = ale->next) {
		ymin = ymax - NLACHANNEL_STEP(snla);
		
		/* perform vertical suitability check (if applicable) */
		if ((mode == NLA_BORDERSEL_FRAMERANGE) ||
		    !((ymax < rectf.ymin) || (ymin > rectf.ymax)))
		{
			/* loop over data selecting (only if NLA-Track) */
			if (ale->type == ANIMTYPE_NLATRACK) {
				NlaTrack *nlt = (NlaTrack *)ale->data;
				NlaStrip *strip;
				
				/* only select strips if they fall within the required ranges (if applicable) */
				for (strip = nlt->strips.first; strip; strip = strip->next) {
					if ((mode == NLA_BORDERSEL_CHANNELS) ||
					    BKE_nlastrip_within_bounds(strip, rectf.xmin, rectf.xmax))
					{
						/* set selection */
						ACHANNEL_SET_FLAG(strip, selectmode, NLASTRIP_FLAG_SELECT);
						
						/* clear active flag */
						strip->flag &= ~NLASTRIP_FLAG_ACTIVE;
					}
				}
			}
		}
		
		/* set minimum extent to be the maximum of the next channel */
		ymax = ymin;
	}
	
	/* cleanup */
	ANIM_animdata_freelist(&anim_data);
}

/* Deselects strips in the NLA Editor
 *	- This is called by the deselect all operator, as well as other ones!
 *
 *  - test: check if select or deselect all (1) or clear all active (2)
 *	- sel: how to select keyframes 
 *		0 = deselect
 *		1 = select
 *		2 = invert
 */
static void deselect_nla_strips(bAnimContext *ac, short test, short sel)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	short smode;
	
	/* determine type-based settings */
	// FIXME: double check whether ANIMFILTER_LIST_VISIBLE is needed!
	filter = (ANIMFILTER_DATA_VISIBLE);
	
	/* filter data */
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* See if we should be selecting or deselecting */
	if (test == DESELECT_STRIPS_TEST) {
		for (ale = anim_data.first; ale; ale = ale->next) {
			NlaTrack *nlt = (NlaTrack *)ale->data;
			NlaStrip *strip;
			
			/* if any strip is selected, break out, since we should now be deselecting */
			for (strip = nlt->strips.first; strip; strip = strip->next) {
				if (strip->flag & NLASTRIP_FLAG_SELECT) {
					sel = SELECT_SUBTRACT;
					break;
				}
			}
			
			if (sel == SELECT_SUBTRACT)
				break;
		}
	}
	
	/* convert selection modes to selection modes */
	smode = selmodes_to_flagmodes(sel);
	
	/* Now set the flags */
	for (ale = anim_data.first; ale; ale = ale->next) {
		NlaTrack *nlt = (NlaTrack *)ale->data;
		NlaStrip *strip;
		
		/* apply same selection to all strips */
		for (strip = nlt->strips.first; strip; strip = strip->next) {
			/* set selection */
			if (test != DESELECT_STRIPS_CLEARACTIVE)
				ACHANNEL_SET_FLAG(strip, smode, NLASTRIP_FLAG_SELECT);
			
			/* clear active flag */
			// TODO: for clear active, do we want to limit this to only doing this on a certain set of tracks though?
			strip->flag &= ~NLASTRIP_FLAG_ACTIVE;
		}
	}
	
	/* Cleanup */
	ANIM_animdata_freelist(&anim_data);
}

static void nlaedit_select_leftright(bContext *C, bAnimContext *ac, short leftright, short select_mode)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	Scene *scene = ac->scene;
	float xmin, xmax;
	
	/* if currently in tweakmode, exit tweakmode first */
	if (scene->flag & SCE_NLA_EDIT_ON)
		WM_operator_name_call(C, "NLA_OT_tweakmode_exit", WM_OP_EXEC_DEFAULT, NULL);
	
	/* if select mode is replace, deselect all keyframes (and channels) first */
	if (select_mode == SELECT_REPLACE) {
		select_mode = SELECT_ADD;
		
		/* - deselect all other keyframes, so that just the newly selected remain
		 * - channels aren't deselected, since we don't re-select any as a consequence
		 */
		deselect_nla_strips(ac, 0, SELECT_SUBTRACT);
	}
	
	/* get range, and get the right flag-setting mode */
	if (leftright == NLAEDIT_LRSEL_LEFT) {
		xmin = MINAFRAMEF;
		xmax = (float)(CFRA + 0.1f);
	}
	else {
		xmin = (float)(CFRA - 0.1f);
		xmax = MAXFRAMEF;
	}
	
	select_mode = selmodes_to_flagmodes(select_mode);
	
	
	/* filter data */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* select strips on the side where most data occurs */
	for (ale = anim_data.first; ale; ale = ale->next) {
		NlaTrack *nlt = (NlaTrack *)ale->data;
		NlaStrip *strip;
		
		/* check each strip to see if it is appropriate */
		for (strip = nlt->strips.first; strip; strip = strip->next) {
			if (BKE_nlastrip_within_bounds(strip, xmin, xmax)) {
				ACHANNEL_SET_FLAG(strip, select_mode, NLASTRIP_FLAG_SELECT);
			}
		}
	}
	
	/* Cleanup */
	ANIM_animdata_freelist(&anim_data);
}

static int graphview_curves_reveal_exec(bContext *C, wmOperator *op)
{
	bAnimContext ac;
	ListBase anim_data = {NULL, NULL};
	ListBase all_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	const bool select = RNA_boolean_get(op->ptr, "select");
	
	/* get editor data */
	if (ANIM_animdata_get_context(C, &ac) == 0)
		return OPERATOR_CANCELLED;
		
	/* get list of all channels that selection may need to be flushed to 
	 * - hierarchy must not affect what we have access to here...
	 */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_CHANNELS | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(&ac, &all_data, filter, ac.data, ac.datatype);
	
	/* filter data
	 * - just go through all visible channels, ensuring that everything is set to be curve-visible
	 */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
	
	for (ale = anim_data.first; ale; ale = ale->next) {
		/* hack: skip object channels for now, since flushing those will always flush everything, but they are always included */
		/* TODO: find out why this is the case, and fix that */
		if (ale->type == ANIMTYPE_OBJECT)
			continue;
		
		/* select if it is not visible */
		if (ANIM_channel_setting_get(&ac, ale, ACHANNEL_SETTING_VISIBLE) == 0) {
			ANIM_channel_setting_set(
			        &ac, ale, ACHANNEL_SETTING_SELECT,
			        select ? ACHANNEL_SETFLAG_ADD : ACHANNEL_SETFLAG_CLEAR);
		}
		
		/* change the visibility setting */
		ANIM_channel_setting_set(&ac, ale, ACHANNEL_SETTING_VISIBLE, ACHANNEL_SETFLAG_ADD);
		
		/* now, also flush selection status up/down as appropriate */
		ANIM_flush_setting_anim_channels(&ac, &all_data, ale, ACHANNEL_SETTING_VISIBLE, true);
	}
	
	/* cleanup */
	ANIM_animdata_freelist(&anim_data);
	BLI_freelistN(&all_data);
	
	/* send notifier that things have changed */
	WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_EDITED, NULL);
	
	return OPERATOR_FINISHED;
}

static void graphkeys_select_leftright(bAnimContext *ac, short leftright, short select_mode)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	KeyframeEditFunc ok_cb, select_cb;
	KeyframeEditData ked = {{NULL}};
	Scene *scene = ac->scene;
	
	/* if select mode is replace, deselect all keyframes (and channels) first */
	if (select_mode == SELECT_REPLACE) {
		select_mode = SELECT_ADD;
		
		/* - deselect all other keyframes, so that just the newly selected remain
		 * - channels aren't deselected, since we don't re-select any as a consequence
		 */
		deselect_graph_keys(ac, 0, SELECT_SUBTRACT, false);
	}
	
	/* set callbacks and editing data */
	ok_cb = ANIM_editkeyframes_ok(BEZT_OK_FRAMERANGE);
	select_cb = ANIM_editkeyframes_select(select_mode);
	
	if (leftright == GRAPHKEYS_LRSEL_LEFT) {
		ked.f1 = MINAFRAMEF;
		ked.f2 = (float)(CFRA + 0.1f);
	}
	else {
		ked.f1 = (float)(CFRA - 0.1f);
		ked.f2 = MAXFRAMEF;
	}
	
	/* filter data */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
		
	/* select keys */
	for (ale = anim_data.first; ale; ale = ale->next) {
		AnimData *adt = ANIM_nla_mapping_get(ac, ale);
		
		if (adt) {
			ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 0, 1);
			ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
			ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 1, 1);
		}
		else
			ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
	}

	/* Cleanup */
	ANIM_animdata_freelist(&anim_data);
}

/* this function is responsible for mirroring keyframes */
static void mirror_action_keys(bAnimContext *ac, short mode) 
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	KeyframeEditData ked = {{NULL}};
	KeyframeEditFunc edit_cb;
	
	/* get beztriple editing callbacks */
	edit_cb = ANIM_editkeyframes_mirror(mode);

	ked.scene = ac->scene;
	
	/* for 'first selected marker' mode, need to find first selected marker first! */
	/* XXX should this be made into a helper func in the API? */
	if (mode == ACTKEYS_MIRROR_MARKER) {
		TimeMarker *marker = ED_markers_get_first_selected(ac->markers);
		
		if (marker)
			ked.f1 = (float)marker->frame;
		else
			return;
	}
	
	/* filter data */
	if (ELEM(ac->datatype, ANIMCONT_GPENCIL, ANIMCONT_MASK))
		filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT | ANIMFILTER_NODUPLIS);
	else
		filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT /*| ANIMFILTER_CURVESONLY*/ | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* mirror keyframes */
	for (ale = anim_data.first; ale; ale = ale->next) {
		AnimData *adt = ANIM_nla_mapping_get(ac, ale);
		
		if (adt) {
			ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 0, 1); 
			ANIM_fcurve_keyframes_loop(&ked, ale->key_data, NULL, edit_cb, calchandles_fcurve);
			ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 1, 1);
		}
		//else if (ale->type == ACTTYPE_GPLAYER)
		//	snap_gplayer_frames(ale->data, mode);
		else 
			ANIM_fcurve_keyframes_loop(&ked, ale->key_data, NULL, edit_cb, calchandles_fcurve);

		ale->update |= ANIM_UPDATE_DEFAULT;
	}

	ANIM_animdata_update(ac, &anim_data);
	ANIM_animdata_freelist(&anim_data);
}

/* this function is responsible for snapping keyframes to frame-times */
static void snap_action_keys(bAnimContext *ac, short mode) 
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	KeyframeEditData ked = {{NULL}};
	KeyframeEditFunc edit_cb;
	
	/* filter data */
	if (ELEM(ac->datatype, ANIMCONT_GPENCIL, ANIMCONT_MASK))
		filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT);
	else
		filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT /*| ANIMFILTER_CURVESONLY*/ | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* get beztriple editing callbacks */
	edit_cb = ANIM_editkeyframes_snap(mode);

	ked.scene = ac->scene;
	if (mode == ACTKEYS_SNAP_NEAREST_MARKER) {
		ked.list.first = (ac->markers) ? ac->markers->first : NULL;
		ked.list.last = (ac->markers) ? ac->markers->last : NULL;
	}
	
	/* snap keyframes */
	for (ale = anim_data.first; ale; ale = ale->next) {
		AnimData *adt = ANIM_nla_mapping_get(ac, ale);
		
		if (ale->type == ANIMTYPE_GPLAYER) {
			ED_gplayer_snap_frames(ale->data, ac->scene, mode);
		}
		else if (ale->type == ANIMTYPE_MASKLAYER) {
			ED_masklayer_snap_frames(ale->data, ac->scene, mode);
		}
		else if (adt) {
			ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 0, 1); 
			ANIM_fcurve_keyframes_loop(&ked, ale->key_data, NULL, edit_cb, calchandles_fcurve);
			ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 1, 1);
		}
		else {
			ANIM_fcurve_keyframes_loop(&ked, ale->key_data, NULL, edit_cb, calchandles_fcurve);
		}

		ale->update |= ANIM_UPDATE_DEFAULT;
	}

	ANIM_animdata_update(ac, &anim_data);
	ANIM_animdata_freelist(&anim_data);
}

/* this function is responsible for snapping keyframes to frame-times */
static void insert_action_keys(bAnimContext *ac, short mode) 
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	ReportList *reports = ac->reports;
	Scene *scene = ac->scene;
	short flag = 0;
	
	/* filter data */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT /*| ANIMFILTER_CURVESONLY*/ | ANIMFILTER_NODUPLIS);
	if (mode == 2) filter |= ANIMFILTER_SEL;
	else if (mode == 3) filter |= ANIMFILTER_ACTGROUPED;
	
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* init keyframing flag */
	flag = ANIM_get_keyframing_flags(scene, 1);
	
	/* insert keyframes */
	for (ale = anim_data.first; ale; ale = ale->next) {
		AnimData *adt = ANIM_nla_mapping_get(ac, ale);
		FCurve *fcu = (FCurve *)ale->key_data;
		float cfra;
		
		/* adjust current frame for NLA-scaling */
		if (adt)
			cfra = BKE_nla_tweakedit_remap(adt, (float)CFRA, NLATIME_CONVERT_UNMAP);
		else 
			cfra = (float)CFRA;
			
		/* read value from property the F-Curve represents, or from the curve only?
		 * - ale->id != NULL:    Typically, this means that we have enough info to try resolving the path
		 * - ale->owner != NULL: If this is set, then the path may not be resolvable from the ID alone,
		 *                       so it's easier for now to just read the F-Curve directly.
		 *                       (TODO: add the full-blown PointerRNA relative parsing case here...)
		 */
		if (ale->id && !ale->owner)
			insert_keyframe(reports, ale->id, NULL, ((fcu->grp) ? (fcu->grp->name) : (NULL)), fcu->rna_path, fcu->array_index, cfra, flag);
		else
			insert_vert_fcurve(fcu, cfra, fcu->curval, 0);

		ale->update |= ANIM_UPDATE_DEFAULT;
	}

	ANIM_animdata_update(ac, &anim_data);
	ANIM_animdata_freelist(&anim_data);
}

/* TODO, this is almost an _exact_ duplicate of a function of the same name in graph_select.c
 * should de-duplicate - campbell */
static void markers_selectkeys_between(bAnimContext *ac)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	KeyframeEditFunc ok_cb, select_cb;
	KeyframeEditData ked = {{NULL}};
	float min, max;
	
	/* get extreme markers */
	ED_markers_get_minmax(ac->markers, 1, &min, &max);
	min -= 0.5f;
	max += 0.5f;
	
	/* get editing funcs + data */
	ok_cb = ANIM_editkeyframes_ok(BEZT_OK_FRAMERANGE);
	select_cb = ANIM_editkeyframes_select(SELECT_ADD);

	ked.f1 = min;
	ked.f2 = max;
	
	/* filter data */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE /*| ANIMFILTER_CURVESONLY */ | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* select keys in-between */
	for (ale = anim_data.first; ale; ale = ale->next) {
		AnimData *adt = ANIM_nla_mapping_get(ac, ale);
		
		if (adt) {
			ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 0, 1);
			ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
			ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 1, 1);
		}
		else if (ale->type == ANIMTYPE_GPLAYER) {
			ED_gplayer_frames_select_border(ale->data, min, max, SELECT_ADD);
		}
		else if (ale->type == ANIMTYPE_MASKLAYER) {
			ED_masklayer_frames_select_border(ale->data, min, max, SELECT_ADD);
		}
		else {
			ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
		}
	}
	
	/* Cleanup */
	ANIM_animdata_freelist(&anim_data);
}

static bool delete_action_keys(bAnimContext *ac)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	bool changed_final = false;

	/* filter data */
	if (ELEM(ac->datatype, ANIMCONT_GPENCIL, ANIMCONT_MASK))
		filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT | ANIMFILTER_NODUPLIS);
	else
		filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT /*| ANIMFILTER_CURVESONLY*/ | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

	/* loop through filtered data and delete selected keys */
	for (ale = anim_data.first; ale; ale = ale->next) {
		bool changed = false;

		if (ale->type == ANIMTYPE_GPLAYER) {
			changed = ED_gplayer_frames_delete((bGPDlayer *)ale->data);
		}
		else if (ale->type == ANIMTYPE_MASKLAYER) {
			changed = ED_masklayer_frames_delete((MaskLayer *)ale->data);
		}
		else {
			FCurve *fcu = (FCurve *)ale->key_data;
			AnimData *adt = ale->adt;
			
			/* delete selected keyframes only */
			changed = delete_fcurve_keys(fcu);
			
			/* Only delete curve too if it won't be doing anything anymore */
			if ((fcu->totvert == 0) && (list_has_suitable_fmodifier(&fcu->modifiers, 0, FMI_TYPE_GENERATE_CURVE) == 0)) {
				ANIM_fcurve_delete_from_animdata(ac, adt, fcu);
				ale->key_data = NULL;
			}
		}

		if (changed) {
			ale->update |= ANIM_UPDATE_DEFAULT;
			changed_final = true;
		}
	}

	ANIM_animdata_update(ac, &anim_data);
	ANIM_animdata_freelist(&anim_data);

	return changed_final;
}

/* this function is responsible for setting extrapolation mode for keyframes */
static void setexpo_action_keys(bAnimContext *ac, short mode) 
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	/* filter data */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FOREDIT | ANIMFILTER_SEL /*| ANIMFILTER_CURVESONLY*/ | ANIMFILTER_NODUPLIS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* loop through setting mode per F-Curve */
	for (ale = anim_data.first; ale; ale = ale->next) {
		FCurve *fcu = (FCurve *)ale->data;
		
		if (mode >= 0) {
			/* just set mode setting */
			fcu->extend = mode;
		}
		else {
			/* shortcuts for managing Cycles F-Modifiers to make it easier to toggle cyclic animation 
			 * without having to go through FModifier UI in Graph Editor to do so
			 */
			if (mode == MAKE_CYCLIC_EXPO) {
				/* only add if one doesn't exist */
				if (list_has_suitable_fmodifier(&fcu->modifiers, FMODIFIER_TYPE_CYCLES, -1) == 0) {
					/* TODO: add some more preset versions which set different extrapolation options? */
					add_fmodifier(&fcu->modifiers, FMODIFIER_TYPE_CYCLES);
				}
			}
			else if (mode == CLEAR_CYCLIC_EXPO) {
				/* remove all the modifiers fitting this description */
				FModifier *fcm, *fcn = NULL;
				
				for (fcm = fcu->modifiers.first; fcm; fcm = fcn) {
					fcn = fcm->next;
					
					if (fcm->type == FMODIFIER_TYPE_CYCLES)
						remove_fmodifier(&fcu->modifiers, fcm);
				}
			}
		}

		ale->update |= ANIM_UPDATE_DEFAULT;
	}

	ANIM_animdata_update(ac, &anim_data);
	ANIM_animdata_freelist(&anim_data);
}

/**
 * Find the extents of the active channel
 *
 * \param[out] min Bottom y-extent of channel
 * \param[out] max Top y-extent of channel
 * \return Success of finding a selected channel
 */
static bool actkeys_channels_get_selected_extents(bAnimContext *ac, float *min, float *max)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	
	short found = 0; /* NOTE: not bool, since we want prioritise individual channels over expanders */
	float y;
	
	/* get all items - we need to do it this way */
	filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_LIST_CHANNELS);
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* loop through all channels, finding the first one that's selected */
	y = (float)ACHANNEL_FIRST;
	
	for (ale = anim_data.first; ale; ale = ale->next) {
		const bAnimChannelType *acf = ANIM_channel_get_typeinfo(ale);
		
		/* must be selected... */
		if (acf && acf->has_setting(ac, ale, ACHANNEL_SETTING_SELECT) && 
		    ANIM_channel_setting_get(ac, ale, ACHANNEL_SETTING_SELECT))
		{
			/* update best estimate */
			*min = (float)(y - ACHANNEL_HEIGHT_HALF);
			*max = (float)(y + ACHANNEL_HEIGHT_HALF);
			
			/* is this high enough priority yet? */
			found = acf->channel_role;
			
			/* only stop our search when we've found an actual channel
			 * - datablock expanders get less priority so that we don't abort prematurely
			 */
			if (found == ACHANNEL_ROLE_CHANNEL) {
				break;
			}
		}
		
		/* adjust y-position for next one */
		y -= ACHANNEL_STEP;
	}
	
	/* free all temp data */
	ANIM_animdata_freelist(&anim_data);
	
	return (found != 0);
}