NLA SoC: More work on Meta-Strips

* Added several API functions for Meta-Strips editing. One of these (flush transform) still needs a few tweaks before it does its job well enough for all cases.

* Meta strips are now drawn with a purple-ish colour. The start/end points of the strips they encompass are shown with lines along the length of the strips, with lines starting from the top indicating start-points and lines starting from the bottom indicating end-points.

* Meta strips can be made (i.e. strips can be assigned to meta-strips) by selecting some strips and pressing Shift-G. 
Meta strips can be removed by selecting some meta-strips and pressing Alt-G.

* Strips can now be 'snapped' to start from: the current frame, the nearest frame, the nearest second, or the nearest marker; using the Shift-S hotkey. 
'Islands' of adjacent selected strips occurring in the same track are moved together as a single strip so that the start-point of the first strip is on the sepcified time, but all the relative lengths of strips stay the same. Internally, temporary meta-strips are created to facilitate this.

9 files changed, 415 insertions, 9 deletions

diff --git a/source/blender/blenkernel/BKE_nla.h b/source/blender/blenkernel/BKE_nla.h
index efa0591bd53..3fcd799310e 100644
--- a/source/blender/blenkernel/BKE_nla.h
+++ b/source/blender/blenkernel/BKE_nla.h
@@ -58,6 +58,12 @@ void BKE_nlastrips_sort_strips(ListBase *strips);
 
 short BKE_nlastrips_add_strip(ListBase *strips, struct NlaStrip *strip);
 
+
+void BKE_nlastrips_make_metas(ListBase *strips, short temp);
+void BKE_nlastrips_clear_metas(ListBase *strips, short onlySel, short onlyTemp);
+short BKE_nlameta_add_strip(struct NlaStrip *mstrip, struct NlaStrip *strip);
+void BKE_nlameta_flush_transforms(struct NlaStrip *mstrip);
+
 /* ............ */
 
 struct NlaTrack *BKE_nlatrack_find_active(ListBase *tracks);
diff --git a/source/blender/blenkernel/intern/nla.c b/source/blender/blenkernel/intern/nla.c
index d01fa2c1965..715f99c820f 100644
--- a/source/blender/blenkernel/intern/nla.c
+++ b/source/blender/blenkernel/intern/nla.c
@@ -616,6 +616,199 @@ short BKE_nlastrips_add_strip (ListBase *strips, NlaStrip *strip)
 	return 1;
 }
 
+
+/* Meta-Strips ------------------------------------ */
+
+/* Convert 'islands' (i.e. continuous string of) selected strips to be
+ * contained within 'Meta-Strips' which act as strips which contain strips.
+ *	temp: are the meta-strips to be created 'temporary' ones used for transforms?
+ */
+void BKE_nlastrips_make_metas (ListBase *strips, short temp)
+{
+	NlaStrip *mstrip = NULL;
+	NlaStrip *strip, *stripn;
+	
+	/* sanity checks */
+	if ELEM(NULL, strips, strips->first)
+		return;
+	
+	/* group all continuous chains of selected strips into meta-strips */
+	for (strip= strips->first; strip; strip= stripn) {
+		stripn= strip->next;
+		
+		if (strip->flag & NLASTRIP_FLAG_SELECT) {
+			/* if there is an existing meta-strip, add this strip to it, otherwise, create a new one */
+			if (mstrip == NULL) {
+				/* add a new meta-strip, and add it before the current strip that it will replace... */
+				mstrip= MEM_callocN(sizeof(NlaStrip), "Meta-NlaStrip");
+				mstrip->type = NLASTRIP_TYPE_META;
+				BLI_insertlinkbefore(strips, strip, mstrip);
+				
+				/* set flags */
+				mstrip->flag = NLASTRIP_FLAG_SELECT;
+				
+				/* set temp flag if appropriate (i.e. for transform-type editing) */
+				if (temp)
+					mstrip->flag |= NLASTRIP_FLAG_TEMP_META;
+				
+				/* make its start frame be set to the start frame of the current strip */
+				mstrip->start= strip->start;
+			}
+			
+			/* remove the selected strips from the track, and add to the meta */
+			BLI_remlink(strips, strip);
+			BLI_addtail(&mstrip->strips, strip);
+			
+			/* expand the meta's dimensions to include the newly added strip- i.e. its last frame */
+			mstrip->end= strip->end;
+		}
+		else {
+			/* current strip wasn't selected, so the end of 'island' of selected strips has been reached,
+			 * so stop adding strips to the current meta
+			 */
+			mstrip= NULL;
+		}
+	}
+}
+
+/* Remove meta-strips (i.e. flatten the list of strips) from the top-level of the list of strips
+ *	sel: only consider selected meta-strips, otherwise all meta-strips are removed
+ *	onlyTemp: only remove the 'temporary' meta-strips used for transforms
+ */
+void BKE_nlastrips_clear_metas (ListBase *strips, short onlySel, short onlyTemp)
+{
+	NlaStrip *strip, *stripn;
+	
+	/* sanity checks */
+	if ELEM(NULL, strips, strips->first)
+		return;
+	
+	/* remove meta-strips fitting the criteria of the arguments */
+	for (strip= strips->first; strip; strip= stripn) {
+		stripn= strip->next;
+		
+		/* check if strip is a meta-strip */
+		if (strip->type == NLASTRIP_TYPE_META) {
+			/* if check if selection and 'temporary-only' considerations are met */
+			if ((onlySel==0) || (strip->flag & NLASTRIP_FLAG_SELECT)) {
+				if ((!onlyTemp) || (strip->flag & NLASTRIP_FLAG_TEMP_META)) {
+					NlaStrip *cs, *csn;
+					
+					/* move each one of the meta-strip's children before the meta-strip
+					 * in the list of strips after unlinking them from the meta-strip
+					 */
+					for (cs= strip->strips.first; cs; cs= csn) {
+						csn= cs->next;
+						BLI_remlink(&strip->strips, cs);
+						BLI_insertlinkbefore(strips, strip, cs);
+					}
+					
+					/* free the meta-strip now */
+					BLI_freelinkN(strips, strip);
+				}
+			}
+		}
+	}
+}
+
+/* Add the given NLA-Strip to the given Meta-Strip, assuming that the
+ * strip isn't attached to anyy list of strips 
+ */
+short BKE_nlameta_add_strip (NlaStrip *mstrip, NlaStrip *strip)
+{
+	/* sanity checks */
+	if ELEM(NULL, mstrip, strip)
+		return 0;
+		
+	/* firstly, check if the meta-strip has space for this */
+	if (BKE_nlastrips_has_space(&mstrip->strips, strip->start, strip->end) == 0)
+		return 0;
+		
+	/* check if this would need to be added to the ends of the meta,
+	 * and subsequently, if the neighbouring strips allow us enough room
+	 */
+	if (strip->start < mstrip->start) {
+		/* check if strip to the left (if it exists) ends before the 
+		 * start of the strip we're trying to add 
+		 */
+		if ((mstrip->prev == NULL) || (mstrip->prev->end <= strip->start)) {
+			/* add strip to start of meta's list, and expand dimensions */
+			BLI_addhead(&mstrip->strips, strip);
+			mstrip->start= strip->start;
+			
+			return 1;
+		}
+		else /* failed... no room before */
+			return 0;
+	}
+	else if (strip->end > mstrip->end) {
+		/* check if strip to the right (if it exists) starts before the 
+		 * end of the strip we're trying to add 
+		 */
+		if ((mstrip->next == NULL) || (mstrip->next->start >= strip->end)) {
+			/* add strip to end of meta's list, and expand dimensions */
+			BLI_addtail(&mstrip->strips, strip);
+			mstrip->end= strip->end;
+			
+			return 1;
+		}
+		else /* failed... no room after */
+			return 0;
+	}
+	else {
+		/* just try to add to the meta-strip (no dimension changes needed) */
+		return BKE_nlastrips_add_strip(&mstrip->strips, strip);
+	}
+}
+
+/* Adjust the settings of NLA-Strips contained within a Meta-Strip (recursively), 
+ * until the Meta-Strips children all fit within the Meta-Strip's new dimensions
+ */
+void BKE_nlameta_flush_transforms (NlaStrip *mstrip) 
+{
+	NlaStrip *strip;
+	float oStart, oEnd, offset;
+	
+	/* sanity checks 
+	 *	- strip must exist
+	 *	- strip must be a meta-strip with some contents
+	 */
+	if ELEM(NULL, mstrip, mstrip->strips.first)
+		return;
+	if (mstrip->type != NLASTRIP_TYPE_META)
+		return;
+		
+	/* get the original start/end points, and calculate the start-frame offset
+	 *	- these are simply the start/end frames of the child strips, 
+	 *	  since we assume they weren't transformed yet
+	 */
+	oStart= ((NlaStrip *)mstrip->strips.first)->start;
+	oEnd= ((NlaStrip *)mstrip->strips.last)->end;
+	offset= mstrip->start - oStart;
+	
+	/* optimisation:
+	 * don't flush if nothing changed yet
+	 *	TODO: maybe we need a flag to say always flush?
+	 */
+	if (IS_EQ(oStart, mstrip->start) && IS_EQ(oEnd, mstrip->end))
+		return;
+	
+	/* for each child-strip, calculate new start/end points based on this new info */
+	for (strip= mstrip->strips.first; strip; strip= strip->next) {
+		//PointerRNA strip_ptr;
+		
+		/* firstly, just apply the changes in offset to both ends of the strip */
+		strip->start += offset;
+		strip->end += offset;
+		
+		/* now, we need to fix the endpoint to take into account scaling */
+		// TODO..
+		
+		/* finally, make sure the strip's children (if it is a meta-itself), get updated */
+		BKE_nlameta_flush_transforms(strip);
+	}
+}
+
 /* NLA-Tracks ---------------------------------------- */
 
 /* Find the active NLA-track for the given stack */
diff --git a/source/blender/editors/space_nla/nla_draw.c b/source/blender/editors/space_nla/nla_draw.c
index ab33434077e..e31aebf0155 100644
--- a/source/blender/editors/space_nla/nla_draw.c
+++ b/source/blender/editors/space_nla/nla_draw.c
@@ -176,6 +176,23 @@ static void nla_strip_get_color_inside (AnimData *adt, NlaStrip *strip, float co
 			color[2]= 0.19f;
 		}
 	}	
+	else if (strip->type == NLASTRIP_TYPE_META) {
+		/* Meta Clip */
+		if (strip->flag & NLASTRIP_FLAG_SELECT) {
+			/* selected - use a bold purple color */
+			// FIXME: hardcoded temp-hack colors
+			color[0]= 0.41f;
+			color[1]= 0.13f;
+			color[2]= 0.59f;
+		}
+		else {
+			/* normal, unselected strip - use (hardly noticable) dark purple tinge */
+			// FIXME: hardcoded temp-hack colors
+			color[0]= 0.20f;
+			color[1]= 0.15f;
+			color[2]= 0.26f;
+		}
+	}	
 	else {
 		/* Action Clip (default/normal type of strip) */
 		if ((strip->flag & NLASTRIP_FLAG_ACTIVE) && (adt && (adt->flag & ADT_NLA_EDIT_ON))) {
@@ -293,7 +310,7 @@ static void nla_draw_strip (AnimData *adt, NlaTrack *nlt, NlaStrip *strip, View2
 	/* draw outline */
 	gl_round_box_shade(GL_LINE_LOOP, strip->start, yminc, strip->end, ymaxc, 0.0, 0.0, 0.1);
 	
-	/* if action-clip strip, draw lines delimiting repeats too (in the same colour */
+	/* if action-clip strip, draw lines delimiting repeats too (in the same color as outline) */
 	if ((strip->type == NLASTRIP_TYPE_CLIP) && IS_EQ(strip->repeat, 1.0f)==0) {
 		float repeatLen = (strip->actend - strip->actstart) * strip->scale;
 		int i;
@@ -309,6 +326,26 @@ static void nla_draw_strip (AnimData *adt, NlaTrack *nlt, NlaStrip *strip, View2
 				fdrawline(repeatPos, yminc, repeatPos, ymaxc);
 		}
 	}
+	/* or if meta-strip, draw lines delimiting extents of sub-strips (in same color as outline, if more than 1 exists) */
+	else if ((strip->type == NLASTRIP_TYPE_META) && (strip->strips.first != strip->strips.last)) {
+		NlaStrip *cs;
+		float y= (ymaxc-yminc)/2.0f + yminc;
+		
+		/* only draw first-level of child-strips, but don't draw any lines on the endpoints */
+		for (cs= strip->strips.first; cs; cs= cs->next) {
+			/* draw start-line if not same as end of previous (and only if not the first strip) 
+			 *	- on upper half of strip
+			 */
+			if ((cs->prev) && IS_EQ(cs->prev->end, cs->start)==0)
+				fdrawline(cs->start, y, cs->start, ymaxc);
+				
+			/* draw end-line if not the last strip
+			 *	- on lower half of strip
+			 */
+			if (cs->next) 
+				fdrawline(cs->end, yminc, cs->end, y);
+		}
+	}
 	
 	/* reset linestyle */
 	setlinestyle(0);
diff --git a/source/blender/editors/space_nla/nla_edit.c b/source/blender/editors/space_nla/nla_edit.c
index e95d0b1a50a..f7d4db17e2c 100644
--- a/source/blender/editors/space_nla/nla_edit.c
+++ b/source/blender/editors/space_nla/nla_edit.c
@@ -346,7 +346,6 @@ void NLA_OT_add_actionclip (wmOperatorType *ot)
 /* ******************** Add Transition Operator ***************************** */
 /* Add a new transition strip between selected strips */
 
-/* add the specified action as new strip */
 static int nlaedit_add_transition_exec (bContext *C, wmOperator *op)
 {
 	bAnimContext ac;
@@ -453,6 +452,113 @@ void NLA_OT_add_transition (wmOperatorType *ot)
 	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
 }
 
+/* ******************** Add Meta-Strip Operator ***************************** */
+/* Add new meta-strips incorporating the selected strips */
+
+/* add the specified action as new strip */
+static int nlaedit_add_meta_exec (bContext *C, wmOperator *op)
+{
+	bAnimContext ac;
+	
+	ListBase anim_data = {NULL, NULL};
+	bAnimListElem *ale;
+	int filter;
+	
+	/* get editor data */
+	if (ANIM_animdata_get_context(C, &ac) == 0)
+		return OPERATOR_CANCELLED;
+	
+	/* get a list of the editable tracks being shown in the NLA */
+	filter= (ANIMFILTER_VISIBLE | ANIMFILTER_NLATRACKS | ANIMFILTER_FOREDIT);
+	ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
+	
+	/* for each track, find pairs of strips to add transitions to */
+	for (ale= anim_data.first; ale; ale= ale->next) {
+		NlaTrack *nlt= (NlaTrack *)ale->data;
+		
+		/* create meta-strips from the continuous chains of selected strips */
+		BKE_nlastrips_make_metas(&nlt->strips, 0);
+	}
+	
+	/* free temp data */
+	BLI_freelistN(&anim_data);
+	
+	/* set notifier that things have changed */
+	ANIM_animdata_send_notifiers(C, &ac, ANIM_CHANGED_BOTH);
+	WM_event_add_notifier(C, NC_SCENE, NULL);
+	
+	/* done */
+	return OPERATOR_FINISHED;
+}
+
+void NLA_OT_add_meta (wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Add Meta-Strips";
+	ot->idname= "NLA_OT_add_meta";
+	ot->description= "Add new meta-strips incorporating the selected strips.";
+	
+	/* api callbacks */
+	ot->exec= nlaedit_add_meta_exec;
+	ot->poll= nlaop_poll_tweakmode_off;
+	
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+}
+
+/* ******************** Remove Meta-Strip Operator ***************************** */
+/* Separate out the strips held by the selected meta-strips */
+
+static int nlaedit_remove_meta_exec (bContext *C, wmOperator *op)
+{
+	bAnimContext ac;
+	
+	ListBase anim_data = {NULL, NULL};
+	bAnimListElem *ale;
+	int filter;
+	
+	/* get editor data */
+	if (ANIM_animdata_get_context(C, &ac) == 0)
+		return OPERATOR_CANCELLED;
+	
+	/* get a list of the editable tracks being shown in the NLA */
+	filter= (ANIMFILTER_VISIBLE | ANIMFILTER_NLATRACKS | ANIMFILTER_FOREDIT);
+	ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
+	
+	/* for each track, find pairs of strips to add transitions to */
+	for (ale= anim_data.first; ale; ale= ale->next) {
+		NlaTrack *nlt= (NlaTrack *)ale->data;
+		
+		/* clear all selected meta-strips, regardless of whether they are temporary or not */
+		BKE_nlastrips_clear_metas(&nlt->strips, 1, 0);
+	}
+	
+	/* free temp data */
+	BLI_freelistN(&anim_data);
+	
+	/* set notifier that things have changed */
+	ANIM_animdata_send_notifiers(C, &ac, ANIM_CHANGED_BOTH);
+	WM_event_add_notifier(C, NC_SCENE, NULL);
+	
+	/* done */
+	return OPERATOR_FINISHED;
+}
+
+void NLA_OT_remove_meta (wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Remove Meta-Strips";
+	ot->idname= "NLA_OT_remove_meta";
+	ot->description= "Separate out the strips held by the selected meta-strips.";
+	
+	/* api callbacks */
+	ot->exec= nlaedit_remove_meta_exec;
+	ot->poll= nlaop_poll_tweakmode_off;
+	
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+}
+
 /* ******************** Duplicate Strips Operator ************************** */
 /* Duplicates the selected NLA-Strips, putting them on new tracks above the one
  * the originals were housed in.
@@ -1047,9 +1153,9 @@ static int nlaedit_snap_exec (bContext *C, wmOperator *op)
 	bAnimListElem *ale;
 	int filter;
 	
-	Scene *scene= ac.scene;
+	Scene *scene;
 	int mode = RNA_enum_get(op->ptr, "type");
-	const float secf = (float)FPS;
+	float secf;
 	
 	/* get editor data */
 	if (ANIM_animdata_get_context(C, &ac) == 0)
@@ -1059,17 +1165,28 @@ static int nlaedit_snap_exec (bContext *C, wmOperator *op)
 	filter= (ANIMFILTER_VISIBLE | ANIMFILTER_NLATRACKS | ANIMFILTER_FOREDIT);
 	ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
 	
+	/* get some necessary vars */
+	scene= ac.scene;
+	secf= (float)FPS;
+	
 	/* since we may add tracks, perform this in reverse order */
 	for (ale= anim_data.last; ale; ale= ale->prev) {
 		ListBase tmp_strips = {NULL, NULL};
+		AnimData *adt= BKE_animdata_from_id(ale->id);
 		NlaTrack *nlt= (NlaTrack *)ale->data;
 		NlaStrip *strip, *stripn;
+		NlaTrack *track;
 		
-		/* first pass: move all selected strips to a separate buffer, and apply snapping to them */
+		/* create meta-strips from the continuous chains of selected strips */
+		BKE_nlastrips_make_metas(&nlt->strips, 1);
+		
+		/* apply the snapping to all the temp meta-strips, then put them in a separate list to be added
+		 * back to the original only if they still fit
+		 */
 		for (strip= nlt->strips.first; strip; strip= stripn) {
 			stripn= strip->next;
 			
-			if (strip->flag & NLASTRIP_FLAG_SELECT) {
+			if (strip->flag & NLASTRIP_FLAG_TEMP_META) {
 				float start, end;
 				
 				/* get the existing end-points */
@@ -1098,13 +1215,32 @@ static int nlaedit_snap_exec (bContext *C, wmOperator *op)
 				/* get new endpoint based on start-point (and old length) */
 				strip->end= strip->start + (end - start);
 				
+				/* apply transforms to meta-strip to its children */
+				BKE_nlameta_flush_transforms(strip);
+				
 				/* remove strip from track, and add to the temp buffer */
 				BLI_remlink(&nlt->strips, strip);
 				BLI_addtail(&tmp_strips, strip);
 			}
 		}
 		
-		// TODO: finish this...
+		/* try adding each meta-strip back to the track one at a time, to make sure they'll fit */
+		for (strip= tmp_strips.first; strip; strip= stripn) {
+			stripn= strip->next;
+			
+			/* remove from temp-strips list */
+			BLI_remlink(&tmp_strips, strip);
+			
+			/* in case there's no space in the current track, try adding */
+			if (BKE_nlatrack_add_strip(nlt, strip) == 0) {
+				/* need to add a new track above the current one */
+				track= add_nlatrack(adt, nlt);
+				BKE_nlatrack_add_strip(track, strip);
+			}
+		}
+		
+		/* remove the meta-strips now that we're done */
+		BKE_nlastrips_clear_metas(&nlt->strips, 0, 1);
 	}
 	
 	/* free temp data */
diff --git a/source/blender/editors/space_nla/nla_header.c b/source/blender/editors/space_nla/nla_header.c
index fc6db76ba65..9b9b21629cc 100644
--- a/source/blender/editors/space_nla/nla_header.c
+++ b/source/blender/editors/space_nla/nla_header.c
@@ -70,6 +70,8 @@
 
 #include "ED_markers.h"
 
+#include "nla_intern.h"
+
 /* button events */
 enum {
 	B_REDR 	= 0,
@@ -142,9 +144,18 @@ static void nla_edit_transformmenu(bContext *C, uiLayout *layout, void *arg_unus
 	uiItemEnumO(layout, "Scale", 0, "TFM_OT_transform", "mode", TFM_TIME_SCALE);
 }
 
+static void nla_edit_snapmenu(bContext *C, uiLayout *layout, void *arg_unused)
+{
+	uiItemEnumO(layout, NULL, 0, "NLA_OT_snap", "type", NLAEDIT_SNAP_CFRA);
+	uiItemEnumO(layout, NULL, 0, "NLA_OT_snap", "type", NLAEDIT_SNAP_NEAREST_FRAME);
+	uiItemEnumO(layout, NULL, 0, "NLA_OT_snap", "type", NLAEDIT_SNAP_NEAREST_SECOND);
+	uiItemEnumO(layout, NULL, 0, "NLA_OT_snap", "type", NLAEDIT_SNAP_NEAREST_MARKER);
+}
+
 static void nla_editmenu(bContext *C, uiLayout *layout, void *arg_unused)
 {
 	uiItemMenuF(layout, "Transform", 0, nla_edit_transformmenu);
+	uiItemMenuF(layout, "Snap", 0, nla_edit_snapmenu);
 	
 	uiItemS(layout);
 	
@@ -173,6 +184,11 @@ static void nla_addmenu(bContext *C, uiLayout *layout, void *arg_unused)
 	
 	uiItemS(layout);
 	
+	uiItemO(layout, NULL, 0, "NLA_OT_add_meta");
+	uiItemO(layout, NULL, 0, "NLA_OT_remove_meta");
+	
+	uiItemS(layout);
+	
 	uiItemO(layout, NULL, 0, "NLA_OT_add_tracks");
 	uiItemBooleanO(layout, "Add Tracks Above Selected", 0, "NLA_OT_add_tracks", "above_selected", 1);
 }
diff --git a/source/blender/editors/space_nla/nla_intern.h b/source/blender/editors/space_nla/nla_intern.h
index 422686bb424..4391a019207 100644
--- a/source/blender/editors/space_nla/nla_intern.h
+++ b/source/blender/editors/space_nla/nla_intern.h
@@ -106,6 +106,9 @@ void NLA_OT_tweakmode_exit(wmOperatorType *ot);
 void NLA_OT_add_actionclip(wmOperatorType *ot);
 void NLA_OT_add_transition(wmOperatorType *ot);
 
+void NLA_OT_add_meta(wmOperatorType *ot);
+void NLA_OT_remove_meta(wmOperatorType *ot);
+
 void NLA_OT_duplicate(wmOperatorType *ot);
 void NLA_OT_delete(wmOperatorType *ot);
 void NLA_OT_split(wmOperatorType *ot);
@@ -116,6 +119,8 @@ void NLA_OT_move_down(wmOperatorType *ot);
 void NLA_OT_apply_scale(wmOperatorType *ot);
 void NLA_OT_clear_scale(wmOperatorType *ot);
 
+void NLA_OT_snap(wmOperatorType *ot);
+
 void NLA_OT_fmodifier_add(wmOperatorType *ot);
 
 
diff --git a/source/blender/editors/space_nla/nla_ops.c b/source/blender/editors/space_nla/nla_ops.c
index 7caab02d6a0..25fd8db668c 100644
--- a/source/blender/editors/space_nla/nla_ops.c
+++ b/source/blender/editors/space_nla/nla_ops.c
@@ -146,6 +146,9 @@ void nla_operatortypes(void)
 	WM_operatortype_append(NLA_OT_add_actionclip);
 	WM_operatortype_append(NLA_OT_add_transition);
 	
+	WM_operatortype_append(NLA_OT_add_meta);
+	WM_operatortype_append(NLA_OT_remove_meta);
+	
 	WM_operatortype_append(NLA_OT_duplicate);
 	WM_operatortype_append(NLA_OT_delete);
 	WM_operatortype_append(NLA_OT_split);
@@ -156,6 +159,8 @@ void nla_operatortypes(void)
 	WM_operatortype_append(NLA_OT_apply_scale);
 	WM_operatortype_append(NLA_OT_clear_scale);
 	
+	WM_operatortype_append(NLA_OT_snap);
+	
 	WM_operatortype_append(NLA_OT_fmodifier_add);
 }
 
@@ -236,6 +241,10 @@ static void nla_keymap_main (wmWindowManager *wm, ListBase *keymap)
 		/* add strips */
 	WM_keymap_add_item(keymap, "NLA_OT_add_actionclip", AKEY, KM_PRESS, KM_SHIFT, 0);
 	WM_keymap_add_item(keymap, "NLA_OT_add_transition", TKEY, KM_PRESS, KM_SHIFT, 0);
+	
+		/* meta-strips */
+	WM_keymap_add_item(keymap, "NLA_OT_add_meta", GKEY, KM_PRESS, KM_SHIFT, 0);
+	WM_keymap_add_item(keymap, "NLA_OT_remove_meta", GKEY, KM_PRESS, KM_ALT, 0);
 		
 		/* duplicate */
 	WM_keymap_add_item(keymap, "NLA_OT_duplicate", DKEY, KM_PRESS, KM_SHIFT, 0);	
@@ -257,6 +266,9 @@ static void nla_keymap_main (wmWindowManager *wm, ListBase *keymap)
 		/* clear scale */
 	WM_keymap_add_item(keymap, "NLA_OT_clear_scale", SKEY, KM_PRESS, KM_ALT, 0);
 	
+		/* snap */
+	WM_keymap_add_item(keymap, "NLA_OT_snap", SKEY, KM_PRESS, KM_SHIFT, 0);
+	
 		/* add f-modifier */
 	WM_keymap_add_item(keymap, "NLA_OT_fmodifier_add", MKEY, KM_PRESS, KM_CTRL|KM_SHIFT, 0);
 	
diff --git a/source/blender/makesdna/DNA_anim_types.h b/source/blender/makesdna/DNA_anim_types.h
index a8220099a11..cb9dc8f0bc7 100644
--- a/source/blender/makesdna/DNA_anim_types.h
+++ b/source/blender/makesdna/DNA_anim_types.h
@@ -510,8 +510,8 @@ enum {
 	
 	/* temporary editing flags */
 		/* NLA-Strip is really just a temporary meta used to facilitate easier transform code */
-	NLASTRIP_FLAG_TEMP_META		= (1<<30),
-	NLASTRIP_FLAG_EDIT_TOUCHED	= (1<<31),
+	NLASTRIP_FLAG_TEMP_META		= (1<<14),
+	NLASTRIP_FLAG_EDIT_TOUCHED	= (1<<15),
 } eNlaStrip_Flag;
 
 /* NLA Strip Type */
diff --git a/source/blender/makesrna/intern/rna_nla.c b/source/blender/makesrna/intern/rna_nla.c
index dfa496fd8f3..28a422dd601 100644
--- a/source/blender/makesrna/intern/rna_nla.c
+++ b/source/blender/makesrna/intern/rna_nla.c
@@ -207,6 +207,7 @@ void rna_def_nlastrip(BlenderRNA *brna)
 	static EnumPropertyItem prop_type_items[] = {
 		{NLASTRIP_TYPE_CLIP, "CLIP", 0, "Action Clip", "NLA Strip references some Action."},
 		{NLASTRIP_TYPE_TRANSITION, "TRANSITION", 0, "Transition", "NLA Strip 'transitions' between adjacent strips."},
+		{NLASTRIP_TYPE_META, "META", 0, "Strip Container", "NLA Strip acts as a container for adjacent strips."},
 		{0, NULL, 0, NULL, NULL}};
 	static EnumPropertyItem prop_mode_blend_items[] = {
 		{NLASTRIP_MODE_BLEND, "BLEND", 0, "Blend", "Results of strip and accumulated results are combined in ratio governed by influence."},