Animation channels can now be renamed by Ctrl-Clicking on them, as in

the Outliner

Channels which can be renamed include:
- Scenes, Objects, World, Material, Texture, etc. (i.e. "ID-blocks",
or the dark and light blue channels)
- Action Groups (green channels)
- Action expanders (i.e. "CubeAction", "WorldAction", etc.)
- Grease Pencil stuff

Channels which CANNOT be renamed, as they mostly use hardcoded values
or otherwise include:
- Drivers expander
- FCurves (they don't technically have a "name"; what is shown is just
a user-friendly representation of their rna_paths)

source/blender/editors/animation/anim_channels_defines.c

@@ -325,6 +325,26 @@ static void acf_generic_idblock_name(bAnimListElem *ale, char *name)
 		BLI_strncpy(name, id->name+2, ANIM_CHAN_NAME_SIZE);
 }
 
+/* name property for ID block entries */
+static short acf_generic_idblock_nameprop(bAnimListElem *ale, PointerRNA *ptr, PropertyRNA **prop)
+{
+	RNA_id_pointer_create(ale->id, ptr);
+	*prop = RNA_struct_name_property(ptr->type);
+	
+	return (*prop != NULL);
+}
+
+
+/* name property for ID block entries which are just subheading "fillers" */
+static short acf_generic_idfill_nameprop(bAnimListElem *ale, PointerRNA *ptr, PropertyRNA **prop)
+{
+	/* actual ID we're representing is stored in ale->data not ale->id, as id gives the owner */
+	RNA_id_pointer_create(ale->data, ptr);
+	*prop = RNA_struct_name_property(ptr->type);
+	
+	return (*prop != NULL);
+}
+
 /* Settings ------------------------------------------- */
 
 #if 0
@@ -455,6 +475,7 @@ static bAnimChannelType ACF_SUMMARY =
 	NULL,								/* offset */
 	
 	acf_summary_name,					/* name */
+	NULL,								/* name prop */
 	acf_summary_icon,					/* icon */
 	
 	acf_summary_setting_valid,			/* has setting */
@@ -556,6 +577,7 @@ static bAnimChannelType ACF_SCENE =
 	NULL,							/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_scene_icon,					/* icon */
 	
 	acf_scene_setting_valid,		/* has setting */
@@ -702,6 +724,7 @@ static bAnimChannelType ACF_OBJECT =
 	NULL,							/* offset */
 	
 	acf_object_name,				/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_object_icon,				/* icon */
 	
 	acf_object_setting_valid,		/* has setting */
@@ -749,6 +772,15 @@ static void acf_group_name(bAnimListElem *ale, char *name)
 		BLI_strncpy(name, agrp->name, ANIM_CHAN_NAME_SIZE);
 }
 
+/* name property for group entries */
+static short acf_group_name_prop(bAnimListElem *ale, PointerRNA *ptr, PropertyRNA **prop)
+{
+	RNA_pointer_create(ale->id, &RNA_ActionGroup, ale->data, ptr);
+	*prop = RNA_struct_name_property(ptr->type);
+	
+	return (*prop != NULL);
+}
+
 /* check if some setting exists for this channel */
 static short acf_group_setting_valid(bAnimContext *ac, bAnimListElem *UNUSED(ale), int setting)
 {
@@ -819,6 +851,7 @@ static bAnimChannelType ACF_GROUP =
 	acf_generic_group_offset,		/* offset */
 	
 	acf_group_name,					/* name */
+	acf_group_name_prop,			/* name prop */
 	NULL,							/* icon */
 	
 	acf_group_setting_valid,		/* has setting */
@@ -905,6 +938,7 @@ static bAnimChannelType ACF_FCURVE =
 	acf_generic_group_offset,		/* offset */
 	
 	acf_fcurve_name,				/* name */
+	NULL,							/* name prop */
 	NULL,							/* icon */
 	
 	acf_fcurve_setting_valid,		/* has setting */
@@ -989,6 +1023,7 @@ static bAnimChannelType ACF_FILLACTD =
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idfill_nameprop,	/* name prop */
 	acf_fillactd_icon,				/* icon */
 	
 	acf_fillactd_setting_valid,		/* has setting */
@@ -1067,6 +1102,7 @@ static bAnimChannelType ACF_FILLDRIVERS =
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_filldrivers_name,			/* name */
+	NULL,							/* name prop */
 	acf_filldrivers_icon,			/* icon */
 	
 	acf_filldrivers_setting_valid,	/* has setting */
@@ -1144,6 +1180,7 @@ static bAnimChannelType ACF_DSMAT=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dsmat_icon,					/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1220,6 +1257,7 @@ static bAnimChannelType ACF_DSLAM=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dslam_icon,					/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1303,6 +1341,7 @@ static bAnimChannelType ACF_DSTEX=
 	acf_dstex_offset,				/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idfill_nameprop,	/* name prop */
 	acf_dstex_icon,					/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1379,6 +1418,7 @@ static bAnimChannelType ACF_DSCAM=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idfill_nameprop,	/* name prop */
 	acf_dscam_icon,					/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1465,6 +1505,7 @@ static bAnimChannelType ACF_DSCUR=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dscur_icon,					/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1541,6 +1582,7 @@ static bAnimChannelType ACF_DSSKEY=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dsskey_icon,				/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1617,6 +1659,7 @@ static bAnimChannelType ACF_DSWOR=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idfill_nameprop,	/* name prop */
 	acf_dswor_icon,					/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1693,6 +1736,7 @@ static bAnimChannelType ACF_DSPART=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dspart_icon,				/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1769,6 +1813,7 @@ static bAnimChannelType ACF_DSMBALL=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dsmball_icon,				/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1845,6 +1890,7 @@ static bAnimChannelType ACF_DSARM=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dsarm_icon,				/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -1932,6 +1978,7 @@ static bAnimChannelType ACF_DSNTREE=
 	acf_dsntree_offset,				/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dsntree_icon,				/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -2008,6 +2055,7 @@ static bAnimChannelType ACF_DSMESH=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dsmesh_icon,				/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -2084,6 +2132,7 @@ static bAnimChannelType ACF_DSLAT=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dslat_icon,					/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -2160,6 +2209,7 @@ static bAnimChannelType ACF_DSSPK=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idblock_nameprop,	/* name prop */
 	acf_dsspk_icon,					/* icon */
 	
 	acf_generic_dataexpand_setting_valid,	/* has setting */
@@ -2184,6 +2234,22 @@ static void acf_shapekey_name(bAnimListElem *ale, char *name)
 	}
 }
 
+/* name property for ShapeKey entries */
+static short acf_shapekey_nameprop(bAnimListElem *ale, PointerRNA *ptr, PropertyRNA **prop)
+{
+	KeyBlock *kb= (KeyBlock *)ale->data;
+	
+	/* if the KeyBlock had a name, use it, otherwise use the index */
+	if (kb && kb->name[0]) {
+		RNA_pointer_create(ale->id, &RNA_ShapeKey, kb, ptr);
+		*prop = RNA_struct_name_property(ptr->type);
+		
+		return (*prop != NULL);
+	}
+	
+	return 0;
+}
+
 /* check if some setting exists for this channel */
 static short acf_shapekey_setting_valid(bAnimContext *UNUSED(ac), bAnimListElem *UNUSED(ale), int setting)
 {
@@ -2250,6 +2316,7 @@ static bAnimChannelType ACF_SHAPEKEY=
 	acf_generic_basic_offset,		/* offset */
 	
 	acf_shapekey_name,				/* name */
+	acf_shapekey_nameprop,			/* name prop */
 	NULL,							/* icon */
 	
 	acf_shapekey_setting_valid,		/* has setting */
@@ -2324,6 +2391,7 @@ static bAnimChannelType ACF_GPD =
 	acf_generic_group_offset,		/* offset */
 	
 	acf_generic_idblock_name,		/* name */
+	acf_generic_idfill_nameprop,	/* name prop */
 	acf_gpd_icon,					/* icon */
 	
 	acf_gpd_setting_valid,			/* has setting */
@@ -2342,6 +2410,19 @@ static void acf_gpl_name(bAnimListElem *ale, char *name)
 		BLI_strncpy(name, gpl->info, ANIM_CHAN_NAME_SIZE);
 }
 
+/* name property for grease pencil layer entries */
+static short acf_gpl_name_prop(bAnimListElem *ale, PointerRNA *ptr, PropertyRNA **prop)
+{
+	if (ale->data) {
+		RNA_pointer_create(ale->id, &RNA_GPencilLayer, ale->data, ptr);
+		*prop = RNA_struct_name_property(ptr->type);
+		
+		return (*prop != NULL);
+	}
+	
+	return 0;
+}
+
 /* check if some setting exists for this channel */
 static short acf_gpl_setting_valid(bAnimContext *UNUSED(ac), bAnimListElem *UNUSED(ale), int setting)
 {
@@ -2399,6 +2480,7 @@ static bAnimChannelType ACF_GPL =
 	acf_generic_group_offset,		/* offset */
 	
 	acf_gpl_name,					/* name */
+	acf_gpl_name_prop,				/* name prop */
 	NULL,							/* icon */
 	
 	acf_gpl_setting_valid,			/* has setting */
@@ -2642,6 +2724,8 @@ void ANIM_channel_setting_set (bAnimContext *ac, bAnimListElem *ale, int setting
 #define ICON_WIDTH		17
 // XXX hardcoded width of sliders
 #define SLIDER_WIDTH	80
+// XXX hardcoded width of rename textboxes
+#define RENAME_TEXT_WIDTH 100
 
 /* Draw the given channel */
 // TODO: make this use UI controls for the buttons
@@ -2731,6 +2815,7 @@ void ANIM_channel_draw (bAnimContext *ac, bAnimListElem *ale, float yminc, float
 	}
 	
 	/* step 5) draw name ............................................... */
+	// TODO: when renaming, we might not want to draw this, especially if name happens to be longer than channel
 	if (acf->name) {
 		char name[ANIM_CHAN_NAME_SIZE]; /* hopefully this will be enough! */
 		
@@ -2868,6 +2953,19 @@ static void achannel_setting_flush_widget_cb(bContext *C, void *ale_npoin, void
 	BLI_freelistN(&anim_data);
 }
 
+/* callback for rename widgets - clear rename-in-progress */
+static void achannel_setting_rename_done_cb(bContext *C, void *ads_poin, void *UNUSED(arg2))
+{
+	bDopeSheet *ads = (bDopeSheet *)ads_poin;
+	
+	/* reset rename index so that edit box disappears now that editing is done */
+	ads->renameIndex = 0;
+	
+	/* send notifiers */
+	// XXX: right notifier?
+	WM_event_add_notifier(C, NC_ANIMATION|ND_ANIMCHAN|NA_RENAME, NULL);
+}
+
 /* callback for widget sliders - insert keyframes */
 static void achannel_setting_slider_cb(bContext *C, void *id_poin, void *fcu_poin)
 {
@@ -3060,12 +3158,11 @@ static void draw_setting_widget (bAnimContext *ac, bAnimListElem *ale, bAnimChan
 }
 
 /* Draw UI widgets the given channel */
-// TODO: make this use UI controls for the buttons
-void ANIM_channel_draw_widgets (bAnimContext *ac, bAnimListElem *ale, uiBlock *block, float yminc, float ymaxc)
+void ANIM_channel_draw_widgets (bContext *C, bAnimContext *ac, bAnimListElem *ale, uiBlock *block, float yminc, float ymaxc, size_t channel_index)
 {
 	bAnimChannelType *acf= ANIM_channel_get_typeinfo(ale);
 	View2D *v2d= &ac->ar->v2d;
-	float y, ymid /*, ytext*/;
+	float y, ymid/*, ytext*/;
 	short offset;
 	
 	/* sanity checks - don't draw anything */
@@ -3116,11 +3213,31 @@ void ANIM_channel_draw_widgets (bAnimContext *ac, bAnimListElem *ale, uiBlock *b
 			draw_setting_widget(ac, ale, acf, block, offset, ymid, ACHANNEL_SETTING_SOLO);
 			offset += ICON_WIDTH; 
 		}
-		(void)offset;
 	}
 	
-	/* step 4) draw text... */
-	/* NOTE: this is not done here, since nothing to be clicked on... */
+	/* step 4) draw text - check if renaming widget is in use... */
+	if (acf->name_prop && ac->ads) {
+		float channel_height = ymaxc - yminc;
+		
+		/* if rename index matches, add widget for this */
+		if (ac->ads->renameIndex == channel_index+1) {
+			PointerRNA ptr;
+			PropertyRNA *prop;
+			
+			/* draw renaming widget if we can get RNA pointer for it */
+			if (acf->name_prop(ale, &ptr, &prop)) {
+				uiBut *but;
+				
+				uiBlockSetEmboss(block, UI_EMBOSS);
+				
+				but = uiDefButR(block, TEX, 1, "", offset+3, yminc, RENAME_TEXT_WIDTH, channel_height, &ptr, RNA_property_identifier(prop), -1, 0, 0, -1, -1, NULL);
+				uiButSetFunc(but, achannel_setting_rename_done_cb, ac->ads, NULL);
+				uiButActiveOnly(C, block, but);
+				
+				uiBlockSetEmboss(block, UI_EMBOSSN);
+			}
+		}
+	}
 	
 	/* step 5) draw mute+protection toggles + (sliders) ....................... */
 	/* reset offset - now goes from RHS of panel */

source/blender/editors/animation/anim_channels_edit.c

@@ -1965,6 +1965,107 @@ static void ANIM_OT_channels_select_border(wmOperatorType *ot)
 	WM_operator_properties_gesture_border(ot, FALSE);
 }
 
+/* ******************* Rename Operator ***************************** */
+/* Allow renaming some channels by clicking on them */
+
+static void rename_anim_channels (bAnimContext *ac, int channel_index)
+{
+	ListBase anim_data = {NULL, NULL};
+	bAnimChannelType *acf;
+	bAnimListElem *ale;
+	int filter;
+	
+	/* get the channel that was clicked on */
+		/* filter channels */
+	filter= (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_LIST_CHANNELS);
+	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
+	
+		/* get channel from index */
+	ale= BLI_findlink(&anim_data, channel_index);
+	if (ale == NULL) {
+		/* channel not found */
+		if (G.f & G_DEBUG)
+			printf("Error: animation channel (index = %d) not found in rename_anim_channels() \n", channel_index);
+		
+		BLI_freelistN(&anim_data);
+		return;
+	}
+	
+	/* check that channel can be renamed */
+	acf = ANIM_channel_get_typeinfo(ale);
+	if (acf && acf->name_prop) {
+		PointerRNA ptr;
+		PropertyRNA *prop;
+		
+		/* ok if we can get name property to edit from this channel */
+		if (acf->name_prop(ale, &ptr, &prop)) {
+			/* actually showing the rename textfield is done on redraw,
+			 * so here we just store the index of this channel in the 
+			 * dopesheet data, which will get utilised when drawing the
+			 * channel...
+			 *
+			 * +1 factor is for backwards compat issues
+			 */
+			if (ac->ads) {
+				ac->ads->renameIndex = channel_index + 1;
+			}
+		}
+	}
+	
+	/* free temp data and tag for refresh */
+	BLI_freelistN(&anim_data);
+	ED_region_tag_redraw(ac->ar);
+}
+
+static int animchannels_rename_invoke (bContext *C, wmOperator *op, wmEvent *evt)
+{
+	bAnimContext ac;
+	ARegion *ar;
+	View2D *v2d;
+	int channel_index;
+	float x, y;
+	
+	/* get editor data */
+	if (ANIM_animdata_get_context(C, &ac) == 0)
+		return OPERATOR_CANCELLED;
+		
+	/* get useful pointers from animation context data */
+	ar= ac.ar;
+	v2d= &ar->v2d;
+	
+	/* figure out which channel user clicked in 
+	 * Note: although channels technically start at y= ACHANNEL_FIRST, we need to adjust by half a channel's height
+	 *		so that the tops of channels get caught ok. Since ACHANNEL_FIRST is really ACHANNEL_HEIGHT, we simply use
+	 *		ACHANNEL_HEIGHT_HALF.
+	 */
+	UI_view2d_region_to_view(v2d, evt->mval[0], evt->mval[1], &x, &y);
+	
+	if (ac.datatype == ANIMCONT_NLA) {
+		SpaceNla *snla = (SpaceNla *)ac.sl;
+		UI_view2d_listview_view_to_cell(v2d, NLACHANNEL_NAMEWIDTH, NLACHANNEL_STEP(snla), 0, (float)NLACHANNEL_HEIGHT_HALF(snla), x, y, NULL, &channel_index);
+	}
+	else {
+		UI_view2d_listview_view_to_cell(v2d, ACHANNEL_NAMEWIDTH, ACHANNEL_STEP, 0, (float)ACHANNEL_HEIGHT_HALF, x, y, NULL, &channel_index);
+	}
+	
+	/* handle click */
+	rename_anim_channels(&ac, channel_index);
+	
+	return OPERATOR_FINISHED;
+}
+
+static void ANIM_OT_channels_rename (wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Rename Channels";
+	ot->idname= "ANIM_OT_channels_rename";
+	ot->description= "Rename animation channel under mouse";
+	
+	/* api callbacks */
+	ot->invoke= animchannels_rename_invoke;
+	ot->poll= animedit_poll_channels_active;
+}
+
 /* ******************** Mouse-Click Operator *********************** */
 /* Handle selection changes due to clicking on channels. Settings will get caught by UI code... */
 
@@ -2288,7 +2389,9 @@ void ED_operatortypes_animchannels(void)
 {
 	WM_operatortype_append(ANIM_OT_channels_select_all_toggle);
 	WM_operatortype_append(ANIM_OT_channels_select_border);
+	
 	WM_operatortype_append(ANIM_OT_channels_click);
+	WM_operatortype_append(ANIM_OT_channels_rename);
 	
 	WM_operatortype_append(ANIM_OT_channels_setting_enable);
 	WM_operatortype_append(ANIM_OT_channels_setting_disable);
@@ -2323,6 +2426,9 @@ void ED_keymap_animchannels(wmKeyConfig *keyconf)
 	RNA_boolean_set(WM_keymap_add_item(keymap, "ANIM_OT_channels_click", LEFTMOUSE, KM_PRESS, KM_SHIFT, 0)->ptr, "extend", 1);
 	RNA_boolean_set(WM_keymap_add_item(keymap, "ANIM_OT_channels_click", LEFTMOUSE, KM_PRESS, KM_CTRL|KM_SHIFT, 0)->ptr, "children_only", 1);
 	
+		/* rename */
+	WM_keymap_add_item(keymap, "ANIM_OT_channels_rename", LEFTMOUSE, KM_PRESS, KM_CTRL, 0);
+	
 		/* deselect all */
 	WM_keymap_add_item(keymap, "ANIM_OT_channels_select_all_toggle", AKEY, KM_PRESS, 0, 0);
 	RNA_boolean_set(WM_keymap_add_item(keymap, "ANIM_OT_channels_select_all_toggle", IKEY, KM_PRESS, KM_CTRL, 0)->ptr, "invert", 1);

source/blender/editors/include/ED_anim_api.h

@@ -57,6 +57,9 @@ struct FModifier;
 struct uiBlock;
 struct uiLayout;
 
+struct PointerRNA;
+struct PropertyRNA;
+
 /* ************************************************ */
 /* ANIMATION CHANNEL FILTERING */
 /* anim_filter.c */
@@ -375,6 +378,8 @@ typedef struct bAnimChannelType {
 	
 	/* get name (for channel lists) */
 	void (*name)(bAnimListElem *ale, char *name);
+	/* get RNA property+pointer for editing the name */
+	short (*name_prop)(bAnimListElem *ale, struct PointerRNA *ptr, struct PropertyRNA **prop);
 	/* get icon (for channel lists) */
 	int (*icon)(bAnimListElem *ale);
 	
@@ -401,7 +406,7 @@ void ANIM_channel_debug_print_info(bAnimListElem *ale, short indent_level);
 /* Draw the given channel */
 void ANIM_channel_draw(bAnimContext *ac, bAnimListElem *ale, float yminc, float ymaxc);
 /* Draw the widgets for the given channel */
-void ANIM_channel_draw_widgets(bAnimContext *ac, bAnimListElem *ale, struct uiBlock *block, float yminc, float ymaxc);
+void ANIM_channel_draw_widgets(struct bContext *C, bAnimContext *ac, bAnimListElem *ale, struct uiBlock *block, float yminc, float ymaxc, size_t channel_index);
 
 
 /* ------------------------ Editing API -------------------------- */

source/blender/editors/space_action/action_draw.c

@@ -122,6 +122,7 @@ void draw_channel_names(bContext *C, bAnimContext *ac, ARegion *ar)
 	}
 	{	/* second pass: widgets */
 		uiBlock *block= uiBeginBlock(C, ar, "dopesheet channel buttons", UI_EMBOSS);
+		size_t channel_index = 0;
 		
 		y= (float)ACHANNEL_FIRST;
 		
@@ -134,11 +135,12 @@ void draw_channel_names(bContext *C, bAnimContext *ac, ARegion *ar)
 				 IN_RANGE(ymaxc, v2d->cur.ymin, v2d->cur.ymax) ) 
 			{
 				/* draw all channels using standard channel-drawing API */
-				ANIM_channel_draw_widgets(ac, ale, block, yminc, ymaxc);
+				ANIM_channel_draw_widgets(C, ac, ale, block, yminc, ymaxc, channel_index);
 			}
 			
 			/* adjust y-position for next one */
 			y -= ACHANNEL_STEP;
+			channel_index++;
 		}
 		
 		uiEndBlock(C, block);

source/blender/editors/space_graph/graph_draw.c

@@ -1006,6 +1006,7 @@ void graph_draw_channel_names(bContext *C, bAnimContext *ac, ARegion *ar)
 	}
 	{	/* second pass: widgets */
 		uiBlock *block= uiBeginBlock(C, ar, "graph channel buttons", UI_EMBOSS);
+		size_t channel_index = 0;
 		
 		y= (float)ACHANNEL_FIRST;
 		
@@ -1022,11 +1023,12 @@ void graph_draw_channel_names(bContext *C, bAnimContext *ac, ARegion *ar)
 				 IN_RANGE(ymaxc, v2d->cur.ymin, v2d->cur.ymax) ) 
 			{
 				/* draw all channels using standard channel-drawing API */
-				ANIM_channel_draw_widgets(ac, ale, block, yminc, ymaxc);
+				ANIM_channel_draw_widgets(C, ac, ale, block, yminc, ymaxc, channel_index);
 			}
 			
 			/* adjust y-position for next one */
 			y -= ACHANNEL_STEP;
+			channel_index++;
 		}
 		
 		uiEndBlock(C, block);

source/blender/editors/space_nla/nla_draw.c

@@ -947,6 +947,7 @@ void draw_nla_channel_list (bContext *C, bAnimContext *ac, ARegion *ar)
 	}
 	{	/* second pass: UI widgets */
 		uiBlock *block= uiBeginBlock(C, ar, "NLA channel buttons", UI_EMBOSS);
+		size_t channel_index = 0;
 		
 		y= (float)(-NLACHANNEL_HEIGHT(snla));
 		
@@ -964,11 +965,12 @@ void draw_nla_channel_list (bContext *C, bAnimContext *ac, ARegion *ar)
 				 IN_RANGE(ymaxc, v2d->cur.ymin, v2d->cur.ymax) ) 
 			{
 				/* draw all channels using standard channel-drawing API */
-				ANIM_channel_draw_widgets(ac, ale, block, yminc, ymaxc);
+				ANIM_channel_draw_widgets(C, ac, ale, block, yminc, ymaxc, channel_index);
 			}
 			
 			/* adjust y-position for next one */
 			y -= NLACHANNEL_STEP(snla);
+			channel_index++;
 		}
 		
 		uiEndBlock(C, block);

source/blender/makesdna/DNA_action_types.h

@@ -519,6 +519,9 @@ typedef struct bDopeSheet {
 	
 	int filterflag;				/* flags to use for filtering data */
 	int flag;					/* standard flags */
+	
+	int renameIndex;			/* index+1 of channel to rename - only gets set by renaming operator */
+	int pad;
 } bDopeSheet;