Sequencer drawing cleanup (Part 1)

Separated preview drawing into own ARegion, this should make using View2D possible
The Sequencer now has three view types: Sequencer, Preview and split Sequencer/Preview.

Changing the preview can be done either by the combobox in the header or toggling through those types with CTRL+TAB.

Notes:
* Icon for split Sequencer/Preview view missing still. 
* Naming items in the comboboxes can be improved (just Preview instead of Image Preview?)

Next steps:
* bringing back View2D handling (zoom/pan) for image preview
* experimenting with splitting the Preview ARegion for In/Out editing

10 files changed, 350 insertions, 63 deletions

diff --git a/release/scripts/ui/space_sequencer.py b/release/scripts/ui/space_sequencer.py
index 2beb2ff22d9..54fe48758f1 100644
--- a/release/scripts/ui/space_sequencer.py
+++ b/release/scripts/ui/space_sequencer.py
@@ -44,20 +44,37 @@ class SEQUENCER_HT_header(bpy.types.Header):
 
             row.separator()
 
-            if st.display_mode == 'SEQUENCER':
+            if (st.view_type == 'SEQUENCER') or (st.view_type == 'SEQUENCER_PREVIEW'):
                 sub.menu("SEQUENCER_MT_select")
                 sub.menu("SEQUENCER_MT_marker")
                 sub.menu("SEQUENCER_MT_add")
                 sub.menu("SEQUENCER_MT_strip")
 
-        layout.prop(st, "display_mode", text="")
+        layout.prop(st, "view_type", text="")
 
-        if st.display_mode == 'SEQUENCER':
+        if (st.view_type == 'PREVIEW') or (st.view_type == 'SEQUENCER_PREVIEW'):
+            layout.prop(st, "display_mode", text="")
+
+        if (st.view_type == 'SEQUENCER'):
+            layout.separator()
+            layout.operator("sequencer.refresh_all")
+        elif (st.view_type == 'SEQUENCER_PREVIEW'):
             layout.separator()
             layout.operator("sequencer.refresh_all")
+            layout.prop(st, "display_channel", text="Channel")
         else:
             layout.prop(st, "display_channel", text="Channel")
 
+class SEQUENCER_MT_view_toggle(bpy.types.Menu):
+    bl_label = "View Type"
+
+    def draw(self, context):
+        layout = self.layout
+        
+        layout.operator("sequencer.view_toggle").type = 'SEQUENCER'
+        layout.operator("sequencer.view_toggle").type = 'PREVIEW'
+        layout.operator("sequencer.view_toggle").type = 'SEQUENCER_PREVIEW'
+
 
 class SEQUENCER_MT_view(bpy.types.Menu):
     bl_label = "View"
@@ -98,7 +115,10 @@ class SEQUENCER_MT_view(bpy.types.Menu):
 
         """
         layout.separator()
-        layout.operator("sequencer.view_all")
+        if (st.view_type == 'SEQUENCER') or (st.view_type == 'SEQUENCER_PREVIEW'):
+            layout.operator("sequencer.view_all", text='View all Sequences')
+        if (st.view_type == 'PREVIEW') or (st.view_type == 'SEQUENCER_PREVIEW'):
+            layout.operator("sequencer.view_all_preview", text='Fit preview in window')
         layout.operator("sequencer.view_selected")
 
         layout.prop(st, "draw_frames")
@@ -262,17 +282,23 @@ class SEQUENCER_MT_strip(bpy.types.Menu):
 class SequencerButtonsPanel(bpy.types.Panel):
     bl_space_type = 'SEQUENCE_EDITOR'
     bl_region_type = 'UI'
+    
+    def has_sequencer(self, context):
+        return (context.space_data.view_type == 'SEQUENCER') or (context.space_data.view_type == 'SEQUENCER_PREVIEW')
 
     def poll(self, context):
-        return (context.space_data.display_mode == 'SEQUENCER') and (act_strip(context) is not None)
+        return self.has_sequencer(context) and (act_strip(context) is not None)
 
 
 class SequencerButtonsPanel_Output(bpy.types.Panel):
     bl_space_type = 'SEQUENCE_EDITOR'
     bl_region_type = 'UI'
 
+    def has_preview(self, context):
+        return (context.space_data.view_type == 'PREVIEW') or (context.space_data.view_type == 'SEQUENCER_PREVIEW')
+
     def poll(self, context):
-        return context.space_data.display_mode != 'SEQUENCER'
+        return self.has_preview(context)
 
 
 class SEQUENCER_PT_edit(SequencerButtonsPanel):
@@ -331,7 +357,7 @@ class SEQUENCER_PT_effect(SequencerButtonsPanel):
     bl_label = "Effect Strip"
 
     def poll(self, context):
-        if context.space_data.display_mode != 'SEQUENCER':
+        if not self.has_sequencer(context):
             return False
 
         strip = act_strip(context)
@@ -429,7 +455,7 @@ class SEQUENCER_PT_input(SequencerButtonsPanel):
     bl_label = "Strip Input"
 
     def poll(self, context):
-        if context.space_data.display_mode != 'SEQUENCER':
+        if not self.has_sequencer(context):
             return False
 
         strip = act_strip(context)
@@ -485,7 +511,7 @@ class SEQUENCER_PT_sound(SequencerButtonsPanel):
     bl_label = "Sound"
 
     def poll(self, context):
-        if context.space_data.display_mode != 'SEQUENCER':
+        if not self.has_sequencer(context):
             return False
 
         strip = act_strip(context)
@@ -519,7 +545,7 @@ class SEQUENCER_PT_scene(SequencerButtonsPanel):
     bl_label = "Scene"
 
     def poll(self, context):
-        if context.space_data.display_mode != 'SEQUENCER':
+        if not self.has_sequencer(context):
             return False
 
         strip = act_strip(context)
@@ -540,7 +566,7 @@ class SEQUENCER_PT_filter(SequencerButtonsPanel):
     bl_label = "Filter"
 
     def poll(self, context):
-        if context.space_data.display_mode != 'SEQUENCER':
+        if not self.has_sequencer(context):
             return False
 
         strip = act_strip(context)
@@ -590,7 +616,7 @@ class SEQUENCER_PT_proxy(SequencerButtonsPanel):
     bl_label = "Proxy"
 
     def poll(self, context):
-        if context.space_data.display_mode != 'SEQUENCER':
+        if not self.has_sequencer(context):
             return False
 
         strip = act_strip(context)
@@ -630,6 +656,7 @@ class SEQUENCER_PT_view(SequencerButtonsPanel_Output):
 
 bpy.types.register(SEQUENCER_HT_header) # header/menu classes
 bpy.types.register(SEQUENCER_MT_view)
+bpy.types.register(SEQUENCER_MT_view_toggle)
 bpy.types.register(SEQUENCER_MT_select)
 bpy.types.register(SEQUENCER_MT_marker)
 bpy.types.register(SEQUENCER_MT_add)
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 384b1fcfd4d..ef0022ccb66 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -6003,6 +6003,12 @@ static void area_add_window_regions(ScrArea *sa, SpaceLink *sl, ListBase *lb)
 				ar->regiontype= RGN_TYPE_UI;
 				ar->alignment= RGN_ALIGN_TOP;
 				break;
+			case SPACE_SEQ:
+				ar= MEM_callocN(sizeof(ARegion), "preview area for sequencer");
+				BLI_addtail(lb, ar);
+				ar->regiontype= RGN_TYPE_UI;
+				ar->alignment= RGN_ALIGN_TOP;
+				break;
 			case SPACE_VIEW3D:
 				/* toolbar */
 				ar= MEM_callocN(sizeof(ARegion), "toolbar for view3d");
@@ -10169,6 +10175,23 @@ static void do_versions(FileData *fd, Library *lib, Main *main)
 			}
 		}
 	}
+	{ /* fix for new view type in sequencer */
+		bScreen *screen;
+		ScrArea *sa;
+		SpaceLink *sl;
+		
+		for(screen= main->screen.first; screen; screen= screen->id.next) {
+			for(sa= screen->areabase.first; sa; sa= sa->next) {
+				for(sl= sa->spacedata.first; sl; sl= sl->next) {
+					if(sl->spacetype==SPACE_SEQ) {
+						SpaceSeq *sseq = (SpaceSeq *)sl;
+						if (sseq->view == 0) sseq->view = SEQ_VIEW_SEQUENCE;
+						if (sseq->mainb == 0) sseq->mainb = SEQ_DRAW_IMG_IMBUF;
+					}
+				}
+			}
+		}
+	}
 
 	/* WATCH IT!!!: pointers from libdata have not been converted yet here! */
 	/* WATCH IT 2!: Userdef struct init has to be in src/usiblender.c! */
diff --git a/source/blender/editors/include/ED_sequencer.h b/source/blender/editors/include/ED_sequencer.h
index 2a3b5445dfe..07c4dd6ca41 100644
--- a/source/blender/editors/include/ED_sequencer.h
+++ b/source/blender/editors/include/ED_sequencer.h
@@ -28,4 +28,7 @@
 #define SEQ_ZOOM_FAC(szoom) (szoom > 0)? (szoom) : (szoom == 0)? (1.0) : (-1.0/szoom)
 
 
+/* in space_sequencer.c, for rna update function */
+void ED_sequencer_update_view(bContext *C, int view);
+
 #endif /*  ED_SEQUENCER_H */
diff --git a/source/blender/editors/space_sequencer/sequencer_edit.c b/source/blender/editors/space_sequencer/sequencer_edit.c
index c421c7fbb85..277d32d6360 100644
--- a/source/blender/editors/space_sequencer/sequencer_edit.c
+++ b/source/blender/editors/space_sequencer/sequencer_edit.c
@@ -83,6 +83,7 @@
 #include "ED_screen.h"
 #include "ED_transform.h"
 #include "ED_util.h"
+#include "ED_sequencer.h"
 
 #include "UI_interface.h"
 #include "UI_resources.h"
@@ -2268,58 +2269,85 @@ static int sequencer_view_all_exec(bContext *C, wmOperator *op)
 	bScreen *sc= CTX_wm_screen(C);
 	ScrArea *area= CTX_wm_area(C);
 	ARegion *ar= CTX_wm_region(C);
+	View2D *v2d= UI_view2d_fromcontext(C);
+
+	v2d->cur= v2d->tot;
+	UI_view2d_curRect_validate(v2d);
+	UI_view2d_sync(sc, area, v2d, V2D_LOCK_COPY);
+	
+	ED_area_tag_redraw(CTX_wm_area(C));
+	return OPERATOR_FINISHED;
+}
+
+void SEQUENCER_OT_view_all(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "View All";
+	ot->idname= "SEQUENCER_OT_view_all";
+	ot->description="View all the strips in the sequencer.";
+	
+	/* api callbacks */
+	ot->exec= sequencer_view_all_exec;
+
+	ot->poll= ED_operator_sequencer_active;
+	
+	/* flags */
+	ot->flag= OPTYPE_REGISTER;
+}
+
+/* view_all operator */
+static int sequencer_view_all_preview_exec(bContext *C, wmOperator *op)
+{
+	Scene *scene= CTX_data_scene(C);
+	bScreen *sc= CTX_wm_screen(C);
+	ScrArea *area= CTX_wm_area(C);
+	ARegion *ar= CTX_wm_region(C);
 	SpaceSeq *sseq= area->spacedata.first;
 	View2D *v2d= UI_view2d_fromcontext(C);
 
-	if (sseq->mainb==SEQ_DRAW_SEQUENCE) {
-		v2d->cur= v2d->tot;
-		UI_view2d_curRect_validate(v2d);
-		UI_view2d_sync(sc, area, v2d, V2D_LOCK_COPY);
-	} else {
-		/* Like zooming on an image view */
-		float zoomX, zoomY;
-		int width, height, imgwidth, imgheight;
 
-		width = ar->winx;
-		height = ar->winy;
+	/* Like zooming on an image view */
+	float zoomX, zoomY;
+	int width, height, imgwidth, imgheight;
 
-		seq_reset_imageofs(sseq);
+	width = ar->winx;
+	height = ar->winy;
 
-		imgwidth= (scene->r.size*scene->r.xsch)/100;
-		imgheight= (scene->r.size*scene->r.ysch)/100;
+	seq_reset_imageofs(sseq);
 
-		/* Apply aspect, dosnt need to be that accurate */
-		imgwidth= (int)(imgwidth * ((float)scene->r.xasp / (float)scene->r.yasp));
+	imgwidth= (scene->r.size*scene->r.xsch)/100;
+	imgheight= (scene->r.size*scene->r.ysch)/100;
 
-		if (((imgwidth >= width) || (imgheight >= height)) &&
-			((width > 0) && (height > 0))) {
+	/* Apply aspect, dosnt need to be that accurate */
+	imgwidth= (int)(imgwidth * ((float)scene->r.xasp / (float)scene->r.yasp));
 
-			/* Find the zoom value that will fit the image in the image space */
-			zoomX = ((float)width) / ((float)imgwidth);
-			zoomY = ((float)height) / ((float)imgheight);
-			sseq->zoom= (zoomX < zoomY) ? zoomX : zoomY;
+	if (((imgwidth >= width) || (imgheight >= height)) &&
+		((width > 0) && (height > 0))) {
 
-			sseq->zoom = 1.0f / power_of_2(1/ MIN2(zoomX, zoomY) );
-		}
-		else {
-			sseq->zoom= 1.0f;
-		}
-	}
+		/* Find the zoom value that will fit the image in the image space */
+		zoomX = ((float)width) / ((float)imgwidth);
+		zoomY = ((float)height) / ((float)imgheight);
+		sseq->zoom= (zoomX < zoomY) ? zoomX : zoomY;
 
+		sseq->zoom = 1.0f / power_of_2(1/ MIN2(zoomX, zoomY) );
+	}
+	else {
+		sseq->zoom= 1.0f;
+	}
 
 	ED_area_tag_redraw(CTX_wm_area(C));
 	return OPERATOR_FINISHED;
 }
 
-void SEQUENCER_OT_view_all(wmOperatorType *ot)
+void SEQUENCER_OT_view_all_preview(wmOperatorType *ot)
 {
 	/* identifiers */
 	ot->name= "View All";
-	ot->idname= "SEQUENCER_OT_view_all";
-	ot->description="View all the strips in the sequencer.";
+	ot->idname= "SEQUENCER_OT_view_all_preview";
+	ot->description="Zoom preview to fit in the area.";
 	
 	/* api callbacks */
-	ot->exec= sequencer_view_all_exec;
+	ot->exec= sequencer_view_all_preview_exec;
 
 	ot->poll= ED_operator_sequencer_active;
 	
@@ -2327,8 +2355,42 @@ void SEQUENCER_OT_view_all(wmOperatorType *ot)
 	ot->flag= OPTYPE_REGISTER;
 }
 
+static EnumPropertyItem view_type_items[] = {
+		{SEQ_VIEW_SEQUENCE, "SEQUENCER", ICON_SEQ_SEQUENCER, "Sequencer", ""},
+		{SEQ_VIEW_PREVIEW,  "PREVIEW", ICON_SEQ_PREVIEW, "Image Preview", ""},
+		{SEQ_VIEW_SEQUENCE_PREVIEW,  "SEQUENCER_PREVIEW", ICON_SEQ_SEQUENCER, "Sequencer and Image Preview", ""},
+		{0, NULL, 0, NULL, NULL}};
 
 /* view_all operator */
+static int sequencer_view_toggle_exec(bContext *C, wmOperator *op)
+{
+	SpaceSeq *sseq= CTX_wm_space_data(C);
+
+	sseq->view++;
+	if (sseq->view > SEQ_VIEW_SEQUENCE_PREVIEW) sseq->view = SEQ_VIEW_SEQUENCE;
+
+	ED_sequencer_update_view(C, sseq->view);
+
+	return OPERATOR_FINISHED;
+}
+
+void SEQUENCER_OT_view_toggle(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "View Toggle";
+	ot->idname= "SEQUENCER_OT_view_toggle";
+	ot->description="Toggle between sequencer views (sequence, preview, both).";
+	
+	/* api callbacks */
+	ot->exec= sequencer_view_toggle_exec;
+	ot->poll= ED_operator_sequencer_active;
+	
+	/* flags */
+	ot->flag= OPTYPE_REGISTER;
+}
+
+
+/* view_selected operator */
 static int sequencer_view_selected_exec(bContext *C, wmOperator *op)
 {
 	Scene *scene= CTX_data_scene(C);
diff --git a/source/blender/editors/space_sequencer/sequencer_intern.h b/source/blender/editors/space_sequencer/sequencer_intern.h
index a68001e536b..e5e159138fc 100644
--- a/source/blender/editors/space_sequencer/sequencer_intern.h
+++ b/source/blender/editors/space_sequencer/sequencer_intern.h
@@ -95,9 +95,13 @@ void SEQUENCER_OT_swap_right(struct wmOperatorType *ot);
 void SEQUENCER_OT_swap_left(struct wmOperatorType *ot);
 void SEQUENCER_OT_rendersize(struct wmOperatorType *ot);
 
+void SEQUENCER_OT_view_toggle(struct wmOperatorType *ot);
 void SEQUENCER_OT_view_all(struct wmOperatorType *ot);
 void SEQUENCER_OT_view_selected(struct wmOperatorType *ot);
 
+/* preview specific operators */
+void SEQUENCER_OT_view_all_preview(struct wmOperatorType *ot);
+
 /* sequencer_select.c */
 void SEQUENCER_OT_select_all_toggle(struct wmOperatorType *ot);
 void SEQUENCER_OT_select(struct wmOperatorType *ot);
diff --git a/source/blender/editors/space_sequencer/sequencer_ops.c b/source/blender/editors/space_sequencer/sequencer_ops.c
index 73a2070ca54..2636fa67c47 100644
--- a/source/blender/editors/space_sequencer/sequencer_ops.c
+++ b/source/blender/editors/space_sequencer/sequencer_ops.c
@@ -85,7 +85,9 @@ void sequencer_operatortypes(void)
 
 	WM_operatortype_append(SEQUENCER_OT_view_all);
 	WM_operatortype_append(SEQUENCER_OT_view_selected);
-	
+	WM_operatortype_append(SEQUENCER_OT_view_all_preview);
+	WM_operatortype_append(SEQUENCER_OT_view_toggle);
+
 	/* sequencer_select.c */
 	WM_operatortype_append(SEQUENCER_OT_select_all_toggle);
 	WM_operatortype_append(SEQUENCER_OT_select_inverse);
@@ -110,9 +112,14 @@ void sequencer_operatortypes(void)
 
 void sequencer_keymap(wmKeyConfig *keyconf)
 {
-	wmKeyMap *keymap= WM_keymap_find(keyconf, "Sequencer", SPACE_SEQ, 0);
+	wmKeyMap *keymap= WM_keymap_find(keyconf, "SequencerCommon", SPACE_SEQ, 0);
 	wmKeyMapItem *kmi;
-	
+
+	/* operators common to sequence and preview view */
+	WM_keymap_add_item(keymap, "SEQUENCER_OT_view_toggle", TABKEY, KM_PRESS, KM_CTRL, 0);
+
+	/* operators for sequence */
+	keymap= WM_keymap_find(keyconf, "Sequencer", SPACE_SEQ, 0);
 	WM_keymap_add_item(keymap, "SEQUENCER_OT_properties", NKEY, KM_PRESS, 0, 0);
 	
 	WM_keymap_add_item(keymap, "SEQUENCER_OT_select_all_toggle", AKEY, KM_PRESS, 0, 0);
@@ -214,5 +221,8 @@ void sequencer_keymap(wmKeyConfig *keyconf)
 	WM_keymap_add_menu(keymap, "SEQUENCER_MT_add", AKEY, KM_PRESS, KM_SHIFT, 0);
 	
 	transform_keymap_for_space(keyconf, keymap, SPACE_SEQ);
+
+	keymap= WM_keymap_find(keyconf, "SequencerPreview", SPACE_SEQ, 0);
+	WM_keymap_add_item(keymap, "SEQUENCER_OT_view_all_preview", HOMEKEY, KM_PRESS, 0, 0);
 }
 
diff --git a/source/blender/editors/space_sequencer/space_sequencer.c b/source/blender/editors/space_sequencer/space_sequencer.c
index 1e2fc1f59d3..4c610dc6668 100644
--- a/source/blender/editors/space_sequencer/space_sequencer.c
+++ b/source/blender/editors/space_sequencer/space_sequencer.c
@@ -90,6 +90,69 @@ ARegion *sequencer_has_buttons_region(ScrArea *sa)
 	return arnew;
 }
 
+ARegion *sequencer_find_region(ScrArea *sa, short type)
+{
+	ARegion *ar=NULL;
+	
+	for(ar= sa->regionbase.first; ar; ar= ar->next)
+		if(ar->regiontype==type)
+			return ar;
+
+	return ar;
+}
+
+void ED_sequencer_update_view(bContext *C, int view)
+{
+	ScrArea *sa= CTX_wm_area(C);
+	
+	ARegion *ar_main= sequencer_find_region(sa, RGN_TYPE_WINDOW);
+	ARegion *ar_preview= sequencer_find_region(sa, RGN_TYPE_PREVIEW);
+
+	switch (view) {
+		case SEQ_VIEW_SEQUENCE:
+			if (ar_main->flag & RGN_FLAG_HIDDEN) {
+				ar_main->flag &= ~RGN_FLAG_HIDDEN;
+				ar_main->v2d.flag &= ~V2D_IS_INITIALISED;
+			}
+			if (!(ar_preview->flag & RGN_FLAG_HIDDEN)) {
+				ar_preview->flag |= RGN_FLAG_HIDDEN;
+				ar_preview->v2d.flag &= ~V2D_IS_INITIALISED;
+				WM_event_remove_handlers(C, &ar_preview->handlers);
+			}
+			ar_main->alignment= RGN_ALIGN_NONE;
+			ar_preview->alignment= RGN_ALIGN_NONE;
+			break;
+		case SEQ_VIEW_PREVIEW:
+			if (!(ar_main->flag & RGN_FLAG_HIDDEN)) {
+				ar_main->flag |= RGN_FLAG_HIDDEN;
+				ar_main->v2d.flag &= ~V2D_IS_INITIALISED;
+				WM_event_remove_handlers(C, &ar_main->handlers);
+			}
+			if (ar_preview->flag & RGN_FLAG_HIDDEN) {
+				ar_preview->flag &= ~RGN_FLAG_HIDDEN;
+				ar_preview->v2d.flag &= ~V2D_IS_INITIALISED;
+			}
+			ar_main->alignment= RGN_ALIGN_NONE;
+			ar_preview->alignment= RGN_ALIGN_NONE;
+			break;
+		case SEQ_VIEW_SEQUENCE_PREVIEW:
+			if (ar_main->flag & RGN_FLAG_HIDDEN) {
+				ar_main->flag &= ~RGN_FLAG_HIDDEN;
+				ar_main->v2d.flag &= ~V2D_IS_INITIALISED;
+			}
+			if (ar_preview->flag & RGN_FLAG_HIDDEN) {
+				ar_preview->flag &= ~RGN_FLAG_HIDDEN;
+				ar_preview->v2d.flag &= ~V2D_IS_INITIALISED;
+			}
+			ar_main->alignment= RGN_ALIGN_NONE;
+			ar_preview->alignment= RGN_ALIGN_TOP;
+			break;
+	}
+
+	ED_area_initialize(CTX_wm_manager(C), CTX_wm_window(C), sa);
+	ED_area_tag_redraw(sa);
+}
+
 
 /* ******************** default callbacks for sequencer space ***************** */
 
@@ -103,8 +166,8 @@ static SpaceLink *sequencer_new(const bContext *C)
 	sseq->spacetype= SPACE_SEQ;
 	sseq->zoom= 4;
 	sseq->chanshown = 0;
-	
-	
+	sseq->view = SEQ_VIEW_SEQUENCE;
+	sseq->mainb = SEQ_DRAW_IMG_IMBUF;
 	/* header */
 	ar= MEM_callocN(sizeof(ARegion), "header for sequencer");
 	
@@ -120,6 +183,13 @@ static SpaceLink *sequencer_new(const bContext *C)
 	ar->alignment= RGN_ALIGN_RIGHT;
 	ar->flag = RGN_FLAG_HIDDEN;
 	
+	/* preview area */
+	ar= MEM_callocN(sizeof(ARegion), "preview area for sequencer");
+	BLI_addtail(&sseq->regionbase, ar);
+	ar->regiontype= RGN_TYPE_PREVIEW;
+	ar->alignment= RGN_ALIGN_TOP;
+	ar->flag |= RGN_FLAG_HIDDEN;
+
 	/* main area */
 	ar= MEM_callocN(sizeof(ARegion), "main area for sequencer");
 	
@@ -150,7 +220,7 @@ static SpaceLink *sequencer_new(const bContext *C)
 	ar->v2d.keepzoom= 0;
 	ar->v2d.keeptot= 0;
 	ar->v2d.align= V2D_ALIGN_NO_NEG_Y;
-	
+
 	return (SpaceLink *)sseq;
 }
 
@@ -181,7 +251,7 @@ static SpaceLink *sequencer_duplicate(SpaceLink *sl)
 }
 
 
-
+/* *********************** sequencer (main) region ************************ */
 /* add handlers, stuff you only do once or on area/region changes */
 static void sequencer_main_area_init(wmWindowManager *wm, ARegion *ar)
 {
@@ -189,6 +259,9 @@ static void sequencer_main_area_init(wmWindowManager *wm, ARegion *ar)
 	
 	UI_view2d_region_reinit(&ar->v2d, V2D_COMMONVIEW_CUSTOM, ar->winx, ar->winy);
 	
+	keymap= WM_keymap_find(wm->defaultconf, "SequencerCommon", SPACE_SEQ, 0);
+	WM_event_add_keymap_handler_bb(&ar->handlers, keymap, &ar->v2d.mask, &ar->winrct);
+	
 	/* own keymap */
 	keymap= WM_keymap_find(wm->defaultconf, "Sequencer", SPACE_SEQ, 0);
 	WM_event_add_keymap_handler_bb(&ar->handlers, keymap, &ar->v2d.mask, &ar->winrct);
@@ -197,18 +270,9 @@ static void sequencer_main_area_init(wmWindowManager *wm, ARegion *ar)
 static void sequencer_main_area_draw(const bContext *C, ARegion *ar)
 {
 	ScrArea *sa= CTX_wm_area(C);
-	SpaceSeq *sseq= sa->spacedata.first;
-	Scene *scene= CTX_data_scene(C);
-	
 	
-	if (sseq->mainb != SEQ_DRAW_SEQUENCE) {
-		/* image-viewer types */
-		draw_image_seq(scene, ar, sseq);
-	}
-	else {
-		/* NLE - strip editing timeline interface */
-		draw_timeline_seq(C, ar);
-	}
+	/* NLE - strip editing timeline interface */
+	draw_timeline_seq(C, ar);
 }
 
 
@@ -248,6 +312,60 @@ static void sequencer_main_area_listener(ARegion *ar, wmNotifier *wmn)
 	}
 }
 
+/* *********************** preview region ************************ */
+static void sequencer_preview_area_init(wmWindowManager *wm, ARegion *ar)
+{
+	wmKeyMap *keymap;
+	
+	UI_view2d_region_reinit(&ar->v2d, V2D_COMMONVIEW_STANDARD, ar->winx, ar->winy);
+	
+	keymap= WM_keymap_find(wm->defaultconf, "SequencerCommon", SPACE_SEQ, 0);
+	WM_event_add_keymap_handler_bb(&ar->handlers, keymap, &ar->v2d.mask, &ar->winrct);
+
+	/* own keymap */
+	keymap= WM_keymap_find(wm->defaultconf, "SequencerPreview", SPACE_SEQ, 0);
+	WM_event_add_keymap_handler_bb(&ar->handlers, keymap, &ar->v2d.mask, &ar->winrct);
+}
+
+static void sequencer_preview_area_draw(const bContext *C, ARegion *ar)
+{
+	ScrArea *sa= CTX_wm_area(C);
+	SpaceSeq *sseq= sa->spacedata.first;
+	Scene *scene= CTX_data_scene(C);
+	
+	/* XXX temp fix for wrong setting in sseq->mainb */
+	if (sseq->mainb == SEQ_DRAW_SEQUENCE) sseq->mainb = SEQ_DRAW_IMG_IMBUF;
+	draw_image_seq(scene, ar, sseq);
+}
+
+static void sequencer_preview_area_listener(ARegion *ar, wmNotifier *wmn)
+{
+	/* context changes */
+	switch(wmn->category) {
+		case NC_SCENE:
+			switch(wmn->data) {
+				case ND_FRAME:
+				case ND_MARKERS:
+				case ND_SEQUENCER:
+				case ND_SEQUENCER_SELECT:
+					ED_region_tag_redraw(ar);
+					break;
+			}
+			break;
+		case NC_SPACE:
+			if(wmn->data == ND_SPACE_SEQUENCER)
+				ED_region_tag_redraw(ar);
+			break;
+		case NC_ID:
+			switch(wmn->data) {
+				case NA_RENAME:
+					ED_region_tag_redraw(ar);
+					break;
+			}
+			break;
+	}
+}
+
 /* *********************** buttons region ************************ */
 
 /* add handlers, stuff you only do once or on area/region changes */
@@ -312,6 +430,16 @@ void ED_spacetype_sequencer(void)
 	art->keymapflag= ED_KEYMAP_VIEW2D|ED_KEYMAP_FRAMES|ED_KEYMAP_ANIMATION;
 
 	BLI_addhead(&st->regiontypes, art);
+
+	/* preview */
+	art= MEM_callocN(sizeof(ARegionType), "spacetype sequencer region");
+	art->regionid = RGN_TYPE_PREVIEW;
+	art->minsizey = 240; // XXX
+	art->init= sequencer_preview_area_init;
+	art->draw= sequencer_preview_area_draw;
+	art->listener= sequencer_preview_area_listener;
+	art->keymapflag= ED_KEYMAP_VIEW2D|ED_KEYMAP_FRAMES|ED_KEYMAP_ANIMATION;
+	BLI_addhead(&st->regiontypes, art);
 	
 	/* regions: listview/buttons */
 	art= MEM_callocN(sizeof(ARegionType), "spacetype sequencer region");
diff --git a/source/blender/makesdna/DNA_screen_types.h b/source/blender/makesdna/DNA_screen_types.h
index 18c7a819eb3..2bc7b1e8431 100644
--- a/source/blender/makesdna/DNA_screen_types.h
+++ b/source/blender/makesdna/DNA_screen_types.h
@@ -219,6 +219,7 @@ typedef struct ARegion {
 #define RGN_TYPE_UI			4
 #define RGN_TYPE_TOOLS		5
 #define RGN_TYPE_TOOL_PROPS	6
+#define RGN_TYPE_PREVIEW	7
 
 /* region alignment */
 #define RGN_ALIGN_NONE		0
diff --git a/source/blender/makesdna/DNA_space_types.h b/source/blender/makesdna/DNA_space_types.h
index 40d59b666bf..e02d719470f 100644
--- a/source/blender/makesdna/DNA_space_types.h
+++ b/source/blender/makesdna/DNA_space_types.h
@@ -146,7 +146,9 @@ typedef struct SpaceSeq {
 	short zebra;
 	int flag;
 	float zoom;
-	
+	int view; /* see SEQ_VIEW_* below */
+	int pad;
+
 	struct bGPdata *gpd;		/* grease-pencil data */
 } SpaceSeq;
 
@@ -857,6 +859,12 @@ enum {
 #define SEQ_DRAW_GPENCIL			16
 #define SEQ_NO_DRAW_CFRANUM			32
 
+/* sseq->view */
+#define SEQ_VIEW_SEQUENCE			1
+#define SEQ_VIEW_PREVIEW			2
+#define SEQ_VIEW_SEQUENCE_PREVIEW	3
+
+
 /* space types, moved from DNA_screen_types.h */
 enum {
 	SPACE_EMPTY,
diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index 382ab96f059..2fd0bf1810a 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -106,6 +106,7 @@ EnumPropertyItem autosnap_items[] = {
 #include "ED_image.h"
 #include "ED_screen.h"
 #include "ED_view3d.h"
+#include "ED_sequencer.h"
 
 #include "IMB_imbuf_types.h"
 
@@ -482,6 +483,13 @@ static int rna_SpaceGraphEditor_has_ghost_curves_get(PointerRNA *ptr)
 	return (sipo->ghostCurves.first != NULL);
 }
 
+static void rna_Sequencer_display_mode_update(bContext *C, PointerRNA *ptr)
+{
+	int view = RNA_int_get(ptr, "view_type");
+
+	ED_sequencer_update_view(C, view);
+}
+
 #else
 
 static void rna_def_space(BlenderRNA *brna)
@@ -1068,8 +1076,13 @@ static void rna_def_space_sequencer(BlenderRNA *brna)
 	StructRNA *srna;
 	PropertyRNA *prop;
 	
+	static EnumPropertyItem view_type_items[] = {
+		{SEQ_VIEW_SEQUENCE, "SEQUENCER", ICON_SEQ_SEQUENCER, "Sequencer", ""},
+		{SEQ_VIEW_PREVIEW,  "PREVIEW", ICON_SEQ_PREVIEW, "Image Preview", ""},
+		{SEQ_VIEW_SEQUENCE_PREVIEW,  "SEQUENCER_PREVIEW", ICON_SEQ_SEQUENCER, "Sequencer and Image Preview", ""},
+		{0, NULL, 0, NULL, NULL}};
+
 	static EnumPropertyItem display_mode_items[] = {
-		{SEQ_DRAW_SEQUENCE, "SEQUENCER", ICON_SEQ_SEQUENCER, "Sequencer", ""},
 		{SEQ_DRAW_IMG_IMBUF, "IMAGE", ICON_SEQ_PREVIEW, "Image Preview", ""},
 		{SEQ_DRAW_IMG_WAVEFORM, "WAVEFORM", ICON_SEQ_LUMA_WAVEFORM, "Luma Waveform", ""},
 		{SEQ_DRAW_IMG_VECTORSCOPE, "VECTOR_SCOPE", ICON_SEQ_CHROMA_SCOPE, "Chroma Vectorscope", ""},
@@ -1080,6 +1093,14 @@ static void rna_def_space_sequencer(BlenderRNA *brna)
 	RNA_def_struct_sdna(srna, "SpaceSeq");
 	RNA_def_struct_ui_text(srna, "Space Sequence Editor", "Sequence editor space data.");
 	
+	/* view type, fairly important */
+	prop= RNA_def_property(srna, "view_type", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_sdna(prop, NULL, "view");
+	RNA_def_property_enum_items(prop, view_type_items);
+	RNA_def_property_ui_text(prop, "View Type", "The type of the Sequencere view (sequencer, preview or both).");
+	RNA_def_property_flag(prop, PROP_CONTEXT_UPDATE);
+	RNA_def_property_update(prop, 0, "rna_Sequencer_display_mode_update");
+
 	/* display type, fairly important */
 	prop= RNA_def_property(srna, "display_mode", PROP_ENUM, PROP_NONE);
 	RNA_def_property_enum_sdna(prop, NULL, "mainb");