15 files changed, 100 insertions, 9 deletions

diff --git a/source/blender/blenkernel/BKE_blender_version.h b/source/blender/blenkernel/BKE_blender_version.h
index 6435fe461cc..b95e2e504d0 100644
--- a/source/blender/blenkernel/BKE_blender_version.h
+++ b/source/blender/blenkernel/BKE_blender_version.h
@@ -28,7 +28,7 @@
  * and keep comment above the defines.
  * Use STRINGIFY() rather than defining with quotes */
 #define BLENDER_VERSION         280
-#define BLENDER_SUBVERSION      28
+#define BLENDER_SUBVERSION      29
 /* Several breakages with 280, e.g. collections vs layers */
 #define BLENDER_MINVERSION      280
 #define BLENDER_MINSUBVERSION   0
diff --git a/source/blender/blenloader/intern/versioning_280.c b/source/blender/blenloader/intern/versioning_280.c
index 52c83d83454..25c243fa589 100644
--- a/source/blender/blenloader/intern/versioning_280.c
+++ b/source/blender/blenloader/intern/versioning_280.c
@@ -2179,4 +2179,30 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
 			}
 		}
 	}
+
+	if (!MAIN_VERSION_ATLEAST(bmain, 280, 29)) {
+		for (bScreen *screen = bmain->screen.first; screen; screen = screen->id.next) {
+			for (ScrArea *sa = screen->areabase.first; sa; sa = sa->next) {
+				for (SpaceLink *sl = sa->spacedata.first; sl; sl = sl->next) {
+					if (sl->spacetype == SPACE_BUTS) {
+						ListBase *regionbase = (sl == sa->spacedata.first) ? &sa->regionbase : &sl->regionbase;
+						ARegion *ar = MEM_callocN(sizeof(ARegion), "navigation bar for properties");
+						ARegion *ar_header = NULL;
+
+						for (ar_header = regionbase->first; ar_header; ar_header = ar_header->next) {
+							if (ar_header->regiontype == RGN_TYPE_HEADER) {
+								break;
+							}
+						}
+						BLI_assert(ar_header);
+
+						BLI_insertlinkafter(regionbase, ar_header, ar);
+
+						ar->regiontype = RGN_TYPE_NAV_BAR;
+						ar->alignment = RGN_ALIGN_LEFT;
+					}
+				}
+			}
+		}
+	}
 }
diff --git a/source/blender/blenloader/intern/versioning_userdef.c b/source/blender/blenloader/intern/versioning_userdef.c
index b622bc016f5..e3748d9a74b 100644
--- a/source/blender/blenloader/intern/versioning_userdef.c
+++ b/source/blender/blenloader/intern/versioning_userdef.c
@@ -81,8 +81,12 @@ static void do_versions_theme(UserDef *userdef, bTheme *btheme)
 	if (!USER_VERSION_ATLEAST(280, 28)) {
 		copy_v4_v4_char(btheme->tact.ds_ipoline, U_theme_default.tact.ds_ipoline);
 	}
-#undef USER_VERSION_ATLEAST
 
+	if (!USER_VERSION_ATLEAST(280, 29)) {
+		copy_v4_v4_char(btheme->tbuts.navigation_bar, U_theme_default.ttopbar.header);
+	}
+
+#undef USER_VERSION_ATLEAST
 }
 
 /* patching UserDef struct and Themes */
diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index efdc9ae0118..cbca7c8c921 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -915,6 +915,7 @@ void UI_exit(void);
 #define UI_LAYOUT_MENU          2
 #define UI_LAYOUT_TOOLBAR       3
 #define UI_LAYOUT_PIEMENU       4
+#define UI_LAYOUT_VERT_BAR      5
 
 #define UI_UNIT_X               ((void)0, U.widget_unit)
 #define UI_UNIT_Y               ((void)0, U.widget_unit)
diff --git a/source/blender/editors/interface/interface_layout.c b/source/blender/editors/interface/interface_layout.c
index a826c55afb5..e2b1818c958 100644
--- a/source/blender/editors/interface/interface_layout.c
+++ b/source/blender/editors/interface/interface_layout.c
@@ -4260,7 +4260,7 @@ uiLayout *UI_block_layout(uiBlock *block, int dir, int type, int x, int y, int s
 	root->opcontext = WM_OP_INVOKE_REGION_WIN;
 
 	layout = MEM_callocN(sizeof(uiLayout), "uiLayout");
-	layout->item.type = ITEM_LAYOUT_ROOT;
+	layout->item.type = (type == UI_LAYOUT_VERT_BAR) ? ITEM_LAYOUT_COLUMN : ITEM_LAYOUT_ROOT;
 
 	/* Only used when 'UI_ITEM_PROP_SEP' is set. */
 	layout->item.flag = UI_ITEM_PROP_DECORATE;
diff --git a/source/blender/editors/interface/interface_panel.c b/source/blender/editors/interface/interface_panel.c
index 1897df41fd0..efa3c24afd0 100644
--- a/source/blender/editors/interface/interface_panel.c
+++ b/source/blender/editors/interface/interface_panel.c
@@ -134,7 +134,7 @@ static int panel_aligned(ScrArea *sa, ARegion *ar)
 		return BUT_VERTICAL;
 	else if (sa->spacetype == SPACE_IMAGE && ar->regiontype == RGN_TYPE_PREVIEW)
 		return BUT_VERTICAL;
-	else if (ELEM(ar->regiontype, RGN_TYPE_UI, RGN_TYPE_TOOLS, RGN_TYPE_TOOL_PROPS, RGN_TYPE_HUD))
+	else if (ELEM(ar->regiontype, RGN_TYPE_UI, RGN_TYPE_TOOLS, RGN_TYPE_TOOL_PROPS, RGN_TYPE_HUD, RGN_TYPE_NAV_BAR))
 		return BUT_VERTICAL;
 
 	return 0;
diff --git a/source/blender/editors/interface/resources.c b/source/blender/editors/interface/resources.c
index 0ac534e5fcf..09b8933206e 100644
--- a/source/blender/editors/interface/resources.c
+++ b/source/blender/editors/interface/resources.c
@@ -181,6 +181,8 @@ const unsigned char *UI_ThemeGetColorPtr(bTheme *btheme, int spacetype, int colo
 						cp = ts->list;
 					else if (theme_regionid == RGN_TYPE_HEADER)
 						cp = ts->header;
+					else if (theme_regionid == RGN_TYPE_NAV_BAR)
+						cp = ts->navigation_bar;
 					else
 						cp = ts->button;
 
diff --git a/source/blender/editors/screen/area.c b/source/blender/editors/screen/area.c
index b914dd5ecae..79f2bebd0d3 100644
--- a/source/blender/editors/screen/area.c
+++ b/source/blender/editors/screen/area.c
@@ -1159,7 +1159,11 @@ static void region_rect_recursive(ScrArea *sa, ARegion *ar, rcti *remainder, rct
 	int prefsizex = UI_DPI_FAC * ((ar->sizex > 1) ? ar->sizex + 0.5f : ar->type->prefsizex);
 	int prefsizey;
 
-	if (ar->regiontype == RGN_TYPE_HEADER) {
+	if (ar->flag & RGN_FLAG_PREFSIZE_OR_HIDDEN) {
+		prefsizex = UI_DPI_FAC * ar->type->prefsizex;
+		prefsizey = UI_DPI_FAC * ar->type->prefsizey;
+	}
+	else if (ar->regiontype == RGN_TYPE_HEADER) {
 		prefsizey = ED_area_headersize();
 	}
 	else if (ED_area_is_global(sa)) {
@@ -2020,14 +2024,21 @@ static void ed_panel_draw(
 		short panelContext;
 
 		/* panel context can either be toolbar region or normal panels region */
-		if (ar->regiontype == RGN_TYPE_TOOLS)
+		if (pt->flag & PNL_LAYOUT_VERT_BAR) {
+			panelContext = UI_LAYOUT_VERT_BAR;
+		}
+		else if (ar->regiontype == RGN_TYPE_TOOLS) {
 			panelContext = UI_LAYOUT_TOOLBAR;
-		else
+		}
+		else {
 			panelContext = UI_LAYOUT_PANEL;
+		}
 
 		panel->layout = UI_block_layout(
 		        block, UI_LAYOUT_VERTICAL, panelContext,
-		        style->panelspace, 0, w - 2 * style->panelspace, em, 0, style);
+		        (pt->flag & PNL_LAYOUT_VERT_BAR) ? 0 : style->panelspace, 0,
+		        (pt->flag & PNL_LAYOUT_VERT_BAR) ? 0 : w - 2 * style->panelspace,
+		        em, 0, style);
 
 		pt->draw(C, panel);
 
diff --git a/source/blender/editors/screen/screen_edit.c b/source/blender/editors/screen/screen_edit.c
index 8f815dd3b44..f0f8cb6d9d8 100644
--- a/source/blender/editors/screen/screen_edit.c
+++ b/source/blender/editors/screen/screen_edit.c
@@ -1251,7 +1251,7 @@ ScrArea *ED_screen_state_toggle(bContext *C, wmWindow *win, ScrArea *sa, const s
 			for (ar = newa->regionbase.first; ar; ar = ar->next) {
 				ar->flagfullscreen = ar->flag;
 
-				if (ELEM(ar->regiontype, RGN_TYPE_UI, RGN_TYPE_HEADER, RGN_TYPE_TOOLS)) {
+				if (ELEM(ar->regiontype, RGN_TYPE_UI, RGN_TYPE_HEADER, RGN_TYPE_TOOLS, RGN_TYPE_NAV_BAR)) {
 					ar->flag |= RGN_FLAG_HIDDEN;
 				}
 			}
diff --git a/source/blender/editors/screen/screen_ops.c b/source/blender/editors/screen/screen_ops.c
index e570340698f..3d32f10582d 100644
--- a/source/blender/editors/screen/screen_ops.c
+++ b/source/blender/editors/screen/screen_ops.c
@@ -3585,6 +3585,7 @@ static int region_flip_exec(bContext *C, wmOperator *UNUSED(op))
 		ar->alignment = RGN_ALIGN_LEFT;
 
 	ED_area_tag_redraw(CTX_wm_area(C));
+	WM_event_add_mousemove(C);
 	WM_event_add_notifier(C, NC_SCREEN | NA_EDITED, NULL);
 
 	return OPERATOR_FINISHED;
diff --git a/source/blender/editors/space_buttons/space_buttons.c b/source/blender/editors/space_buttons/space_buttons.c
index 8d2b5f994b3..50018b212a6 100644
--- a/source/blender/editors/space_buttons/space_buttons.c
+++ b/source/blender/editors/space_buttons/space_buttons.c
@@ -75,6 +75,13 @@ static SpaceLink *buttons_new(const ScrArea *UNUSED(area), const Scene *UNUSED(s
 	ar->regiontype = RGN_TYPE_HEADER;
 	ar->alignment = RGN_ALIGN_TOP;
 
+	/* navigation bar */
+	ar = MEM_callocN(sizeof(ARegion), "navigation bar for buts");
+
+	BLI_addtail(&sbuts->regionbase, ar);
+	ar->regiontype = RGN_TYPE_NAV_BAR;
+	ar->alignment = RGN_ALIGN_LEFT;
+
 #if 0
 	/* context region */
 	ar = MEM_callocN(sizeof(ARegion), "context region for buts");
@@ -390,6 +397,21 @@ static void buttons_header_region_message_subscribe(
 	}
 }
 
+static void buttons_navigation_bar_region_init(wmWindowManager *wm, ARegion *ar)
+{
+	ar->flag |= RGN_FLAG_PREFSIZE_OR_HIDDEN;
+	ED_region_panels_init(wm, ar);
+	ar->v2d.keepzoom |= V2D_LOCKZOOM_X | V2D_LOCKZOOM_Y;
+}
+
+static void buttons_navigation_bar_region_draw(const bContext *C, ARegion *ar)
+{
+	for (PanelType *pt = ar->type->paneltypes.first; pt; pt = pt->next) {
+		pt->flag |= PNL_LAYOUT_VERT_BAR;
+	}
+	ED_region_panels(C, ar);
+}
+
 /* draw a certain button set only if properties area is currently
  * showing that button set, to reduce unnecessary drawing. */
 static void buttons_area_redraw(ScrArea *sa, short buttons)
@@ -680,5 +702,14 @@ void ED_spacetype_buttons(void)
 	art->message_subscribe = buttons_header_region_message_subscribe;
 	BLI_addhead(&st->regiontypes, art);
 
+	/* regions: navigation bar */
+	art = MEM_callocN(sizeof(ARegionType), "spacetype nav buttons region");
+	art->regionid = RGN_TYPE_NAV_BAR;
+	art->prefsizex = AREAMINX - 3; /* XXX Works and looks best, should we update AREAMINX accordingly? */
+	art->keymapflag = ED_KEYMAP_UI | ED_KEYMAP_FRAMES;
+	art->init = buttons_navigation_bar_region_init;
+	art->draw = buttons_navigation_bar_region_draw;
+	BLI_addhead(&st->regiontypes, art);
+
 	BKE_spacetype_register(st);
 }
diff --git a/source/blender/makesdna/DNA_screen_types.h b/source/blender/makesdna/DNA_screen_types.h
index 50bf24e0b55..99404fbf057 100644
--- a/source/blender/makesdna/DNA_screen_types.h
+++ b/source/blender/makesdna/DNA_screen_types.h
@@ -420,6 +420,7 @@ enum {
 /* paneltype flag */
 #define PNL_DEFAULT_CLOSED		1
 #define PNL_NO_HEADER			2
+#define PNL_LAYOUT_VERT_BAR		4
 
 /* Fallback panel category (only for old scripts which need updating) */
 #define PNL_CATEGORY_FALLBACK "Misc"
@@ -473,6 +474,8 @@ enum {
 	RGN_TYPE_TOOL_PROPS = 6,
 	RGN_TYPE_PREVIEW = 7,
 	RGN_TYPE_HUD = 8,
+	/* Region to navigate the main region from (RGN_TYPE_WINDOW). */
+	RGN_TYPE_NAV_BAR = 9,
 };
 /* use for function args */
 #define RGN_TYPE_ANY -1
@@ -503,6 +506,8 @@ enum {
 	RGN_FLAG_DYNAMIC_SIZE       = (1 << 2),
 	/* Region data is NULL'd on read, never written. */
 	RGN_FLAG_TEMP_REGIONDATA    = (1 << 3),
+	/* The region must either use its prefsizex/y or be hidden. */
+	RGN_FLAG_PREFSIZE_OR_HIDDEN = (1 << 4),
 };
 
 /* region do_draw */
diff --git a/source/blender/makesdna/DNA_userdef_types.h b/source/blender/makesdna/DNA_userdef_types.h
index d03cd1517c0..ebe27cd3b38 100644
--- a/source/blender/makesdna/DNA_userdef_types.h
+++ b/source/blender/makesdna/DNA_userdef_types.h
@@ -243,6 +243,10 @@ typedef struct ThemeSpace {
 	char list_text[4];
 	char list_text_hi[4];
 
+	/* navigation bar regions */
+	char navigation_bar[4];			/* region background */
+	int pad2;
+
 	/* float panel */
 /*	char panel[4];			unused */
 /*	char panel_title[4];	unused */
diff --git a/source/blender/makesrna/intern/rna_screen.c b/source/blender/makesrna/intern/rna_screen.c
index 05e5587c9c4..5220d0ef4fb 100644
--- a/source/blender/makesrna/intern/rna_screen.c
+++ b/source/blender/makesrna/intern/rna_screen.c
@@ -46,6 +46,7 @@ const EnumPropertyItem rna_enum_region_type_items[] = {
 	{RGN_TYPE_TOOLS, "TOOLS", 0, "Tools", ""},
 	{RGN_TYPE_TOOL_PROPS, "TOOL_PROPS", 0, "Tool Properties", ""},
 	{RGN_TYPE_PREVIEW, "PREVIEW", 0, "Preview", ""},
+	{RGN_TYPE_NAV_BAR, "NAVIGATION_BAR", 0, "Navigation Bar", ""},
 	{0, NULL, 0, NULL, NULL}
 };
 
diff --git a/source/blender/makesrna/intern/rna_userdef.c b/source/blender/makesrna/intern/rna_userdef.c
index bbad0ebf26b..eec0bdccded 100644
--- a/source/blender/makesrna/intern/rna_userdef.c
+++ b/source/blender/makesrna/intern/rna_userdef.c
@@ -1325,6 +1325,11 @@ static void rna_def_userdef_theme_space_common(StructRNA *srna)
 	RNA_def_property_ui_text(prop, "Region Text Highlight", "");
 	RNA_def_property_update(prop, 0, "rna_userdef_update");
 
+	prop = RNA_def_property(srna, "navigation_bar", PROP_FLOAT, PROP_COLOR_GAMMA);
+	RNA_def_property_array(prop, 4);
+	RNA_def_property_ui_text(prop, "Navigation Bar Background", "");
+	RNA_def_property_update(prop, 0, "rna_userdef_update");
+
 	/* tabs */
 	prop = RNA_def_property(srna, "tab_active", PROP_FLOAT, PROP_COLOR_GAMMA);
 	RNA_def_property_array(prop, 3);