Region scrollbar fix!

Now scrollbars correctly hide and show, making space for the actual contents
in a region. It solves several old hacks, and puts view2d code a bit more
back in control as well. 

Implementation notes:

- The view2d mask feature is working again
- The #define V2D_SCROLL_HORIZONTAL_HIDE means: "turn on hiding".
- Code for UI_view2d_region_reinit() is enforcing better standard view settings

But... two hack/patches needed to be added:

- Region panel drawing: if after generating the button panels it appears
  a scroller hides or reveils, it calls all the generating code again.
  (a simple scale doesn't work due to rounding differences in layout code)

- View2d code that maps 'tot' and 'cur' rects: if this code detects that
  the mask changes, it calcs the map code again.

Also a bugfix (issue in 2.65)

- The left/bottom area split widget was drawing 1 pixel too large sometimes, 
  leaving bad trails on moving area dividers.

1 files changed, 27 insertions, 3 deletions

diff --git a/source/blender/editors/interface/interface_panel.c b/source/blender/editors/interface/interface_panel.c
index 5b6a609e4d2..9fbf2fe8898 100644
--- a/source/blender/editors/interface/interface_panel.c
+++ b/source/blender/editors/interface/interface_panel.c
@@ -112,7 +112,7 @@ static int panel_aligned(ScrArea *sa, ARegion *ar)
 	else if (sa->spacetype == SPACE_FILE && ar->regiontype == RGN_TYPE_CHANNELS)
 		return BUT_VERTICAL;
 	else if (sa->spacetype == SPACE_IMAGE && ar->regiontype == RGN_TYPE_PREVIEW)
-		return BUT_VERTICAL; 
+		return BUT_VERTICAL;
 	else if (ELEM3(ar->regiontype, RGN_TYPE_UI, RGN_TYPE_TOOLS, RGN_TYPE_TOOL_PROPS))
 		return BUT_VERTICAL;
 	
@@ -812,8 +812,8 @@ static void ui_panels_size(ScrArea *sa, ARegion *ar, int *x, int *y)
 {
 	Panel *pa;
 	int align = panel_aligned(sa, ar);
-	int sizex = UI_PANEL_WIDTH;
-	int sizey = UI_PANEL_WIDTH;
+	int sizex = 0;
+	int sizey = 0;
 
 	/* compute size taken up by panels, for setting in view2d */
 	for (pa = ar->panels.first; pa; pa = pa->next) {
@@ -834,6 +834,11 @@ static void ui_panels_size(ScrArea *sa, ARegion *ar, int *x, int *y)
 		}
 	}
 
+	if (sizex == 0)
+		sizex = UI_PANEL_WIDTH;
+	if (sizey == 0)
+		sizey = -UI_PANEL_WIDTH;
+	
 	*x = sizex;
 	*y = sizey;
 }
@@ -956,6 +961,25 @@ void uiDrawPanels(const bContext *C, ARegion *ar)
 	}
 }
 
+void uiScalePanels(ARegion *ar, float new_width)
+{
+	uiBlock *block;
+	uiBut *but;
+	
+	for (block = ar->uiblocks.first; block; block = block->next) {
+		if (block->panel) {
+			float fac = new_width / (float)block->panel->sizex;
+			printf("scaled %f\n", fac);
+			block->panel->sizex = new_width;
+			
+			for (but = block->buttons.first; but; but = but->next) {
+				but->rect.xmin *= fac;
+				but->rect.xmax *= fac;
+			}
+		}
+	}
+}
+
 /* ------------ panel merging ---------------- */
 
 static void check_panel_overlap(ARegion *ar, Panel *panel)