Various tweaks to View2D code for handling of scrollbar interactions in relation to bug 19881:

* Clearly labelled the way that the scrollbar hiding works. Also see the report comments for an overview
* Added another pair of flags for another one of the cases in which scrollbars should also get ignored; when the entire contents of the view are visible, a pair of flags is now set in the view2d data (instead of for the scrollers tempdata only) for detecting this case too
* Fixed the potential for scrollbars without zoom handles shown to have those handles still considered. This still happened in the User Preferences window, but has now been disabled.

--

These changes still don't solve the bug though. Currently after the scrollbar operator passes through, the Outliner's activate-selection operators still fail to start. 

1 files changed, 18 insertions, 5 deletions

diff --git a/source/blender/editors/interface/view2d.c b/source/blender/editors/interface/view2d.c
index 7aabc147139..12265715415 100644
--- a/source/blender/editors/interface/view2d.c
+++ b/source/blender/editors/interface/view2d.c
@@ -62,7 +62,12 @@
 
 /* *********************************************************************** */
 
-/* helper to allow scrollbars to dynamically hide */
+/* helper to allow scrollbars to dynamically hide
+ * 	- returns a copy of the scrollbar settings with the flags to display 
+ *	  horizontal/vertical scrollbars removed
+ *	- input scroll value is the v2d->scroll var
+ *	- hide flags are set per region at drawtime
+ */
 static int view2d_scroll_mapped(int scroll)
 {
 	if(scroll & V2D_SCROLL_HORIZONTAL_HIDE)
@@ -1411,10 +1416,14 @@ View2DScrollers *UI_view2d_scrollers_calc(const bContext *C, View2D *v2d, short
 			CLAMP(scrollers->hor_min, hor.xmin, hor.xmax-V2D_SCROLLER_HANDLE_SIZE);
 		}
 		
-		/* check whether sliders can disappear */
+		/* check whether sliders can disappear due to the full-range being used */
 		if(v2d->keeptot) {
-			if(fac1 <= 0.0f && fac2 >= 1.0f) 
+			if ((fac1 <= 0.0f) && (fac2 >= 1.0f)) { 
+				v2d->scroll |= V2D_SCROLL_HORIZONTAL_FULLR;
 				scrollers->horfull= 1;
+			}
+			else	
+				v2d->scroll &= ~V2D_SCROLL_HORIZONTAL_FULLR;
 		}
 	}
 	
@@ -1448,10 +1457,14 @@ View2DScrollers *UI_view2d_scrollers_calc(const bContext *C, View2D *v2d, short
 			CLAMP(scrollers->vert_min, vert.ymin, vert.ymax-V2D_SCROLLER_HANDLE_SIZE);
 		}
 
-		/* check whether sliders can disappear */
+		/* check whether sliders can disappear due to the full-range being used */
 		if(v2d->keeptot) {
-			if(fac1 <= 0.0f && fac2 >= 1.0f) 
+			if ((fac1 <= 0.0f) && (fac2 >= 1.0f)) { 
+				v2d->scroll |= V2D_SCROLL_VERTICAL_FULLR;
 				scrollers->vertfull= 1;
+			}
+			else	
+				v2d->scroll &= ~V2D_SCROLL_VERTICAL_FULLR;
 		}
 	}