Merge lp:~brandontschaefer/unity/lp.1163616-fix into lp:unity

[Brandon Schaefer]

Allows dragging of the normal scrollbar if the overlay scrollbars have reached the top/bottom.

Nick mentioned that it is very hard to use the scroll bar to drag all the way down. It is very noticeable in the previews for an application. I think it would be better if it would stop scrolling when the scroll bar it self hit the bottom/top not the overlay thumb.

Here is what it looks like in unity right now:
http://ubuntuone.com/1jc4PcPg8dsFH85r0AoO0U

As you can see, it is hard to scroll through the text, as the thumb it self is larger then the scrollbar, so you will have to scroll down, then move up and scroll down....slightly annoying.

**Note** John (Design) has approved of this change.

[Andrea Azzarone (azzar1)]

LGTM.

review: Approve

[PS Jenkins bot (ps-jenkins)]

review: Approve (continuous-integration)

=== modified file 'tests/test_overlay_scrollbar.cpp'
--- tests/test_overlay_scrollbar.cpp	2013-01-17 16:11:14 +0000
+++ tests/test_overlay_scrollbar.cpp	2013-04-02 23:43:24 +0000
@@ -64,6 +64,7 @@
     : PlacesOverlayVScrollBar(NUX_FILE_LINE_PARAM)
     , scroll_tick_(1000 * 401)
     , scroll_dy_(0)
+    , thumbs_height_(overlay_window_->GetThumbGeometry().height)
     , scroll_up_signal_(false)
     , scroll_down_signal_(false)
     {
@@ -182,6 +183,11 @@
       tick_source_.tick(scroll_tick_);
     }
 
+    void FakeDragDown()
+    {
+      OnMouseDrag(0, overlay_window_->GetThumbOffsetY() + 1, 0, 5, 0, 0);
+    }
+
     nux::NuxTimerTickSource tick_source_;
 
     using PlacesOverlayVScrollBar::connector_height_;
@@ -189,6 +195,7 @@
 
     int scroll_tick_;
     int scroll_dy_;
+    int thumbs_height_;
     bool scroll_up_signal_;
     bool scroll_down_signal_;
 };
@@ -419,5 +426,17 @@
   EXPECT_EQ(connector_height, 0);
 }
 
+
+TEST_F(TestOverlayVScrollBar, TestAllowDragIfOverlayIsAtMaximum)
+{
+  // Offset that sets the thumb at the bottom of the scrollbar
+  int thumb_offset = scroll_view_->scroll_bar_->GetHeight() -
+                     scroll_view_->scroll_bar_->thumbs_height_;
+
+  scroll_view_->scroll_bar_->SetThumbOffset(thumb_offset);
+  scroll_view_->scroll_bar_->FakeDragDown();
+  EXPECT_TRUE(scroll_view_->scroll_bar_->scroll_down_signal_);
+}
+
 }
 
 
=== modified file 'unity-shared/PlacesOverlayVScrollBar.cpp'
--- unity-shared/PlacesOverlayVScrollBar.cpp	2012-12-13 14:26:56 +0000
+++ unity-shared/PlacesOverlayVScrollBar.cpp	2013-04-02 23:43:24 +0000
@@ -85,7 +85,7 @@
   if (!sensitive)
   {
     overlay_window_->ResetStates();
-    ResetConnector();    
+    ResetConnector();
   }
 }
 
@@ -353,17 +353,15 @@
   MouseDraggingOverlay(y, dy);
 }
 
-void PlacesOverlayVScrollBar::MouseDraggingOverlay(int y, int dys)
+void PlacesOverlayVScrollBar::MouseDraggingOverlay(int y, int dy)
 {
-  int const dy = y - overlay_window_->GetThumbOffsetY() - mouse_down_offset_;
-  int const at_min = overlay_window_->GetThumbOffsetY() <= 0;
-  int const at_max = overlay_window_->GetThumbOffsetY() + overlay_window_->GetThumbHeight() >= _track->GetBaseHeight();
+  int const thumb_offset = overlay_window_->GetThumbOffsetY() + mouse_down_offset_;
 
-  if (dy < 0 && !at_min)
+  if (dy < 0 && !AtMinimum() && y <= thumb_offset)
   {
     OnScrollUp.emit(stepY, abs(dy));
   }
-  else if (dy > 0 && !at_max)
+  else if (dy > 0 && !AtMaximum() && y >= thumb_offset)
   {
     OnScrollDown.emit(stepY, dy);
   }