Bug 1172450 - Size and position the dropdown arrow properly in vertical writing modes. r=smontagu

layout/forms/nsComboboxControlFrame.cpp

@@ -733,7 +733,7 @@ nsComboboxControlFrame::GetIntrinsicISize(nsRenderingContext* aRenderingContext,
     nsIScrollableFrame* scrollable = do_QueryFrame(mListControlFrame);
     NS_ASSERTION(scrollable, "List must be a scrollable frame");
     scrollbarWidth = scrollable->GetNondisappearingScrollbarWidth(
-      presContext, aRenderingContext);
+      presContext, aRenderingContext, GetWritingMode());
   }
 
   nscoord displayISize = 0;
@@ -848,6 +848,7 @@ nsComboboxControlFrame::Reflow(nsPresContext*          aPresContext,
 
   // Get the width of the vertical scrollbar.  That will be the inline
   // size of the dropdown button.
+  WritingMode wm = aReflowState.GetWritingMode();
   nscoord buttonISize;
   const nsStyleDisplay *disp = StyleDisplay();
   if ((IsThemed(disp) && !aPresContext->GetTheme()->ThemeNeedsComboboxDropmarker()) ||
@@ -858,7 +859,7 @@ nsComboboxControlFrame::Reflow(nsPresContext*          aPresContext,
     nsIScrollableFrame* scrollable = do_QueryFrame(mListControlFrame);
     NS_ASSERTION(scrollable, "List must be a scrollable frame");
     buttonISize = scrollable->GetNondisappearingScrollbarWidth(
-      PresContext(), aReflowState.rendContext);
+      PresContext(), aReflowState.rendContext, wm);
     if (buttonISize > aReflowState.ComputedISize()) {
       buttonISize = 0;
     }
@@ -869,8 +870,7 @@ nsComboboxControlFrame::Reflow(nsPresContext*          aPresContext,
   nsBlockFrame::Reflow(aPresContext, aDesiredSize, aReflowState, aStatus);
 
   // The button should occupy the same space as a scrollbar
-  WritingMode wm = aReflowState.GetWritingMode();
+  nsSize containerSize = aDesiredSize.PhysicalSize();
-  nsSize containerSize = aReflowState.ComputedSizeAsContainerIfConstrained();
   LogicalRect buttonRect = mButtonFrame->GetLogicalRect(containerSize);
 
   buttonRect.IStart(wm) =

layout/generic/nsGfxScrollFrame.cpp

@@ -1042,34 +1042,38 @@ ScrollFrameHelper::GetDesiredScrollbarSizes(nsBoxLayoutState* aState)
 }
 
 nscoord
-ScrollFrameHelper::GetNondisappearingScrollbarWidth(nsBoxLayoutState* aState)
+ScrollFrameHelper::GetNondisappearingScrollbarWidth(nsBoxLayoutState* aState,
+                                                    WritingMode aWM)
 {
   NS_ASSERTION(aState && aState->GetRenderingContext(),
                "Must have rendering context in layout state for size "
                "computations");
 
+  bool verticalWM = aWM.IsVertical();
   if (LookAndFeel::GetInt(LookAndFeel::eIntID_UseOverlayScrollbars) != 0) {
     // We're using overlay scrollbars, so we need to get the width that
     // non-disappearing scrollbars would have.
     nsITheme* theme = aState->PresContext()->GetTheme();
     if (theme &&
         theme->ThemeSupportsWidget(aState->PresContext(),
-                                   mVScrollbarBox,
+                                   verticalWM ? mHScrollbarBox
+                                              : mVScrollbarBox,
                                    NS_THEME_SCROLLBAR_NON_DISAPPEARING)) {
       LayoutDeviceIntSize size;
       bool canOverride = true;
       theme->GetMinimumWidgetSize(aState->PresContext(),
-                                  mVScrollbarBox,
+                                  verticalWM ? mHScrollbarBox
+                                             : mVScrollbarBox,
                                   NS_THEME_SCROLLBAR_NON_DISAPPEARING,
                                   &size,
                                   &canOverride);
-      if (size.width) {
+      return aState->PresContext()->
-        return aState->PresContext()->DevPixelsToAppUnits(size.width);
+             DevPixelsToAppUnits(verticalWM ? size.height : size.width);
-      }
     }
   }
 
-  return GetDesiredScrollbarSizes(aState).LeftRight();
+  nsMargin sizes(GetDesiredScrollbarSizes(aState));
+  return verticalWM ? sizes.TopBottom() : sizes.LeftRight();
 }
 
 void

layout/generic/nsGfxScrollFrame.h

@@ -304,7 +304,8 @@ public:
   }
   nsMargin GetActualScrollbarSizes() const;
   nsMargin GetDesiredScrollbarSizes(nsBoxLayoutState* aState);
-  nscoord GetNondisappearingScrollbarWidth(nsBoxLayoutState* aState);
+  nscoord GetNondisappearingScrollbarWidth(nsBoxLayoutState* aState,
+                                           mozilla::WritingMode aVerticalWM);
   bool IsLTR() const;
   bool IsScrollbarOnRight() const;
   bool IsScrollingActive(nsDisplayListBuilder* aBuilder) const;
@@ -691,9 +692,9 @@ public:
     return GetDesiredScrollbarSizes(&bls);
   }
   virtual nscoord GetNondisappearingScrollbarWidth(nsPresContext* aPresContext,
-          nsRenderingContext* aRC) override {
+          nsRenderingContext* aRC, mozilla::WritingMode aWM) override {
     nsBoxLayoutState bls(aPresContext, aRC, 0);
-    return mHelper.GetNondisappearingScrollbarWidth(&bls);
+    return mHelper.GetNondisappearingScrollbarWidth(&bls, aWM);
   }
   virtual nsRect GetScrolledRect() const override {
     return mHelper.GetScrolledRect();
@@ -1095,9 +1096,9 @@ public:
     return GetDesiredScrollbarSizes(&bls);
   }
   virtual nscoord GetNondisappearingScrollbarWidth(nsPresContext* aPresContext,
-          nsRenderingContext* aRC) override {
+          nsRenderingContext* aRC, mozilla::WritingMode aWM) override {
     nsBoxLayoutState bls(aPresContext, aRC, 0);
-    return mHelper.GetNondisappearingScrollbarWidth(&bls);
+    return mHelper.GetNondisappearingScrollbarWidth(&bls, aWM);
   }
   virtual nsRect GetScrolledRect() const override {
     return mHelper.GetScrolledRect();

layout/generic/nsIScrollableFrame.h

@@ -107,8 +107,10 @@ public:
   /**
    * Return the width for non-disappearing scrollbars.
    */
-  virtual nscoord GetNondisappearingScrollbarWidth(nsPresContext* aPresContext,
+  virtual nscoord
-                                                   nsRenderingContext* aRC) = 0;
+  GetNondisappearingScrollbarWidth(nsPresContext* aPresContext,
+                                   nsRenderingContext* aRC,
+                                   mozilla::WritingMode aWM) = 0;
   /**
    * GetScrolledRect is designed to encapsulate deciding which
    * directions of overflow should be reachable by scrolling and which