Bug 1212527 - Set background color to NSColor before calling showDefinitionForAttributedString on 10.11. r=mstange

When calling showDefinitionforAttributedString on OSX 10.11, it always return error due to the following exception.

Exception: decodeObjectForKey: class "TitlebarAndBackgroundColor" not loaded or does not exist

So before calling it, we set temporary color value, then restore color after calling it.

MozReview-Commit-ID: 1YeY6X1W6AV

--HG--
extra : rebase_source : 1bfafdb24f7d6df0ad2552b786b8af84b71cc28a

widget/cocoa/nsChildView.mm

@@ -2880,6 +2880,36 @@ nsChildView::DispatchAPZWheelInputEvent(InputData& aEvent, bool aCanTriggerSwipe
   }
 }
 
+// When using 10.11, calling showDefinitionForAttributedString causes the
+// following exception on LookupViewService. (rdar://26476091)
+//
+// Exception: decodeObjectForKey: class "TitlebarAndBackgroundColor" not
+// loaded or does not exist
+//
+// So we set temporary color that is NSColor before calling it.
+
+class MOZ_RAII AutoBackgroundSetter final {
+public:
+  AutoBackgroundSetter(NSView* aView) {
+    if (nsCocoaFeatures::OnElCapitanOrLater() &&
+        [[aView window] isKindOfClass:[ToolbarWindow class]]) {
+      mWindow = (ToolbarWindow*)[aView window];
+      [mWindow setTemporaryBackgroundColor];
+    } else {
+      mWindow = nullptr;
+    }
+  }
+
+  ~AutoBackgroundSetter() {
+    if (mWindow) {
+      [mWindow restoreBackgroundColor];
+    }
+  }
+
+private:
+  ToolbarWindow* mWindow;
+};
+
 void
 nsChildView::LookUpDictionary(
                const nsAString& aText,
@@ -2904,6 +2934,8 @@ nsChildView::LookUpDictionary(
       pt.y += [font ascender];
     }
   }
+
+  AutoBackgroundSetter setter(mView);
   [mView showDefinitionForAttributedString:attrStr atPoint:pt];
 
   NS_OBJC_END_TRY_ABORT_BLOCK;

widget/cocoa/nsCocoaWindow.h

@@ -241,6 +241,8 @@ typedef struct _nsCocoaWindowList {
 - (void)placeFullScreenButton:(NSRect)aRect;
 - (NSPoint)windowButtonsPositionWithDefaultPosition:(NSPoint)aDefaultPosition;
 - (NSPoint)fullScreenButtonPositionWithDefaultPosition:(NSPoint)aDefaultPosition;
+- (void)setTemporaryBackgroundColor;
+- (void)restoreBackgroundColor;
 @end
 
 class nsCocoaWindow : public nsBaseWidget, public nsPIWidgetCocoa

widget/cocoa/nsCocoaWindow.mm

@@ -3401,6 +3401,16 @@ static const NSString* kStateCollectionBehavior = @"collectionBehavior";
   return mBackgroundColor;
 }
 
+- (void)setTemporaryBackgroundColor
+{
+  [super setBackgroundColor:[NSColor whiteColor]];
+}
+
+- (void)restoreBackgroundColor
+{
+  [super setBackgroundColor:mBackgroundColor];
+}
+
 - (void)setTitlebarNeedsDisplayInRect:(NSRect)aRect
 {
   [self setTitlebarNeedsDisplayInRect:aRect sync:NO];