bug 803030 - convert display to device pixels before creating the popup child view. r=smichaud

widget/cocoa/nsCocoaWindow.mm

@@ -195,7 +195,7 @@ static NSScreen *FindTargetScreenForRect(const nsIntRect& aRect)
 
 // fits the rect to the screen that contains the largest area of it,
 // or to aScreen if a screen is passed in
-// NB: this operates with aRect in global CSS pixels
+// NB: this operates with aRect in global display pixels
 static void FitRectToVisibleAreaForScreen(nsIntRect &aRect, NSScreen *aScreen)
 {
   if (!aScreen) {
@@ -239,7 +239,7 @@ static bool UseNativePopupWindows()
 #endif /* MOZ_USE_NATIVE_POPUP_WINDOWS */
 }
 
-// aRect here is specified in CSS pixels
+// aRect here is specified in global display pixels
 nsresult nsCocoaWindow::Create(nsIWidget *aParent,
                                nsNativeWidget aNativeParent,
                                const nsIntRect &aRect,
@@ -262,6 +262,10 @@ nsresult nsCocoaWindow::Create(nsIWidget *aParent,
   // Ensure that the toolkit is created.
   nsToolkit::GetToolkit();
 
+  // newBounds is still display (global screen) pixels at this point;
+  // fortunately, BaseCreate doesn't actually use it so we don't
+  // need to worry about trying to convert it to device pixels
+  // when we don't have a window (or dev context, perhaps) yet
   Inherited::BaseCreate(aParent, newBounds, aContext, aInitData);
 
   mParent = aParent;
@@ -270,14 +274,22 @@ nsresult nsCocoaWindow::Create(nsIWidget *aParent,
   if ((mWindowType == eWindowType_popup) && UseNativePopupWindows())
     return NS_OK;
 
-  nsresult rv = CreateNativeWindow(nsCocoaUtils::GeckoRectToCocoaRect(newBounds),
-                                   mBorderStyle, false);
+  nsresult rv =
+    CreateNativeWindow(nsCocoaUtils::GeckoRectToCocoaRect(newBounds),
+                       mBorderStyle, false);
   NS_ENSURE_SUCCESS(rv, rv);
 
   if (mWindowType == eWindowType_popup) {
     if (aInitData->mIsDragPopup) {
       [mWindow setIgnoresMouseEvents:YES];
     }
+    // now we can convert newBounds to device pixels for the window we created,
+    // as the child view expects a rect expressed in the dev pix of its parent
+    double scale = BackingScaleFactor();
+    newBounds.x *= scale;
+    newBounds.y *= scale;
+    newBounds.width *= scale;
+    newBounds.height *= scale;
     return CreatePopupContentView(newBounds, aContext);
   }