Bug 631473 - Don't consume mouse scroll events outside arrow panels on OS X. r=mstange r=enndeakin

content/base/src/nsGkAtomList.h

@@ -94,6 +94,7 @@ GK_ATOM(applyTemplates, "apply-templates")
 GK_ATOM(mozapptype, "mozapptype")
 GK_ATOM(archive, "archive")
 GK_ATOM(area, "area")
+GK_ATOM(arrow, "arrow")
 GK_ATOM(article, "article")
 GK_ATOM(ascending, "ascending")
 GK_ATOM(aside, "aside")

layout/forms/nsComboboxControlFrame.h

@@ -178,6 +178,9 @@ public:
   virtual bool ShouldRollupOnMouseWheelEvent()
     { return true; }
 
+  virtual bool ShouldConsumeOnMouseWheelEvent()
+    { return false; }
+
   /**
    * A combobox should not roll up if activated by a mouse activate message
    * (eg. X-mouse).

layout/xul/base/public/nsXULPopupManager.h

@@ -288,6 +288,7 @@ public:
   // nsIRollupListener
   virtual bool Rollup(uint32_t aCount, nsIContent** aLastRolledUp);
   virtual bool ShouldRollupOnMouseWheelEvent();
+  virtual bool ShouldConsumeOnMouseWheelEvent();
   virtual bool ShouldRollupOnMouseActivate();
   virtual uint32_t GetSubmenuWidgetChain(nsTArray<nsIWidget*> *aWidgetChain);
   virtual void NotifyGeometryChange() {}

layout/xul/base/src/nsXULPopupManager.cpp

@@ -238,6 +238,21 @@ bool nsXULPopupManager::ShouldRollupOnMouseWheelEvent()
   return StringBeginsWith(value, NS_LITERAL_STRING("autocomplete"));
 }
 
+bool nsXULPopupManager::ShouldConsumeOnMouseWheelEvent()
+{
+  nsMenuChainItem* item = GetTopVisibleMenu();
+  if (!item)
+    return false;
+
+  nsMenuPopupFrame* frame = item->Frame();
+  if (frame->PopupType() != ePopupTypePanel)
+    return true;
+
+  nsIContent* content = frame->GetContent();
+  return !(content && content->AttrValueIs(kNameSpaceID_None, nsGkAtoms::type,
+                                           nsGkAtoms::arrow, eCaseMatters));
+}
+
 // a menu should not roll up if activated by a mouse activate message (eg. X-mouse)
 bool nsXULPopupManager::ShouldRollupOnMouseActivate()
 {

widget/cocoa/nsChildView.mm

@@ -2867,8 +2867,9 @@ NSEvent* gLastDragMouseDownEvent = nil;
       // check to see if scroll events should roll up the popup
       if ([theEvent type] == NSScrollWheel) {
         shouldRollup = rollupListener->ShouldRollupOnMouseWheelEvent();
-        // always consume scroll events that aren't over the popup
+        // consume scroll events that aren't over the popup
-        consumeEvent = YES;
+        // unless the popup is an arrow panel
+        consumeEvent = rollupListener->ShouldConsumeOnMouseWheelEvent();
       }
 
       // if we're dealing with menus, we probably have submenus and

widget/nsIRollupListener.h

@@ -29,10 +29,15 @@ class nsIRollupListener {
   virtual bool Rollup(uint32_t aCount, nsIContent** aLastRolledUp) = 0;
 
   /**
-   * Asks the RollupListener if it should rollup on mousevents
+   * Asks the RollupListener if it should rollup on mouse wheel events
    */
   virtual bool ShouldRollupOnMouseWheelEvent() = 0;
 
+  /**
+   * Asks the RollupListener if it should consume mouse wheel events
+   */
+  virtual bool ShouldConsumeOnMouseWheelEvent() = 0;
+
   /**
    * Asks the RollupListener if it should rollup on mouse activate, eg. X-Mouse
    */