Bug 943759, [Australis], support mousethrough on panels to allow mouse events to pass through to the content behind, implemented on Windows, Mac and Linux, use this for the UI tour highlight, r=neil,jmathies,karlt

browser/base/content/browser.xul

@@ -223,7 +223,8 @@
            noautofocus="true"
            noautohide="true"
            flip="none"
-           consumeoutsideclicks="false">
+           consumeoutsideclicks="false"
+           mousethrough="always">
       <box id="UITourHighlight"></box>
     </panel>
 

layout/xul/nsMenuPopupFrame.cpp

@@ -96,7 +96,7 @@ nsMenuPopupFrame::nsMenuPopupFrame(nsIPresShell* aShell, nsStyleContext* aContex
   mShouldAutoPosition(true),
   mInContentShell(true),
   mIsMenuLocked(false),
-  mIsDragPopup(false),
+  mMouseTransparent(false),
   mHFlip(false),
   mVFlip(false)
 {
@@ -141,12 +141,6 @@ nsMenuPopupFrame::Init(nsIContent*      aContent,
       mPopupType = ePopupTypeTooltip;
   }
 
-  if (mPopupType == ePopupTypePanel &&
-      aContent->AttrValueIs(kNameSpaceID_None, nsGkAtoms::type,
-                            nsGkAtoms::drag, eIgnoreCase)) {
-    mIsDragPopup = true;
-  }
-
   nsCOMPtr<nsIDocShellTreeItem> dsti = PresContext()->GetDocShell();
   if (dsti && dsti->ItemType() == nsIDocShellTreeItem::typeChrome) {
     mInContentShell = false;
@@ -243,7 +237,22 @@ nsMenuPopupFrame::CreateWidgetForView(nsView* aView)
   widgetData.clipSiblings = true;
   widgetData.mPopupHint = mPopupType;
   widgetData.mNoAutoHide = IsNoAutoHide();
-  widgetData.mIsDragPopup = mIsDragPopup;
+
+  if (!mInContentShell) {
+    // A drag popup may be used for non-static translucent drag feedback
+    bool isDragPopup = false;
+    if (mPopupType == ePopupTypePanel &&
+        mContent->AttrValueIs(kNameSpaceID_None, nsGkAtoms::type,
+                              nsGkAtoms::drag, eIgnoreCase)) {
+      widgetData.mIsDragPopup = true;
+      isDragPopup = true;
+    }
+
+    // If mousethrough="always" is set directly on the popup, then the widget
+    // should ignore mouse events, passing them through to the content behind.
+    mMouseTransparent = GetStateBits() & NS_FRAME_MOUSE_THROUGH_ALWAYS;
+    widgetData.mMouseTransparent = mMouseTransparent;
+  }
 
   nsAutoString title;
   if (mContent && widgetData.mNoAutoHide) {
@@ -1814,19 +1823,6 @@ nsMenuPopupFrame::AttachedDismissalListener()
   mConsumeRollupEvent = nsIPopupBoxObject::ROLLUP_DEFAULT;
 }
 
-void
-nsMenuPopupFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
-                                   const nsRect&           aDirtyRect,
-                                   const nsDisplayListSet& aLists)
-{
-  // don't pass events to drag popups
-  if (aBuilder->IsForEventDelivery() && mIsDragPopup) {
-    return;
-  }
-
-  nsBoxFrame::BuildDisplayList(aBuilder, aDirtyRect, aLists);
-}
-
 // helpers /////////////////////////////////////////////////////////////
 
 NS_IMETHODIMP 

layout/xul/nsMenuPopupFrame.h

@@ -230,7 +230,7 @@ public:
   bool IsMenu() MOZ_OVERRIDE { return mPopupType == ePopupTypeMenu; }
   bool IsOpen() MOZ_OVERRIDE { return mPopupState == ePopupOpen || mPopupState == ePopupOpenAndVisible; }
 
-  bool IsDragPopup() { return mIsDragPopup; }
+  bool IsMouseTransparent() { return mMouseTransparent; }
 
   static nsIContent* GetTriggerContent(nsMenuPopupFrame* aMenuPopupFrame);
   void ClearTriggerContent() { mTriggerContent = nullptr; }
@@ -334,10 +334,6 @@ public:
   // This position is in CSS pixels.
   nsIntPoint ScreenPosition() const { return nsIntPoint(mScreenXPos, mScreenYPos); }
 
-  virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
-                                const nsRect&           aDirtyRect,
-                                const nsDisplayListSet& aLists) MOZ_OVERRIDE;
-
   nsIntPoint GetLastClientOffset() const { return mLastClientOffset; }
 
   // Return the alignment of the popup
@@ -480,7 +476,7 @@ protected:
   bool mShouldAutoPosition; // Should SetPopupPosition be allowed to auto position popup?
   bool mInContentShell; // True if the popup is in a content shell
   bool mIsMenuLocked; // Should events inside this menu be ignored?
-  bool mIsDragPopup; // True if this is a popup used for drag feedback
+  bool mMouseTransparent; // True if this is a popup is transparent to mouse events
 
   // the flip modes that were used when the popup was opened
   bool mHFlip;

layout/xul/nsXULPopupManager.cpp

@@ -1385,21 +1385,21 @@ nsXULPopupManager::GetVisiblePopups(nsTArray<nsIFrame *>& aPopups)
 {
   aPopups.Clear();
 
+  // Iterate over both lists of popups
   nsMenuChainItem* item = mPopups;
-  while (item) {
-    if (item->Frame()->PopupState() == ePopupOpenAndVisible)
-      aPopups.AppendElement(static_cast<nsIFrame*>(item->Frame()));
-    item = item->GetParent();
-  }
+  for (int32_t list = 0; list < 2; list++) {
+    while (item) {
+      // Skip panels which are not open and visible as well as popups that
+      // are transparent to mouse events.
+      if (item->Frame()->PopupState() == ePopupOpenAndVisible &&
+          !item->Frame()->IsMouseTransparent()) {
+        aPopups.AppendElement(item->Frame());
+      }
 
-  item = mNoHidePanels;
-  while (item) {
-    // skip panels which are not open and visible as well as draggable popups,
-    // as those don't respond to events.
-    if (item->Frame()->PopupState() == ePopupOpenAndVisible && !item->Frame()->IsDragPopup()) {
-      aPopups.AppendElement(static_cast<nsIFrame*>(item->Frame()));
+      item = item->GetParent();
     }
-    item = item->GetParent();
+
+    item = mNoHidePanels;
   }
 }
 

widget/cocoa/nsCocoaWindow.mm

@@ -290,7 +290,7 @@ nsresult nsCocoaWindow::Create(nsIWidget *aParent,
   NS_ENSURE_SUCCESS(rv, rv);
 
   if (mWindowType == eWindowType_popup) {
-    if (aInitData->mIsDragPopup) {
+    if (aInitData->mMouseTransparent) {
       [mWindow setIgnoresMouseEvents:YES];
     }
     // now we can convert newBounds to device pixels for the window we created,

widget/gtk/nsWindow.cpp

@@ -3586,6 +3586,23 @@ nsWindow::Create(nsIWidget        *aParent,
                 if (wmd != -1)
                   gdk_window_set_decorations(gtk_widget_get_window(mShell), (GdkWMDecoration) wmd);
             }
+
+            // If the popup ignores mouse events, set an empty input shape.
+            if (aInitData->mMouseTransparent) {
+#if (MOZ_WIDGET_GTK == 2)
+              GdkRectangle rect = { 0, 0, 0, 0 };
+              GdkRegion *region = gdk_region_rectangle(&rect);
+
+              gdk_window_input_shape_combine_region(mGdkWindow, region, 0, 0);
+              gdk_region_destroy(region);
+#else
+              cairo_rectangle_int_t rect = { 0, 0, 0, 0 };
+              cairo_region_t *region = cairo_region_create_rectangle(&rect);
+
+              gdk_window_input_shape_combine_region(mGdkWindow, region, 0, 0);
+              cairo_region_destroy(region);
+#endif
+            }
         }
     }
         break;

widget/nsWidgetInitData.h

@@ -101,7 +101,8 @@ struct nsWidgetInitData {
       mNoAutoHide(false),
       mIsDragPopup(false),
       mIsAnimationSuppressed(false),
-      mSupportTranslucency(false)
+      mSupportTranslucency(false),
+      mMouseTransparent(false)
   {
   }
 
@@ -120,6 +121,9 @@ struct nsWidgetInitData {
   bool          mIsAnimationSuppressed;
   // true if the window should support an alpha channel, if available.
   bool          mSupportTranslucency;
+  // true if the window should be transparent to mouse events. Currently this is
+  // only valid for eWindowType_popup widgets
+  bool          mMouseTransparent;
 };
 
 #endif // nsWidgetInitData_h__

widget/windows/nsWindow.cpp

@@ -334,6 +334,8 @@ nsWindow::nsWindow() : nsWindowBase()
   mFullscreenMode       = false;
   mMousePresent         = false;
   mDestroyCalled        = false;
+  mHasTaskbarIconBeenCreated = false;
+  mMouseTransparent     = false;
   mPickerDisplayCount   = 0;
   mWindowType           = eWindowType_child;
   mBorderStyle          = eBorderStyle_default;
@@ -362,7 +364,6 @@ nsWindow::nsWindow() : nsWindowBase()
   mForeground           = ::GetSysColor(COLOR_WINDOWTEXT);
 
   mTaskbarPreview = nullptr;
-  mHasTaskbarIconBeenCreated = false;
 
   // Global initialization
   if (!sInstanceCount) {
@@ -490,8 +491,9 @@ nsWindow::Create(nsIWidget *aParent,
       extendedStyle |= WS_EX_COMPOSITED;
     }
 
-    if (aInitData->mIsDragPopup) {
+    if (aInitData->mMouseTransparent) {
       // This flag makes the window transparent to mouse events
+      mMouseTransparent = true;
       extendedStyle |= WS_EX_TRANSPARENT;
     }
   } else if (mWindowType == eWindowType_invisible) {
@@ -4673,6 +4675,13 @@ nsWindow::ProcessMessage(UINT msg, WPARAM& wParam, LPARAM& lParam,
 
     case WM_NCHITTEST:
     {
+      if (mMouseTransparent) {
+        // Treat this window as transparent.
+        *aRetValue = HTTRANSPARENT;
+        result = true;
+        break;
+      }
+
       /*
        * If an nc client area margin has been moved, we are responsible
        * for calculating where the resize margins are and returning the

widget/windows/nsWindow.h

@@ -572,6 +572,10 @@ protected:
   // icon has been created on the taskbar.
   bool                  mHasTaskbarIconBeenCreated;
 
+  // Indicates that mouse events should be ignored and pass through to the
+  // window below. This is currently only used for popups.
+  bool                  mMouseTransparent;
+
   // The point in time at which the last paint completed. We use this to avoid
   //  painting too rapidly in response to frequent input events.
   TimeStamp mLastPaintEndTime;