Bug 541904 - Accept middle mouse clicks and Cmd+left clicks on background windows. r=josh

widget/src/cocoa/nsChildView.mm

@@ -6329,11 +6329,11 @@ ChildViewMouseTracker::WindowForEvent(NSEvent* anEvent)
 }
 
 BOOL
-ChildViewMouseTracker::WindowAcceptsEvent(NSWindow* aWindow, NSEvent* anEvent)
+ChildViewMouseTracker::WindowAcceptsEvent(NSWindow* aWindow, NSEvent* aEvent)
 {
   // Right mouse down events may get through to all windows, even to a top level
   // window with an open sheet.
-  if (!aWindow || [anEvent type] == NSRightMouseDown)
+  if (!aWindow || [aEvent type] == NSRightMouseDown)
     return YES;
 
   id delegate = [aWindow delegate];
@@ -6347,33 +6347,46 @@ ChildViewMouseTracker::WindowAcceptsEvent(NSWindow* aWindow, NSEvent* anEvent)
   nsWindowType windowType;
   windowWidget->GetWindowType(windowType);
 
+  NSWindow* topLevelWindow = nil;
+
   switch (windowType) {
     case eWindowType_popup:
       // If this is a context menu, it won't have a parent. So we'll always
       // accept mouse move events on context menus even when none of our windows
       // is active, which is the right thing to do.
       // For panels, the parent window is the XUL window that owns the panel.
-      return WindowAcceptsEvent([aWindow parentWindow], anEvent);
+      return WindowAcceptsEvent([aWindow parentWindow], aEvent);
 
     case eWindowType_toplevel:
     case eWindowType_dialog:
-      // Block all mouse events other than RightMouseDown on background windows
-      // and on windows behind sheets.
-      return [aWindow isMainWindow] && ![aWindow attachedSheet];
+      if ([aWindow attachedSheet])
+        return NO;
 
+      topLevelWindow = aWindow;
+      break;
     case eWindowType_sheet: {
       nsIWidget* parentWidget = windowWidget->GetSheetWindowParent();
       if (!parentWidget)
         return YES;
 
-      // Only accept mouse events on a sheet whose containing window is active.
-      NSWindow* parentWindow = (NSWindow*)parentWidget->GetNativeData(NS_NATIVE_WINDOW);
-      return [parentWindow isMainWindow];
+      topLevelWindow = (NSWindow*)parentWidget->GetNativeData(NS_NATIVE_WINDOW);
+      break;
     }
 
     default:
       return YES;
   }
+
+  if (!topLevelWindow ||
+      [topLevelWindow isMainWindow] ||
+      [aEvent type] == NSOtherMouseDown ||
+      (([aEvent modifierFlags] & NSCommandKeyMask) != 0 &&
+       [aEvent type] != NSMouseMoved))
+    return YES;
+
+  // If we're here then we're dealing with a left click or mouse move on an
+  // inactive window or something similar. Return NO for now.
+  return NO;
 }
 
 #pragma mark -

widget/tests/native_mouse_mac_window.xul

@@ -113,6 +113,15 @@
           NSEventTypeBeginGesture = 19,
           NSEventTypeEndGesture   = 20;
 
+    const NSAlphaShiftKeyMask = 1 << 16,
+          NSShiftKeyMask      = 1 << 17,
+          NSControlKeyMask    = 1 << 18,
+          NSAlternateKeyMask  = 1 << 19,
+          NSCommandKeyMask    = 1 << 20,
+          NSNumericPadKeyMask = 1 << 21,
+          NSHelpKeyMask       = 1 << 22,
+          NSFunctionKeyMask   = 1 << 23;
+
     const gDebug = false;
 
     function printDebug(msg) { if (gDebug) dump(msg); }
@@ -120,7 +129,7 @@
     var gExpectedEvents = [];
     var gRightWindow = null, gPopup = null;
 
-    function testMouse(x, y, msg, elem, win, exp, callback) {
+    function testMouse(x, y, msg, elem, win, exp, flags, callback) {
       clearExpectedEvents();
       exp.forEach(function (expEv) {
         expEv.screenX = x;
@@ -131,7 +140,7 @@
       netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
       var utils = win.QueryInterface(Components.interfaces.nsIInterfaceRequestor).
                                      getInterface(Components.interfaces.nsIDOMWindowUtils);
-      utils.sendNativeMouseEvent(x, y, msg, 0, elem);
+      utils.sendNativeMouseEvent(x, y, msg, flags || 0, elem);
       SimpleTest.executeSoon(function () {
         clearExpectedEvents();
         callback();
@@ -249,6 +258,22 @@
         [400, 150, NSMouseMoved, null, right, [
           { type: "mouseout", target: leftElem },
         ]],
+        // Left-clicking while holding Cmd and middle clicking should work even
+        // on inactive windows, but without making them active.
+        [400, 150, NSLeftMouseDown, null, right, [
+          { type: "mousedown", target: rightElem },
+        ], NSCommandKeyMask],
+        [400, 150, NSLeftMouseUp, null, right, [
+          { type: "mouseup", target: rightElem },
+          { type: "click", target: rightElem },
+        ], NSCommandKeyMask],
+        [400, 150, NSOtherMouseDown, null, right, [
+          { type: "mousedown", target: rightElem },
+        ]],
+        [400, 150, NSOtherMouseUp, null, right, [
+          { type: "mouseup", target: rightElem },
+          { type: "click", target: rightElem },
+        ]],
         // Clicking an inactive window should make it active and fire a mouseover
         // event.
         [400, 150, NSLeftMouseDown, null, right, [
@@ -482,8 +507,8 @@
         if (typeof test == "function")
           return test(runNextTest);
 
-        var [x, y, msg, elem, win, exp] = test;
-        testMouse(x, y, msg, elem, win, exp, runNextTest);
+        var [x, y, msg, elem, win, exp, flags] = test;
+        testMouse(x, y, msg, elem, win, exp, flags, runNextTest);
       }
       runNextTest();
     }