Implement MouseEvent buttons attribute.

Source/web/WebInputEventConversion.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 94 matching lines @@
         newModifiers |= PlatformEvent::ShiftKey;
     if (webModifiers & WebInputEvent::ControlKey)
         newModifiers |= PlatformEvent::CtrlKey;
     if (webModifiers & WebInputEvent::AltKey)
         newModifiers |= PlatformEvent::AltKey;
     if (webModifiers & WebInputEvent::MetaKey)
         newModifiers |= PlatformEvent::MetaKey;
     return newModifiers;
 }
 
+static unsigned toPlatformMouseEventModifiers(int webModifiers)
+{
+    unsigned newModifiers = toPlatformEventModifiers(webModifiers);
+    if (webModifiers & WebInputEvent::LeftButtonDown)
+        newModifiers |= PlatformEvent::LeftButtonDown;
+    if (webModifiers & WebInputEvent::MiddleButtonDown)
+        newModifiers |= PlatformEvent::MiddleButtonDown;
+    if (webModifiers & WebInputEvent::RightButtonDown)
+        newModifiers |= PlatformEvent::RightButtonDown;
+    return newModifiers;
+}
+
+static unsigned toPlatformModifierFrom(WebMouseEvent::Button button)
+{
+    if (button == WebMouseEvent::ButtonNone)
+        return 0;
+
+    unsigned webMouseButtonToPlatformModifier[] = {
+        PlatformEvent::LeftButtonDown,
+        PlatformEvent::MiddleButtonDown,
+        PlatformEvent::RightButtonDown
+    };
+
+    return webMouseButtonToPlatformModifier[button];
+}
+
 // MakePlatformMouseEvent -----------------------------------------------------
 
 PlatformMouseEventBuilder::PlatformMouseEventBuilder(Widget* widget, const WebMouseEvent& e)
 {
     // FIXME: Widget is always toplevel, unless it's a popup. We may be able
     // to get rid of this once we abstract popups into a WebKit API.
     m_position = widget->convertFromContainingWindow(flooredIntPoint(convertHitPointToWindow(widget, IntPoint(e.x, e.y))));
     m_globalPosition = IntPoint(e.globalX, e.globalY);
     m_movementDelta = IntPoint(scaleDeltaToWindow(widget, e.movementX), scaleDeltaToWindow(widget, e.movementY));
     m_button = static_cast<MouseButton>(e.button);
-    m_modifiers = toPlatformEventModifiers(e.modifiers);
+    m_modifiers = toPlatformMouseEventModifiers(e.modifiers);
 
     m_timestamp = e.timeStampSeconds;
     m_clickCount = e.clickCount;
 
     switch (e.type) {
     case WebInputEvent::MouseMove:
     case WebInputEvent::MouseLeave:  // synthesize a move event
         m_type = PlatformEvent::MouseMoved;
         break;
 
     case WebInputEvent::MouseDown:
         m_type = PlatformEvent::MousePressed;
         break;
 
     case WebInputEvent::MouseUp:
         m_type = PlatformEvent::MouseReleased;
+
+        // The MouseEvent spec requires that buttons indicates the state
+        // immediately after the event takes place. To ensure consistency
+        // between platforms here, we explicitly clear the button that is
+        // in the process of being released.
+        m_modifiers &= ~toPlatformModifierFrom(e.button);
         break;
 
     default:
         ASSERT_NOT_REACHED();
     }
 }
 
 // PlatformWheelEventBuilder --------------------------------------------------
 
 PlatformWheelEventBuilder::PlatformWheelEventBuilder(Widget* widget, const WebMouseWheelEvent& e)
 {
     m_position = widget->convertFromContainingWindow(flooredIntPoint(convertHitPointToWindow(widget, FloatPoint(e.x, e.y))));
     m_globalPosition = IntPoint(e.globalX, e.globalY);
     m_deltaX = e.deltaX;
     m_deltaY = e.deltaY;
     m_wheelTicksX = e.wheelTicksX;
     m_wheelTicksY = e.wheelTicksY;
     m_granularity = e.scrollByPage ?
         ScrollByPageWheelEvent : ScrollByPixelWheelEvent;
 
     m_type = PlatformEvent::Wheel;
 
-    m_modifiers = toPlatformEventModifiers(e.modifiers);
+    m_modifiers = toPlatformMouseEventModifiers(e.modifiers);
 
     m_hasPreciseScrollingDeltas = e.hasPreciseScrollingDeltas;
 #if OS(MACOSX)
     m_phase = static_cast<PlatformWheelEventPhase>(e.phase);
     m_momentumPhase = static_cast<PlatformWheelEventPhase>(e.momentumPhase);
     m_timestamp = e.timeStampSeconds;
     m_canRubberbandLeft = e.canRubberbandLeft;
     m_canRubberbandRight = e.canRubberbandRight;
 #endif
 }
@@ skipping 593 matching lines @@
     modifiers = getWebInputModifiers(event);
 
     globalX = event.screenX();
     globalY = event.screenY();
     IntPoint localPoint = convertAbsoluteLocationForRenderObject(event.absoluteLocation(), *renderObject);
     x = localPoint.x();
     y = localPoint.y();
 }
 
 } // namespace blink