Add GesturePinchBegin/End events on Mac

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ skipping 2221 matching lines @@
   }
 
   if (endWheelMonitor_) {
     [NSEvent removeMonitor:endWheelMonitor_];
     endWheelMonitor_ = nil;
   }
 }
 
 - (void)beginGestureWithEvent:(NSEvent*)event {
   [responderDelegate_ beginGestureWithEvent:event];
+  gestureBeginEvent_.reset(
+      new WebGestureEvent(WebInputEventFactory::gestureEvent(event, self)));
 }
+
 - (void)endGestureWithEvent:(NSEvent*)event {
   [responderDelegate_ endGestureWithEvent:event];
+  gestureBeginEvent_.reset();
+
+  if (!renderWidgetHostView_->render_widget_host_)
+    return;
+
+  if (gestureBeginPinchSent_) {
+    WebGestureEvent endEvent(WebInputEventFactory::gestureEvent(event, self));
+    endEvent.type = WebInputEvent::GesturePinchEnd;
+    renderWidgetHostView_->render_widget_host_->ForwardGestureEvent(endEvent);
+    gestureBeginPinchSent_ = NO;
+  }
 }
+
 - (void)touchesMovedWithEvent:(NSEvent*)event {
   [responderDelegate_ touchesMovedWithEvent:event];
 }
+
 - (void)touchesBeganWithEvent:(NSEvent*)event {
   [responderDelegate_ touchesBeganWithEvent:event];
 }
+
 - (void)touchesCancelledWithEvent:(NSEvent*)event {
   [responderDelegate_ touchesCancelledWithEvent:event];
 }
+
 - (void)touchesEndedWithEvent:(NSEvent*)event {
   [responderDelegate_ touchesEndedWithEvent:event];
 }
 
 // This is invoked only on 10.8 or newer when the user taps a word using
 // three fingers.
 - (void)quickLookWithEvent:(NSEvent*)event {
   NSPoint point = [self convertPoint:[event locationInWindow] fromView:nil];
   TextInputClientMac::GetInstance()->GetStringAtPoint(
       renderWidgetHostView_->render_widget_host_,
@@ skipping 58 matching lines @@
     BOOL canRubberbandLeft = [responderDelegate_ canRubberbandLeft:self];
     BOOL canRubberbandRight = [responderDelegate_ canRubberbandRight:self];
     const WebMouseWheelEvent webEvent = WebInputEventFactory::mouseWheelEvent(
         event, self, canRubberbandLeft, canRubberbandRight);
     renderWidgetHostView_->render_widget_host_->ForwardWheelEvent(webEvent);
   }
 }
 
 // Called repeatedly during a pinch gesture, with incremental change values.
 - (void)magnifyWithEvent:(NSEvent*)event {
-  if (renderWidgetHostView_->render_widget_host_) {
-    // Send a GesturePinchUpdate event.
-    // Note that we don't attempt to bracket these by GesturePinchBegin/End (or
-    // GestureSrollBegin/End) as is done for touchscreen.  Keeping track of when
-    // a pinch is active would take a little more work here, and we don't need
-    // it for anything yet.
-    const WebGestureEvent& webEvent =
-        WebInputEventFactory::gestureEvent(event, self);
-    renderWidgetHostView_->render_widget_host_->ForwardGestureEvent(webEvent);
+  if (!renderWidgetHostView_->render_widget_host_)
+    return;
+
+  // If, due to nesting of multiple gestures (e.g, from multiple touch
+  // devices), the beginning of the gesture has been lost, skip the remainder
+  // of the gesture.
+  if (!gestureBeginEvent_)
+    return;
+
+  // Send a GesturePinchBegin event if none has been sent yet.
+  if (!gestureBeginPinchSent_) {
+    WebGestureEvent beginEvent(*gestureBeginEvent_);
+    beginEvent.type = WebInputEvent::GesturePinchBegin;
+    renderWidgetHostView_->render_widget_host_->ForwardGestureEvent(beginEvent);
+    gestureBeginPinchSent_ = YES;
   }
+
+  // Send a GesturePinchUpdate event.
+  const WebGestureEvent& updateEvent =
+      WebInputEventFactory::gestureEvent(event, self);
+  renderWidgetHostView_->render_widget_host_->ForwardGestureEvent(updateEvent);
 }
 
 - (void)viewWillMoveToWindow:(NSWindow*)newWindow {
   NSWindow* oldWindow = [self window];
 
   NSNotificationCenter* notificationCenter =
       [NSNotificationCenter defaultCenter];
 
   // Backing property notifications crash on 10.6 when building with the 10.7
   // SDK, see http://crbug.com/260595.
@@ skipping 1030 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end