Implement support for touch-action: pan-x/pan-y in chromium

content/renderer/render_widget.cc

 // 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/renderer/render_widget.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 2780 matching lines @@
 }
 
 void RenderWidget::setTouchAction(
     blink::WebTouchAction web_touch_action) {
 
   // Ignore setTouchAction calls that result from synthetic touch events (eg.
   // when blink is emulating touch with mouse).
   if (!handling_touchstart_event_)
     return;
 
-  content::TouchAction content_touch_action;
-  switch(web_touch_action) {
-    case blink::WebTouchActionNone:
-      content_touch_action = content::TOUCH_ACTION_NONE;
-      break;
-    case blink::WebTouchActionAuto:
-      content_touch_action = content::TOUCH_ACTION_AUTO;
-      break;
-    default:
-      NOTREACHED();
-  }
+   // Verify the same values are used by the types so we can cast between them.
+   COMPILE_ASSERT(static_cast<blink::WebTouchAction>(TOUCH_ACTION_AUTO) ==
+                      blink::WebTouchActionAuto,
+                  enum_values_must_match_for_touch_action);
+   COMPILE_ASSERT(static_cast<blink::WebTouchAction>(TOUCH_ACTION_NONE) ==
+                      blink::WebTouchActionNone,
+                  enum_values_must_match_for_touch_action);
+   COMPILE_ASSERT(static_cast<blink::WebTouchAction>(TOUCH_ACTION_PAN_X) ==
+                      blink::WebTouchActionPanX,
+                  enum_values_must_match_for_touch_action);
+   COMPILE_ASSERT(static_cast<blink::WebTouchAction>(TOUCH_ACTION_PAN_Y) ==
+                      blink::WebTouchActionPanY,
+                  enum_values_must_match_for_touch_action);
+
+   content::TouchAction content_touch_action =
+       static_cast<content::TouchAction>(web_touch_action);
   Send(new InputHostMsg_SetTouchAction(routing_id_, content_touch_action));
 }
 
 bool RenderWidget::HasTouchEventHandlersAt(const gfx::Point& point) const {
   return true;
 }
 
 scoped_ptr<WebGraphicsContext3DCommandBufferImpl>
 RenderWidget::CreateGraphicsContext3D(
     const blink::WebGraphicsContext3D::Attributes& attributes) {
@@ skipping 40 matching lines @@
           surface_id(),
           GetURLForGraphicsContext3D(),
           gpu_channel_host.get(),
           attributes,
           false /* bind generates resources */,
           limits));
   return context.Pass();
 }
 
 }  // namespace content