Initial browser-side implementation for touch-action

content/browser/renderer_host/input/touch_action_filter.cc

Index: content/browser/renderer_host/input/touch_action_filter.cc
diff --git a/content/browser/renderer_host/input/touch_action_filter.cc b/content/browser/renderer_host/input/touch_action_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c095f3d804eaaf8e82e7c0a55017f83fd0e0a302
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+++ b/content/browser/renderer_host/input/touch_action_filter.cc
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+// Copyright 2013 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/input/touch_action_filter.h"
+
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+
+using blink::WebInputEvent;
+using blink::WebGestureEvent;
+
+namespace content {
+
+bool TouchActionFilter::FilterGestureEvent(
+    const WebGestureEvent& gesture_event)
+{
+  // Filter for allowable touch actions first (eg. before the TouchEventQueue
+  // can decide to send a touch cancel event).
+  // TODO(rbyers): Add touch-action control over for pinch.  crbug.com/247566.
+  switch(gesture_event.type) {
+  case WebInputEvent::GestureScrollBegin:
+    if (allowed_touch_action_ == TOUCH_ACTION_NONE)
+      drop_scroll_gesture_events_ = true;
+    // FALL THROUGH
+  case WebInputEvent::GestureScrollUpdate:
+  case WebInputEvent::GestureScrollUpdateWithoutPropagation:
+    if (drop_scroll_gesture_events_)
+      return true;
+    break;
+
+  case WebInputEvent::GestureScrollEnd:
+  case WebInputEvent::GestureFlingStart:
+    allowed_touch_action_ = content::TOUCH_ACTION_AUTO;
+    if (drop_scroll_gesture_events_) {
+      drop_scroll_gesture_events_ = false;
+      return true;
+    }
+    break;
+
+  default:
+    break;
+  }
+
+  return false;
+}
+
+void TouchActionFilter::OnSetTouchAction(
+    int touch_id,
+    content::TouchAction touchAction)
+{
+  // For multiple fingers, we take the intersection of the touch actions for
+  // all fingers that have gone down during this action.
+  // TODO(rbyers): Get some agreed upon multi-finger semantic for touch-action
+  // included in the pointer events specification. crbug.com/241964
+  if (touchAction == content::TOUCH_ACTION_NONE)
+    allowed_touch_action_ = content::TOUCH_ACTION_NONE;
+}
+
+}