Unified Gesture Recognizer

ui/events/gesture_detection/ui_gesture_provider.cc

+// Copyright 2014 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 "ui/events/gesture_detection/ui_gesture_provider.h"
+
+#include "base/logging.h"
+#include "ui/events/event.h"
+#include "ui/events/gesture_detection/gesture_config_helper.h"
+#include "ui/events/gesture_detection/gesture_event_data.h"
+
+namespace ui {
+namespace {
+
+ui::GestureEvent CreateGesture(const ui::GestureEventData& data, int flags) {
+  return ui::GestureEvent(data.type,
+                          data.x,
+                          data.y,
+                          flags,
+                          data.time - base::TimeTicks(),
+                          data.details,
+                          // ui::GestureEvent stores a bitfield indicating the
+                          // ids of active touch points. This is currently only
+                          // used when one finger is down, and will eventually
+                          // be cleaned up. See crbug.com/366707.
+                          1 << data.motion_event_id);
+}
+
+}  // namespace
+
+UIGestureProvider* UIGestureProvider::Create(UIGestureProviderClient* client) {
+  return new UIGestureProvider(scoped_ptr<GestureProviderClientConverter>(
+      new GestureProviderClientConverter(client)));
+}
+
+UIGestureProvider::UIGestureProvider(
+    scoped_ptr<GestureProviderClientConverter> converter)
+    : FilteredGestureProvider(ui::DefaultGestureProviderConfig(),
+                              converter.get()),
+      converter_(converter.Pass()) {
+  SetDoubleTapSupportForPlatformEnabled(false);
+}
+
+UIGestureProvider::~UIGestureProvider() {}
+
+bool UIGestureProvider::OnTouchEvent(const TouchEvent& event) {
+  converter_->set_flags(event.flags());
+  bool pointer_id_is_active = false;
+  for (size_t i = 0; i < motion_event_.GetPointerCount(); ++i) {
+    if (event.touch_id() != motion_event_.GetPointerId(i))
+      continue;
+    pointer_id_is_active = true;
+    break;
+  }
+
+  if (event.type() == ET_TOUCH_PRESSED && pointer_id_is_active) {
+    // Ignore touch press events if we already believe the pointer is down.
+    return false;
+  } else if (event.type() != ET_TOUCH_PRESSED && !pointer_id_is_active) {
+    // We could have an active touch stream transfered to us, resulting in touch
+    // move or touch up events without associated touch down events. Ignore
+    // them.
+    return false;
+  }
+
+  motion_event_.OnTouch(event);
+
+  DCHECK(motion_event_.GetPointerCount());
+  bool result = FilteredGestureProvider::OnTouchEvent(motion_event_);

[jdduke (slow), 2014/05/02 17:56:43]

I think this will be a little cleaner if the FilteredGestureProvider is a member
(see header comments).

[tdresser, 2014/05/05 15:42:35]

Done.

+  motion_event_.CleanupRemovedTouchPoints(event);
+  return result;
+}
+
+void UIGestureProvider::GestureProviderClientConverter::OnGestureEvent(
+    const GestureEventData& gesture) {
+  ui::GestureEvent event = CreateGesture(gesture, flags_);
+  client_->OnGestureEvent(&event);
+}
+
+}  // namespace content