Show a visual indicator for the progress of auto-click.

ash/autoclick/autoclick_ring_handler.h

Index: ash/autoclick/autoclick_ring_handler.h
diff --git a/ash/autoclick/autoclick_ring_handler.h b/ash/autoclick/autoclick_ring_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..89261708e5334f44315da33c79cf4d618177c8d5
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+++ b/ash/autoclick/autoclick_ring_handler.h
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+// Copyright (c) 2016 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.
+
+#ifndef ASH_AUTOCLICK_AUTOCLICK_RING_HANDLER_H_
+#define ASH_AUTOCLICK_AUTOCLICK_RING_HANDLER_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "base/timer/timer.h"
+#include "ui/aura/window_observer.h"
+#include "ui/events/event.h"
+#include "ui/gfx/animation/linear_animation.h"
+#include "ui/gfx/geometry/point.h"
+
+namespace ui {
+class GestureEvent;
+}
+
+namespace ash {
+
+namespace test {
+class SystemGestureEventFilterTest;
+}
+
+// LongPressAutoclickRingHandler displays an animated affordance that is shown
+// on a TAP_DOWN gesture. The animation sequence consists of two parts:
+// The first part is a grow animation that starts at semi-long-press and
+// completes on a long-press gesture. The affordance animates to full size
+// during grow animation.
+// The second part is a shrink animation that start after grow and shrinks the
+// affordance out of view.
+class LongPressAutoclickRingHandler : public gfx::LinearAnimation,
+                                      public aura::WindowObserver {
+ public:
+  LongPressAutoclickRingHandler();
+  ~LongPressAutoclickRingHandler() override;
+
+  // Displays or removes long press affordance according to the |event|.
+  void ProcessEvent(ui::LocatedEvent* event,
+                    int delay_ms,
+                    bool start_animation);
+
+ private:
+  friend class ash::test::SystemGestureEventFilterTest;
+
+  class LongPressAutoclickRingView;
+
+  enum LongPressAnimationType {
+    NONE,
+    GROW_ANIMATION,
+    SHRINK_ANIMATION,
+  };
+
+  gfx::Point GetLastMouseLocation();
+  aura::Window* GetTargetWindow();
+  void SetTapDownLocationAndTarget();
+  void StartAnimation(int delay_ms);
+  void StopAutoclickRing();
+  void SetTapDownTarget(aura::Window* target);
+
+  // Overridden from gfx::LinearAnimation.
+  void AnimateToState(double state) override;
+  void AnimationStopped() override;
+
+  // Overridden from aura::WindowObserver.
+  void OnWindowDestroying(aura::Window* window) override;
+
+  std::unique_ptr<LongPressAutoclickRingView> view_;
+  gfx::Point tap_down_location_;
+  aura::Window* tap_down_target_;
+  LongPressAnimationType current_animation_type_;
+
+  DISALLOW_COPY_AND_ASSIGN(LongPressAutoclickRingHandler);
+};
+
+}  // namespace ash
+
+#endif  // ASH_AUTOCLICK_AUTOCLICK_RING_HANDLER_H_