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

chrome/browser/chromeos/ui/autoclick_ring_handler.h

+// 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 CHROME_BROWSER_CHROMEOS_UI_AUTOCLICK_RING_HANDLER_H_
+#define CHROME_BROWSER_CHROMEOS_UI_AUTOCLICK_RING_HANDLER_H_
+
+#include <memory>
+
+#include "ash/autoclick/autoclickgesture_delegate.h"
+#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 chromeos {
+
+// LongPressAutoclickRingHandler displays an animated affordance that is shown
+// on a TAP_DOWN gesture. The animation sequence consists of two parts:

[jdufault, 2016/06/03 22:02:45]

Remove the "TAP_DOWN" bit since this class doesn't know about events/gestures
anymore.

[sammiequon, 2016/06/07 18:06:16]

Done.

+// 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,

[jdufault, 2016/06/03 22:02:44]

Remove the LongPress bit, since the class doesn't know about that anymore.

[sammiequon, 2016/06/07 18:06:16]

Done.

+                                      public ash::AutoclickgestureDelegate {
+ public:
+  LongPressAutoclickRingHandler();
+  ~LongPressAutoclickRingHandler() override;
+
+  // Overriden from ash::AutoclickgestureDelegate.
+  void StartGesture(int delay_ms, gfx::Point center) override;

[jdufault, 2016/06/03 22:02:44]

Should delay_ms be renamed to duration_ms?

Let's also use a base::TimeDuration type instead of an int, then there is no
worry about the type of time value stored in the int.

[sammiequon, 2016/06/07 18:06:16]

I couldn't find a base::TimeDuration type, but there is a base::TimeDelta uses
which gfx::Animation converts an int to using SetDuration(int) which is in the
call stack for StartGesture. delay_ms changed to duration_ms.

[jdufault, 2016/06/08 17:50:19]

Sorry, I'm a bit confused now. How does gfx::Animation come into this? I don't
think it'd be too much work to convert the entire class to use base::TimeDelta.

+  void StopGesture() override;
+  void SetGestureCenter(gfx::Point center) override;
+
+ private:
+  class LongPressAutoclickRingView;
+
+  enum LongPressAnimationType {
+    NONE,
+    GROW_ANIMATION,
+    SHRINK_ANIMATION,
+  };
+
+  aura::Window* GetTargetWindow();
+  void SetTapDownTarget();
+  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 chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_UI_AUTOCLICK_RING_HANDLER_H_