Separate projection mode from rest of touch HUD

ash/touch/touch_hud_projection.cc

+// Copyright (c) 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 "ash/touch/touch_hud_projection.h"
+
+#include "ash/root_window_controller.h"
+#include "ash/shell.h"
+#include "ash/wm/property_util.h"
+#include "third_party/skia/include/effects/SkGradientShader.h"
+#include "ui/base/animation/animation_delegate.h"
+#include "ui/base/animation/linear_animation.h"
+#include "ui/base/events/event.h"
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/size.h"
+#include "ui/views/widget/widget.h"
+
+namespace ash {
+namespace internal {
+
+const int kPointRadius = 20;
+const SkColor kProjectionFillColor = SkColorSetRGB(0xF5, 0xF5, 0xDC);
+const SkColor kProjectionStrokeColor = SK_ColorGRAY;
+const int kProjectionAlpha = 0xB0;
+const int kFadeoutDurationInMs = 250;
+const int kFadeoutFrameRate = 60;
+
+// TouchPointView draws a single touch point. This object manages its own
+// lifetime and deletes itself upon fade-out completion or whenever |Remove()|
+// is explicitly called.
+class TouchPointView : public views::View,
+                       public ui::AnimationDelegate,
+                       public views::WidgetObserver {
+ public:
+  explicit TouchPointView(views::Widget* parent_widget)
+      : circle_center_(kPointRadius + 1, kPointRadius + 1),
+        gradient_center_(SkPoint::Make(kPointRadius + 1,
+                                       kPointRadius + 1)) {
+    SetPaintToLayer(true);
+    SetFillsBoundsOpaquely(false);
+
+    SetSize(gfx::Size(2 * kPointRadius + 2, 2 * kPointRadius + 2));
+
+    stroke_paint_.setStyle(SkPaint::kStroke_Style);
+    stroke_paint_.setColor(kProjectionStrokeColor);
+
+    gradient_colors_[0] = kProjectionFillColor;
+    gradient_colors_[1] = kProjectionStrokeColor;
+
+    gradient_pos_[0] = SkFloatToScalar(0.9f);
+    gradient_pos_[1] = SkFloatToScalar(1.0f);
+
+    parent_widget->GetContentsView()->AddChildView(this);
+
+    parent_widget->AddObserver(this);
+  }
+
+  void UpdateTouch(const ui::TouchEvent& touch) {
+    if (touch.type() == ui::ET_TOUCH_RELEASED ||
+        touch.type() == ui::ET_TOUCH_CANCELLED) {
+      fadeout_.reset(new ui::LinearAnimation(kFadeoutDurationInMs,
+                                             kFadeoutFrameRate,
+                                             this));
+      fadeout_->Start();
+    } else {
+      SetX(touch.root_location().x() - kPointRadius - 1);
+      SetY(touch.root_location().y() - kPointRadius - 1);
+    }
+  }
+
+  void Remove() {
+    delete this;
+  }
+
+ private:
+  virtual ~TouchPointView() {
+    GetWidget()->RemoveObserver(this);
+    parent()->RemoveChildView(this);
+  }
+
+  // Overridden from views::View.
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
+    int alpha = kProjectionAlpha;
+    if (fadeout_)
+      alpha = static_cast<int>(fadeout_->CurrentValueBetween(alpha, 0));
+    fill_paint_.setAlpha(alpha);
+    stroke_paint_.setAlpha(alpha);
+    SkShader* shader = SkGradientShader::CreateRadial(
+        gradient_center_,
+        SkIntToScalar(kPointRadius),
+        gradient_colors_,
+        gradient_pos_,
+        arraysize(gradient_colors_),
+        SkShader::kMirror_TileMode,
+        NULL);
+    fill_paint_.setShader(shader);
+    shader->unref();
+    canvas->DrawCircle(circle_center_, SkIntToScalar(kPointRadius),
+                       fill_paint_);
+    canvas->DrawCircle(circle_center_, SkIntToScalar(kPointRadius),
+                       stroke_paint_);
+  }
+
+  // Overridden from ui::AnimationDelegate.
+  virtual void AnimationEnded(const ui::Animation* animation) OVERRIDE {
+    DCHECK_EQ(fadeout_.get(), animation);
+    delete this;
+  }
+
+  virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE {
+    DCHECK_EQ(fadeout_.get(), animation);
+    SchedulePaint();
+  }
+
+  virtual void AnimationCanceled(const ui::Animation* animation) OVERRIDE {
+    AnimationEnded(animation);
+  }
+
+  // Overridden from views::WidgetObserver.
+  virtual void OnWidgetDestroying(views::Widget* widget) OVERRIDE {
+    fadeout_->Stop();
+  }
+
+  const gfx::Point circle_center_;
+  const SkPoint gradient_center_;
+
+  SkPaint fill_paint_;
+  SkPaint stroke_paint_;
+  SkColor gradient_colors_[2];
+  SkScalar gradient_pos_[2];
+
+  scoped_ptr<ui::Animation> fadeout_;
+
+  DISALLOW_COPY_AND_ASSIGN(TouchPointView);
+};
+
+TouchHudProjection::TouchHudProjection(aura::RootWindow* initial_root)
+    : TouchObserverHUD(initial_root) {
+}
+
+TouchHudProjection::~TouchHudProjection() {
+}
+
+void TouchHudProjection::Clear() {
+  for (std::map<int, TouchPointView*>::iterator iter = points_.begin();
+      iter != points_.end(); iter++)
+    iter->second->Remove();
+  points_.clear();
+}
+
+void TouchHudProjection::OnTouchEvent(ui::TouchEvent* event) {
+  if (event->type() == ui::ET_TOUCH_PRESSED) {
+    TouchPointView* point = new TouchPointView(widget());
+    point->UpdateTouch(*event);
+    std::pair<std::map<int, TouchPointView*>::iterator, bool> result =
+        points_.insert(std::make_pair(event->touch_id(), point));
+    // If a |TouchPointView| is already mapped to the touch id, remove it and
+    // replace it with the new one.
+    if (!result.second) {
+      result.first->second->Remove();
+      result.first->second = point;
+    }
+  } else {
+    std::map<int, TouchPointView*>::iterator iter =
+        points_.find(event->touch_id());
+    if (iter != points_.end()) {
+      iter->second->UpdateTouch(*event);
+      if (event->type() == ui::ET_TOUCH_RELEASED ||
+          event->type() == ui::ET_TOUCH_CANCELLED)
+        points_.erase(iter);
+    }
+  }
+}
+
+void TouchHudProjection::SetHudForRootWindowController(
+    RootWindowController* controller) {
+  controller->set_touch_hud_projection(this);
+}
+
+void TouchHudProjection::UnsetHudForRootWindowController(
+    RootWindowController* controller) {
+  controller->set_touch_hud_projection(NULL);
+}
+
+}  // namespace internal
+}  // namespace ash