ash/wm/gestures/long_press_affordance_handler.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ash/wm/gestures/long_press_affordance_handler.h"
   6
   7 #include "ash/display/display_controller.h"
   8 #include "ash/root_window_controller.h"
   9 #include "ash/shell.h"
  10 #include "ash/shell_window_ids.h"
  11 #include "third_party/skia/include/core/SkColor.h"
  12 #include "third_party/skia/include/core/SkPaint.h"
  13 #include "third_party/skia/include/core/SkPath.h"
  14 #include "third_party/skia/include/core/SkRect.h"
  15 #include "third_party/skia/include/effects/SkGradientShader.h"
  16 #include "ui/aura/client/screen_position_client.h"
  17 #include "ui/aura/window.h"
  18 #include "ui/aura/window_event_dispatcher.h"
  19 #include "ui/compositor/layer.h"
  20 #include "ui/events/gesture_detection/gesture_configuration.h"
  21 #include "ui/gfx/canvas.h"
  22 #include "ui/gfx/screen.h"
  23 #include "ui/gfx/transform.h"
  24 #include "ui/views/view.h"
  25 #include "ui/views/widget/widget.h"
  26
  27 namespace ash {
  28 namespace {
  29
  30 const int kAffordanceOuterRadius = 60;
  31 const int kAffordanceInnerRadius = 50;
  32
  33 // Angles from x-axis at which the outer and inner circles start.
  34 const int kAffordanceOuterStartAngle = -109;
  35 const int kAffordanceInnerStartAngle = -65;
  36
  37 const int kAffordanceGlowWidth = 20;
  38 // The following is half width to avoid division by 2.
  39 const int kAffordanceArcWidth = 3;
  40
  41 // Start and end values for various animations.
  42 const double kAffordanceScaleStartValue = 0.8;
  43 const double kAffordanceScaleEndValue = 1.0;
  44 const double kAffordanceShrinkScaleEndValue = 0.5;
  45 const double kAffordanceOpacityStartValue = 0.1;
  46 const double kAffordanceOpacityEndValue = 0.5;
  47 const int kAffordanceAngleStartValue = 0;
  48 // The end angle is a bit greater than 360 to make sure the circle completes at
  49 // the end of the animation.
  50 const int kAffordanceAngleEndValue = 380;
  51 const int kAffordanceDelayBeforeShrinkMs = 200;
  52 const int kAffordanceShrinkAnimationDurationMs = 100;
  53
  54 // Visual constants.
  55 const SkColor kAffordanceGlowStartColor = SkColorSetARGB(24, 255, 255, 255);
  56 const SkColor kAffordanceGlowEndColor = SkColorSetARGB(0, 255, 255, 255);
  57 const SkColor kAffordanceArcColor = SkColorSetARGB(80, 0, 0, 0);
  58 const int kAffordanceFrameRateHz = 60;
  59
  60 views::Widget* CreateAffordanceWidget(aura::Window* root_window) {
  61   views::Widget* widget = new views::Widget;
  62   views::Widget::InitParams params;
  63   params.type = views::Widget::InitParams::TYPE_WINDOW_FRAMELESS;
  64   params.keep_on_top = true;
  65   params.accept_events = false;
  66   params.activatable = views::Widget::InitParams::ACTIVATABLE_NO;
  67   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
  68   params.context = root_window;
  69   params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
  70   widget->Init(params);
  71   widget->SetOpacity(0xFF);
  72   GetRootWindowController(root_window)->GetContainer(
  73       kShellWindowId_OverlayContainer)->AddChild(widget->GetNativeWindow());
  74   return widget;
  75 }
  76
  77 void PaintAffordanceArc(gfx::Canvas* canvas,
  78                         gfx::Point& center,
  79                         int radius,
  80                         int start_angle,
  81                         int end_angle) {
  82   SkPaint paint;
  83   paint.setStyle(SkPaint::kStroke_Style);
  84   paint.setStrokeWidth(2 * kAffordanceArcWidth);
  85   paint.setColor(kAffordanceArcColor);
  86   paint.setAntiAlias(true);
  87
  88   SkPath arc_path;
  89   arc_path.addArc(SkRect::MakeXYWH(center.x() - radius,
  90                                    center.y() - radius,
  91                                    2 * radius,
  92                                    2 * radius),
  93                   start_angle, end_angle);
  94   canvas->DrawPath(arc_path, paint);
  95 }
  96
  97 void PaintAffordanceGlow(gfx::Canvas* canvas,
  98                          gfx::Point& center,
  99                          int start_radius,
 100                          int end_radius,
 101                          SkColor* colors,
 102                          SkScalar* pos,
 103                          int num_colors) {
 104   SkPoint sk_center;
 105   int radius = (end_radius + start_radius) / 2;
 106   int glow_width = end_radius - start_radius;
 107   sk_center.iset(center.x(), center.y());
 108   skia::RefPtr<SkShader> shader = skia::AdoptRef(
 109       SkGradientShader::CreateTwoPointRadial(
 110           sk_center,
 111           SkIntToScalar(start_radius),
 112           sk_center,
 113           SkIntToScalar(end_radius),
 114           colors,
 115           pos,
 116           num_colors,
 117           SkShader::kClamp_TileMode));
 118   DCHECK(shader);
 119   SkPaint paint;
 120   paint.setStyle(SkPaint::kStroke_Style);
 121   paint.setStrokeWidth(glow_width);
 122   paint.setShader(shader.get());
 123   paint.setAntiAlias(true);
 124   SkPath arc_path;
 125   arc_path.addArc(SkRect::MakeXYWH(center.x() - radius,
 126                                    center.y() - radius,
 127                                    2 * radius,
 128                                    2 * radius),
 129                   0, 360);
 130   canvas->DrawPath(arc_path, paint);
 131 }
 132
 133 }  // namespace
 134
 135 // View of the LongPressAffordanceHandler. Draws the actual contents and
 136 // updates as the animation proceeds. It also maintains the views::Widget that
 137 // the animation is shown in.
 138 class LongPressAffordanceHandler::LongPressAffordanceView
 139     : public views::View {
 140  public:
 141   LongPressAffordanceView(const gfx::Point& event_location,
 142                           aura::Window* root_window)
 143       : views::View(),
 144         widget_(CreateAffordanceWidget(root_window)),
 145         current_angle_(kAffordanceAngleStartValue),
 146         current_scale_(kAffordanceScaleStartValue) {
 147     widget_->SetContentsView(this);
 148     widget_->SetAlwaysOnTop(true);
 149
 150     // We are owned by the LongPressAffordance.
 151     set_owned_by_client();
 152     gfx::Point point = event_location;
 153     aura::client::GetScreenPositionClient(root_window)->ConvertPointToScreen(
 154         root_window, &point);
 155     widget_->SetBounds(gfx::Rect(
 156         point.x() - (kAffordanceOuterRadius + kAffordanceGlowWidth),
 157         point.y() - (kAffordanceOuterRadius + kAffordanceGlowWidth),
 158         GetPreferredSize().width(),
 159         GetPreferredSize().height()));
 160     widget_->Show();
 161     widget_->GetNativeView()->layer()->SetOpacity(kAffordanceOpacityStartValue);
 162   }
 163
 164   ~LongPressAffordanceView() override {}
 165
 166   void UpdateWithGrowAnimation(gfx::Animation* animation) {
 167     // Update the portion of the circle filled so far and re-draw.
 168     current_angle_ = animation->CurrentValueBetween(kAffordanceAngleStartValue,
 169         kAffordanceAngleEndValue);
 170     current_scale_ = animation->CurrentValueBetween(kAffordanceScaleStartValue,
 171         kAffordanceScaleEndValue);
 172     widget_->GetNativeView()->layer()->SetOpacity(
 173         animation->CurrentValueBetween(kAffordanceOpacityStartValue,
 174             kAffordanceOpacityEndValue));
 175     SchedulePaint();
 176   }
 177
 178   void UpdateWithShrinkAnimation(gfx::Animation* animation) {
 179     current_scale_ = animation->CurrentValueBetween(kAffordanceScaleEndValue,
 180         kAffordanceShrinkScaleEndValue);
 181     widget_->GetNativeView()->layer()->SetOpacity(
 182         animation->CurrentValueBetween(kAffordanceOpacityEndValue,
 183             kAffordanceOpacityStartValue));
 184     SchedulePaint();
 185   }
 186
 187  private:
 188   // Overridden from views::View.
 189   gfx::Size GetPreferredSize() const override {
 190     return gfx::Size(2 * (kAffordanceOuterRadius + kAffordanceGlowWidth),
 191         2 * (kAffordanceOuterRadius + kAffordanceGlowWidth));
 192   }
 193
 194   void OnPaint(gfx::Canvas* canvas) override {
 195     gfx::Point center(GetPreferredSize().width() / 2,
 196                       GetPreferredSize().height() / 2);
 197     canvas->Save();
 198
 199     gfx::Transform scale;
 200     scale.Scale(current_scale_, current_scale_);
 201     // We want to scale from the center.
 202     canvas->Translate(center.OffsetFromOrigin());
 203     canvas->Transform(scale);
 204     canvas->Translate(-center.OffsetFromOrigin());
 205
 206     // Paint affordance glow
 207     int start_radius = kAffordanceInnerRadius - kAffordanceGlowWidth;
 208     int end_radius = kAffordanceOuterRadius + kAffordanceGlowWidth;
 209     const int num_colors = 3;
 210     SkScalar pos[num_colors] = {0, 0.5, 1};
 211     SkColor colors[num_colors] = {kAffordanceGlowEndColor,
 212         kAffordanceGlowStartColor, kAffordanceGlowEndColor};
 213     PaintAffordanceGlow(canvas, center, start_radius, end_radius, colors, pos,
 214         num_colors);
 215
 216     // Paint inner circle.
 217     PaintAffordanceArc(canvas, center, kAffordanceInnerRadius,
 218         kAffordanceInnerStartAngle, -current_angle_);
 219     // Paint outer circle.
 220     PaintAffordanceArc(canvas, center, kAffordanceOuterRadius,
 221         kAffordanceOuterStartAngle, current_angle_);
 222
 223     canvas->Restore();
 224   }
 225
 226   scoped_ptr<views::Widget> widget_;
 227   int current_angle_;
 228   double current_scale_;
 229
 230   DISALLOW_COPY_AND_ASSIGN(LongPressAffordanceView);
 231 };
 232
 233 ////////////////////////////////////////////////////////////////////////////////
 234 // LongPressAffordanceHandler, public
 235
 236 LongPressAffordanceHandler::LongPressAffordanceHandler()
 237     : gfx::LinearAnimation(kAffordanceFrameRateHz, NULL),
 238       tap_down_target_(NULL),
 239       current_animation_type_(NONE) {}
 240
 241 LongPressAffordanceHandler::~LongPressAffordanceHandler() {
 242   StopAffordance();
 243 }
 244
 245 void LongPressAffordanceHandler::ProcessEvent(aura::Window* target,
 246                                               ui::GestureEvent* event) {
 247   // Once we have a target, we are only interested in events with that target.
 248   if (tap_down_target_ && tap_down_target_ != target)
 249     return;
 250   switch (event->type()) {
 251     case ui::ET_GESTURE_TAP_DOWN: {
 252       // Start timer that will start animation on "semi-long-press".
 253       tap_down_location_ = event->root_location();
 254       SetTapDownTarget(target);
 255       current_animation_type_ = GROW_ANIMATION;
 256       timer_.Start(FROM_HERE,
 257                    base::TimeDelta::FromMilliseconds(
 258                        ui::GestureConfiguration::GetInstance()
 259                            ->semi_long_press_time_in_ms()),
 260                    this,
 261                    &LongPressAffordanceHandler::StartAnimation);
 262       break;
 263     }
 264     case ui::ET_GESTURE_TAP:
 265     case ui::ET_GESTURE_TAP_CANCEL:
 266       StopAffordance();
 267       break;
 268     case ui::ET_GESTURE_LONG_PRESS:
 269       End();
 270       break;
 271     default:
 272       break;
 273   }
 274 }
 275
 276 ////////////////////////////////////////////////////////////////////////////////
 277 // LongPressAffordanceHandler, private
 278
 279 void LongPressAffordanceHandler::StartAnimation() {
 280   switch (current_animation_type_) {
 281     case GROW_ANIMATION: {
 282       aura::Window* root_window = tap_down_target_->GetRootWindow();
 283       if (!root_window) {
 284         StopAffordance();
 285         return;
 286       }
 287       view_.reset(new LongPressAffordanceView(tap_down_location_, root_window));
 288       SetDuration(
 289           ui::GestureConfiguration::GetInstance()->long_press_time_in_ms() -
 290           ui::GestureConfiguration::GetInstance()
 291               ->semi_long_press_time_in_ms() -
 292           kAffordanceDelayBeforeShrinkMs);
 293       Start();
 294       break;
 295     }
 296     case SHRINK_ANIMATION:
 297       SetDuration(kAffordanceShrinkAnimationDurationMs);
 298       Start();
 299       break;
 300     default:
 301       NOTREACHED();
 302       break;
 303   }
 304 }
 305
 306 void LongPressAffordanceHandler::StopAffordance() {
 307   if (timer_.IsRunning())
 308     timer_.Stop();
 309   // Since, Animation::Stop() calls AnimationStopped(), we need to reset the
 310   // |current_animation_type_| before Stop(), otherwise AnimationStopped() may
 311   // start the timer again.
 312   current_animation_type_ = NONE;
 313   Stop();
 314   view_.reset();
 315   SetTapDownTarget(NULL);
 316 }
 317
 318 void LongPressAffordanceHandler::SetTapDownTarget(aura::Window* target) {
 319   if (tap_down_target_ == target)
 320     return;
 321
 322   if (tap_down_target_)
 323     tap_down_target_->RemoveObserver(this);
 324   tap_down_target_ = target;
 325   if (tap_down_target_)
 326     tap_down_target_->AddObserver(this);
 327 }
 328
 329 void LongPressAffordanceHandler::AnimateToState(double state) {
 330   DCHECK(view_.get());
 331   switch (current_animation_type_) {
 332     case GROW_ANIMATION:
 333       view_->UpdateWithGrowAnimation(this);
 334       break;
 335     case SHRINK_ANIMATION:
 336       view_->UpdateWithShrinkAnimation(this);
 337       break;
 338     default:
 339       NOTREACHED();
 340       break;
 341   }
 342 }
 343
 344 void LongPressAffordanceHandler::AnimationStopped() {
 345   switch (current_animation_type_) {
 346     case GROW_ANIMATION:
 347       current_animation_type_ = SHRINK_ANIMATION;
 348       timer_.Start(FROM_HERE,
 349           base::TimeDelta::FromMilliseconds(kAffordanceDelayBeforeShrinkMs),
 350           this, &LongPressAffordanceHandler::StartAnimation);
 351       break;
 352     case SHRINK_ANIMATION:
 353       current_animation_type_ = NONE;
 354       // fall through to reset the view.
 355     default:
 356       view_.reset();
 357       SetTapDownTarget(NULL);
 358       break;
 359   }
 360 }
 361
 362 void LongPressAffordanceHandler::OnWindowDestroying(aura::Window* window) {
 363   DCHECK_EQ(tap_down_target_, window);
 364   StopAffordance();
 365 }
 366
 367 }  // namespace ash