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 =
 109       skia::AdoptRef(SkGradientShader::CreateTwoPointConical(
 110           sk_center, SkIntToScalar(start_radius), sk_center,
 111           SkIntToScalar(end_radius), colors, pos, num_colors,
 112           SkShader::kClamp_TileMode));
 113   DCHECK(shader);
 114   SkPaint paint;
 115   paint.setStyle(SkPaint::kStroke_Style);
 116   paint.setStrokeWidth(glow_width);
 117   paint.setShader(shader.get());
 118   paint.setAntiAlias(true);
 119   SkPath arc_path;
 120   arc_path.addArc(SkRect::MakeXYWH(center.x() - radius,
 121                                    center.y() - radius,
 122                                    2 * radius,
 123                                    2 * radius),
 124                   0, 360);
 125   canvas->DrawPath(arc_path, paint);
 126 }
 127
 128 }  // namespace
 129
 130 // View of the LongPressAffordanceHandler. Draws the actual contents and
 131 // updates as the animation proceeds. It also maintains the views::Widget that
 132 // the animation is shown in.
 133 class LongPressAffordanceHandler::LongPressAffordanceView
 134     : public views::View {
 135  public:
 136   LongPressAffordanceView(const gfx::Point& event_location,
 137                           aura::Window* root_window)
 138       : views::View(),
 139         widget_(CreateAffordanceWidget(root_window)),
 140         current_angle_(kAffordanceAngleStartValue),
 141         current_scale_(kAffordanceScaleStartValue) {
 142     widget_->SetContentsView(this);
 143     widget_->SetAlwaysOnTop(true);
 144
 145     // We are owned by the LongPressAffordance.
 146     set_owned_by_client();
 147     gfx::Point point = event_location;
 148     aura::client::GetScreenPositionClient(root_window)->ConvertPointToScreen(
 149         root_window, &point);
 150     widget_->SetBounds(gfx::Rect(
 151         point.x() - (kAffordanceOuterRadius + kAffordanceGlowWidth),
 152         point.y() - (kAffordanceOuterRadius + kAffordanceGlowWidth),
 153         GetPreferredSize().width(),
 154         GetPreferredSize().height()));
 155     widget_->Show();
 156     widget_->GetNativeView()->layer()->SetOpacity(kAffordanceOpacityStartValue);
 157   }
 158
 159   ~LongPressAffordanceView() override {}
 160
 161   void UpdateWithGrowAnimation(gfx::Animation* animation) {
 162     // Update the portion of the circle filled so far and re-draw.
 163     current_angle_ = animation->CurrentValueBetween(kAffordanceAngleStartValue,
 164         kAffordanceAngleEndValue);
 165     current_scale_ = animation->CurrentValueBetween(kAffordanceScaleStartValue,
 166         kAffordanceScaleEndValue);
 167     widget_->GetNativeView()->layer()->SetOpacity(
 168         animation->CurrentValueBetween(kAffordanceOpacityStartValue,
 169             kAffordanceOpacityEndValue));
 170     SchedulePaint();
 171   }
 172
 173   void UpdateWithShrinkAnimation(gfx::Animation* animation) {
 174     current_scale_ = animation->CurrentValueBetween(kAffordanceScaleEndValue,
 175         kAffordanceShrinkScaleEndValue);
 176     widget_->GetNativeView()->layer()->SetOpacity(
 177         animation->CurrentValueBetween(kAffordanceOpacityEndValue,
 178             kAffordanceOpacityStartValue));
 179     SchedulePaint();
 180   }
 181
 182  private:
 183   // Overridden from views::View.
 184   gfx::Size GetPreferredSize() const override {
 185     return gfx::Size(2 * (kAffordanceOuterRadius + kAffordanceGlowWidth),
 186         2 * (kAffordanceOuterRadius + kAffordanceGlowWidth));
 187   }
 188
 189   void OnPaint(gfx::Canvas* canvas) override {
 190     gfx::Point center(GetPreferredSize().width() / 2,
 191                       GetPreferredSize().height() / 2);
 192     canvas->Save();
 193
 194     gfx::Transform scale;
 195     scale.Scale(current_scale_, current_scale_);
 196     // We want to scale from the center.
 197     canvas->Translate(center.OffsetFromOrigin());
 198     canvas->Transform(scale);
 199     canvas->Translate(-center.OffsetFromOrigin());
 200
 201     // Paint affordance glow
 202     int start_radius = kAffordanceInnerRadius - kAffordanceGlowWidth;
 203     int end_radius = kAffordanceOuterRadius + kAffordanceGlowWidth;
 204     const int num_colors = 3;
 205     SkScalar pos[num_colors] = {0, 0.5, 1};
 206     SkColor colors[num_colors] = {kAffordanceGlowEndColor,
 207         kAffordanceGlowStartColor, kAffordanceGlowEndColor};
 208     PaintAffordanceGlow(canvas, center, start_radius, end_radius, colors, pos,
 209         num_colors);
 210
 211     // Paint inner circle.
 212     PaintAffordanceArc(canvas, center, kAffordanceInnerRadius,
 213         kAffordanceInnerStartAngle, -current_angle_);
 214     // Paint outer circle.
 215     PaintAffordanceArc(canvas, center, kAffordanceOuterRadius,
 216         kAffordanceOuterStartAngle, current_angle_);
 217
 218     canvas->Restore();
 219   }
 220
 221   scoped_ptr<views::Widget> widget_;
 222   int current_angle_;
 223   double current_scale_;
 224
 225   DISALLOW_COPY_AND_ASSIGN(LongPressAffordanceView);
 226 };
 227
 228 ////////////////////////////////////////////////////////////////////////////////
 229 // LongPressAffordanceHandler, public
 230
 231 LongPressAffordanceHandler::LongPressAffordanceHandler()
 232     : gfx::LinearAnimation(kAffordanceFrameRateHz, NULL),
 233       tap_down_target_(NULL),
 234       current_animation_type_(NONE) {}
 235
 236 LongPressAffordanceHandler::~LongPressAffordanceHandler() {
 237   StopAffordance();
 238 }
 239
 240 void LongPressAffordanceHandler::ProcessEvent(aura::Window* target,
 241                                               ui::GestureEvent* event) {
 242   // Once we have a target, we are only interested in events with that target.
 243   if (tap_down_target_ && tap_down_target_ != target)
 244     return;
 245   switch (event->type()) {
 246     case ui::ET_GESTURE_TAP_DOWN: {
 247       // Start timer that will start animation on "semi-long-press".
 248       tap_down_location_ = event->root_location();
 249       SetTapDownTarget(target);
 250       current_animation_type_ = GROW_ANIMATION;
 251       timer_.Start(FROM_HERE,
 252                    base::TimeDelta::FromMilliseconds(
 253                        ui::GestureConfiguration::GetInstance()
 254                            ->semi_long_press_time_in_ms()),
 255                    this,
 256                    &LongPressAffordanceHandler::StartAnimation);
 257       break;
 258     }
 259     case ui::ET_GESTURE_TAP:
 260     case ui::ET_GESTURE_TAP_CANCEL:
 261       StopAffordance();
 262       break;
 263     case ui::ET_GESTURE_LONG_PRESS:
 264       End();
 265       break;
 266     default:
 267       break;
 268   }
 269 }
 270
 271 ////////////////////////////////////////////////////////////////////////////////
 272 // LongPressAffordanceHandler, private
 273
 274 void LongPressAffordanceHandler::StartAnimation() {
 275   switch (current_animation_type_) {
 276     case GROW_ANIMATION: {
 277       aura::Window* root_window = tap_down_target_->GetRootWindow();
 278       if (!root_window) {
 279         StopAffordance();
 280         return;
 281       }
 282       view_.reset(new LongPressAffordanceView(tap_down_location_, root_window));
 283       SetDuration(
 284           ui::GestureConfiguration::GetInstance()->long_press_time_in_ms() -
 285           ui::GestureConfiguration::GetInstance()
 286               ->semi_long_press_time_in_ms() -
 287           kAffordanceDelayBeforeShrinkMs);
 288       Start();
 289       break;
 290     }
 291     case SHRINK_ANIMATION:
 292       SetDuration(kAffordanceShrinkAnimationDurationMs);
 293       Start();
 294       break;
 295     default:
 296       NOTREACHED();
 297       break;
 298   }
 299 }
 300
 301 void LongPressAffordanceHandler::StopAffordance() {
 302   if (timer_.IsRunning())
 303     timer_.Stop();
 304   // Since, Animation::Stop() calls AnimationStopped(), we need to reset the
 305   // |current_animation_type_| before Stop(), otherwise AnimationStopped() may
 306   // start the timer again.
 307   current_animation_type_ = NONE;
 308   Stop();
 309   view_.reset();
 310   SetTapDownTarget(NULL);
 311 }
 312
 313 void LongPressAffordanceHandler::SetTapDownTarget(aura::Window* target) {
 314   if (tap_down_target_ == target)
 315     return;
 316
 317   if (tap_down_target_)
 318     tap_down_target_->RemoveObserver(this);
 319   tap_down_target_ = target;
 320   if (tap_down_target_)
 321     tap_down_target_->AddObserver(this);
 322 }
 323
 324 void LongPressAffordanceHandler::AnimateToState(double state) {
 325   DCHECK(view_.get());
 326   switch (current_animation_type_) {
 327     case GROW_ANIMATION:
 328       view_->UpdateWithGrowAnimation(this);
 329       break;
 330     case SHRINK_ANIMATION:
 331       view_->UpdateWithShrinkAnimation(this);
 332       break;
 333     default:
 334       NOTREACHED();
 335       break;
 336   }
 337 }
 338
 339 void LongPressAffordanceHandler::AnimationStopped() {
 340   switch (current_animation_type_) {
 341     case GROW_ANIMATION:
 342       current_animation_type_ = SHRINK_ANIMATION;
 343       timer_.Start(FROM_HERE,
 344           base::TimeDelta::FromMilliseconds(kAffordanceDelayBeforeShrinkMs),
 345           this, &LongPressAffordanceHandler::StartAnimation);
 346       break;
 347     case SHRINK_ANIMATION:
 348       current_animation_type_ = NONE;
 349       // fall through to reset the view.
 350     default:
 351       view_.reset();
 352       SetTapDownTarget(NULL);
 353       break;
 354   }
 355 }
 356
 357 void LongPressAffordanceHandler::OnWindowDestroying(aura::Window* window) {
 358   DCHECK_EQ(tap_down_target_, window);
 359   StopAffordance();
 360 }
 361
 362 }  // namespace ash