src/athena/wm/split_view_controller.cc

   1 // Copyright 2014 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 "athena/wm/split_view_controller.h"
   6
   7 #include <cmath>
   8
   9 #include "athena/screen/public/screen_manager.h"
  10 #include "athena/wm/public/window_list_provider.h"
  11 #include "athena/wm/public/window_manager.h"
  12 #include "base/bind.h"
  13 #include "ui/aura/scoped_window_targeter.h"
  14 #include "ui/aura/window.h"
  15 #include "ui/aura/window_targeter.h"
  16 #include "ui/compositor/closure_animation_observer.h"
  17 #include "ui/compositor/layer.h"
  18 #include "ui/compositor/scoped_layer_animation_settings.h"
  19 #include "ui/events/event_handler.h"
  20 #include "ui/gfx/display.h"
  21 #include "ui/gfx/screen.h"
  22 #include "ui/views/background.h"
  23 #include "ui/views/layout/box_layout.h"
  24 #include "ui/views/widget/root_view.h"
  25 #include "ui/views/widget/root_view_targeter.h"
  26 #include "ui/views/widget/widget.h"
  27 #include "ui/wm/core/window_util.h"
  28 #include "ui/wm/public/activation_client.h"
  29
  30 namespace athena {
  31
  32 namespace {
  33
  34 const int kDragHandleWidth = 4;
  35 const int kDragHandleHeight = 80;
  36 const int kDragHandleMargin = 1;
  37 const int kDividerWidth = kDragHandleWidth + 2 * kDragHandleMargin;
  38
  39 // Always returns the same target.
  40 class StaticViewTargeterDelegate : public views::ViewTargeterDelegate {
  41  public:
  42   explicit StaticViewTargeterDelegate(views::View* target) : target_(target) {}
  43
  44   virtual ~StaticViewTargeterDelegate() {}
  45
  46  private:
  47   // views::ViewTargeterDelegate:
  48   virtual views::View* TargetForRect(views::View* root,
  49                                      const gfx::Rect& rect) OVERRIDE {
  50     return target_;
  51   }
  52
  53   // Not owned.
  54   views::View* target_;
  55
  56   DISALLOW_COPY_AND_ASSIGN(StaticViewTargeterDelegate);
  57 };
  58
  59 // Expands the effective target area of the window of the widget containing the
  60 // specified view. If the view is large enough to begin with, there should be
  61 // no change from the default targeting behavior.
  62 class PriorityWindowTargeter : public aura::WindowTargeter,
  63                                public aura::WindowObserver {
  64  public:
  65   explicit PriorityWindowTargeter(views::View* priority_view)
  66       : priority_view_(priority_view) {
  67     CHECK(priority_view->GetWidget());
  68     window_ = priority_view->GetWidget()->GetNativeWindow();
  69     CHECK(window_);
  70     window_->AddObserver(this);
  71   }
  72
  73   virtual ~PriorityWindowTargeter() {
  74     window_->RemoveObserver(this);
  75   }
  76
  77  private:
  78   // aura::WindowTargeter:
  79   virtual ui::EventTarget* FindTargetForLocatedEvent(
  80       ui::EventTarget* root,
  81       ui::LocatedEvent* event) OVERRIDE {
  82     if (!window_ || (event->type() != ui::ET_TOUCH_PRESSED))
  83       return WindowTargeter::FindTargetForLocatedEvent(root, event);
  84     CHECK_EQ(window_, priority_view_->GetWidget()->GetNativeWindow());
  85
  86     // Bounds of the view in root window's coordinates.
  87     gfx::Rect view_bounds = priority_view_->GetBoundsInScreen();
  88     // If there is a transform on the window's layer - apply it.
  89     gfx::Transform window_transform = window_->layer()->transform();
  90     gfx::RectF transformed_bounds_f = view_bounds;
  91     window_transform.TransformRect(&transformed_bounds_f);
  92     gfx::Rect transformed_bounds = gfx::Rect(transformed_bounds_f.x(),
  93                                              transformed_bounds_f.y(),
  94                                              transformed_bounds_f.width(),
  95                                              transformed_bounds_f.height());
  96     // Now expand the bounds to be at least
  97     // kMinTouchDimension x kMinTouchDimension and target the event to the
  98     // window if it falls within the expanded bounds
  99     gfx::Point center = transformed_bounds.CenterPoint();
 100     gfx::Rect extension_rect = gfx::Rect(
 101         center.x() - kMinTouchDimension / 2,
 102         center.y() - kMinTouchDimension / 2,
 103         kMinTouchDimension,
 104         kMinTouchDimension);
 105     gfx::Rect extended_bounds =
 106         gfx::UnionRects(transformed_bounds, extension_rect);
 107     if (extended_bounds.Contains(event->root_location())) {
 108       root->ConvertEventToTarget(window_, event);
 109       return window_;
 110     }
 111
 112     return WindowTargeter::FindTargetForLocatedEvent(root, event);
 113   }
 114
 115   // aura::WindowObserver:
 116   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE {
 117     DCHECK_EQ(window, window_);
 118     window_->RemoveObserver(this);
 119     window_ = NULL;
 120   }
 121
 122   // Minimum dimension of a target to be comfortably touchable.
 123   // The effective touch target area of |priority_window_| gets expanded so
 124   // that it's width and height is ayt least |kMinTouchDimension|.
 125   int const kMinTouchDimension = 26;
 126
 127   aura::Window* window_;
 128   views::View* priority_view_;
 129
 130   DISALLOW_COPY_AND_ASSIGN(PriorityWindowTargeter);
 131 };
 132
 133 // Returns a target transform required to transform |from| to |to|.
 134 gfx::Transform GetTransformForBounds(const gfx::Rect& from,
 135                                      const gfx::Rect& to) {
 136   gfx::Transform transform;
 137   transform.Translate(to.x() - from.x(), to.y() - from.y());
 138   transform.Scale(to.width() / static_cast<float>(from.width()),
 139                   to.height() / static_cast<float>(from.height()));
 140   return transform;
 141 }
 142
 143 bool IsLandscapeOrientation(gfx::Display::Rotation rotation) {
 144   return rotation == gfx::Display::ROTATE_0 ||
 145          rotation == gfx::Display::ROTATE_180;
 146 }
 147
 148 }  // namespace
 149
 150 SplitViewController::SplitViewController(
 151     aura::Window* container,
 152     WindowListProvider* window_list_provider)
 153     : state_(INACTIVE),
 154       container_(container),
 155       window_list_provider_(window_list_provider),
 156       left_window_(NULL),
 157       right_window_(NULL),
 158       divider_position_(0),
 159       divider_scroll_start_position_(0),
 160       divider_widget_(NULL),
 161       drag_handle_(NULL),
 162       weak_factory_(this) {
 163 }
 164
 165 SplitViewController::~SplitViewController() {
 166 }
 167
 168 bool SplitViewController::CanActivateSplitViewMode() const {
 169   // TODO(mfomitchev): return false in full screen.
 170   return (!IsSplitViewModeActive() &&
 171               window_list_provider_->GetWindowList().size() >= 2 &&
 172               IsLandscapeOrientation(gfx::Screen::GetNativeScreen()->
 173                   GetDisplayNearestWindow(container_).rotation()));
 174 }
 175
 176 bool SplitViewController::IsSplitViewModeActive() const {
 177   return state_ == ACTIVE;
 178 }
 179
 180 void SplitViewController::ActivateSplitMode(aura::Window* left,
 181                                             aura::Window* right,
 182                                             aura::Window* to_activate) {
 183   const aura::Window::Windows& windows = window_list_provider_->GetWindowList();
 184   aura::Window::Windows::const_reverse_iterator iter = windows.rbegin();
 185   if (state_ == ACTIVE) {
 186     if (!left && left_window_ != right)
 187       left = left_window_;
 188     if (!right && right_window_ != left)
 189       right = right_window_;
 190   }
 191
 192   if (!left && iter != windows.rend()) {
 193     left = *iter;
 194     iter++;
 195     if (left == right && iter != windows.rend()) {
 196       left = *iter;
 197       iter++;
 198     }
 199   }
 200
 201   if (!right && iter != windows.rend()) {
 202     right = *iter;
 203     iter++;
 204     if (right == left && iter != windows.rend()) {
 205       right = *iter;
 206       iter++;
 207     }
 208   }
 209
 210   to_hide_.clear();
 211   if (left_window_ && left_window_ != left && left_window_ != right)
 212     to_hide_.push_back(left_window_);
 213   if (right_window_ && right_window_ != left && right_window_ != right)
 214     to_hide_.push_back(right_window_);
 215
 216   left_window_ = left;
 217   right_window_ = right;
 218
 219   divider_position_ = GetDefaultDividerPosition();
 220   SetState(ACTIVE);
 221   UpdateLayout(true);
 222
 223   aura::client::ActivationClient* activation_client =
 224       aura::client::GetActivationClient(container_->GetRootWindow());
 225   aura::Window* active_window = activation_client->GetActiveWindow();
 226   if (to_activate) {
 227     CHECK(to_activate == left_window_ || to_activate == right_window_);
 228     wm::ActivateWindow(to_activate);
 229   } else if (active_window != left_window_ &&
 230              active_window != right_window_) {
 231     // A window which does not belong to an activity could be active.
 232     wm::ActivateWindow(left_window_);
 233   }
 234   active_window = activation_client->GetActiveWindow();
 235
 236   if (active_window == left_window_)
 237     window_list_provider_->StackWindowBehindTo(right_window_, left_window_);
 238   else
 239     window_list_provider_->StackWindowBehindTo(left_window_, right_window_);
 240 }
 241
 242 void SplitViewController::ReplaceWindow(aura::Window* window,
 243                                         aura::Window* replace_with) {
 244   CHECK(IsSplitViewModeActive());
 245   CHECK(replace_with);
 246   CHECK(window == left_window_ || window == right_window_);
 247   CHECK(replace_with != left_window_ && replace_with != right_window_);
 248   DCHECK(window_list_provider_->IsWindowInList(replace_with));
 249
 250   aura::Window* not_replaced = NULL;
 251   if (window == left_window_) {
 252     left_window_ = replace_with;
 253     not_replaced = right_window_;
 254   } else {
 255     right_window_ = replace_with;
 256     not_replaced = left_window_;
 257   }
 258   UpdateLayout(false);
 259
 260   wm::ActivateWindow(replace_with);
 261   window_list_provider_->StackWindowBehindTo(not_replaced, replace_with);
 262
 263   window->SetTransform(gfx::Transform());
 264   window->Hide();
 265 }
 266
 267 void SplitViewController::DeactivateSplitMode() {
 268   CHECK_EQ(ACTIVE, state_);
 269   SetState(INACTIVE);
 270   UpdateLayout(false);
 271   left_window_ = right_window_ = NULL;
 272 }
 273
 274 void SplitViewController::InitializeDivider() {
 275   CHECK(!divider_widget_);
 276   CHECK(!drag_handle_);
 277
 278   drag_handle_ = CreateDragHandleView(DRAG_HANDLE_HORIZONTAL,
 279                                       this,
 280                                       kDragHandleWidth,
 281                                       kDragHandleHeight);
 282   views::View* content_view = new views::View;
 283   content_view->set_background(
 284       views::Background::CreateSolidBackground(SK_ColorBLACK));
 285   views::BoxLayout* layout =
 286       new views::BoxLayout(views::BoxLayout::kHorizontal,
 287                            kDragHandleMargin,
 288                            kDragHandleMargin,
 289                            0);
 290   layout->set_main_axis_alignment(views::BoxLayout::MAIN_AXIS_ALIGNMENT_CENTER);
 291   layout->set_cross_axis_alignment(
 292       views::BoxLayout::CROSS_AXIS_ALIGNMENT_CENTER);
 293   content_view->SetLayoutManager(layout);
 294   content_view->AddChildView(drag_handle_);
 295
 296   divider_widget_ = new views::Widget();
 297   views::Widget::InitParams params(views::Widget::InitParams::TYPE_POPUP);
 298   params.parent = container_;
 299   params.bounds = gfx::Rect(-kDividerWidth / 2,
 300                             0,
 301                             kDividerWidth,
 302                             container_->bounds().height());
 303   divider_widget_->Init(params);
 304   divider_widget_->SetContentsView(content_view);
 305
 306   // Install a static view targeter on the root view which always targets
 307   // divider_view.
 308   // TODO(mfomitchev,tdanderson): This should not be needed:
 309   // 1. crbug.com/414339 - divider_view is the only view and it completely
 310   //    overlaps the root view.
 311   // 2. The logic in ViewTargeterDelegate::TargetForRect could be improved to
 312   //    work better for views that are narrow in one dimension and long in
 313   //    another dimension.
 314   views::internal::RootView* root_view =
 315       static_cast<views::internal::RootView*>(divider_widget_->GetRootView());
 316   view_targeter_delegate_.reset(new StaticViewTargeterDelegate(drag_handle_));
 317   views::ViewTargeter* targeter =
 318       new views::RootViewTargeter(view_targeter_delegate_.get(), root_view);
 319   divider_widget_->GetRootView()->SetEventTargeter(
 320       scoped_ptr<views::ViewTargeter>(targeter));
 321 }
 322
 323 void SplitViewController::HideDivider() {
 324   divider_widget_->Hide();
 325   window_targeter_.reset();
 326 }
 327
 328 void SplitViewController::ShowDivider() {
 329   divider_widget_->Show();
 330   if (!window_targeter_) {
 331     scoped_ptr<ui::EventTargeter> window_targeter =
 332         scoped_ptr<ui::EventTargeter>(new PriorityWindowTargeter(drag_handle_));
 333     window_targeter_.reset(
 334         new aura::ScopedWindowTargeter(container_, window_targeter.Pass()));
 335   }
 336 }
 337
 338 gfx::Rect SplitViewController::GetLeftAreaBounds() {
 339   gfx::Rect work_area =
 340       gfx::Screen::GetNativeScreen()->GetPrimaryDisplay().work_area();
 341   return gfx::Rect(
 342       0, 0, divider_position_ - kDividerWidth / 2, work_area.height());
 343 }
 344
 345 gfx::Rect SplitViewController::GetRightAreaBounds() {
 346   gfx::Rect work_area =
 347       gfx::Screen::GetNativeScreen()->GetPrimaryDisplay().work_area();
 348   int container_width = container_->bounds().width();
 349   return gfx::Rect(divider_position_ + kDividerWidth / 2,
 350                    0,
 351                    container_width - divider_position_ - kDividerWidth / 2,
 352                    work_area.height());
 353 }
 354
 355 void SplitViewController::SetState(SplitViewController::State state) {
 356   if (state_ == state)
 357     return;
 358
 359   if (divider_widget_ == NULL)
 360     InitializeDivider();
 361
 362   state_ = state;
 363
 364   ScreenManager::Get()->SetRotationLocked(state_ != INACTIVE);
 365   if (state == INACTIVE)
 366     HideDivider();
 367   else
 368     ShowDivider();
 369 }
 370
 371 void SplitViewController::UpdateLayout(bool animate) {
 372   CHECK(left_window_);
 373   CHECK(right_window_);
 374   // Splitview can be activated from SplitViewController::ActivateSplitMode or
 375   // SplitViewController::ScrollEnd. Additionally we don't want to rotate the
 376   // screen while engaging splitview (i.e. state_ == SCROLLING).
 377   if (state_ == INACTIVE && !animate) {
 378     gfx::Rect work_area =
 379         gfx::Screen::GetNativeScreen()->GetPrimaryDisplay().work_area();
 380     aura::Window* top_window = window_list_provider_->GetWindowList().back();
 381     if (top_window != left_window_) {
 382       // TODO(mfomitchev): Use to_hide_ instead
 383       left_window_->Hide();
 384       right_window_->SetBounds(gfx::Rect(work_area.size()));
 385     }
 386     if (top_window != right_window_) {
 387       left_window_->SetBounds(gfx::Rect(work_area.size()));
 388       // TODO(mfomitchev): Use to_hide_ instead
 389       right_window_->Hide();
 390     }
 391     SetWindowTransforms(
 392         gfx::Transform(), gfx::Transform(), gfx::Transform(), false);
 393     return;
 394   }
 395
 396   left_window_->Show();
 397   right_window_->Show();
 398
 399   gfx::Transform divider_transform;
 400   divider_transform.Translate(divider_position_, 0);
 401   if (state_ == ACTIVE) {
 402     if (animate) {
 403       gfx::Transform left_transform =
 404           GetTransformForBounds(left_window_->bounds(), GetLeftAreaBounds());
 405       gfx::Transform right_transform =
 406           GetTransformForBounds(right_window_->bounds(), GetRightAreaBounds());
 407       SetWindowTransforms(
 408           left_transform, right_transform, divider_transform, true);
 409     } else {
 410       left_window_->SetBounds(GetLeftAreaBounds());
 411       right_window_->SetBounds(GetRightAreaBounds());
 412       SetWindowTransforms(
 413           gfx::Transform(), gfx::Transform(), divider_transform, false);
 414     }
 415   } else {
 416     gfx::Transform left_transform;
 417     gfx::Transform right_transform;
 418     gfx::Rect left_area_bounds = GetLeftAreaBounds();
 419     gfx::Rect right_area_bounds = GetRightAreaBounds();
 420     // If the width of the window is greater than the width of the area which it
 421     // is supposed to occupy - translate the window. Otherwise scale the window
 422     // up to fill the target area.
 423     if (left_window_->bounds().width() >= left_area_bounds.width()) {
 424       left_transform.Translate(
 425           left_area_bounds.right() - left_window_->bounds().right(), 0);
 426     } else {
 427       left_transform =
 428           GetTransformForBounds(left_window_->bounds(), left_area_bounds);
 429     }
 430     if (right_window_->bounds().width() >= right_area_bounds.width()) {
 431       right_transform.Translate(
 432           right_area_bounds.x() - right_window_->bounds().x(), 0);
 433     } else {
 434       right_transform =
 435           GetTransformForBounds(right_window_->bounds(), right_area_bounds);
 436     }
 437     SetWindowTransforms(
 438         left_transform, right_transform, divider_transform, animate);
 439   }
 440   // Note: |left_window_| and |right_window_| may be NULL if calling
 441   // SetWindowTransforms():
 442   // - caused the in-progress animation to abort.
 443   // - started a zero duration animation.
 444 }
 445
 446 void SplitViewController::SetWindowTransforms(
 447     const gfx::Transform& left_transform,
 448     const gfx::Transform& right_transform,
 449     const gfx::Transform& divider_transform,
 450     bool animate) {
 451   if (animate) {
 452     ui::ScopedLayerAnimationSettings left_settings(
 453         left_window_->layer()->GetAnimator());
 454     left_settings.SetPreemptionStrategy(
 455         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 456     left_window_->SetTransform(left_transform);
 457
 458     ui::ScopedLayerAnimationSettings divider_widget_settings(
 459         divider_widget_->GetNativeWindow()->layer()->GetAnimator());
 460     divider_widget_settings.SetPreemptionStrategy(
 461         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 462     divider_widget_->GetNativeWindow()->SetTransform(divider_transform);
 463
 464     ui::ScopedLayerAnimationSettings right_settings(
 465         right_window_->layer()->GetAnimator());
 466     right_settings.SetPreemptionStrategy(
 467         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 468     right_settings.AddObserver(new ui::ClosureAnimationObserver(
 469         base::Bind(&SplitViewController::OnAnimationCompleted,
 470                    weak_factory_.GetWeakPtr())));
 471     right_window_->SetTransform(right_transform);
 472   } else {
 473     left_window_->SetTransform(left_transform);
 474     divider_widget_->GetNativeWindow()->SetTransform(divider_transform);
 475     right_window_->SetTransform(right_transform);
 476   }
 477 }
 478
 479 void SplitViewController::OnAnimationCompleted() {
 480   // Animation can be cancelled when deactivated.
 481   if (left_window_ == NULL)
 482     return;
 483   UpdateLayout(false);
 484
 485   for (size_t i = 0; i < to_hide_.size(); ++i)
 486     to_hide_[i]->Hide();
 487   to_hide_.clear();
 488
 489   if (state_ == INACTIVE) {
 490     left_window_ = NULL;
 491     right_window_ = NULL;
 492   }
 493 }
 494
 495 int SplitViewController::GetDefaultDividerPosition() {
 496   return container_->GetBoundsInScreen().width() / 2;
 497 }
 498
 499 ///////////////////////////////////////////////////////////////////////////////
 500 // BezelController::ScrollDelegate:
 501
 502 void SplitViewController::BezelScrollBegin(BezelController::Bezel bezel,
 503                                            float delta) {
 504   if (!BezelCanScroll())
 505     return;
 506
 507   SetState(SCROLLING);
 508
 509   const aura::Window::Windows& windows = window_list_provider_->GetWindowList();
 510   CHECK(windows.size() >= 2);
 511   aura::Window::Windows::const_reverse_iterator iter = windows.rbegin();
 512   aura::Window* current_window = *(iter);
 513
 514   if (delta > 0) {
 515     right_window_ = current_window;
 516     left_window_ = *(iter + 1);
 517   } else {
 518     left_window_ = current_window;
 519     right_window_ = *(iter + 1);
 520   }
 521
 522   CHECK(left_window_);
 523   CHECK(right_window_);
 524
 525   // Calculate divider_scroll_start_position_
 526   gfx::Screen* screen = gfx::Screen::GetScreenFor(container_);
 527   const gfx::Rect& display_bounds =
 528       screen->GetDisplayNearestWindow(container_).bounds();
 529   gfx::Rect container_bounds = container_->GetBoundsInScreen();
 530   divider_scroll_start_position_ =
 531       delta > 0 ? display_bounds.x() - container_bounds.x()
 532                 : display_bounds.right() - container_bounds.x();
 533
 534   divider_position_ = divider_scroll_start_position_ + delta;
 535   UpdateLayout(false);
 536 }
 537
 538 void SplitViewController::BezelScrollEnd() {
 539   if (state_ != SCROLLING)
 540     return;
 541
 542   // Max distance from the scroll end position to the middle of the screen where
 543   // we would go into the split view mode.
 544   const int kMaxDistanceFromMiddle = 120;
 545   const int default_divider_position = GetDefaultDividerPosition();
 546   if (std::abs(default_divider_position - divider_position_) <=
 547       kMaxDistanceFromMiddle) {
 548     divider_position_ = default_divider_position;
 549     SetState(ACTIVE);
 550   } else if (divider_position_ < default_divider_position) {
 551     divider_position_ = 0;
 552     SetState(INACTIVE);
 553     wm::ActivateWindow(right_window_);
 554   } else {
 555     divider_position_ = container_->GetBoundsInScreen().width();
 556     SetState(INACTIVE);
 557     wm::ActivateWindow(left_window_);
 558   }
 559   UpdateLayout(true);
 560 }
 561
 562 void SplitViewController::BezelScrollUpdate(float delta) {
 563   if (state_ != SCROLLING)
 564     return;
 565   divider_position_ = divider_scroll_start_position_ + delta;
 566   UpdateLayout(false);
 567 }
 568
 569 bool SplitViewController::BezelCanScroll() {
 570   return CanActivateSplitViewMode();
 571 }
 572
 573 ///////////////////////////////////////////////////////////////////////////////
 574 // DragHandleScrollDelegate:
 575
 576 void SplitViewController::HandleScrollBegin(float delta) {
 577   CHECK(state_ == ACTIVE);
 578   state_ = SCROLLING;
 579   divider_scroll_start_position_ = GetDefaultDividerPosition();
 580   divider_position_ = divider_scroll_start_position_ + delta;
 581   UpdateLayout(false);
 582 }
 583
 584 void SplitViewController::HandleScrollEnd() {
 585   BezelScrollEnd();
 586 }
 587
 588 void SplitViewController::HandleScrollUpdate(float delta) {
 589   BezelScrollUpdate(delta);
 590 }
 591
 592 ///////////////////////////////////////////////////////////////////////////////
 593 // WindowManagerObserver:
 594
 595 void SplitViewController::OnOverviewModeEnter() {
 596   if (divider_widget_)
 597     HideDivider();
 598 }
 599
 600 void SplitViewController::OnOverviewModeExit() {
 601   if (state_ != INACTIVE)
 602     ShowDivider();
 603 }
 604
 605 void SplitViewController::OnSplitViewModeEnter() {
 606 }
 607
 608 void SplitViewController::OnSplitViewModeExit() {
 609 }
 610
 611 }  // namespace athena