Added arrow key navigation to Overview Mode

ash/wm/overview/window_selector.cc

 // Copyright 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/wm/overview/window_selector.h"
 
 #include <algorithm>
 
 #include "ash/accessibility_delegate.h"
 #include "ash/ash_switches.h"
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/root_window_controller.h"
-#include "ash/screen_util.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/switchable_windows.h"
 #include "ash/wm/overview/scoped_transform_overview_window.h"
+#include "ash/wm/overview/window_grid.h"
 #include "ash/wm/overview/window_selector_delegate.h"
 #include "ash/wm/overview/window_selector_item.h"
 #include "ash/wm/overview/window_selector_panels.h"
 #include "ash/wm/overview/window_selector_window.h"
 #include "ash/wm/window_state.h"
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/aura/client/cursor_client.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_observer.h"
-#include "ui/compositor/layer_animation_observer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/events/event.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/background.h"
 #include "ui/views/widget/widget.h"
 #include "ui/wm/core/window_util.h"
 #include "ui/wm/public/activation_client.h"
 
 namespace ash {
 
 namespace {
 
-// Conceptually the window overview is a table or grid of cells having this
-// fixed aspect ratio. The number of columns is determined by maximizing the
-// area of them based on the number of windows.
-const float kCardAspectRatio = 4.0f / 3.0f;
-
-// In the conceptual overview table, the window margin is the space reserved
-// around the window within the cell. This margin does not overlap so the
-// closest distance between adjacent windows will be twice this amount.
-const int kWindowMargin = 30;
-
-// The minimum number of cards along the major axis (i.e. horizontally on a
-// landscape orientation).
-const int kMinCardsMajor = 3;
-
-// A comparator for locating a given target window.
-struct WindowSelectorItemComparator
-    : public std::unary_function<WindowSelectorItem*, bool> {
-  explicit WindowSelectorItemComparator(const aura::Window* target_window)
-      : target(target_window) {
+// A comparator for locating a grid with a given root window.
+struct RootWindowGridComparator
+    : public std::unary_function<WindowGrid*, bool> {
+  explicit RootWindowGridComparator(const aura::Window* root_window)
+      : root_window_(root_window) {
   }
 
-  bool operator()(WindowSelectorItem* window) const {
-    return window->HasSelectableWindow(target);
+  bool operator()(WindowGrid* grid) const {
+    return (grid->root_window() == root_window_);
   }
 
-  const aura::Window* target;
+  const aura::Window* root_window_;
 };
 
-// An observer which holds onto the passed widget until the animation is
-// complete.
-class CleanupWidgetAfterAnimationObserver : public ui::LayerAnimationObserver {
- public:
-  explicit CleanupWidgetAfterAnimationObserver(
-      scoped_ptr<views::Widget> widget);
-
-  // ui::LayerAnimationObserver:
-  virtual void OnLayerAnimationEnded(
-      ui::LayerAnimationSequence* sequence) OVERRIDE;
-  virtual void OnLayerAnimationAborted(
-      ui::LayerAnimationSequence* sequence) OVERRIDE;
-  virtual void OnLayerAnimationScheduled(
-      ui::LayerAnimationSequence* sequence) OVERRIDE;
-
- private:
-  virtual ~CleanupWidgetAfterAnimationObserver();
-
-  scoped_ptr<views::Widget> widget_;
-
-  DISALLOW_COPY_AND_ASSIGN(CleanupWidgetAfterAnimationObserver);
-};
-
-CleanupWidgetAfterAnimationObserver::CleanupWidgetAfterAnimationObserver(
-    scoped_ptr<views::Widget> widget)
-    : widget_(widget.Pass()) {
-  widget_->GetNativeWindow()->layer()->GetAnimator()->AddObserver(this);
-}
-
-CleanupWidgetAfterAnimationObserver::~CleanupWidgetAfterAnimationObserver() {
-  widget_->GetNativeWindow()->layer()->GetAnimator()->RemoveObserver(this);
-}
-
-void CleanupWidgetAfterAnimationObserver::OnLayerAnimationEnded(
-    ui::LayerAnimationSequence* sequence) {
-  delete this;
-}
-
-void CleanupWidgetAfterAnimationObserver::OnLayerAnimationAborted(
-    ui::LayerAnimationSequence* sequence) {
-  delete this;
-}
-
-void CleanupWidgetAfterAnimationObserver::OnLayerAnimationScheduled(
-    ui::LayerAnimationSequence* sequence) {
-}
-
 // A comparator for locating a selectable window given a targeted window.
 struct WindowSelectorItemTargetComparator
     : public std::unary_function<WindowSelectorItem*, bool> {
   explicit WindowSelectorItemTargetComparator(const aura::Window* target_window)
       : target(target_window) {
   }
 
   bool operator()(WindowSelectorItem* window) const {
     return window->TargetedWindow(target) != NULL;
   }
@@ skipping 26 matching lines @@
   }
 }
 
 }  // namespace
 
 WindowSelector::WindowSelector(const WindowList& windows,
                                WindowSelectorDelegate* delegate)
     : delegate_(delegate),
       restore_focus_window_(aura::client::GetFocusClient(
           Shell::GetPrimaryRootWindow())->GetFocusedWindow()),
-      ignore_activations_(false) {
+      ignore_activations_(false),
+      root_index_(0) {
   DCHECK(delegate_);
 
   if (restore_focus_window_)
     restore_focus_window_->AddObserver(this);
 
   std::vector<WindowSelectorPanels*> panels_items;
   for (size_t i = 0; i < windows.size(); ++i) {
     WindowSelectorItem* item = NULL;
     if (windows[i] != restore_focus_window_)
       windows[i]->AddObserver(this);
@@ skipping 98 matching lines @@
 void WindowSelector::CancelSelection() {
   delegate_->OnSelectionCanceled();
 }
 
 void WindowSelector::OnKeyEvent(ui::KeyEvent* event) {
   if (GetTargetedWindow(static_cast<aura::Window*>(event->target())))
     event->StopPropagation();
   if (event->type() != ui::ET_KEY_PRESSED)
     return;
 
-  if (event->key_code() == ui::VKEY_ESCAPE)
-    CancelSelection();
+  switch (event->key_code()) {
+    case ui::VKEY_ESCAPE:
+      CancelSelection();
+      break;
+    case ui::VKEY_UP:
+      Move(WindowSelector::UP);

[flackr, 2014/05/29 20:04:25]

I think any of these handled events should set handled or call StopPropagation
on the event.

[Nina, 2014/06/02 22:04:38]

Done.

+      break;
+    case ui::VKEY_DOWN:
+      Move(WindowSelector::DOWN);
+      break;
+    case ui::VKEY_RIGHT:
+      Move(WindowSelector::RIGHT);
+      break;
+    case ui::VKEY_LEFT:
+      Move(WindowSelector::LEFT);
+      break;
+    case ui::VKEY_RETURN:
+      SelectWindow(
+          grid_list_[root_index_]->SelectedWindow()->SelectionWindow());
+      break;
+    default:
+      // Not a key we are interested in.
+      break;
+  }
 }
 
 void WindowSelector::OnMouseEvent(ui::MouseEvent* event) {
   aura::Window* target = GetEventTarget(event);
   if (!target)
     return;
 
   event->SetHandled();
   if (event->type() != ui::ET_MOUSE_RELEASED)
     return;
@@ skipping 48 matching lines @@
     if (new_window->parent()->id() == kSwitchableWindowContainerIds[i] &&
         !::wm::GetTransientParent(new_window)) {
       // The new window is in one of the switchable containers, abort overview.
       CancelSelection();
       return;
     }
   }
 }
 
 void WindowSelector::OnWindowDestroying(aura::Window* window) {
-  // window is one of a container, the restore_focus_window and/or
-  // one of the selectable windows in overview.
-  ScopedVector<WindowSelectorItem>::iterator iter =
-      std::find_if(windows_.begin(), windows_.end(),
-                   WindowSelectorItemComparator(window));
+  WindowSelectorItem* removed_item = NULL;
+
+  // Find the grid corresponding to the window's root window.
+  ScopedVector<WindowGrid>::iterator grid_iter =
+      std::find_if(grid_list_.begin(), grid_list_.end(),
+                   RootWindowGridComparator(window->GetRootWindow()));
+
+  DCHECK(grid_iter != grid_list_.end());
+  removed_item = (*grid_iter)->RemoveWindow(window);
+
   window->RemoveObserver(this);
   observed_windows_.erase(window);
   if (window == restore_focus_window_)
     restore_focus_window_ = NULL;
-  if (iter == windows_.end())
+
+  // If removing the window doesn't cause the removal of an item, we are done.
+  if (!removed_item)
     return;
 
-  (*iter)->RemoveWindow(window);
-  // If there are still windows in this selector entry then the overview is
-  // still active and the active selection remains the same.
-  if (!(*iter)->empty())
-    return;
+  windows_.erase(std::find(windows_.begin(), windows_.end(), removed_item));

[flackr, 2014/05/29 20:04:25]

So we have two vectors of WindowSelectorItem pointers which we need to keep in
sync? Could we instead have the WindowGrid own the items?

[Nina, 2014/06/02 22:04:38]

I refactored the code so that the WindowGrid owns the items. WindowSelector is
still the observer for changes - I think this is an ideal approach. Do you think
the implementation is correct?

 
-  windows_.erase(iter);
-  if (windows_.empty()) {
-    CancelSelection();
-    return;
+  if (grid_iter != grid_list_.end() && (*grid_iter)->empty()) {

[flackr, 2014/05/29 20:04:25]

if we have a removed item, it must have come from grid_iter, why would it no
longer be valid? I think the grid_iter != grid_list_.end() check is unnnecessary
at this point.

[Nina, 2014/06/02 22:04:38]

Done.

+    grid_list_.erase(grid_iter);
+    root_index_ = 0;
+    if (grid_list_.size() == 0)
+      CancelSelection();
   }
-  PositionWindows(true);
 }
 
 void WindowSelector::OnWindowBoundsChanged(aura::Window* window,
                                            const gfx::Rect& old_bounds,
                                            const gfx::Rect& new_bounds) {
   ScopedVector<WindowSelectorItem>::iterator iter =
       std::find_if(windows_.begin(), windows_.end(),
                    WindowSelectorItemTargetComparator(window));
   if (iter == windows_.end())
     return;
@@ skipping 29 matching lines @@
   aura::client::GetFocusClient(
       Shell::GetPrimaryRootWindow())->FocusWindow(NULL);
 
   Shell* shell = Shell::GetInstance();
   shell->OnOverviewModeStarting();
 
   for (WindowSelectorItemList::iterator iter = windows_.begin();
        iter != windows_.end(); ++iter) {
     (*iter)->PrepareForOverview();
   }
-  PositionWindows(/* animate */ true);
+  PositionWindows(true);

[flackr, 2014/05/29 20:04:25]

Why remove the animate comment?

[Nina, 2014/06/02 22:04:38]

Hmmm that slipped. Restored.

   DCHECK(!windows_.empty());
   cursor_client_ = aura::client::GetCursorClient(
       windows_.front()->GetRootWindow());
   if (cursor_client_) {
     cursor_client_->SetCursor(ui::kCursorPointer);
     cursor_client_->ShowCursor();
     // TODO(flackr): Only prevent cursor changes for windows in the overview.
     // This will be easier to do without exposing the overview mode code if the
     // cursor changes are moved to ToplevelWindowEventHandler::HandleMouseMoved
     // as suggested there.
     cursor_client_->LockCursor();
   }
   shell->PrependPreTargetHandler(this);
   shell->GetScreen()->AddObserver(this);
   shell->metrics()->RecordUserMetricsAction(UMA_WINDOW_OVERVIEW);
   HideAndTrackNonOverviewWindows();
   // Send an a11y alert.
   shell->accessibility_delegate()->TriggerAccessibilityAlert(
       A11Y_ALERT_WINDOW_OVERVIEW_MODE_ENTERED);
 
   UpdateShelfVisibility();
 }
 
 void WindowSelector::PositionWindows(bool animate) {
+  grid_list_.clear();

[flackr, 2014/05/29 20:04:25]

Instead of rebuilding grid_list_, can we construct it on creation of
WindowSelector and then have each one manage their windows from that point on?

[Nina, 2014/06/02 22:04:38]

I believe it is still better to handle window activation and display metrics
changes from window_selector, but we can call PositionWindows on the existing
grids. What do you think?

   aura::Window::Windows root_window_list = Shell::GetAllRootWindows();
-  for (size_t i = 0; i < root_window_list.size(); ++i)
-    PositionWindowsFromRoot(root_window_list[i], animate);
-}
-
-void WindowSelector::PositionWindowsFromRoot(aura::Window* root_window,
-                                             bool animate) {
-  std::vector<WindowSelectorItem*> windows;
-  for (WindowSelectorItemList::iterator iter = windows_.begin();
-       iter != windows_.end(); ++iter) {
-    if ((*iter)->GetRootWindow() == root_window)
-      windows.push_back(*iter);
-  }
-
-  if (windows.empty())
-    return;
-
-  gfx::Size window_size;
-  gfx::Rect total_bounds = ScreenUtil::ConvertRectToScreen(
-      root_window,
-      ScreenUtil::GetDisplayWorkAreaBoundsInParent(
-          Shell::GetContainer(root_window, kShellWindowId_DefaultContainer)));
-
-  // Find the minimum number of windows per row that will fit all of the
-  // windows on screen.
-  size_t columns = std::max(
-      total_bounds.width() > total_bounds.height() ? kMinCardsMajor : 1,
-      static_cast<int>(ceil(sqrt(total_bounds.width() * windows.size() /
-                                 (kCardAspectRatio * total_bounds.height())))));
-  size_t rows = ((windows.size() + columns - 1) / columns);
-  window_size.set_width(std::min(
-      static_cast<int>(total_bounds.width() / columns),
-      static_cast<int>(total_bounds.height() * kCardAspectRatio / rows)));
-  window_size.set_height(window_size.width() / kCardAspectRatio);
-
-  // Calculate the X and Y offsets necessary to center the grid.
-  int x_offset = total_bounds.x() + ((windows.size() >= columns ? 0 :
-      (columns - windows.size()) * window_size.width()) +
-      (total_bounds.width() - columns * window_size.width())) / 2;
-  int y_offset = total_bounds.y() + (total_bounds.height() -
-      rows * window_size.height()) / 2;
-  for (size_t i = 0; i < windows.size(); ++i) {
-    gfx::Transform transform;
-    int column = i % columns;
-    int row = i / columns;
-    gfx::Rect target_bounds(window_size.width() * column + x_offset,
-                            window_size.height() * row + y_offset,
-                            window_size.width(),
-                            window_size.height());
-    target_bounds.Inset(kWindowMargin, kWindowMargin);
-    windows[i]->SetBounds(root_window, target_bounds, animate);
+  for (size_t i = 0; i < root_window_list.size(); ++i) {
+    std::vector<WindowSelectorItem*> windows;
+    for (WindowSelectorItemList::iterator iter = windows_.begin();
+         iter != windows_.end(); ++iter) {
+      if ((*iter)->GetRootWindow() == root_window_list[i])
+        windows.push_back(*iter);
+    }
+    if (!windows.empty())
+      grid_list_.push_back(new WindowGrid(root_window_list[i], windows));
   }
 }
 
 void WindowSelector::HideAndTrackNonOverviewWindows() {
   // Add the windows to hidden_windows first so that if any are destroyed
   // while hiding them they are tracked.
   aura::Window::Windows root_windows = Shell::GetAllRootWindows();
   for (aura::Window::Windows::const_iterator root_iter = root_windows.begin();
        root_iter != root_windows.end(); ++root_iter) {
     for (size_t i = 0; i < kSwitchableWindowContainerIdsLength; ++i) {
@@ skipping 59 matching lines @@
 aura::Window* WindowSelector::GetTargetedWindow(aura::Window* window) {
   for (WindowSelectorItemList::iterator iter = windows_.begin();
        iter != windows_.end(); ++iter) {
     aura::Window* selected = (*iter)->TargetedWindow(window);
     if (selected)
       return selected;
   }
   return NULL;
 }
 
+void WindowSelector::Move(Direction direction) {
+  if (!grid_list_[root_index_]->is_selecting()) {
+    grid_list_[root_index_]->CreateSelectionWidget(direction);

[flackr, 2014/05/29 20:04:25]

This seems like something calling GridList::Move could do if it's not created
yet.

[Nina, 2014/06/02 22:04:38]

Done.

+    return;
+  }
+  if (grid_list_[root_index_]->Move(direction)) {
+    // The grid reported that the movement command corresponds to the next
+    // root window, identify it and call Move() on it to initialize the
+    // selection widget.
+    if (root_index_ >= grid_list_.size() - 1)
+      root_index_ = 0;
+    else
+      root_index_++;

[flackr, 2014/05/29 20:04:25]

root_index_ = (root_index + 1) % grid_list_.size() ?

[Nina, 2014/06/02 22:04:38]

Done.

+    grid_list_[root_index_]->CreateSelectionWidget(direction);
+  }
+}
+
 }  // namespace ash