CrOS Tablet Window management - Split Screen part I

ash/wm/overview/window_selector.cc

Index: ash/wm/overview/window_selector.cc
diff --git a/ash/wm/overview/window_selector.cc b/ash/wm/overview/window_selector.cc
index 76bdee5d0a5df0d43b389118d44f1869d3de38f4..632e2457ac7fa1e4699e61fbf2a0a981e89d18de 100644
--- a/ash/wm/overview/window_selector.cc
+++ b/ash/wm/overview/window_selector.cc
@@ -20,10 +20,12 @@
 #include "ash/shell.h"
 #include "ash/shell_port.h"
 #include "ash/wm/mru_window_tracker.h"
+#include "ash/wm/overview/overview_window_drag_controller.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/panels/panel_layout_manager.h"
+#include "ash/wm/splitview/split_view_controller.h"
 #include "ash/wm/switchable_windows.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
@@ -138,13 +140,40 @@ void UpdateShelfVisibility() {
     Shelf::ForWindow(root)->UpdateVisibilityState();
 }
 
+// Returns the bounds for the overview window grids according to the split view
+// state.
+gfx::Rect GetGridsBoundsInScreen(aura::Window* root_window) {
+  gfx::Rect bounds_in_screen;
+  if (Shell::Get()->IsSplitViewModeActive()) {
+    SplitViewController::State state =
+        Shell::Get()->split_view_controller()->state();
+    DCHECK(state != SplitViewController::NOSNAP);
+    if (state == SplitViewController::RIGHT_SNAPPED) {
+      // Open overview in the left side of the screen.
+      bounds_in_screen =
+          Shell::Get()->split_view_controller()->GetLeftWindowBoundsInScreen(

[oshima, 2017/06/14 00:19:27]

it's probably better to have

GetSnappedWindowBoundsInScreen(root_window, snap_state);

[xdai1, 2017/06/15 22:11:41]

Done.

+              root_window);
+    } else if (state == SplitViewController::LEFT_SNAPPED) {
+      // Open overview in the right side of the screen.
+      bounds_in_screen =
+          Shell::Get()->split_view_controller()->GetRightWindowBoundsInScreen(
+              root_window);
+    }
+  } else {
+    bounds_in_screen = ScreenUtil::GetDisplayWorkAreaBoundsInParent(
+        root_window->GetChildById(kShellWindowId_DefaultContainer));
+    ::wm::ConvertRectToScreen(root_window, &bounds_in_screen);
+  }
+
+  return bounds_in_screen;
+}
+
 gfx::Rect GetTextFilterPosition(aura::Window* root_window) {
-  gfx::Rect total_bounds = ScreenUtil::GetDisplayWorkAreaBoundsInParent(
-      root_window->GetChildById(kShellWindowId_DefaultContainer));
-  ::wm::ConvertRectToScreen(root_window, &total_bounds);
+  gfx::Rect total_bounds = GetGridsBoundsInScreen(root_window);
   return gfx::Rect(
       0.5 * (total_bounds.width() -
-             std::min(kTextFilterWidth, total_bounds.width())),
+             std::min(kTextFilterWidth, total_bounds.width())) +
+          total_bounds.x(),
       total_bounds.y() + total_bounds.height() * kTextFilterTopScreenProportion,
       std::min(kTextFilterWidth, total_bounds.width()), kTextFilterHeight);
 }
@@ -271,7 +300,8 @@ void WindowSelector::Init(const WindowList& windows) {
     // root windows that don't contain any panel windows.
     PanelLayoutManager::Get(root)->SetShowCalloutWidgets(false);
 
-    std::unique_ptr<WindowGrid> grid(new WindowGrid(root, windows, this));
+    std::unique_ptr<WindowGrid> grid(
+        new WindowGrid(root, windows, this, GetGridsBoundsInScreen(root)));
     if (grid->empty())
       continue;
     num_items_ += grid->size();
@@ -308,6 +338,7 @@ void WindowSelector::Init(const WindowList& windows) {
   UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.Items", num_items_);
 
   Shell::Get()->activation_client()->AddObserver(this);
+  Shell::Get()->split_view_controller()->AddObserver(this);
 
   display::Screen::GetScreen()->AddObserver(this);
   ShellPort::Get()->RecordUserMetricsAction(UMA_WINDOW_OVERVIEW);
@@ -327,6 +358,11 @@ void WindowSelector::Shutdown() {
   // windows in response to work area changes from window activation.
   display::Screen::GetScreen()->RemoveObserver(this);
 
+  // Stop observing split view state changes before restoring window focus.
+  // Otherwise the activation of the window triggers OnSplitViewStateChanged()
+  // that will call into this function again.
+  Shell::Get()->split_view_controller()->RemoveObserver(this);
+
   size_t remaining_items = 0;
   for (std::unique_ptr<WindowGrid>& window_grid : grid_list_) {
     for (const auto& window_selector_item : window_grid->window_list())
@@ -446,6 +482,45 @@ void WindowSelector::WindowClosing(WindowSelectorItem* window) {
   grid_list_[selected_grid_index_]->WindowClosing(window);
 }
 
+void WindowSelector::SetBoundsForWindowGridsInScreen(const gfx::Rect bounds) {
+  for (std::unique_ptr<WindowGrid>& grid : grid_list_)
+    grid->SetBoundsInScreen(bounds);
+}
+
+void WindowSelector::RemoveWindowSelectorItem(WindowSelectorItem* item) {
+  if (item->GetWindow()->HasObserver(this)) {
+    item->GetWindow()->RemoveObserver(this);
+    observed_windows_.erase(item->GetWindow());
+    if (item->GetWindow() == restore_focus_window_)
+      restore_focus_window_ = nullptr;
+  }
+
+  // Remove |item| from the corresponding grid.
+  for (std::unique_ptr<WindowGrid>& grid : grid_list_) {
+    if (grid->Contains(item->GetWindow())) {
+      grid->RemoveItem(item);
+      break;
+    }
+  }
+}
+
+void WindowSelector::InitiateDrag(WindowSelectorItem* item,
+                                  const gfx::Point& location_in_screen) {
+  window_drag_controller_.reset(new OverviewWindowDragController(this));

[oshima, 2017/06/14 00:19:27]

MakeUnique

[xdai1, 2017/06/15 22:11:42]

reset is better here since |window_drag_controller_| might not be nullptr?

+  window_drag_controller_->InitiateDrag(item, location_in_screen);
+}
+
+void WindowSelector::Drag(WindowSelectorItem* item,
+                          const gfx::Point& location_in_screen) {
+  DCHECK(window_drag_controller_.get());

[oshima, 2017/06/14 00:19:27]

it'll crash immediately, so you don't need this.

[xdai1, 2017/06/15 22:11:41]

I don't understand. Why will it crash immediately? 

+  window_drag_controller_->Drag(item, location_in_screen);
+}
+
+void WindowSelector::CompleteDrag(WindowSelectorItem* item) {
+  DCHECK(window_drag_controller_.get());

[oshima, 2017/06/14 00:19:27]

same here

[xdai1, 2017/06/15 22:11:41]

ditto

+  window_drag_controller_->CompleteDrag(item);
+}
+
 bool WindowSelector::HandleKeyEvent(views::Textfield* sender,
                                     const ui::KeyEvent& key_event) {
   if (key_event.type() != ui::ET_KEY_PRESSED)
@@ -512,6 +587,11 @@ void WindowSelector::OnDisplayRemoved(const display::Display& display) {
 
 void WindowSelector::OnDisplayMetricsChanged(const display::Display& display,
                                              uint32_t metrics) {
+  // Re-calculate the bounds for the window grids and position all the windows.
+  for (std::unique_ptr<WindowGrid>& grid : grid_list_) {
+    SetBoundsForWindowGridsInScreen(
+        GetGridsBoundsInScreen(const_cast<aura::Window*>(grid->root_window())));
+  }
   PositionWindows(/* animate */ false);
   RepositionTextFilterOnDisplayMetricsChange();
 }
@@ -574,6 +654,9 @@ void WindowSelector::OnWindowActivated(ActivationReason reason,
     return;
   }
 
+  if (Shell::Get()->IsSplitViewModeActive())
+    return;

[oshima, 2017/06/14 00:19:27]

not clear to me why you need this. Can you elaborate?

[xdai1, 2017/06/15 22:11:41]

The window activation might be caused by window snap. In this case we should not
cancel overview mode. 

Only when two windows are both snapped to both sides of the screen, the overview
mode should be cancelled, and this logic is addressed in line 718-719 in this
patch.

+
   // Don't restore focus on exit if a window was just activated.
   ResetFocusRestoreWindow(false);
   CancelSelection();
@@ -624,8 +707,34 @@ void WindowSelector::ContentsChanged(views::Textfield* sender,
   Move(WindowSelector::RIGHT, false);
 }
 
-aura::Window* WindowSelector::GetTextFilterWidgetWindow() {
-  return text_filter_widget_->GetNativeWindow();
+void WindowSelector::OnSplitViewStateChanged(
+    SplitViewController::State previous_state,
+    SplitViewController::State state) {
+  if (state != SplitViewController::NOSNAP) {
+    // Do not restore focus if a window was just snapped and activated.
+    ResetFocusRestoreWindow(false);
+  }
+
+  if (state == SplitViewController::BOTH_SNAPPED) {
+    CancelSelection();
+  } else if (state == SplitViewController::LEFT_SNAPPED) {
+    aura::Window* snapped_window =
+        Shell::Get()->split_view_controller()->left_window();
+    gfx::Rect bounds_in_screen =

[oshima, 2017/06/14 00:19:27]

nit: const

[xdai1, 2017/06/15 22:11:42]

Done.

+        Shell::Get()->split_view_controller()->GetRightWindowBoundsInScreen(
+            snapped_window);
+    SetBoundsForWindowGridsInScreen(bounds_in_screen);
+  } else if (state == SplitViewController::RIGHT_SNAPPED) {
+    aura::Window* snapped_window =
+        Shell::Get()->split_view_controller()->right_window();
+    gfx::Rect bounds_in_screen =

[oshima, 2017/06/14 00:19:27]

const

[xdai1, 2017/06/15 22:11:41]

Done.

+        Shell::Get()->split_view_controller()->GetLeftWindowBoundsInScreen(
+            snapped_window);
+    SetBoundsForWindowGridsInScreen(bounds_in_screen);
+  } else {
+    DCHECK(state == SplitViewController::NOSNAP);

[oshima, 2017/06/14 00:19:27]

DCHECK_EQ

[xdai1, 2017/06/15 22:11:41]

Done.

+    // TODO(xdai): Decide what to do here.
+  }
 }
 
 void WindowSelector::PositionWindows(bool animate) {
@@ -633,6 +742,10 @@ void WindowSelector::PositionWindows(bool animate) {
     grid->PositionWindows(animate);
 }
 
+aura::Window* WindowSelector::GetTextFilterWidgetWindow() {
+  return text_filter_widget_->GetNativeWindow();
+}
+
 void WindowSelector::RepositionTextFilterOnDisplayMetricsChange() {
   const gfx::Rect rect = GetTextFilterPosition(Shell::GetPrimaryRootWindow());
   text_filter_bottom_ = rect.bottom() + kTextFieldBottomMargin;