[ash-md] Adds support for gesture to move selection in overview mode

ash/common/wm/overview/window_selector.cc

Index: ash/common/wm/overview/window_selector.cc
diff --git a/ash/common/wm/overview/window_selector.cc b/ash/common/wm/overview/window_selector.cc
index 7233f45e74b677eeb27623179f90e6d01b0a8843..8110aed7c4a061992145c5445cd2fb84078c3fe6 100644
--- a/ash/common/wm/overview/window_selector.cc
+++ b/ash/common/wm/overview/window_selector.cc
@@ -254,6 +254,7 @@ void WindowSelector::Init(const WindowList& windows) {
                      (b->GetBoundsInScreen().x() + b->GetBoundsInScreen().y());
             });
 
+  bool first_grid = true;
   for (WmWindow* root : root_windows) {
     // Observed switchable containers for newly created windows on all root
     // windows.
@@ -271,6 +272,10 @@ void WindowSelector::Init(const WindowList& windows) {
     std::unique_ptr<WindowGrid> grid(new WindowGrid(root, windows, this));
     if (grid->empty())
       continue;
+    if (first_grid) {

[tdanderson, 2017/02/10 16:05:19]

I'm not 100% convinced this is the right thing to do, actually - what's your
reasoning for skipping the first item? Is this to be consistent with Alt+Tab?
There may be a user expectation (especially from an a11y point of view) to be
able to cycle through the MRU beginning with the current window.

[varkha, 2017/02/10 17:34:30]

Yes, I'll take this offline.

+      grid->set_skip_first(true);
+      first_grid = false;
+    }
     num_items_ += grid->size();
     grid_list_.push_back(std::move(grid));
   }
@@ -404,6 +409,20 @@ void WindowSelector::OnGridEmpty(WindowGrid* grid) {
     CancelSelection();
 }
 
+void WindowSelector::IncrementSelection(int increment) {
+  const Direction direction =
+      increment > 0 ? WindowSelector::RIGHT : WindowSelector::LEFT;
+  for (int step = 0; step < abs(increment); ++step)
+    Move(direction, true);
+}
+
+bool WindowSelector::AcceptSelection() {
+  if (!grid_list_[selected_grid_index_]->is_selecting())
+    return false;
+  SelectWindow(grid_list_[selected_grid_index_]->SelectedWindow());
+  return true;
+}
+
 void WindowSelector::SelectWindow(WindowSelectorItem* item) {
   WmWindow* window = item->GetWindow();
   std::vector<WmWindow*> window_list =