Add keyboard navigation for start page tiles in experimental app list.

ui/app_list/views/start_page_view.cc

 // Copyright 2014 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 "ui/app_list/views/start_page_view.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_item.h"
 #include "ui/app_list/app_list_model.h"
@@ skipping 128 matching lines @@
 void StartPageView::UpdateForTesting() {
   Update();
 }
 
 TileItemView* StartPageView::all_apps_button() const {
   return all_apps_button_;
 }
 
 void StartPageView::OnShow() {
   UpdateCustomPageClickzoneVisibility();
+  ClearSelectedIndex();
 }
 
 void StartPageView::OnHide() {
   UpdateCustomPageClickzoneVisibility();
 }
 
 void StartPageView::Layout() {
   gfx::Rect bounds(GetContentsBounds());
   bounds.set_height(instant_container_->GetHeightForWidth(bounds.width()));
   instant_container_->SetBoundsRect(bounds);
 
   // Tiles begin where the instant container ends.
   bounds.set_y(bounds.bottom());
   bounds.set_height(tiles_container_->GetHeightForWidth(bounds.width()));
   tiles_container_->SetBoundsRect(bounds);
 }
 
+bool StartPageView::OnKeyPressed(const ui::KeyEvent& event) {
+  if (selected_index() >= 0 &&
+      tiles_container_->child_at(selected_index())->OnKeyPressed(event))

[Matt Giuca, 2014/12/09 08:02:01]

Question: Does this mean the all apps button will work now if you hit enter? Or
not.

If true, then I think you should fix SpokenFeedbackTest (pseudo-revert
https://codereview.chromium.org/762113004/). Or I can do that in a follow-up CL.
(If the all apps button doesn't work, then I will fix that and revert the test
in a follow-up.)

[calamity, 2014/12/10 04:39:46]

Yes.
It wouldn't be a pseudo-revert, you'd need to actually go and select it and
stuff first, changing the things that are in the utterance queue.

[Matt Giuca, 2014/12/10 07:04:28]

OK I will do it.

+    return true;
+
+  int dir = 0;
+  switch (event.key_code()) {
+    case ui::VKEY_LEFT:
+      dir = -1;
+      break;
+    case ui::VKEY_RIGHT:
+      dir = 1;
+      break;
+    case ui::VKEY_DOWN:
+      dir = 1;
+      break;
+    case ui::VKEY_TAB:
+      dir = event.IsShiftDown() ? -1 : 1;
+      break;
+    default:
+      break;
+  }
+
+  if (dir == 0)
+    return false;
+
+  if (!IsValidSelectionIndex(selected_index())) {
+    OnContainerSelected(dir == -1);

[Matt Giuca, 2014/12/09 08:02:01]

I don't really get why you use OnContainerSelected here. I thought OCS was for a
parent container to start moving into this container. But SPV doesn't have a
parent container. You're essentially just using this to get out of an invalid
state (which is unclear to me why you'd be in it). Why should you come up from
the bottom if you were in an invalid state and pressed left?

[calamity, 2014/12/10 04:39:46]

Eh. This is a bit of a semantic choice. I guess we can just put the
functionality here.

FYI, the state is invalid when there's no selection. i.e, on initialization.

+    return true;
+  }
+
+  int selection_index = selected_index() + dir;
+  if (IsValidSelectionIndex(selection_index)) {
+    SetSelectedIndex(selection_index);
+    return true;
+  }
+
+  return false;
+}
+
 void StartPageView::OnContainerSelected(bool from_bottom) {
+  SetSelectedIndex(from_bottom ? num_results() - 1 : 0);
 }
 
 gfx::Rect StartPageView::GetSearchBoxBounds() const {
   return search_box_spacer_view_->bounds();
 }
 
 void StartPageView::UpdateCustomPageClickzoneVisibility() {
   // This can get called before InitWidgets(), so we cannot guarantee that
   // custom_page_clickzone_ will not be null.
   views::Widget* custom_page_clickzone =
@@ skipping 17 matching lines @@
   // Update the tile item results.
   for (size_t i = 0; i < search_result_tile_views_.size(); ++i) {
     SearchResult* item = NULL;
     if (i < display_results.size())
       item = display_results[i];
     search_result_tile_views_[i]->SetSearchResult(item);
   }
 
   tiles_container_->Layout();
   Layout();
-  return display_results.size();
+  // Add 1 to the results size to account for the all apps button.
+  return display_results.size() + 1;

[Matt Giuca, 2014/12/09 08:02:01]

Is this result unrelated?

[calamity, 2014/12/10 04:39:46]

Nope. Necessary to allow the all_apps_button_ to be a valid selection index.

 }
 
 void StartPageView::UpdateSelectedIndex(int old_selected, int new_selected) {
+  if (old_selected >= 0) {
+    tiles_container_->child_at(old_selected)->set_background(nullptr);
+    tiles_container_->child_at(old_selected)->SchedulePaint();
+  }
+
+  if (new_selected >= 0) {
+    tiles_container_->child_at(new_selected)
+        ->set_background(
+            views::Background::CreateSolidBackground(kSelectedColor));
+    tiles_container_->child_at(new_selected)->SchedulePaint();
+  }
 }
 
 }  // namespace app_list