Use button callback instead of listener and misc cleanup.

Bug: 772945
Change-Id: Id3e59075546185b145f7389a2bcf30388ac59060
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2464322
Commit-Queue: Allen Bauer <kylixrd@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816227}

ash/app_list/views/app_list_item_view.cc

@@ -315,7 +315,7 @@ AppListItemView::AppListItemView(AppsGridView* apps_grid_view,
                                  AppListItem* item,
                                  AppListViewDelegate* delegate,
                                  bool is_in_folder)
-    : Button(apps_grid_view),
+    : Button(),
       is_folder_(item->GetItemType() == AppListFolderItem::kItemType),
       item_weak_(item),
       delegate_(delegate),

ash/app_list/views/apps_grid_view.cc

@@ -397,8 +397,7 @@ AppsGridView::AppsGridView(ContentsView* contents_view,
                            AppsGridViewFolderDelegate* folder_delegate)
     : folder_delegate_(folder_delegate),
       contents_view_(contents_view),
-      page_flip_delay_in_ms_(kPageFlipDelayInMsFullscreen),
-      view_structure_(this) {
+      page_flip_delay_in_ms_(kPageFlipDelayInMsFullscreen) {
   DCHECK(contents_view_);
   SetPaintToLayer(ui::LAYER_NOT_DRAWN);
   // Clip any icons that are outside the grid view's bounds. These icons would
@@ -1397,6 +1396,9 @@ std::unique_ptr<AppListItemView> AppsGridView::CreateViewForItemAtIndex(
   std::unique_ptr<AppListItemView> view = std::make_unique<AppListItemView>(
       this, item_list_->item_at(index),
       contents_view_->GetAppListMainView()->view_delegate());
+  view->set_callback(base::BindRepeating(
+      &AppsGridView::OnAppListItemViewPressed, base::Unretained(this),
+      base::Unretained(view.get())));
   return view;
 }
 
@@ -2891,14 +2893,11 @@ bool AppsGridView::IsPointWithinBottomDragBuffer(
          point_in_parent.y() < kBottomDragBufferMax;
 }
 
-void AppsGridView::ButtonPressed(views::Button* sender,
-                                 const ui::Event& event) {
+void AppsGridView::OnAppListItemViewPressed(AppListItemView* pressed_item_view,
+                                            const ui::Event& event) {
   if (dragging())
     return;
 
-  if (strcmp(sender->GetClassName(), AppListItemView::kViewClassName))
-    return;
-
   if (contents_view_->apps_container_view()
           ->app_list_folder_view()
           ->IsAnimationRunning()) {
@@ -2909,7 +2908,6 @@ void AppsGridView::ButtonPressed(views::Button* sender,
   // prevents a case where the item would remain hidden due the
   // |activated_folder_item_view_| changing during the animation. We only
   // need to track |activated_folder_item_view_| in the root level grid view.
-  AppListItemView* pressed_item_view = static_cast<AppListItemView*>(sender);
   if (!folder_delegate_) {
     if (activated_folder_item_view_)
       activated_folder_item_view_->SetVisible(true);

ash/app_list/views/apps_grid_view.h

@@ -34,15 +34,10 @@
 #include "ui/gfx/image/image_skia_operations.h"
 #include "ui/views/animation/bounds_animator.h"
 #include "ui/views/animation/bounds_animator_observer.h"
-#include "ui/views/controls/button/button.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/view.h"
 #include "ui/views/view_model.h"
 
-namespace views {
-class ButtonListener;
-}
-
 namespace ash {
 
 namespace test {
@@ -61,7 +56,7 @@ class GhostImageView;
 
 // Represents the index to an item view in the grid.
 struct APP_LIST_EXPORT GridIndex {
-  GridIndex() : page(-1), slot(-1) {}
+  GridIndex() = default;
   GridIndex(int page, int slot) : page(page), slot(slot) {}
 
   bool operator==(const GridIndex& other) const {
@@ -75,13 +70,12 @@ struct APP_LIST_EXPORT GridIndex {
   }
   std::string ToString() const;
 
-  int page;  // Which page an item view is on.
-  int slot;  // Which slot in the page an item view is in.
+  int page = -1;  // Which page an item view is on.
+  int slot = -1;  // Which slot in the page an item view is in.
 };
 
 // AppsGridView displays a grid for AppListItemList sub model.
 class APP_LIST_EXPORT AppsGridView : public views::View,
-                                     public views::ButtonListener,
                                      public AppListItemListObserver,
                                      public PaginationModelObserver,
                                      public AppListModelObserver,
@@ -512,8 +506,9 @@ class APP_LIST_EXPORT AppsGridView : public views::View,
   // shelf.
   bool IsPointWithinBottomDragBuffer(const gfx::Point& point) const;
 
-  // Overridden from views::ButtonListener:
-  void ButtonPressed(views::Button* sender, const ui::Event& event) override;
+  // AppListItemView pressed callback binds here:
+  void OnAppListItemViewPressed(AppListItemView* pressed_item_view,
+                                const ui::Event& event);
 
   // Overridden from AppListItemListObserver:
   void OnListItemAdded(size_t index, AppListItem* item) override;
@@ -874,7 +869,7 @@ class APP_LIST_EXPORT AppsGridView : public views::View,
   bool is_end_gesture_ = false;
 
   // view structure used only for non-folder.
-  PagedViewStructure view_structure_;
+  PagedViewStructure view_structure_{this};
 
   // True if an extra page is opened after the user drags an app to the bottom
   // of last page with intention to put it in a new page. This is only used for