AppsGridView: Use specific types instead of views::View*.

ui/app_list/views/apps_grid_view.cc

 // Copyright (c) 2012 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/apps_grid_view.h"
 
 #include <algorithm>
 #include <set>
 #include <string>
 
@@ skipping 745 matching lines @@
     folder_delegate_->UpdateFolderViewBackground(false);
 }
 
 void AppsGridView::StopPageFlipTimer() {
   page_flip_timer_.Stop();
   page_flip_target_ = -1;
 }
 
 AppListItemView* AppsGridView::GetItemViewAt(int index) const {
   DCHECK(index >= 0 && index < view_model_.view_size());
   return static_cast<AppListItemView*>(view_model_.view_at(index));

[tapted, 2014/09/25 06:35:28]

I wish we could go further by extending ViewModel with subclass... but I think
it's too brittle anyway.

// Subclass of ViewModel that attempts to hide type-unsafe Adds using
// overload resolution rules, while providing an auto-casting item_at.
class ItemViewModel : public ViewModel {
 public:
  void Add(AppListItemView* view, int index) {
    ViewModel::Add(view, index);
  }
  AppListItemView* view_at(int index) const {
    return static_cast<AppListItemView*>(ViewModel::view_at(index));
  }
};

#hides

[calamity, 2014/09/26 01:47:26]

Could go make ViewModel templated.

#doublehides

[Matt Giuca, 2014/09/26 03:48:39]

I think the template is a good idea. Follow-up patch?

 }
 
 void AppsGridView::SetTopItemViewsVisible(bool visible) {
   int top_item_count = std::min(static_cast<int>(kNumFolderTopItems),
                                 view_model_.view_size());
   for (int i = 0; i < top_item_count; ++i)
     GetItemViewAt(i)->icon()->SetVisible(visible);
 }
 
 void AppsGridView::ScheduleShowHideAnimation(bool show) {
@@ skipping 100 matching lines @@
     ApplicationDragAndDropHost* drag_and_drop_host) {
   drag_and_drop_host_ = drag_and_drop_host;
 }
 
 void AppsGridView::Prerender() {
   Layout();
   int selected_page = std::max(0, pagination_model_.selected_page());
   int start = std::max(0, (selected_page - kPrerenderPages) * tiles_per_page());
   int end = std::min(view_model_.view_size(),
                      (selected_page + 1 + kPrerenderPages) * tiles_per_page());
-  for (int i = start; i < end; i++) {
-    AppListItemView* v = static_cast<AppListItemView*>(view_model_.view_at(i));
-    v->Prerender();
-  }
+  for (int i = start; i < end; i++)
+    GetItemViewAt(i)->Prerender();
 }
 
 bool AppsGridView::IsAnimatingView(views::View* view) {
   return bounds_animator_.IsAnimating(view);
 }
 
 gfx::Size AppsGridView::GetPreferredSize() const {
   const gfx::Insets insets(GetInsets());
   int page_switcher_height = 0;
   if (page_switcher_view_)
@@ skipping 188 matching lines @@
 }
 
 int AppsGridView::GetModelIndexFromIndex(const Index& index) const {
   return index.page * tiles_per_page() + index.slot;
 }
 
 void AppsGridView::SetSelectedItemByIndex(const Index& index) {
   if (GetIndexOfView(selected_view_) == index)
     return;
 
-  views::View* new_selection = GetViewAtIndex(index);
+  AppListItemView* new_selection = GetViewAtIndex(index);
   if (!new_selection)
     return;  // Keep current selection.
 
   if (selected_view_)
     selected_view_->SchedulePaint();
 
   EnsureViewVisible(new_selection);
   selected_view_ = new_selection;
   selected_view_->SchedulePaint();
   selected_view_->NotifyAccessibilityEvent(
       ui::AX_EVENT_FOCUS, true);
 }
 
 bool AppsGridView::IsValidIndex(const Index& index) const {
   return index.page >= 0 && index.page < pagination_model_.total_pages() &&
          index.slot >= 0 && index.slot < tiles_per_page() &&
          GetModelIndexFromIndex(index) < view_model_.view_size();
 }
 
 AppsGridView::Index AppsGridView::GetIndexOfView(
     const views::View* view) const {
   const int model_index = view_model_.GetIndexOfView(view);
   if (model_index == -1)
     return Index();
 
   return GetIndexFromModelIndex(model_index);
 }
 
-views::View* AppsGridView::GetViewAtIndex(const Index& index) const {
+AppListItemView* AppsGridView::GetViewAtIndex(const Index& index) const {
   if (!IsValidIndex(index))
     return NULL;
 
   const int model_index = GetModelIndexFromIndex(index);
-  return view_model_.view_at(model_index);
+  return GetItemViewAt(model_index);
 }
 
 AppsGridView::Index AppsGridView::GetLastViewIndex() const {
   DCHECK_LT(0, view_model_.view_size());
   int view_index = view_model_.view_size() - 1;
   return Index(view_index / tiles_per_page(), view_index % tiles_per_page());
 }
 
 void AppsGridView::MoveSelected(int page_delta,
                                 int slot_x_delta,
@@ skipping 580 matching lines @@
 
   item_list_->RemoveObserver(this);
   item_list_->MoveItem(current_model_index, target_model_index);
   view_model_.Move(current_model_index, target_model_index);
   item_list_->AddObserver(this);
 
   if (pagination_model_.selected_page() != target.page)
     pagination_model_.SelectPage(target.page, false);
 }
 
-void AppsGridView::MoveItemToFolder(views::View* item_view,
+void AppsGridView::MoveItemToFolder(AppListItemView* item_view,
                                     const Index& target) {
-  const std::string& source_item_id =
-      static_cast<AppListItemView*>(item_view)->item()->id();
-  AppListItemView* target_view =
-      static_cast<AppListItemView*>(GetViewAtSlotOnCurrentPage(target.slot));
+  const std::string& source_item_id = item_view->item()->id();
+  AppListItemView* target_view = GetViewAtSlotOnCurrentPage(target.slot);
   const std::string&  target_view_item_id = target_view->item()->id();
 
   // Make change to data model.
   item_list_->RemoveObserver(this);
   std::string folder_item_id =
       model_->MergeItems(target_view_item_id, source_item_id);
   item_list_->AddObserver(this);
   if (folder_item_id.empty()) {
     LOG(ERROR) << "Unable to merge into item id: " << target_view_item_id;
     return;
@@ skipping 20 matching lines @@
   int drag_view_index = view_model_.GetIndexOfView(drag_view_);
   view_model_.Remove(drag_view_index);
   bounds_animator_.AnimateViewTo(drag_view_, drag_view_->bounds());
   bounds_animator_.SetAnimationDelegate(
       drag_view_,
       scoped_ptr<gfx::AnimationDelegate>(
           new ItemRemoveAnimationDelegate(drag_view_)));
   UpdatePaging();
 }
 
-void AppsGridView::ReparentItemForReorder(views::View* item_view,
+void AppsGridView::ReparentItemForReorder(AppListItemView* item_view,
                                           const Index& target) {
   item_list_->RemoveObserver(this);
   model_->RemoveObserver(this);
 
-  AppListItem* reparent_item = static_cast<AppListItemView*>(item_view)->item();
+  AppListItem* reparent_item = item_view->item();
   DCHECK(reparent_item->IsInFolder());
   const std::string source_folder_id = reparent_item->folder_id();
   AppListFolderItem* source_folder =
       static_cast<AppListFolderItem*>(item_list_->FindItem(source_folder_id));
 
   int target_model_index = GetModelIndexFromIndex(target);
 
   // Remove the source folder view if there is only 1 item in it, since the
   // source folder will be deleted after its only child item removed from it.
   if (source_folder->ChildItemCount() == 1u) {
@@ skipping 16 matching lines @@
   model_->MoveItemToFolderAt(reparent_item, "", target_position);
   view_model_.Move(current_model_index, target_model_index);
 
   RemoveLastItemFromReparentItemFolderIfNecessary(source_folder_id);
 
   item_list_->AddObserver(this);
   model_->AddObserver(this);
   UpdatePaging();
 }
 
-void AppsGridView::ReparentItemToAnotherFolder(views::View* item_view,
+void AppsGridView::ReparentItemToAnotherFolder(AppListItemView* item_view,
                                                const Index& target) {
   DCHECK(IsDraggingForReparentInRootLevelGridView());
 
-  AppListItemView* target_view =
-      static_cast<AppListItemView*>(GetViewAtSlotOnCurrentPage(target.slot));
+  AppListItemView* target_view = GetViewAtSlotOnCurrentPage(target.slot);
   if (!target_view)
     return;
 
   // Make change to data model.
   item_list_->RemoveObserver(this);
 
-  AppListItem* reparent_item = static_cast<AppListItemView*>(item_view)->item();
+  AppListItem* reparent_item = item_view->item();
   DCHECK(reparent_item->IsInFolder());
   const std::string source_folder_id = reparent_item->folder_id();
   AppListFolderItem* source_folder =
       static_cast<AppListFolderItem*>(item_list_->FindItem(source_folder_id));
 
   // Remove the source folder view if there is only 1 item in it, since the
   // source folder will be deleted after its only child item merged into the
   // target item.
   if (source_folder->ChildItemCount() == 1u)
     DeleteItemViewAtIndex(
@@ skipping 90 matching lines @@
       target_icon_rect,
       false);    /* animate like closing folder */
   AddChildView(icon_view);
   icon_view->SetBoundsRect(drag_view_icon_to_grid);
   icon_view->TransformView();
 }
 
 void AppsGridView::CancelContextMenusOnCurrentPage() {
   int start = pagination_model_.selected_page() * tiles_per_page();
   int end = std::min(view_model_.view_size(), start + tiles_per_page());
-  for (int i = start; i < end; ++i) {
-    AppListItemView* view =
-        static_cast<AppListItemView*>(view_model_.view_at(i));
-    view->CancelContextMenu();
-  }
+  for (int i = start; i < end; ++i)
+    GetItemViewAt(i)->CancelContextMenu();
 }
 
 void AppsGridView::DeleteItemViewAtIndex(int index) {
   views::View* item_view = view_model_.view_at(index);
   view_model_.Remove(index);
   if (item_view == drag_view_)
     drag_view_ = NULL;
   delete item_view;
 }
 
 bool AppsGridView::IsPointWithinDragBuffer(const gfx::Point& point) const {
   gfx::Rect rect(GetLocalBounds());
   rect.Inset(-kDragBufferPx, -kDragBufferPx, -kDragBufferPx, -kDragBufferPx);
   return rect.Contains(point);
 }
 
 void AppsGridView::ButtonPressed(views::Button* sender,
                                  const ui::Event& event) {
   if (dragging())
     return;
 
   if (strcmp(sender->GetClassName(), AppListItemView::kViewClassName))
     return;
+  AppListItemView* pressed_item_view = static_cast<AppListItemView*>(sender);
 
   if (delegate_) {
     // Always set the previous activated_folder_item_view_ to be visible. This
     // 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.
     if (!folder_delegate_) {
       if (activated_folder_item_view_)
         activated_folder_item_view_->SetVisible(true);
-      AppListItemView* pressed_item_view =
-          static_cast<AppListItemView*>(sender);
       if (IsFolderItem(pressed_item_view->item()))
         activated_folder_item_view_ = pressed_item_view;
       else
         activated_folder_item_view_ = NULL;
     }
-    delegate_->ActivateApp(static_cast<AppListItemView*>(sender)->item(),
-                           event.flags());
+    delegate_->ActivateApp(pressed_item_view->item(), event.flags());
   }
 }
 
 void AppsGridView::OnListItemAdded(size_t index, AppListItem* item) {
   EndDrag(true);
 
   views::View* view = CreateViewForItemAtIndex(index);
   view_model_.Add(view, index);
   AddChildView(view);
 
@@ skipping 70 matching lines @@
     SetVisible(false);
 }
 
 bool AppsGridView::EnableFolderDragDropUI() {
   // Enable drag and drop folder UI only if it is at the app list root level
   // and the switch is on.
   return model_->folders_enabled() && !folder_delegate_;
 }
 
 bool AppsGridView::CanDropIntoTarget(const Index& drop_target) const {
-  views::View* target_view = GetViewAtIndex(drop_target);
+  AppListItemView* target_view = GetViewAtIndex(drop_target);
   if (!target_view)
     return false;
 
-  AppListItem* target_item =
-      static_cast<AppListItemView*>(target_view)->item();
+  AppListItem* target_item = target_view->item();
   // Items can be dropped into non-folders (which have no children) or folders
   // that have fewer than the max allowed items.
   // OEM folder does not allow to drag/drop other items in it.
   return target_item->ChildItemCount() < kMaxFolderItems &&
          !IsOEMFolderItem(target_item);
 }
 
 AppsGridView::Index AppsGridView::GetNearestTileIndexForPoint(
     const gfx::Point& point) const {
   gfx::Rect bounds = GetContentsBounds();
@@ skipping 21 matching lines @@
 gfx::Rect AppsGridView::GetExpectedTileBounds(int row, int col) const {
   gfx::Rect bounds(GetContentsBounds());
   gfx::Size total_tile_size = GetTotalTileSize();
   gfx::Rect tile_bounds(gfx::Point(bounds.x() + col * total_tile_size.width(),
                                    bounds.y() + row * total_tile_size.height()),
                         total_tile_size);
   tile_bounds.ClampToCenteredSize(GetTileViewSize());
   return tile_bounds;
 }
 
-views::View* AppsGridView::GetViewAtSlotOnCurrentPage(int slot) {
+AppListItemView* AppsGridView::GetViewAtSlotOnCurrentPage(int slot) {

[calamity, 2014/09/26 01:47:26]

Ugh. This needs to get a better name that indicates slot may not match the
model. Maybe GetViewDisplayedAtGridSlot()?

Also, add a comment in the header that this will return the view that is
currently displayed at the given slot, which may not match the model.

[Matt Giuca, 2014/09/26 03:48:39]

Done.

Note that I called it GetViewDisplayedAtSlotOnCurrentPage -- got to keep the "on
current page" part because that's an important facet of its functionality.

   if (slot < 0)
     return NULL;
 
   // Calculate the original bound of the tile at |index|.
   int row = slot / cols_;
   int col = slot % cols_;
   gfx::Rect tile_rect = GetExpectedTileBounds(row, col);
 
   for (int i = 0; i < view_model_.view_size(); ++i) {
-    views::View* view = view_model_.view_at(i);
+    AppListItemView* view = GetItemViewAt(i);
     if (view->bounds() == tile_rect && view != drag_view_)
       return view;
   }
   return NULL;
 }
 
 void AppsGridView::SetAsFolderDroppingTarget(const Index& target_index,
                                              bool is_target_folder) {
-  AppListItemView* target_view =
-      static_cast<AppListItemView*>(
-          GetViewAtSlotOnCurrentPage(target_index.slot));
+  AppListItemView* target_view = GetViewAtSlotOnCurrentPage(target_index.slot);
   if (target_view)
     target_view->SetAsAttemptedFolderTarget(is_target_folder);
 }
 
 }  // namespace app_list