Refactor app list so AppsGridView owns the PaginationModel.

ash/wm/app_list_controller.cc

Index: ash/wm/app_list_controller.cc
diff --git a/ash/wm/app_list_controller.cc b/ash/wm/app_list_controller.cc
index 6acf1aef33e2e868892ad2757babfeb9d190a142..6d00993648428c5c3c8873916c27280817d429a0 100644
--- a/ash/wm/app_list_controller.cc
+++ b/ash/wm/app_list_controller.cc
@@ -16,7 +16,11 @@
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/app_list/pagination_model.h"
+#include "ui/app_list/views/app_list_main_view.h"
 #include "ui/app_list/views/app_list_view.h"
+#include "ui/app_list/views/apps_container_view.h"
+#include "ui/app_list/views/apps_grid_view.h"
+#include "ui/app_list/views/contents_view.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
@@ -153,23 +157,28 @@ int GetMinimumBoundsHeightForAppList(const app_list::AppListView* app_list) {
 // AppListController, public:
 
 AppListController::AppListController()
-    : pagination_model_(new app_list::PaginationModel),
-      is_visible_(false),
+    : is_visible_(false),
       is_centered_(false),
       view_(NULL),
+      pagination_model_(NULL),
+      current_app_page_(-1),
       should_snap_back_(false) {
   Shell::GetInstance()->AddShellObserver(this);
-  pagination_model_->AddObserver(this);
 }
 
 AppListController::~AppListController() {
   // Ensures app list view goes before the controller since pagination model
   // lives in the controller and app list view would access it on destruction.
-  if (view_ && view_->GetWidget())
-    view_->GetWidget()->CloseNow();
+  if (view_) {
+    DCHECK(pagination_model_);
+    pagination_model_->RemoveObserver(this);
+    if (view_->GetWidget())
+      view_->GetWidget()->CloseNow();
+  } else {
+    DCHECK(!pagination_model_);
+  }
 
   Shell::GetInstance()->RemoveShellObserver(this);
-  pagination_model_->RemoveObserver(this);
 }
 
 void AppListController::SetVisible(bool visible, aura::Window* window) {
@@ -208,7 +217,6 @@ void AppListController::SetVisible(bool visible, aura::Window* window) {
       // init at (0, 0) and then reset its anchor point.
       view->InitAsBubbleAtFixedLocation(
           container,
-          pagination_model_.get(),
           gfx::Point(),
           views::BubbleBorder::FLOAT,
           true /* border_accepts_events */);
@@ -225,7 +233,6 @@ void AppListController::SetVisible(bool visible, aura::Window* window) {
           applist_button_bounds);
       view->InitAsBubbleAttachedToAnchor(
           container,
-          pagination_model_.get(),
           Shelf::ForWindow(container)->GetAppListButtonView(),
           GetAnchorPositionOffsetToShelf(applist_button_bounds,
               Shelf::ForWindow(container)->GetAppListButtonView()->
@@ -263,6 +270,7 @@ void AppListController::SetDragAndDropHostOfCurrentAppList(
 
 void AppListController::SetView(app_list::AppListView* view) {
   DCHECK(view_ == NULL);
+  DCHECK(pagination_model_ == NULL);
   DCHECK(is_visible_);
 
   view_ = view;
@@ -277,6 +285,15 @@ void AppListController::SetView(app_list::AppListView* view) {
   widget->GetNativeView()->GetRootWindow()->AddObserver(this);
   aura::client::GetFocusClient(widget->GetNativeView())->AddObserver(this);
 
+  pagination_model_ = view_->app_list_main_view()

[tapted, 2014/06/02 04:02:21]

I think this justifies a GetPaginationModel() accessor on AppListView :) - you
can get rid of a lot of #includes that way. And even remove the
pagination_model_ member on AppListController; relying instead on
view_->GetPaginationModel()

[Matt Giuca, 2014/06/02 07:11:23]

Done & Done.

+                          ->contents_view()
+                          ->apps_container_view()
+                          ->apps_grid_view()
+                          ->GetPaginationModel();
+  pagination_model_->AddObserver(this);
+  if (pagination_model_->is_valid_page(current_app_page_))
+    pagination_model_->SelectPage(current_app_page_, false);
+
   view_->ShowWhenReady();
 }
 
@@ -295,6 +312,11 @@ void AppListController::ResetView() {
   Shelf::ForWindow(widget->GetNativeWindow())->RemoveIconObserver(this);
   widget->GetNativeView()->GetRootWindow()->RemoveObserver(this);
   aura::client::GetFocusClient(widget->GetNativeView())->RemoveObserver(this);
+
+  DCHECK(pagination_model_);
+  pagination_model_->RemoveObserver(this);
+  pagination_model_ = NULL;
+
   view_ = NULL;
 }
 
@@ -449,6 +471,7 @@ void AppListController::TotalPagesChanged() {
 
 void AppListController::SelectedPageChanged(int old_selected,
                                             int new_selected) {
+  current_app_page_ = new_selected;
 }
 
 void AppListController::TransitionStarted() {
@@ -459,6 +482,8 @@ void AppListController::TransitionChanged() {
   if (!view_)
     return;
 
+  DCHECK(pagination_model_);
+
   const app_list::PaginationModel::Transition& transition =
       pagination_model_->transition();
   if (pagination_model_->is_valid_page(transition.target_page))