App list: Added contents view custom animation framework.

ui/app_list/views/contents_view.h

 // 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.
 
 #ifndef UI_APP_LIST_VIEWS_CONTENTS_VIEW_H_
 #define UI_APP_LIST_VIEWS_CONTENTS_VIEW_H_
 
 #include <map>
+#include <utility>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/app_list/app_list_export.h"
 #include "ui/app_list/app_list_model.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/app_list/pagination_model_observer.h"
 #include "ui/views/view.h"
 #include "ui/views/view_model.h"
 
 namespace gfx {
 class Rect;
 }
 
 namespace app_list {
 
 class AppsGridView;
 class ApplicationDragAndDropHost;
 class AppListFolderItem;
 class AppListMainView;
 class AppListModel;
 class AppListViewDelegate;
 class AppsContainerView;
+class ContentsAnimator;
 class ContentsSwitcherView;
 class PaginationModel;
 class SearchResultListView;
 class StartPageView;
 
 // A view to manage launcher pages within the Launcher (eg. start page, apps
 // grid view, search results). There can be any number of launcher pages, only
 // one of which can be active at a given time. ContentsView provides the user
 // interface for switching between launcher pages, and animates the transition
 // between them.
@@ skipping 55 matching lines @@
   const PaginationModel& pagination_model() { return pagination_model_; }
 
   // Returns search box bounds to use for content views that do not specify
   // their own custom layout.
   gfx::Rect GetDefaultSearchBoxBounds() const;
 
   // Returns the content area bounds to use for content views that do not
   // specify their own custom layout.
   gfx::Rect GetDefaultContentsBounds() const;
 
+  // Exposes GetAnimatorForTransition for tests.
+  ContentsAnimator* GetAnimatorForTransitionForTests(int from_page,
+                                                     int to_page,
+                                                     bool* reverse) const {
+    return GetAnimatorForTransition(from_page, to_page, reverse);
+  }
+
   // Overridden from views::View:
   gfx::Size GetPreferredSize() const override;
   void Layout() override;
   bool OnKeyPressed(const ui::KeyEvent& event) override;
 
   // Overridden from PaginationModelObserver:
   void TotalPagesChanged() override;
   void SelectedPageChanged(int old_selected, int new_selected) override;
   void TransitionStarted() override;
   void TransitionChanged() override;
 
  private:
   // Sets the active launcher page, accounting for whether the change is for
   // search results.
   void SetActivePageInternal(int page_index, bool show_search_results);
 
   // Invoked when active view is changed.
   void ActivePageChanged(bool show_search_results);
 
   // Returns the size of the default content area.
   gfx::Size GetDefaultContentsSize() const;
 
-  // Gets the origin (the off-screen resting place) for a given launcher page
-  // with index |page_index|.
-  gfx::Rect GetOffscreenPageBounds(int page_index) const;
-
   // Calculates and sets the bounds for the subviews. If there is currently an
   // animation, this positions the views as appropriate for the current frame.
   void UpdatePageBounds();
 
   // Adds |view| as a new page to the end of the list of launcher pages. The
   // view is inserted as a child of the ContentsView, and a button with
   // |resource_id| is added to the ContentsSwitcherView. There is no name
   // associated with the page. Returns the index of the new page.
   int AddLauncherPage(views::View* view, int resource_id);
 
   // Adds |view| as a new page to the end of the list of launcher pages. The
   // view is inserted as a child of the ContentsView, and a button with
   // |resource_id| is added to the ContentsSwitcherView. The page is associated
   // with the name |state|. Returns the index of the new page.
   int AddLauncherPage(views::View* view,
                       int resource_id,
                       AppListModel::State state);
 
   // Gets the PaginationModel owned by the AppsGridView.
   // Note: This is different to |pagination_model_|, which manages top-level
   // launcher-page pagination.
   PaginationModel* GetAppsPaginationModel();
 
+  // Adds a ContentsAnimator for a transition from |from_page| to |to_page|.
+  // Takes ownership of |animator|.
+  void AddAnimator(int from_page, int to_page, ContentsAnimator* animator);

[calamity, 2014/11/05 06:29:07]

If this takes ownership, shouldn't it take a scoped_ptr?

[Matt Giuca, 2014/11/06 00:32:59]

s/scoped_ptr/linked_ptr/ yeah... probably should.

But in doing so it kind of defeats most of the point of having this function,
which is to save as much repetition in the animation listing as possible.
Currently:

AddAnimator(GetPageIndexForState(AppListModel::STATE_START),
            GetPageIndexForState(AppListModel::STATE_APPS),
            new StartToAppsAnimator(this));

If I made it take a linked_ptr, it would mean each animation has to be written
as:

AddAnimator(GetPageIndexForState(AppListModel::STATE_START),
            GetPageIndexForState(AppListModel::STATE_APPS),
            linked_ptr<ContentsAnimator>(new StartToAppsAnimator(this)));

The purpose of AddAnimator is to make the animation insertion code as simple and
readable as possible. Up to you.

[calamity, 2014/11/06 05:34:47]

I think it would still be scoped_ptr and then made into a linked_ptr to insert
it into the map. linked_ptr doesn't imply ownership transfer (since it's
copyable).

In fact, regarding readability, can we just make AddAnimator take a State?

I don't think

AddAnimator(AppListModel::STATE_START,
            AppListModel::STATE_APPS,
            scoped_ptr<ContentsAnimation>(new StartToAppsAnimator(this)));

is so bad.

[Matt Giuca, 2014/11/10 04:08:26]

Sort of depends on https://codereview.chromium.org/683703002/ (because before
that, there is no custom page state). Can we change it to a state later?
Ack.

+
+  // Gets a ContentsAnimator for a transition from |from_page| to |to_page|. If
+  // the animator is should be run in reverse (because it is a |to_page| to

[calamity, 2014/11/05 06:29:07]

s/is//

[Matt Giuca, 2014/11/06 00:32:59]

Done.

+  // |from_page| animator), |reverse| is set to true; otherwise it is set to
+  // false.
+  ContentsAnimator* GetAnimatorForTransition(int from_page,
+                                             int to_page,
+                                             bool* reverse) const;
+
   // Special sub views of the ContentsView. All owned by the views hierarchy.
   AppsContainerView* apps_container_view_;
   SearchResultListView* search_results_view_;
   StartPageView* start_page_view_;
 
   AppListMainView* app_list_main_view_;     // Parent view, owns this.
   // Sibling view, owned by |app_list_main_view_|.
   ContentsSwitcherView* contents_switcher_view_;
 
   scoped_ptr<views::ViewModel> view_model_;
 
   // Maps State onto |view_model_| indices.
   std::map<AppListModel::State, int> state_to_view_;
 
   // Maps |view_model_| indices onto State.
   std::map<int, AppListModel::State> view_to_state_;
 
   // The page that was showing before ShowSearchResults(true) was invoked.
   int page_before_search_;
 
   // Manages the pagination for the launcher pages.
   PaginationModel pagination_model_;
 
+  // Maps from {A, B} pair to ContentsAnimator, where A and B are page
+  // |view_model_| indices for an animation from A to B.
+  std::map<std::pair<int, int>, linked_ptr<ContentsAnimator>>
+      contents_animators_;
+
+  // The animator for a transition not found in |contents_animators_|.

[calamity, 2014/11/05 06:29:07]

s/for a transition/for transitions/

[Matt Giuca, 2014/11/06 00:32:59]

Done.

+  scoped_ptr<ContentsAnimator> default_animator_;
+
   DISALLOW_COPY_AND_ASSIGN(ContentsView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_VIEWS_CONTENTS_VIEW_H_