App list: Added contents view custom animation framework.

ui/app_list/views/contents_view.h

Index: ui/app_list/views/contents_view.h
diff --git a/ui/app_list/views/contents_view.h b/ui/app_list/views/contents_view.h
index ade7fdbf388fe4283e79e5a78e7a565b49903b8e..5d8a5d754c0ae0fe45b3ad49ba2a0d339a4b975f 100644
--- a/ui/app_list/views/contents_view.h
+++ b/ui/app_list/views/contents_view.h
@@ -6,9 +6,11 @@
 #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"
@@ -30,6 +32,7 @@ class AppListMainView;
 class AppListModel;
 class AppListViewDelegate;
 class AppsContainerView;
+class ContentsAnimator;
 class ContentsSwitcherView;
 class PaginationModel;
 class SearchResultListView;
@@ -105,6 +108,13 @@ class APP_LIST_EXPORT ContentsView : public views::View,
   // 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;
@@ -127,10 +137,6 @@ class APP_LIST_EXPORT ContentsView : public views::View,
   // 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();
@@ -154,6 +160,18 @@ class APP_LIST_EXPORT ContentsView : public views::View,
   // 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_;
@@ -177,6 +195,14 @@ class APP_LIST_EXPORT ContentsView : public views::View,
   // 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);
 };