app_list: Add page transition animation for apps grid.

- Add transition data to PaginationModel to indicate a partial page switch;
- Add transition animation to PaginationModel;
- Add unit test for animated and non-animated SelectPage;

BUG=129772
TEST=Verify page switch has a push left/right transition animation on the grid and blue color animates from one button to another.


Review URL: https://chromiumcodereview.appspot.com/10535095

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@141522 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 62 insertions, 11 deletions

diff --git a/ui/app_list/pagination_model.h b/ui/app_list/pagination_model.h
index 39820d8..bcf6321 100644
--- a/ui/app_list/pagination_model.h
+++ b/ui/app_list/pagination_model.h
@@ -6,9 +6,16 @@
 #define UI_APP_LIST_PAGINATION_MODEL_H_
 #pragma once
 
-#include "ui/app_list/app_list_export.h"
 #include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
+#include "ui/app_list/app_list_export.h"
+#include "ui/base/animation/animation_delegate.h"
+
+namespace ui {
+class SlideAnimation;
+}
 
 namespace app_list {
 
@@ -17,28 +24,72 @@ class PaginationModelObserver;
 // A simple pagination model that consists of two numbers: the total pages and
 // the currently selected page. The model is a single selection model that at
 // the most one page can become selected at any time.
-class APP_LIST_EXPORT PaginationModel {
+class APP_LIST_EXPORT PaginationModel : public ui::AnimationDelegate {
  public:
+  // Holds info for transition animation and touch scroll.
+  struct Transition {
+    Transition(int target_page, double progress)
+        : target_page(target_page),
+          progress(progress) {
+    }
+
+    bool operator==(const Transition& rhs) const {
+      return target_page == rhs.target_page && progress == rhs.progress;
+    }
+
+    // Target page for the transition or -1 if there is no target page. For
+    // page switcher, this is the target selected page. For touch scroll,
+    // this is usually the previous or next page (or -1 when there is no
+    // previous or next page).
+    int target_page;
+
+    // A [0, 1] progress indicates how much of the current page is being
+    // transitioned.
+    double progress;
+  };
+
   PaginationModel();
-  ~PaginationModel();
+  virtual ~PaginationModel();
 
   void SetTotalPages(int total_pages);
-  void SelectPage(int page);
+
+  // Selects a page. |animate| is true if the transition should be animated.
+  void SelectPage(int page, bool animate);
+
+  void SetTransition(const Transition& transition);
+  void SetTransitionDuration(int duration_ms);
 
   void AddObserver(PaginationModelObserver* observer);
   void RemoveObserver(PaginationModelObserver* observer);
 
-  int total_pages() const {
-    return total_pages_;
-  }
-
-  int selected_page() const {
-    return selected_page_;
-  }
+  int total_pages() const { return total_pages_; }
+  int selected_page() const { return selected_page_; }
+  const Transition& transition() const { return transition_; }
 
  private:
+  void NotifySelectedPageChanged(int old_selected, int new_selected);
+  void NotifyTransitionChanged();
+
+  void StartTranstionAnimation(int target_page);
+  void ResetTranstionAnimation();
+
+  // ui::AnimationDelegate overrides:
+  virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
+  virtual void AnimationEnded(const ui::Animation* animation) OVERRIDE;
+
   int total_pages_;
   int selected_page_;
+
+  Transition transition_;
+
+  // Pending selected page when SelectedPage is called during a transition. If
+  // multiple SelectPage is called while a transition is in progress, only the
+  // last target page is remembered here.
+  int pending_selected_page_;
+
+  scoped_ptr<ui::SlideAnimation> transition_animation_;
+  int transition_duration_ms_;  // Transition duration in millisecond.
+
   ObserverList<PaginationModelObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(PaginationModel);