App list uses PaginationModel to transition between pages.

ui/app_list/views/contents_view.cc

Index: ui/app_list/views/contents_view.cc
diff --git a/ui/app_list/views/contents_view.cc b/ui/app_list/views/contents_view.cc
index 4c40b448ed9e2e1ba302d9d53c0c9d7ba4b1e148..8bfcd12f9e0214764ded66dd185fb16a209b6cb2 100644
--- a/ui/app_list/views/contents_view.cc
+++ b/ui/app_list/views/contents_view.cc
@@ -10,7 +10,6 @@
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/app_list/app_list_view_delegate.h"
-#include "ui/app_list/pagination_model.h"
 #include "ui/app_list/views/app_list_folder_view.h"
 #include "ui/app_list/views/app_list_main_view.h"
 #include "ui/app_list/views/apps_container_view.h"
@@ -18,7 +17,6 @@
 #include "ui/app_list/views/search_result_list_view.h"
 #include "ui/app_list/views/start_page_view.h"
 #include "ui/events/event.h"
-#include "ui/views/animation/bounds_animator.h"
 #include "ui/views/view_model.h"
 #include "ui/views/view_model_utils.h"
 
@@ -40,8 +38,7 @@ ContentsView::ContentsView(AppListMainView* app_list_main_view,
     : search_results_view_(NULL),
       start_page_view_(NULL),
       app_list_main_view_(app_list_main_view),
-      view_model_(new views::ViewModel),
-      bounds_animator_(new views::BoundsAnimator(this)) {
+      view_model_(new views::ViewModel) {
   DCHECK(model);
 
   if (app_list::switches::IsExperimentalAppListEnabled()) {
@@ -55,11 +52,14 @@ ContentsView::ContentsView(AppListMainView* app_list_main_view,
   }
 
   apps_container_view_ = new AppsContainerView(app_list_main_view, model);
-  active_page_ = AddLauncherPage(apps_container_view_, NAMED_PAGE_APPS);
+  int apps_page_index = AddLauncherPage(apps_container_view_, NAMED_PAGE_APPS);
 
+  pagination_model_.SelectPage(apps_page_index, false);
+  pagination_model_.AddObserver(this);
 }
 
 ContentsView::~ContentsView() {
+  pagination_model_.RemoveObserver(this);
 }
 
 void ContentsView::CancelDrag() {
@@ -79,18 +79,23 @@ void ContentsView::SetDragAndDropHostOfCurrentAppList(
 }
 
 void ContentsView::SetActivePage(int page_index) {
-  if (active_page_ == page_index)
+  if (GetActivePageIndex() == page_index)
     return;
 
   SetActivePageInternal(page_index, false);
 }
 
+int ContentsView::GetActivePageIndex() const {
+  // The active page is changed at the beginning of an animation, not the end.
+  return pagination_model_.SelectedTargetPage();
+}
+
 bool ContentsView::IsNamedPageActive(NamedPage named_page) const {
   std::map<NamedPage, int>::const_iterator it =
       named_page_to_view_.find(named_page);
   if (it == named_page_to_view_.end())
     return false;
-  return it->second == active_page_;
+  return it->second == GetActivePageIndex();
 }
 
 int ContentsView::GetPageIndexForNamedPage(NamedPage named_page) const {
@@ -103,9 +108,14 @@ int ContentsView::GetPageIndexForNamedPage(NamedPage named_page) const {
   return it->second;
 }
 
+int ContentsView::NumLauncherPages() const {
+  return pagination_model_.total_pages();
+}
+
 void ContentsView::SetActivePageInternal(int page_index,
                                          bool show_search_results) {
-  active_page_ = page_index;
+  // Start animating to the new page.
+  pagination_model_.SelectPage(page_index, true);
   ActivePageChanged(show_search_results);
 }
 
@@ -127,8 +137,6 @@ void ContentsView::ActivePageChanged(bool show_search_results) {
 
   // Notify parent AppListMainView of the page change.
   app_list_main_view_->UpdateSearchBoxVisibility();
-
-  AnimateToIdealBounds();
 }
 
 void ContentsView::ShowSearchResults(bool show) {
@@ -146,49 +154,49 @@ bool ContentsView::IsShowingSearchResults() const {
              : IsNamedPageActive(NAMED_PAGE_SEARCH_RESULTS);
 }
 
-void ContentsView::CalculateIdealBounds() {
+void ContentsView::UpdatePageBounds() {
   gfx::Rect rect(GetContentsBounds());
   if (rect.IsEmpty())
     return;
 
-  if (app_list::switches::IsExperimentalAppListEnabled()) {
-    gfx::Rect incoming_target(rect);
-    gfx::Rect outgoing_target(rect);
-    outgoing_target.set_x(-outgoing_target.width());
-
-    for (int i = 0; i < view_model_->view_size(); ++i) {
-      view_model_->set_ideal_bounds(
-          i, i == active_page_ ? incoming_target : outgoing_target);
+  // The bounds calculations will potentially be mid-transition (depending on
+  // the state of the PaginationModel).
+  int current_page = std::max(0, pagination_model_.selected_page());
+  int target_page = current_page;
+  double progress = 1;
+  if (pagination_model_.has_transition()) {
+    const PaginationModel::Transition& transition =
+        pagination_model_.transition();
+    if (pagination_model_.is_valid_page(transition.target_page)) {
+      target_page = transition.target_page;
+      progress = transition.progress;
     }
-    return;
   }
 
-  gfx::Rect container_frame(rect);
-  gfx::Rect results_frame(rect);
-
-  // Offsets apps grid and result list based on |active_page_|.
-  // SearchResultListView is on top of apps grid. Visible view is left in
-  // visible area and invisible ones is put out of the visible area.
-  int contents_area_height = rect.height();
-  if (IsNamedPageActive(NAMED_PAGE_APPS))
-    results_frame.Offset(0, -contents_area_height);
-  else if (IsNamedPageActive(NAMED_PAGE_SEARCH_RESULTS))
-    container_frame.Offset(0, contents_area_height);
-  else
-    NOTREACHED() << "Page " << active_page_ << " invalid in current app list.";
+  gfx::Rect incoming_target(rect);
+  gfx::Rect outgoing_target(rect);
+  int dir = target_page > current_page ? -1 : 1;
 
-  view_model_->set_ideal_bounds(GetPageIndexForNamedPage(NAMED_PAGE_APPS),
-                                container_frame);
-  view_model_->set_ideal_bounds(
-      GetPageIndexForNamedPage(NAMED_PAGE_SEARCH_RESULTS), results_frame);
-}
+  if (app_list::switches::IsExperimentalAppListEnabled()) {
+    // The experimental app list transitions horizontally.
+    int page_width = rect.width();
+    int transition_offset = progress * page_width * dir;
 
-void ContentsView::AnimateToIdealBounds() {
-  CalculateIdealBounds();
-  for (int i = 0; i < view_model_->view_size(); ++i) {
-    bounds_animator_->AnimateViewTo(view_model_->view_at(i),
-                                    view_model_->ideal_bounds(i));
+    outgoing_target.set_x(transition_offset);
+    incoming_target.set_x(dir < 0 ? transition_offset + page_width
+                                  : transition_offset - page_width);
+  } else {
+    // The normal app list transitions vertically.
+    int page_height = rect.height();
+    int transition_offset = progress * page_height * dir;
+
+    outgoing_target.set_y(transition_offset);
+    incoming_target.set_y(dir < 0 ? transition_offset + page_height
+                                  : transition_offset - page_height);
   }
+
+  view_model_->view_at(current_page)->SetBoundsRect(outgoing_target);
+  view_model_->view_at(target_page)->SetBoundsRect(incoming_target);
 }
 
 PaginationModel* ContentsView::GetAppsPaginationModel() {
@@ -205,10 +213,19 @@ void ContentsView::Prerender() {
   apps_container_view_->apps_grid_view()->Prerender(selected_page);
 }
 
+views::View* ContentsView::GetPageView(int index) {
+  return view_model_->view_at(index);
+}
+
+void ContentsView::AddBlankPageForTesting() {
+  AddLauncherPage(new views::View);
+}
+
 int ContentsView::AddLauncherPage(views::View* view) {
   int page_index = view_model_->view_size();
   AddChildView(view);
   view_model_->Add(view, page_index);
+  pagination_model_.SetTotalPages(view_model_->view_size());
   return page_index;
 }
 
@@ -231,12 +248,27 @@ gfx::Size ContentsView::GetPreferredSize() const {
 }
 
 void ContentsView::Layout() {
-  CalculateIdealBounds();
-  views::ViewModelUtils::SetViewBoundsToIdealBounds(*view_model_);
+  // Immediately finish all current animations.
+  pagination_model_.FinishAnimation();
+
+  // Move the current view onto the screen, and all other views off screen to
+  // the left. (Since we are not animating, we don't need to be careful about
+  // which side we place the off-screen views onto.)
+  gfx::Rect rect(GetContentsBounds());
+  if (rect.IsEmpty())
+    return;
+
+  gfx::Rect offscreen_target(rect);
+  offscreen_target.set_x(-rect.width());
+
+  for (int i = 0; i < view_model_->view_size(); ++i) {
+    view_model_->view_at(i)->SetBoundsRect(
+        i == pagination_model_.SelectedTargetPage() ? rect : offscreen_target);
+  }
 }
 
 bool ContentsView::OnKeyPressed(const ui::KeyEvent& event) {
-  return view_model_->view_at(active_page_)->OnKeyPressed(event);
+  return view_model_->view_at(GetActivePageIndex())->OnKeyPressed(event);
 }
 
 bool ContentsView::OnMouseWheel(const ui::MouseWheelEvent& event) {
@@ -259,6 +291,19 @@ bool ContentsView::OnMouseWheel(const ui::MouseWheelEvent& event) {
   return false;
 }
 
+void ContentsView::TotalPagesChanged() {
+}
+
+void ContentsView::SelectedPageChanged(int old_selected, int new_selected) {
+}
+
+void ContentsView::TransitionStarted() {
+}
+
+void ContentsView::TransitionChanged() {
+  UpdatePageBounds();
+}
+
 void ContentsView::OnGestureEvent(ui::GestureEvent* event) {
   if (!IsNamedPageActive(NAMED_PAGE_APPS))
     return;