App list: Added contents view custom animation framework.

ui/app_list/views/contents_animator.cc

+// Copyright 2014 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.
+
+#include "ui/app_list/views/contents_animator.h"
+
+#include "ui/app_list/views/contents_view.h"
+#include "ui/gfx/animation/tween.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace app_list {
+
+// ContentsAnimator
+
+ContentsAnimator::ContentsAnimator(ContentsView* contents_view)
+    : contents_view_(contents_view) {
+}
+
+ContentsAnimator::~ContentsAnimator() {
+}
+
+gfx::Rect ContentsAnimator::GetOffscreenPageBounds(int page_index) const {
+  gfx::Rect bounds(contents_view_->GetContentsBounds());
+  // The start page and search page origins are above; all other pages' origins
+  // are below.
+  int page_height = bounds.height();
+  bool origin_above = contents_view_->GetPageIndexForState(
+                          AppListModel::STATE_START) == page_index ||
+                      contents_view_->GetPageIndexForState(
+                          AppListModel::STATE_SEARCH_RESULTS) == page_index;
+  bounds.set_y(origin_above ? -page_height : page_height);
+  return bounds;
+}
+
+// DefaultAnimator
+
+DefaultAnimator::DefaultAnimator(ContentsView* contents_view)
+    : ContentsAnimator(contents_view) {
+}
+
+std::string DefaultAnimator::NameForTests() const {
+  return "DefaultAnimator";
+}
+
+void DefaultAnimator::Update(double progress, int from_page, int to_page) {
+  // Move the from page from 0 to its origin. Move the to page from its origin
+  // to 0.
+  gfx::Rect on_screen(contents_view()->GetDefaultContentsBounds());
+  gfx::Rect from_page_origin(GetOffscreenPageBounds(from_page));
+  gfx::Rect to_page_origin(GetOffscreenPageBounds(to_page));
+  gfx::Rect from_page_rect(
+      gfx::Tween::RectValueBetween(progress, on_screen, from_page_origin));
+  gfx::Rect to_page_rect(
+      gfx::Tween::RectValueBetween(progress, to_page_origin, on_screen));
+
+  contents_view()->GetPageView(from_page)->SetBoundsRect(from_page_rect);
+  contents_view()->GetPageView(to_page)->SetBoundsRect(to_page_rect);
+}
+
+// StartToAppsAnimator
+
+StartToAppsAnimator::StartToAppsAnimator(ContentsView* contents_view)
+    : ContentsAnimator(contents_view) {
+}
+
+std::string StartToAppsAnimator::NameForTests() const {
+  return "StartToAppsAnimator";
+}
+
+void StartToAppsAnimator::Update(double progress,
+                                 int start_page,
+                                 int apps_page) {
+  // TODO(mgiuca): This is just a clone of DefaultAnimator's animation. Write a
+  // custom animation for the All Apps button on the Start page.
+  gfx::Rect on_screen(contents_view()->GetDefaultContentsBounds());
+  gfx::Rect from_page_origin(GetOffscreenPageBounds(start_page));
+  gfx::Rect to_page_origin(GetOffscreenPageBounds(apps_page));
+  gfx::Rect from_page_rect(
+      gfx::Tween::RectValueBetween(progress, on_screen, from_page_origin));
+  gfx::Rect to_page_rect(
+      gfx::Tween::RectValueBetween(progress, to_page_origin, on_screen));
+
+  contents_view()->GetPageView(start_page)->SetBoundsRect(from_page_rect);
+  contents_view()->GetPageView(apps_page)->SetBoundsRect(to_page_rect);
+}
+
+}  // app_list