Moved FolderImageSource class to a separate file.

Previously, this was a private class in app_list_folder_item.cc. It will
soon be required from multiple locations (to generate folder icons), so
it deserves its own file.

Also moved methods/constants relating to the tiny icon size/position
into static methods of this class (as needed by various clients).

BUG=425444

Review URL: https://codereview.chromium.org/657793004

Cr-Commit-Position: refs/heads/master@{#301028}

ui/app_list/BUILD.gn

@@ -26,6 +26,8 @@ component("app_list") {
     "app_list_switches.h",
     "app_list_view_delegate.cc",
     "app_list_view_delegate.h",
+    "folder_image_source.cc",
+    "folder_image_source.h",
     "pagination_controller.cc",
     "pagination_controller.h",
     "pagination_model.cc",

ui/app_list/app_list.gyp

@@ -74,6 +74,8 @@
         'cocoa/item_drag_controller.mm',
         'cocoa/scroll_view_with_no_scrollbars.h',
         'cocoa/scroll_view_with_no_scrollbars.mm',
+        'folder_image_source.cc',
+        'folder_image_source.h',
         'pagination_controller.cc',
         'pagination_controller.h',
         'pagination_model.cc',

ui/app_list/app_list_folder_item.cc

@@ -7,79 +7,11 @@
 #include "base/guid.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_item_list.h"
-#include "ui/gfx/canvas.h"
+#include "ui/app_list/folder_image_source.h"
 #include "ui/gfx/geometry/rect.h"
-#include "ui/gfx/image/canvas_image_source.h"
-#include "ui/gfx/image/image_skia_operations.h"
 
 namespace app_list {
 
-namespace {
-
-const int kItemIconDimension = 16;
-
-// Generates the folder icon with the top 4 child item icons laid in 2x2 tile.
-class FolderImageSource : public gfx::CanvasImageSource {
- public:
-  typedef std::vector<gfx::ImageSkia> Icons;
-
-  FolderImageSource(const Icons& icons, const gfx::Size& size)
-      : gfx::CanvasImageSource(size, false),
-        icons_(icons),
-        size_(size) {
-    DCHECK(icons.size() <= kNumFolderTopItems);
-  }
-
-  ~FolderImageSource() override {}
-
- private:
-  void DrawIcon(gfx::Canvas* canvas,
-                const gfx::ImageSkia& icon,
-                const gfx::Size icon_size,
-                int x, int y) {
-    if (icon.isNull())
-      return;
-
-    gfx::ImageSkia resized(
-        gfx::ImageSkiaOperations::CreateResizedImage(
-            icon, skia::ImageOperations::RESIZE_BEST, icon_size));
-    canvas->DrawImageInt(resized, 0, 0, resized.width(), resized.height(),
-        x, y, resized.width(), resized.height(), true);
-  }
-
-  // gfx::CanvasImageSource overrides:
-  void Draw(gfx::Canvas* canvas) override {
-    // Draw folder circle.
-    gfx::Point center = gfx::Point(size().width() / 2 , size().height() / 2);
-    SkPaint paint;
-    paint.setStyle(SkPaint::kFill_Style);
-    paint.setAntiAlias(true);
-    paint.setColor(kFolderBubbleColor);
-    canvas->DrawCircle(center, size().width() / 2, paint);
-
-    if (icons_.size() == 0)
-      return;
-
-    // Draw top items' icons.
-    const gfx::Size item_icon_size =
-        gfx::Size(kItemIconDimension, kItemIconDimension);
-    std::vector<gfx::Rect> top_icon_bounds =
-        AppListFolderItem::GetTopIconsBounds(gfx::Rect(size()));
-
-    for (size_t i= 0; i < kNumFolderTopItems && i < icons_.size(); ++i) {
-      DrawIcon(canvas, icons_[i], item_icon_size,
-               top_icon_bounds[i].x(), top_icon_bounds[i].y());
-    }
-  }
-
-  Icons icons_;
-  gfx::Size size_;
-
-  DISALLOW_COPY_AND_ASSIGN(FolderImageSource);
-};
-
-}  // namespace
-
 AppListFolderItem::AppListFolderItem(const std::string& id,
                                      FolderType folder_type)
     : AppListItem(id),
@@ -117,14 +49,13 @@ gfx::Rect AppListFolderItem::GetTargetIconRectInFolderForItem(
   for (size_t i = 0; i < top_items_.size(); ++i) {
     if (item->id() == top_items_[i]->id()) {
       std::vector<gfx::Rect> rects =
-          AppListFolderItem::GetTopIconsBounds(folder_icon_bounds);
+          FolderImageSource::GetTopIconsBounds(folder_icon_bounds);
       return rects[i];
     }
   }
 
   gfx::Rect target_rect(folder_icon_bounds);
-  target_rect.ClampToCenteredSize(
-      gfx::Size(kItemIconDimension, kItemIconDimension));
+  target_rect.ClampToCenteredSize(FolderImageSource::ItemIconSize());
   return target_rect;
 }
 
@@ -135,38 +66,6 @@ void AppListFolderItem::Activate(int event_flags) {
 // static
 const char AppListFolderItem::kItemType[] = "FolderItem";
 
-// static
-std::vector<gfx::Rect> AppListFolderItem::GetTopIconsBounds(
-    const gfx::Rect& folder_icon_bounds) {
-  const int delta_to_center = 1;
-  gfx::Point icon_center = folder_icon_bounds.CenterPoint();
-  std::vector<gfx::Rect> top_icon_bounds;
-
-  // Get the top left icon bounds.
-  int left_x = icon_center.x() - kItemIconDimension - delta_to_center;
-  int top_y = icon_center.y() - kItemIconDimension - delta_to_center;
-  gfx::Rect top_left(left_x, top_y, kItemIconDimension, kItemIconDimension);
-  top_icon_bounds.push_back(top_left);
-
-  // Get the top right icon bounds.
-  int right_x = icon_center.x() + delta_to_center;
-  gfx::Rect top_right(right_x, top_y, kItemIconDimension, kItemIconDimension);
-  top_icon_bounds.push_back(top_right);
-
-  // Get the bottom left icon bounds.
-  int bottom_y = icon_center.y() + delta_to_center;
-  gfx::Rect bottom_left(
-      left_x, bottom_y, kItemIconDimension, kItemIconDimension);
-  top_icon_bounds.push_back(bottom_left);
-
-  // Get the bottom right icon bounds.
-  gfx::Rect bottom_right(
-      right_x, bottom_y, kItemIconDimension, kItemIconDimension);
-  top_icon_bounds.push_back(bottom_right);
-
-  return top_icon_bounds;
-}
-
 const char* AppListFolderItem::GetItemType() const {
   return AppListFolderItem::kItemType;
 }

ui/app_list/app_list_folder_item.h

@@ -68,12 +68,6 @@ class APP_LIST_EXPORT AppListFolderItem : public AppListItem,
   void OnExtensionPreferenceChanged() override;
   bool CompareForTest(const AppListItem* other) const override;
 
-  // Calculates the top item icons' bounds inside |folder_icon_bounds|.
-  // Returns the bounds of top item icons in sequence of top left, top right,
-  // bottom left, bottom right.
-  static std::vector<gfx::Rect> GetTopIconsBounds(
-      const gfx::Rect& folder_icon_bounds);
-
   // Returns an id for a new folder.
   static std::string GenerateId();
 

ui/app_list/folder_image_source.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/folder_image_source.h"
+
+#include "ui/app_list/app_list_constants.h"
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/geometry/point.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/gfx/image/image_skia.h"
+#include "ui/gfx/image/image_skia_operations.h"
+
+namespace {
+
+const int kItemIconDimension = 16;
+
+}  // namespace
+
+namespace app_list {
+
+FolderImageSource::FolderImageSource(const Icons& icons, const gfx::Size& size)
+    : gfx::CanvasImageSource(size, false), icons_(icons), size_(size) {
+  DCHECK(icons.size() <= kNumFolderTopItems);
+}
+
+FolderImageSource::~FolderImageSource() {
+}
+
+// static
+gfx::Size FolderImageSource::ItemIconSize() {
+  return gfx::Size(kItemIconDimension, kItemIconDimension);
+}
+
+// static
+std::vector<gfx::Rect> FolderImageSource::GetTopIconsBounds(
+    const gfx::Rect& folder_icon_bounds) {
+  const int delta_to_center = 1;
+  gfx::Point icon_center = folder_icon_bounds.CenterPoint();
+  std::vector<gfx::Rect> top_icon_bounds;
+
+  // Get the top left icon bounds.
+  int left_x = icon_center.x() - kItemIconDimension - delta_to_center;
+  int top_y = icon_center.y() - kItemIconDimension - delta_to_center;
+  gfx::Rect top_left(left_x, top_y, kItemIconDimension, kItemIconDimension);
+  top_icon_bounds.push_back(top_left);
+
+  // Get the top right icon bounds.
+  int right_x = icon_center.x() + delta_to_center;
+  gfx::Rect top_right(right_x, top_y, kItemIconDimension, kItemIconDimension);
+  top_icon_bounds.push_back(top_right);
+
+  // Get the bottom left icon bounds.
+  int bottom_y = icon_center.y() + delta_to_center;
+  gfx::Rect bottom_left(
+      left_x, bottom_y, kItemIconDimension, kItemIconDimension);
+  top_icon_bounds.push_back(bottom_left);
+
+  // Get the bottom right icon bounds.
+  gfx::Rect bottom_right(
+      right_x, bottom_y, kItemIconDimension, kItemIconDimension);
+  top_icon_bounds.push_back(bottom_right);
+
+  return top_icon_bounds;
+}
+
+void FolderImageSource::DrawIcon(gfx::Canvas* canvas,
+                                 const gfx::ImageSkia& icon,
+                                 const gfx::Size icon_size,
+                                 int x,
+                                 int y) {
+  if (icon.isNull())
+    return;
+
+  gfx::ImageSkia resized(gfx::ImageSkiaOperations::CreateResizedImage(
+      icon, skia::ImageOperations::RESIZE_BEST, icon_size));
+  canvas->DrawImageInt(resized,
+                       0,
+                       0,
+                       resized.width(),
+                       resized.height(),
+                       x,
+                       y,
+                       resized.width(),
+                       resized.height(),
+                       true);
+}
+
+void FolderImageSource::Draw(gfx::Canvas* canvas) {
+  // Draw folder circle.
+  gfx::Point center = gfx::Point(size().width() / 2, size().height() / 2);
+  SkPaint paint;
+  paint.setStyle(SkPaint::kFill_Style);
+  paint.setAntiAlias(true);
+  paint.setColor(kFolderBubbleColor);
+  canvas->DrawCircle(center, size().width() / 2, paint);
+
+  if (icons_.size() == 0)
+    return;
+
+  // Draw top items' icons.
+  const gfx::Size item_icon_size(ItemIconSize());
+  std::vector<gfx::Rect> top_icon_bounds = GetTopIconsBounds(gfx::Rect(size()));
+
+  for (size_t i = 0; i < kNumFolderTopItems && i < icons_.size(); ++i) {
+    DrawIcon(canvas,
+             icons_[i],
+             item_icon_size,
+             top_icon_bounds[i].x(),
+             top_icon_bounds[i].y());
+  }
+}
+
+}  // namespace app_list

ui/app_list/folder_image_source.h

+// 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.
+
+#ifndef UI_APP_LIST_APP_LIST_FOLDER_IMAGE_SOURCE_H_
+#define UI_APP_LIST_APP_LIST_FOLDER_IMAGE_SOURCE_H_
+
+#include <vector>
+
+#include "ui/gfx/image/canvas_image_source.h"
+
+namespace gfx {
+class Canvas;
+class ImageSkia;
+class Rect;
+class Size;
+}
+
+namespace app_list {
+
+// Generates the folder icon with the top 4 child item icons laid in 2x2 tile.
+class FolderImageSource : public gfx::CanvasImageSource {
+ public:
+  typedef std::vector<gfx::ImageSkia> Icons;
+
+  FolderImageSource(const Icons& icons, const gfx::Size& size);
+  ~FolderImageSource() override;
+
+  // Gets the size of a small app icon inside the folder icon.
+  static gfx::Size ItemIconSize();
+
+  // Calculates the top item icons' bounds inside |folder_icon_bounds|.
+  // Returns the bounds of top item icons in sequence of top left, top right,
+  // bottom left, bottom right.
+  static std::vector<gfx::Rect> GetTopIconsBounds(
+      const gfx::Rect& folder_icon_bounds);
+
+ private:
+  void DrawIcon(gfx::Canvas* canvas,
+                const gfx::ImageSkia& icon,
+                const gfx::Size icon_size,
+                int x,
+                int y);
+
+  // gfx::CanvasImageSource overrides:
+  void Draw(gfx::Canvas* canvas) override;
+
+  Icons icons_;
+  gfx::Size size_;
+
+  DISALLOW_COPY_AND_ASSIGN(FolderImageSource);
+};
+
+}  // namespace app_list
+
+#endif  // UI_APP_LIST_APP_LIST_FOLDER_ITEM_H_

ui/app_list/views/apps_container_view.cc

@@ -11,6 +11,7 @@
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_folder_item.h"
 #include "ui/app_list/app_list_switches.h"
+#include "ui/app_list/folder_image_source.h"
 #include "ui/app_list/views/app_list_folder_view.h"
 #include "ui/app_list/views/app_list_item_view.h"
 #include "ui/app_list/views/app_list_main_view.h"
@@ -202,7 +203,7 @@ std::vector<gfx::Rect> AppsContainerView::GetTopItemIconBoundsInActiveFolder() {
       folder_item_view->GetIconBounds());
   gfx::Rect to_container = apps_grid_view_->ConvertRectToParent(to_grid_view);
 
-  return AppListFolderItem::GetTopIconsBounds(to_container);
+  return FolderImageSource::GetTopIconsBounds(to_container);
 }
 
 void AppsContainerView::CreateViewsForFolderTopItemsAnimation(