Moved FolderImageSource class to a separate file.

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