arc-app-launcher: Minimal support for ARC app launcher.

chrome/browser/ui/app_list/arc_app_icon.h

Index: chrome/browser/ui/app_list/arc_app_icon.h
diff --git a/chrome/browser/ui/app_list/arc_app_icon.h b/chrome/browser/ui/app_list/arc_app_icon.h
new file mode 100644
index 0000000000000000000000000000000000000000..8787342e73da64e1708adaa1caab8cee31d6379a
--- /dev/null
+++ b/chrome/browser/ui/app_list/arc_app_icon.h
@@ -0,0 +1,98 @@
+// Copyright 2015 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 CHROME_BROWSER_UI_APP_LIST_ARC_APP_ICON_H_
+#define CHROME_BROWSER_UI_APP_LIST_ARC_APP_ICON_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/scoped_vector.h"
+#include "base/memory/weak_ptr.h"
+#include "ui/base/layout.h"
+#include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_skia.h"
+
+namespace base {
+class FilePath;
+}
+
+namespace content {
+class BrowserContext;
+}
+
+// A class that provides an ImageSkia for UI code to use. It handles Arc app

[Luis Héctor Chávez, 2015/11/12 20:49:16]

Use "ARC" consistently across this change.

[khmel1, 2015/11/13 15:00:55]

Done.

+// icon resource loading, screen scale factor change etc. UI code that uses
+// Arc app icon should host this class.
+class ArcAppIcon {
+ public:
+  class Observer {
+   public:
+    // Invoked when a new image rep for an additional scale factor
+    // is loaded and added to |image|.
+    virtual void OnIconUpdated() = 0;
+
+   protected:
+    virtual ~Observer() {}
+  };
+
+  ArcAppIcon(content::BrowserContext* context,
+             const std::string& app_id,
+             int resource_size_in_dip,
+             Observer* observer);
+  ~ArcAppIcon();
+
+  gfx::Image image() const { return image_; }
+  const gfx::ImageSkia& image_skia() const { return image_skia_; }
+
+  // Icon loading is performed in several steps. It is initiated by
+  // LoadImageForScaleFactor request that specifies a required scale factor.
+  // ArcAppPrefs is used to resolve a path to resource. Content of file is
+  // asynchronously read in context of browser file thread. On success read,

[Luis Héctor Chávez, 2015/11/12 20:49:16]

nit: On successful read.

[khmel1, 2015/11/13 15:00:55]

Done.

+  // an icon data is decoded to an image in the special utility process.
+  // DecodeRequest is used to interact with the utility process, and each
+  // active request is stored at decode_requests_ vector. When decoding is

[Luis Héctor Chávez, 2015/11/12 20:49:16]

nit: |decode_requests_|. Same below.

[khmel1, 2015/11/13 15:00:55]

Done.

+  // complete, results are returned in context of UI thread, and corresponding
+  // request is removed from decode_requests_. In case of some requests are not
+  // completed by the time of deleting this icon, they are automatically
+  // canceled.
+  // In case of the icon file is not available this requests ArcAppPrefs to
+  // install required resource from Android side. ArcAppPrefs notifies UI items

[Luis Héctor Chávez, 2015/11/12 20:49:16]

Try to say "ARC" instead of Android.

[khmel1, 2015/11/13 15:00:55]

Done.

+  // that new icon is available and corresponding item should invoke
+  // LoadImageForScaleFactor again.
+  void LoadForScaleFactor(ui::ScaleFactor scale_factor);
+
+ private:
+  class Source;
+  class DecodeRequest;
+
+  void RequestIcon(ui::ScaleFactor scale_factor);
+  void ReadOnFileThread(ui::ScaleFactor scale_factor,
+                        const base::FilePath& path);
+  void OnIconRead(ui::ScaleFactor scale_factor,
+                  const std::string& unsafe_image_data);
+  void Update(const gfx::ImageSkia* image);
+  void DiscardDecodeRequest(DecodeRequest* request);
+
+  content::BrowserContext* context_;
+  std::string app_id_;
+  const int resource_size_in_dip_;
+  Observer* observer_;
+
+  Source* source_ = nullptr;  // Owned by ImageSkia storage.

[Luis Héctor Chávez, 2015/11/12 20:49:16]

Can this be initialized in the constructor?

[xiyuan, 2015/11/12 21:34:02]

This is the preferred style in chromium code.

See https://chromium-cpp.appspot.com/, check out the "Non-Static Class Member
Initializers" row.

[khmel1, 2015/11/13 15:00:55]

Acknowledged.

[khmel1, 2015/11/13 15:00:55]

Acknowledged.

+  gfx::ImageSkia image_skia_;
+
+  // The image wrapper around |image_skia_|.
+  // Note: this is reset each time a new representation is loaded.
+  gfx::Image image_;
+
+  // Contains pending image decode requests.
+  ScopedVector<DecodeRequest> decode_requests_;
+
+  base::WeakPtrFactory<ArcAppIcon> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcAppIcon);
+};
+
+#endif  // CHROME_BROWSER_UI_APP_LIST_ARC_APP_ICON_H_