Break out manifest icon logic from ShortcutHelper

chrome/browser/android/manifest_icon_selector.h

Index: chrome/browser/android/manifest_icon_selector.h
diff --git a/chrome/browser/android/manifest_icon_selector.h b/chrome/browser/android/manifest_icon_selector.h
new file mode 100644
index 0000000000000000000000000000000000000000..6e857b284fb7cade0f4a56d93a3980ced2c77812
--- /dev/null
+++ b/chrome/browser/android/manifest_icon_selector.h
@@ -0,0 +1,62 @@
+// 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_ANDROID_MANIFEST_ICON_SELECTOR_H_
+#define CHROME_BROWSER_ANDROID_MANIFEST_ICON_SELECTOR_H_
+
+#include "base/basictypes.h"
+#include "content/public/common/manifest.h"

[mlamouri (slow - plz ping), 2015/01/30 19:25:42]

nit: you might want to include gurl.h here.

[gone, 2015/01/30 20:08:11]

Done.

+
+namespace content {
+class WebContents;
+}  // namespace content
+
+namespace IPC {
+class Message;
+}

[mlamouri (slow - plz ping), 2015/01/30 19:25:43]

nit: "// namespace IPC"

[gone, 2015/01/30 20:08:11]

Done.

+
+class GURL;
+
+// Selects the icon most closely matching the size constraints.

[mlamouri (slow - plz ping), 2015/01/30 19:25:42]

nit: I would specify that this is following very basic heuristics and
improvements are welcome.

[gone, 2015/01/30 20:08:11]

Done.

+class ManifestIconSelector {
+ public:
+  ManifestIconSelector(content::WebContents* web_contents,

[mlamouri (slow - plz ping), 2015/01/30 19:25:42]

Instead of having a constructor that takes a WebContents and an int, could you
pass that to |FindBestMatchingIcon| and make it static? (Actually, you would get
only the preferred icon size in pixel, right?)

If you need the preferred_icon_size_in_px_ too much, you could have the ctor
private and create an instance instance inside the static method.

I think that would make it less heavy to use for callers, instead of having a
class member, they could just use ManifestIconSelector as a helper.

[gone, 2015/01/30 20:08:11]

Done.

+                       int preferred_size_in_dp);
+  virtual ~ManifestIconSelector() {}
+
+  // Runs the algorithm to find the best matching icon in the icons listed in
+  // the Manifest.
+  // Returns the icon url if a suitable icon is found. An empty URL otherwise.
+  GURL FindBestMatchingIcon(
+      const std::vector<content::Manifest::Icon>& icons,
+      content::WebContents* web_contents) const;
+
+ private:
+  // Returns an array containing the items in |icons| without the unsupported
+  // image MIME types.
+  static std::vector<content::Manifest::Icon> FilterIconsByType(
+      const std::vector<content::Manifest::Icon>& icons);
+
+  // Runs an algorithm only based on icon declared sizes. It will try to find
+  // size that is the closest to preferred_icon_size_in_px_ but bigger than
+  // preferred_icon_size_in_px_ if possible.
+  // Returns the icon url if a suitable icon is found. An empty URL otherwise.
+  GURL FindBestMatchingIcon(const std::vector<content::Manifest::Icon>& icons,
+                            float density) const;
+
+  // Returns whether the preferred_icon_size_in_px_ is in the given |sizes|.
+  bool IconSizesContainsPreferredSize(
+      const std::vector<gfx::Size>& sizes) const;
+
+  // Returns whether the 'any' (ie. gfx::Size(0,0)) is in the given |sizes|.
+  bool IconSizesContainsAny(const std::vector<gfx::Size>& sizes) const;
+
+  const int preferred_icon_size_in_px_;
+
+  friend class ManifestIconSelectorTest;
+
+  DISALLOW_COPY_AND_ASSIGN(ManifestIconSelector);
+};
+
+#endif  // CHROME_BROWSER_ANDROID_MANIFEST_ICON_SELECTOR_H_