chromeos: Fix pixelated icons in app list and launcher (part 2) (by xiyuan)

chrome/browser/extensions/extension_icon_image.cc

Index: chrome/browser/extensions/extension_icon_image.cc
diff --git a/chrome/browser/extensions/extension_icon_image.cc b/chrome/browser/extensions/extension_icon_image.cc
new file mode 100644
index 0000000000000000000000000000000000000000..95f99d78ca3a9724e1a4c1a465856abe57d876e8
--- /dev/null
+++ b/chrome/browser/extensions/extension_icon_image.cc
@@ -0,0 +1,177 @@
+// Copyright (c) 2012 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 "chrome/browser/extensions/extension_icon_image.h"
+
+#include <vector>
+
+#include "chrome/browser/extensions/extension_icon_image_delegate.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "chrome/common/extensions/extension.h"
+#include "content/public/browser/notification_service.h"
+#include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_skia_source.h"
+#include "ui/gfx/size.h"
+
+namespace {
+
+ExtensionResource GetExtensionIconResource(
+    const extensions::Extension* extension,
+    const ExtensionIconSet& icons,
+    int size,
+    ExtensionIconSet::MatchType match_type) {
+  std::string path = icons.Get(size, match_type);
+  if (path.empty())
+    return ExtensionResource();
+
+  return extension->GetResource(path);
+}
+
+}  // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+// ExtensionIconImage::Source
+
+class ExtensionIconImage::Source : public gfx::ImageSkiaSource {
+ public:
+  explicit Source(ExtensionIconImage* host);
+  virtual ~Source();
+
+  void ResetHost();
+
+ private:
+  // gfx::ImageSkiaSource overrides:
+  virtual gfx::ImageSkiaRep GetImageForScale(
+      ui::ScaleFactor scale_factor) OVERRIDE;
+
+  ExtensionIconImage* host_;
+
+  DISALLOW_COPY_AND_ASSIGN(Source);
+};
+
+ExtensionIconImage::Source::Source(ExtensionIconImage* host)
+    : host_(host) {
+}
+
+ExtensionIconImage::Source::~Source() {
+}
+
+void ExtensionIconImage::Source::ResetHost() {
+  host_ = NULL;
+}
+
+gfx::ImageSkiaRep ExtensionIconImage::Source::GetImageForScale(
+    ui::ScaleFactor scale_factor) {
+  if (host_)
+    host_->LoadImageForScaleFactor(scale_factor);
+  return gfx::ImageSkiaRep();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// ExtensionIconImage
+
+ExtensionIconImage::ExtensionIconImage(
+    const extensions::Extension* extension,
+    const ExtensionIconSet& icon_set,
+    int resource_size_in_dip,
+    ExtensionIconSet::MatchType resource_match_type,
+    const gfx::Size& desired_size_in_dip,
+    ImageLoadingTracker::CacheParam cache_param,
+    ExtensionIconImageDelegate* delegate)
+    : extension_(extension),
+      icon_set_(icon_set),
+      resource_size_in_dip_(resource_size_in_dip),
+      resource_match_type_(resource_match_type),
+      desired_size_in_dip_(desired_size_in_dip),
+      cache_param_(cache_param),
+      delegate_(delegate),
+      source_(NULL),
+      ALLOW_THIS_IN_INITIALIZER_LIST(tracker_(this)) {
+  // Check whether extension has at least 1x resource.
+  const int resource_size_in_pixel = resource_size_in_dip_;
+  const bool can_load = ImageLoadingTracker::CanLoadImage(
+      extension_,
+      GetExtensionIconResource(extension_,
+                               icon_set_,
+                               resource_size_in_pixel,
+                               resource_match_type_));
+  if (!can_load)
+    return;
+
+  source_ = new Source(this);
+  image_skia_ = gfx::ImageSkia(source_, desired_size_in_dip_);
+
+  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
+                 content::NotificationService::AllSources());
+}
+
+ExtensionIconImage::~ExtensionIconImage() {
+  // |source_| could be NULL if resource does not exist.
+  if (source_)
+    source_->ResetHost();
+}
+
+void ExtensionIconImage::LoadImageForScaleFactor(ui::ScaleFactor scale_factor) {
+  // Do nothing if extension is unloaded.
+  if (!extension_)
+    return;
+
+  const float scale = ui::GetScaleFactorScale(scale_factor);
+  const int resource_size_in_pixel =
+      static_cast<int>(resource_size_in_dip_ * scale);
+
+  ExtensionResource resource = GetExtensionIconResource(
+      extension_, icon_set_, resource_size_in_pixel, resource_match_type_);
+  // If resource does not exists, fallback to 1x if needed.
+  if (!ImageLoadingTracker::CanLoadImage(extension_, resource)) {
+    scale_factor = ui::SCALE_FACTOR_100P;
+    if (image_skia_.HasRepresentation(scale_factor))
+      return;
+
+    LoadImageForScaleFactor(scale_factor);
+    return;
+  }
+
+  int id = tracker_.next_id();
+  load_map_[id] = scale_factor;
+
+  std::vector<ImageLoadingTracker::ImageRepInfo> info_list;
+  info_list.push_back(ImageLoadingTracker::ImageRepInfo(
+      resource,
+      ImageLoadingTracker::ImageRepInfo::ALWAYS_RESIZE,
+      desired_size_in_dip_.Scale(scale),
+      scale_factor));
+  tracker_.LoadImages(extension_, info_list, cache_param_);
+}
+
+void ExtensionIconImage::OnImageLoaded(const gfx::Image& image,
+                                       const std::string& extension_id,
+                                       int index) {
+  if (image.IsEmpty())
+    return;
+
+  LoadMap::iterator load_map_it = load_map_.find(index);
+  DCHECK(load_map_it != load_map_.end());
+
+  ui::ScaleFactor scale_factor = load_map_it->second;
+  DCHECK(image.ToImageSkia()->HasRepresentation(scale_factor));
+  gfx::ImageSkiaRep rep = image.ToImageSkia()->GetRepresentation(scale_factor);
+  DCHECK(!rep.is_null());
+  image_skia_.AddRepresentation(rep);
+
+  if (delegate_)
+    delegate_->OnExtensionIconImageChanged(this);
+}
+
+void ExtensionIconImage::Observe(int type,
+                                 const content::NotificationSource& source,
+                                 const content::NotificationDetails& details) {
+  DCHECK_EQ(type, chrome::NOTIFICATION_EXTENSION_UNLOADED);
+
+  const extensions::Extension* extension =
+      content::Details<extensions::UnloadedExtensionInfo>(details)->extension;
+
+  if (extension_ == extension)
+    extension_ = NULL;
+}