Use Manifest.icons instead of favicon in ShortcutHelper when possible.

chrome/browser/android/shortcut_helper.cc

Index: chrome/browser/android/shortcut_helper.cc
diff --git a/chrome/browser/android/shortcut_helper.cc b/chrome/browser/android/shortcut_helper.cc
index a485d40ec62cb6b12304e5e7130fc5b5da01f1d8..339e26ffd0582c4c49f7267e176150cbfc66650a 100644
--- a/chrome/browser/android/shortcut_helper.cc
+++ b/chrome/browser/android/shortcut_helper.cc
@@ -5,12 +5,14 @@
 #include "chrome/browser/android/shortcut_helper.h"
 
 #include <jni.h>
+#include <limits>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/basictypes.h"
 #include "base/location.h"
 #include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "base/threading/worker_pool.h"
 #include "chrome/browser/android/tab_android.h"
@@ -25,12 +27,20 @@
 #include "content/public/common/frame_navigate_params.h"
 #include "content/public/common/manifest.h"
 #include "jni/ShortcutHelper_jni.h"
+#include "net/base/mime_util.h"
 #include "ui/gfx/android/java_bitmap.h"
 #include "ui/gfx/codec/png_codec.h"
 #include "ui/gfx/color_analysis.h"
 #include "ui/gfx/favicon_size.h"
+#include "ui/gfx/screen.h"
 #include "url/gurl.h"
 
+using content::Manifest;
+
+// Android's preferred icon size in DP is 48, as defined in
+// http://developer.android.com/design/style/iconography.html
+const int ShortcutHelper::kPreferredIconSizeInDp = 48;
+
 jlong Initialize(JNIEnv* env, jobject obj, jlong tab_android_ptr) {
   TabAndroid* tab = reinterpret_cast<TabAndroid*>(tab_android_ptr);
 
@@ -49,6 +59,11 @@ ShortcutHelper::ShortcutHelper(JNIEnv* env,
       url_(web_contents->GetURL()),
       display_(content::Manifest::DISPLAY_MODE_BROWSER),
       orientation_(blink::WebScreenOrientationLockDefault),
+      add_shortcut_requested_(false),
+      manifest_icon_status_(MANIFEST_ICON_STATUS_NONE),
+      preferred_icon_size_in_px_(kPreferredIconSizeInDp *
+          gfx::Screen::GetScreenFor(web_contents->GetNativeView())->
+              GetPrimaryDisplay().device_scale_factor()),
       weak_ptr_factory_(this) {
 }
 
@@ -97,6 +112,124 @@ void ShortcutHelper::OnDidGetWebApplicationInfo(
                                          weak_ptr_factory_.GetWeakPtr()));
 }
 
+bool ShortcutHelper::IconSizesContainsPreferredSize(
+    const std::vector<gfx::Size>& sizes) const {
+  for (size_t i = 0; i < sizes.size(); ++i) {
+    if (sizes[i].height() != sizes[i].width())
+      continue;
+    if (sizes[i].width() == preferred_icon_size_in_px_)
+      return true;
+  }
+
+  return false;
+}
+
+bool ShortcutHelper::IconSizesContainsAny(
+    const std::vector<gfx::Size>& sizes) const {
+  for (size_t i = 0; i < sizes.size(); ++i) {
+    if (sizes[i].IsEmpty())
+      return true;
+  }
+
+  return false;
+}
+
+GURL ShortcutHelper::FindBestMatchingIcon(
+    const std::vector<Manifest::Icon>& icons, float density) const {
+  GURL url;
+  int best_delta = std::numeric_limits<int>::min();
+
+  for (size_t i = 0; i < icons.size(); ++i) {
+    if (icons[i].density != density)
+      continue;
+
+    const std::vector<gfx::Size>& sizes = icons[i].sizes;
+    for (size_t j = 0; j < sizes.size(); ++j) {
+      if (sizes[j].height() != sizes[j].width())
+        continue;
+      int delta = sizes[j].width() - preferred_icon_size_in_px_;
+      if (delta == 0)
+        return icons[i].src;
+      if (best_delta > 0 && delta < 0)
+        continue;
+      if ((best_delta > 0 && delta < best_delta) ||
+          (best_delta < 0 && delta > best_delta)) {
+        url = icons[i].src;
+        best_delta = delta;
+      }
+    }
+  }
+
+  return url;
+}
+
+// static
+std::vector<Manifest::Icon> ShortcutHelper::FilterIconsByType(
+    const std::vector<Manifest::Icon>& icons) {
+  std::vector<Manifest::Icon> result;
+
+  for (size_t i = 0; i < icons.size(); ++i) {
+    if (icons[i].type.is_null() ||
+        net::IsSupportedImageMimeType(
+            base::UTF16ToUTF8(icons[i].type.string()))) {
+      result.push_back(icons[i]);
+    }
+  }
+
+  return result;
+}
+
+GURL ShortcutHelper::FindBestMatchingIcon(
+    const std::vector<Manifest::Icon>& unfiltered_icons) const {
+  const float device_scale_factor =
+      gfx::Screen::GetScreenFor(web_contents()->GetNativeView())->
+          GetPrimaryDisplay().device_scale_factor();
+
+  GURL url;
+  std::vector<Manifest::Icon> icons = FilterIconsByType(unfiltered_icons);
+
+  // The first pass is to find the ideal icon. That icon is of the right size
+  // with the default density or the device's density.
+  for (size_t i = 0; i < icons.size(); ++i) {
+    if (icons[i].density == device_scale_factor &&
+        IconSizesContainsPreferredSize(icons[i].sizes)) {
+      return icons[i].src;
+    }
+
+    // If there is an icon with the right size but not the right density, keep
+    // it on the side and only use it if nothing better is found.
+    if (icons[i].density == Manifest::Icon::kDefaultDensity &&
+        IconSizesContainsPreferredSize(icons[i].sizes)) {
+      url = icons[i].src;
+    }
+  }
+
+  // The second pass is to find an icon with 'any'. The current device scale
+  // factor is preferred. Otherwise, the default scale factor is used.
+  for (size_t i = 0; i < icons.size(); ++i) {
+    if (icons[i].density == device_scale_factor &&
+        IconSizesContainsAny(icons[i].sizes)) {
+      return icons[i].src;
+    }
+
+    // If there is an icon with 'any' but not the right density, keep it on the
+    // side and only use it if nothing better is found.
+    if (icons[i].density == Manifest::Icon::kDefaultDensity &&
+        IconSizesContainsAny(icons[i].sizes)) {
+      url = icons[i].src;
+    }
+  }
+
+  // The last pass will try to find the best suitable icon for the device's
+  // scale factor. If none, another pass will be run using kDefaultDensity.
+  if (!url.is_valid())
+    url = FindBestMatchingIcon(icons, device_scale_factor);
+  if (!url.is_valid())
+    url = FindBestMatchingIcon(icons, Manifest::Icon::kDefaultDensity);
+
+  return url;
+}
+
 void ShortcutHelper::OnDidGetManifest(const content::Manifest& manifest) {
   // Set the title based on the manifest value, if any.
   if (!manifest.short_name.is_null())
@@ -128,6 +261,16 @@ void ShortcutHelper::OnDidGetManifest(const content::Manifest& manifest) {
       orientation_ = manifest.orientation;
   }
 
+  GURL icon_src = FindBestMatchingIcon(manifest.icons);
+  if (icon_src.is_valid()) {
+    web_contents()->DownloadImage(icon_src,
+                                  false,
+                                  preferred_icon_size_in_px_,
+                                  base::Bind(&ShortcutHelper::OnDidDownloadIcon,
+                                             weak_ptr_factory_.GetWeakPtr()));
+    manifest_icon_status_ = MANIFEST_ICON_STATUS_FETCHING;
+  }
+
   // The ShortcutHelper is now able to notify its Java counterpart that it is
   // initialized. OnInitialized method is not conceptually part of getting the
   // manifest data but it happens that the initialization is finalized when
@@ -140,6 +283,40 @@ void ShortcutHelper::OnDidGetManifest(const content::Manifest& manifest) {
   Java_ShortcutHelper_onInitialized(env, j_obj.obj(), j_title.obj());
 }
 
+void ShortcutHelper::OnDidDownloadIcon(int id,
+                                       int http_status_code,
+                                       const GURL& url,
+                                       const std::vector<SkBitmap>& bitmaps,
+                                       const std::vector<gfx::Size>& sizes) {
+  // If getting the candidate manifest icon failed, the ShortcutHelper should
+  // fallback to the favicon.
+  // If the user already requested to add the shortcut, it will do so but use
+  // the favicon instead.
+  // Otherwise, it sets the state as if there was no manifest icon pending.
+  if (bitmaps.empty()) {
+    if (add_shortcut_requested_)
+      AddShortcutUsingFavicon();
+    else
+      manifest_icon_status_ = MANIFEST_ICON_STATUS_NONE;
+    return;
+  }
+
+  // There might be multiple bitmaps returned. The one to pick is bigger or
+  // equal to the preferred size. |bitmaps| is ordered from bigger to smaller.
+  int preferred_bitmap_index = 0;
+  for (size_t i = 0; i < bitmaps.size(); ++i) {
+    if (bitmaps[i].height() < preferred_icon_size_in_px_)
+      break;
+    preferred_bitmap_index = i;
+  }
+
+  manifest_icon_ = bitmaps[preferred_bitmap_index];
+  manifest_icon_status_ = MANIFEST_ICON_STATUS_DONE;
+
+  if (add_shortcut_requested_)
+    AddShortcutUsingManifestIcon();
+}
+
 void ShortcutHelper::TearDown(JNIEnv*, jobject) {
   Destroy();
 }
@@ -153,10 +330,43 @@ void ShortcutHelper::AddShortcut(
     jobject obj,
     jstring jtitle,
     jint launcher_large_icon_size) {
+  add_shortcut_requested_ = true;
+
   base::string16 title = base::android::ConvertJavaStringToUTF16(env, jtitle);
   if (!title.empty())
     title_ = title;
 
+  switch (manifest_icon_status_) {
+    case MANIFEST_ICON_STATUS_NONE:
+      AddShortcutUsingFavicon();
+      break;
+    case MANIFEST_ICON_STATUS_FETCHING:
+      // ::OnDidDownloadIcon() will call AddShortcutUsingManifestIcon().
+      break;
+    case MANIFEST_ICON_STATUS_DONE:
+      AddShortcutUsingManifestIcon();
+      break;
+  }
+}
+
+void ShortcutHelper::AddShortcutUsingManifestIcon() {
+  // Stop observing so we don't get destroyed while doing the last steps.
+  Observe(NULL);
+
+  base::WorkerPool::PostTask(
+      FROM_HERE,
+      base::Bind(&ShortcutHelper::AddShortcutInBackgroundWithSkBitmap,
+                 url_,
+                 title_,
+                 display_,
+                 manifest_icon_,
+                 orientation_),
+      true);
+
+  Destroy();
+}
+
+void ShortcutHelper::AddShortcutUsingFavicon() {
   Profile* profile =
       Profile::FromBrowserContext(web_contents()->GetBrowserContext());
 
@@ -172,28 +382,26 @@ void ShortcutHelper::AddShortcut(
 
   // Using favicon if its size is not smaller than platform required size,
   // otherwise using the largest icon among all avaliable icons.
-  int threshold_to_get_any_largest_icon = launcher_large_icon_size_ - 1;
+  int threshold_to_get_any_largest_icon = preferred_icon_size_in_px_ - 1;
   favicon_service->GetLargestRawFaviconForPageURL(url_, icon_types,
       threshold_to_get_any_largest_icon,
-      base::Bind(&ShortcutHelper::FinishAddingShortcut,
+      base::Bind(&ShortcutHelper::OnDidGetFavicon,
                  base::Unretained(this)),
       &cancelable_task_tracker_);
 }
 
-void ShortcutHelper::FinishAddingShortcut(
+void ShortcutHelper::OnDidGetFavicon(
     const favicon_base::FaviconRawBitmapResult& bitmap_result) {
-  icon_ = bitmap_result;
-
   // Stop observing so we don't get destroyed while doing the last steps.
   Observe(NULL);
 
   base::WorkerPool::PostTask(
       FROM_HERE,
-      base::Bind(&ShortcutHelper::AddShortcutInBackground,
+      base::Bind(&ShortcutHelper::AddShortcutInBackgroundWithRawBitmap,
                  url_,
                  title_,
                  display_,
-                 icon_,
+                 bitmap_result,
                  orientation_),
       true);
 
@@ -220,7 +428,7 @@ bool ShortcutHelper::RegisterShortcutHelper(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
-void ShortcutHelper::AddShortcutInBackground(
+void ShortcutHelper::AddShortcutInBackgroundWithRawBitmap(
     const GURL& url,
     const base::string16& title,
     content::Manifest::DisplayMode display,
@@ -228,16 +436,26 @@ void ShortcutHelper::AddShortcutInBackground(
     blink::WebScreenOrientationLockType orientation) {
   DCHECK(base::WorkerPool::RunsTasksOnCurrentThread());
 
-  // Grab the average color from the bitmap.
-  SkColor color = SK_ColorWHITE;
-  SkBitmap favicon_bitmap;
+  SkBitmap icon_bitmap;
   if (bitmap_result.is_valid()) {
-    if (gfx::PNGCodec::Decode(bitmap_result.bitmap_data->front(),
-                              bitmap_result.bitmap_data->size(),
-                              &favicon_bitmap))
-      color = color_utils::CalculateKMeanColorOfBitmap(favicon_bitmap);
+    gfx::PNGCodec::Decode(bitmap_result.bitmap_data->front(),
+                          bitmap_result.bitmap_data->size(),
+                          &icon_bitmap);
   }
 
+  AddShortcutInBackgroundWithSkBitmap(
+      url, title, display, icon_bitmap, orientation);
+}
+
+void ShortcutHelper::AddShortcutInBackgroundWithSkBitmap(
+    const GURL& url,
+    const base::string16& title,
+    content::Manifest::DisplayMode display,
+    const SkBitmap& icon_bitmap,
+    blink::WebScreenOrientationLockType orientation) {
+  DCHECK(base::WorkerPool::RunsTasksOnCurrentThread());
+
+  SkColor color = color_utils::CalculateKMeanColorOfBitmap(icon_bitmap);
   int r_value = SkColorGetR(color);
   int g_value = SkColorGetG(color);
   int b_value = SkColorGetB(color);
@@ -249,8 +467,8 @@ void ShortcutHelper::AddShortcutInBackground(
   ScopedJavaLocalRef<jstring> java_title =
       base::android::ConvertUTF16ToJavaString(env, title);
   ScopedJavaLocalRef<jobject> java_bitmap;
-  if (favicon_bitmap.getSize())
-    java_bitmap = gfx::ConvertToJavaBitmap(&favicon_bitmap);
+  if (icon_bitmap.getSize())
+    java_bitmap = gfx::ConvertToJavaBitmap(&icon_bitmap);
 
   Java_ShortcutHelper_addShortcut(
       env,