Implement WebContents.downloadImage() on Java side

content/browser/web_contents/web_contents_android.cc

 // Copyright 2013 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 "content/browser/web_contents/web_contents_android.h"
 
 #include <stdint.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
@@ skipping 655 matching lines @@
                                              const JavaParamRef<jobject>& obj) {
   static_cast<WebContentsImpl*>(web_contents_)
       ->NotifyContextMenuClosed(CustomContextMenuContext());
 }
 
 void WebContentsAndroid::ReloadLoFiImages(JNIEnv* env,
                                           const JavaParamRef<jobject>& obj) {
   static_cast<WebContentsImpl*>(web_contents_)->ReloadLoFiImages();
 }
 
+void WebContentsAndroid::DownloadImage(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& obj,
+    const base::android::JavaParamRef<jstring>& jurl,
+    jboolean is_fav_icon,
+    jint max_bitmap_size,
+    jboolean bypass_cache,
+    const base::android::JavaParamRef<jobject>& jcallback) {
+  GURL url(base::android::ConvertJavaStringToUTF8(env, jurl));
+  web_contents_->DownloadImage(
+      url, is_fav_icon, max_bitmap_size, bypass_cache,
+      base::Bind(&WebContentsAndroid::OnFinishDownloadImage,
+                 weak_factory_.GetWeakPtr(),
+                 base::Owned(new ScopedJavaGlobalRef<jobject>(
+                     env, obj)),
+                 base::Owned(new ScopedJavaGlobalRef<jobject>(
+                     env, jcallback))));
+}
+
 void WebContentsAndroid::OnFinishGetContentBitmap(
     ScopedJavaGlobalRef<jobject>* obj,
     ScopedJavaGlobalRef<jobject>* callback,
     const SkBitmap& bitmap,
     ReadbackResponse response) {
   JNIEnv* env = base::android::AttachCurrentThread();
   ScopedJavaLocalRef<jobject> java_bitmap;
   if (response == READBACK_SUCCESS)
     java_bitmap = gfx::ConvertToJavaBitmap(&bitmap);
   Java_WebContentsImpl_onGetContentBitmapFinished(env,
                                                   obj->obj(),
                                                   callback->obj(),
                                                   java_bitmap.obj(),
                                                   response);
 }
 
+void WebContentsAndroid::OnFinishDownloadImage(
+    base::android::ScopedJavaGlobalRef<jobject>* obj,
+    base::android::ScopedJavaGlobalRef<jobject>* callback,
+    int id,
+    int http_status_code,
+    const GURL& url,
+    const std::vector<SkBitmap>& bitmaps,
+    const std::vector<gfx::Size>& sizes) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> jbitmaps =
+      Java_WebContentsImpl_createBitmapList(env);
+  ScopedJavaLocalRef<jobject> jsizes =
+      Java_WebContentsImpl_createSizeList(env);
+  ScopedJavaLocalRef<jstring> jurl =
+      base::android::ConvertUTF8ToJavaString(env, url.spec());
+
+  for (const SkBitmap& bitmap : bitmaps) {
+    ScopedJavaLocalRef<jobject> jbitmap = gfx::ConvertToJavaBitmap(&bitmap);

[Ted C, 2016/06/03 16:44:09]

forgive my ignorance (and for my education), but how could multiple bitmaps be
returned?

[Zhiqiang Zhang (Slow), 2016/06/03 18:53:51]

Yes, .ico files can contain multiple images of different sizes.

+    Java_WebContentsImpl_addToBitmapList(env, jbitmaps.obj(), jbitmap.obj());

[Ted C, 2016/06/03 16:44:09]

This is the only really sad line.  Converting to java bitmaps results in
duplicate memory allocations, so we're more likely to hit OOMs here if people
use it incorrectly or for the wrong purposes.

[Zhiqiang Zhang (Slow), 2016/06/03 18:53:51]

Added comments about this.

+  }
+  for (const gfx::Size& size : sizes) {
+    Java_WebContentsImpl_createSizeAndAddToList(
+        env, jsizes.obj(), size.width(), size.height());
+  }
+  Java_WebContentsImpl_onDownloadImageFinished(
+      env, obj->obj(), callback->obj(), id,
+      http_status_code, jurl.obj(), jbitmaps.obj(), jsizes.obj());
+}
 }  // namespace content