Show the image header for the Context Menu

chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuHelper.java

 // 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.
 
 package org.chromium.chrome.browser.contextmenu;
 
 import android.app.Activity;
 import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
 import android.util.Pair;
 import android.view.ContextMenu;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.view.View;
 import android.view.View.OnCreateContextMenuListener;
 
 import org.chromium.base.Callback;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.metrics.RecordHistogram;
+import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeFeatureList;
 import org.chromium.chrome.browser.share.ShareHelper;
 import org.chromium.content.browser.ContentViewCore;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.ui.base.WindowAndroid;
 import org.chromium.ui.base.WindowAndroid.OnCloseContextMenuListener;
 
 import java.util.List;
 
 /**
  * A helper class that handles generating context menus for {@link ContentViewCore}s.
  */
 public class ContextMenuHelper implements OnCreateContextMenuListener {
     private long mNativeContextMenuHelper;
 
     private ContextMenuPopulator mPopulator;
     private ContextMenuParams mCurrentContextMenuParams;
     private Context mContext;
     private Callback<Integer> mCallback;
     private Runnable mOnMenuShown;
     private Runnable mOnMenuClosed;
+    private OnThumbnailReceivedListener mOnThumbnailReceivedListener;
+
+    /**
+     * This waits for a thumbnail to be retrieved by the native code.
+     */
+    interface OnThumbnailReceivedListener {

[Ted C, 2017/03/31 16:19:32]

FWIW, you can just use Callback.java from base/ to make these single value
callback a bit easier to define.

[JJ, 2017/03/31 18:43:59]

Done.

+        /**
+         * When the thumbnail is received it will send the thumbnail via this method. This is
+         * activated after calling {@link #getThumbnail(OnThumbnailReceivedListener)}.
+         * @param bitmap The bitmap that is retrieved from native code.
+         */
+        void onThumbnailReceived(Bitmap bitmap);
+    }
+
+    @VisibleForTesting
+    ContextMenuHelper() {}
 
     private ContextMenuHelper(long nativeContextMenuHelper) {
         mNativeContextMenuHelper = nativeContextMenuHelper;
     }
 
     @CalledByNative
     private static ContextMenuHelper create(long nativeContextMenuHelper) {
         return new ContextMenuHelper(nativeContextMenuHelper);
     }
 
@@ skipping 51 matching lines @@
             public void run() {
                 if (mNativeContextMenuHelper == 0) return;
                 nativeOnContextMenuClosed(mNativeContextMenuHelper);
             }
         };
 
         if (ChromeFeatureList.isEnabled(ChromeFeatureList.CUSTOM_CONTEXT_MENU)) {
             List<Pair<Integer, List<ContextMenuItem>>> items =
                     mPopulator.buildContextMenu(null, mContext, mCurrentContextMenuParams);
 
-            ContextMenuUi menuUi = new TabularContextMenuUi();
+            ContextMenuUi menuUi = new TabularContextMenuUi(this);
             menuUi.displayMenu(mContext, mCurrentContextMenuParams, items, mCallback, mOnMenuShown,
                     mOnMenuClosed);

[Ted C, 2017/03/31 16:19:33]

from my comment in the other file, I think we should do:

final TabularContextMenuUi menuUi = new TabularContextMenuUi(this);
...
if (mCurrentContextMenuParams.isImage()) {
    getThumbnail(new Callback<Bitmap>() {
        @Override
        public void call(Bitmap bitmap) {
            menuUi.onImageThumbnailRetreived(bitmap);
        }
    });
}

Then you don't need to pass in the helper.

[JJ, 2017/03/31 18:43:59]

Done.

             return;
         }
 
         // The Platform Context Menu requires the listener within this hepler since this helper and
         // provides context menu for us to show.
         view.setOnCreateContextMenuListener(this);
         if (view.showContextMenu()) {
             mOnMenuShown.run();
             windowAndroid.addContextMenuCloseListener(new OnCloseContextMenuListener() {
                 @Override
@@ skipping 33 matching lines @@
 
     @CalledByNative
     private void onShareImageReceived(
             WindowAndroid windowAndroid, byte[] jpegImageData) {
         Activity activity = windowAndroid.getActivity().get();
         if (activity == null) return;
 
         ShareHelper.shareImage(activity, jpegImageData);
     }
 
+    /**
+     * Gets the thumbnail of the current image that triggered the context menu.
+     * @param listener Called once the the thumbnail is received
+     */
+    public void getThumbnail(final OnThumbnailReceivedListener listener) {
+        mOnThumbnailReceivedListener = listener;
+        if (mNativeContextMenuHelper == 0) return;
+        int maxSizePx = mContext.getResources().getDimensionPixelSize(
+                R.dimen.context_menu_header_image_max_size);
+        nativeRetrieveHeaderThumbnail(mNativeContextMenuHelper, maxSizePx);
+    }
+
+    @CalledByNative
+    private void onHeaderThumbnailReceived(WindowAndroid windowAndroid, byte[] jpegImageData) {
+        Bitmap bitmap = BitmapFactory.decodeByteArray(jpegImageData, 0, jpegImageData.length);

[Ted C, 2017/03/31 16:19:33]

Can you add another:

// TODO(tedchoc): Decode in separate process before launch.

Here we are receiving image data from the renderer, which is inherently
untrusted, so we can't decode in the browser process safely.  I think we can
either use a separate java process or the utility process.

[JJ, 2017/03/31 18:43:59]

Done.

+        if (mOnThumbnailReceivedListener != null) {
+            mOnThumbnailReceivedListener.onThumbnailReceived(bitmap);
+        }
+    }
+
     @Override
     public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
         List<Pair<Integer, List<ContextMenuItem>>> items =
                 mPopulator.buildContextMenu(menu, v.getContext(), mCurrentContextMenuParams);
         ContextMenuUi menuUi = new PlatformContextMenuUi(menu);
         menuUi.displayMenu(
                 mContext, mCurrentContextMenuParams, items, mCallback, mOnMenuShown, mOnMenuClosed);
     }
 
     /**
      * @return The {@link ContextMenuPopulator} responsible for populating the context menu.
      */
     @VisibleForTesting
     public ContextMenuPopulator getPopulator() {
         return mPopulator;
     }
 
     private native void nativeOnStartDownload(
             long nativeContextMenuHelper, boolean isLink, boolean isDataReductionProxyEnabled);
     private native void nativeSearchForImage(long nativeContextMenuHelper);
     private native void nativeShareImage(long nativeContextMenuHelper);
     private native void nativeOnContextMenuClosed(long nativeContextMenuHelper);
+    private native void nativeRetrieveHeaderThumbnail(long nativeContextMenuHelper, int maxSizePx);
 }