Implementation of ListContentManager for feed

ListContentManagerImpl supports both native view and external view.

The methods defined in feed/v2/FeedActionHandler has been merged to
xsurface/FeedActionsHandler, except navigate* methods that are already
included in xsurface/SurfaceActionHandler.

Bug: 1044139
Change-Id: Ic708a1295e2a0e6700f5b72195940a8bd365c76a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2133110
Commit-Queue: Jian Li <jianli@chromium.org>
Reviewed-by: Cathy Li <chili@chromium.org>
Reviewed-by: Dan H <harringtond@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756484}

chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/v2/FeedActionHandler.java

-// Copyright 2020 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.feed.v2;
-
-/**
- * Interface to handle the actions user can trigger on the feed.
- */
-public interface FeedActionHandler {
-    String KEY = "FeedActions";
-
-    /**
-     * Navigates the current tab to a particular URL.
-     */
-    void navigate(String url);
-
-    /**
-     * Navigates a new tab to a particular URL.
-     */
-    void navigateInNewTab(String url);
-
-    /**
-     * Requests additional content to be loaded. Once the load is completed, onStreamUpdated will be
-     * called.
-     */
-    void loadMore();
-
-    /**
-     * Requests to dismiss a card. A change ID will be returned and it can be used to commit or
-     * discard the change.
-     */
-    int requestDismissal();
-
-    /**
-     * Commits a previous requested dismissal denoted by change ID.
-     */
-    void commitDismissal(int changeId);
-
-    /**
-     * Discards a previous requested dismissal denoted by change ID.
-     */
-    void discardDismissal(int changeId);
-}

chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/v2/FeedListContentManager.java

+// Copyright 2020 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.feed.v2;
+
+import android.view.View;
+import android.view.ViewGroup;
+
+import org.chromium.chrome.browser.xsurface.FeedActionsHandler;
+import org.chromium.chrome.browser.xsurface.ListContentManager;
+import org.chromium.chrome.browser.xsurface.ListContentManagerObserver;
+import org.chromium.chrome.browser.xsurface.SurfaceActionsHandler;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Implementation of ListContentManager that manages a list of feed contents that are supported by
+ * either native view or external surface controlled view.
+ */
+public class FeedListContentManager implements ListContentManager {
+    /**
+     * Encapsulates the content of an item stored and managed by ListContentManager.
+     */
+    public interface FeedContent {
+        /**
+         * Returns true if the content is supported by the native view.
+         */
+        boolean isNativeView();
+    }
+
+    /**
+     * For the content that is supported by external surface controlled view.
+     */
+    public static class ExternalViewContent implements FeedContent {
+        private final byte[] mData;
+
+        public ExternalViewContent(byte[] data) {
+            mData = data;
+        }
+
+        /**
+         * Returns the raw bytes that are passed to the external surface for rendering if the
+         * content is supported by the external surface controlled view.
+         */
+        public byte[] getBytes() {
+            return mData;
+        }
+
+        @Override
+        public boolean isNativeView() {
+            return false;
+        }
+    }
+
+    /**
+     * For the content that is supported by the native view.
+     */
+    public static class NativeViewContent implements FeedContent {
+        private final View mNativeView;
+
+        public NativeViewContent(View nativeView) {
+            mNativeView = nativeView;
+        }
+
+        /**
+         * Returns the native view if the content is supported by it. Null otherwise.
+         */
+        public View getNativeView() {
+            return mNativeView;
+        }
+
+        @Override
+        public boolean isNativeView() {
+            return true;
+        }
+    }
+
+    private ArrayList<FeedContent> mFeedContentList;
+    private ArrayList<ListContentManagerObserver> mObservers;
+    private final Map<String, Object> mHandlers;
+
+    FeedListContentManager(
+            SurfaceActionsHandler surfaceActionsHandler, FeedActionsHandler feedActionsHandler) {
+        mFeedContentList = new ArrayList<FeedContent>();
+        mObservers = new ArrayList<ListContentManagerObserver>();
+        mHandlers = new HashMap<String, Object>();
+        mHandlers.put(SurfaceActionsHandler.KEY, surfaceActionsHandler);
+        mHandlers.put(FeedActionsHandler.KEY, feedActionsHandler);
+    }
+
+    /**
+     * Adds a list of the contents, starting at the specified position.
+     *
+     * @param index The index at which to insert the first content from the specified collection.
+     * @param contents The collection containing contents to be added.
+     */
+    public void addContents(int index, List<FeedContent> contents) {
+        assert index >= 0 && index < mFeedContentList.size();
+        mFeedContentList.addAll(index, contents);
+        for (ListContentManagerObserver observer : mObservers) {
+            observer.onItemRangeInserted(index, contents.size());
+        }
+    }
+
+    /**
+     * Removes the specified count of contents starting from the speicified position.
+     *
+     * @param index The index of the first content to be removed.
+     * @param count The number of contents to be removed.
+     */
+    public void removeContents(int index, int count) {
+        assert index >= 0 && index < mFeedContentList.size();
+        assert index + count < mFeedContentList.size();
+        mFeedContentList.subList(index, index + count).clear();
+        for (ListContentManagerObserver observer : mObservers) {
+            observer.onItemRangeInserted(index, count);
+        }
+    }
+
+    /**
+     * Updates a list of the contents, starting at the specified position.
+     *
+     * @param index The index at which to update the first content from the specified collection.
+     * @param contents The collection containing contents to be updated.
+     */
+    public void updateContents(int index, List<FeedContent> contents) {
+        assert index >= 0 && index < mFeedContentList.size();
+        assert index + contents.size() < mFeedContentList.size();
+        int pos = index;
+        for (FeedContent content : contents) {
+            mFeedContentList.set(pos++, content);
+        }
+        for (ListContentManagerObserver observer : mObservers) {
+            observer.onItemRangeChanged(index, contents.size());
+        }
+    }
+
+    /**
+     * Moves the content to a different position.
+     *
+     * @param curIndex The index of the content to be moved.
+     * @param newIndex The new index where the content is being moved to.
+     */
+    public void moveContents(int curIndex, int newIndex) {
+        assert curIndex >= 0 && curIndex < mFeedContentList.size();
+        assert newIndex >= 0 && newIndex < mFeedContentList.size();
+        int lowIndex;
+        int highIndex;
+        int distance;
+        if (curIndex < newIndex) {
+            lowIndex = curIndex;
+            highIndex = newIndex;
+            distance = -1;
+        } else if (curIndex > newIndex) {
+            lowIndex = newIndex;
+            highIndex = curIndex;
+            distance = 1;
+        } else {
+            return;
+        }
+        Collections.rotate(mFeedContentList.subList(lowIndex, highIndex + 1), distance);
+        for (ListContentManagerObserver observer : mObservers) {
+            observer.onItemMoved(curIndex, newIndex);
+        }
+    }
+
+    @Override
+    public boolean isNativeView(int index) {
+        return index == 0 || mFeedContentList.get(index - 1).isNativeView();
+    }
+
+    @Override
+    public byte[] getExternalViewBytes(int index) {
+        assert !mFeedContentList.get(index - 1).isNativeView();
+        ExternalViewContent externalViewContent =
+                (ExternalViewContent) mFeedContentList.get(index - 1);
+        return externalViewContent.getBytes();
+    }
+
+    @Override
+    public Map<String, Object> getContextValues(int index) {
+        return mHandlers;
+    }
+
+    @Override
+    public View getNativeView(int index, ViewGroup parent) {
+        assert mFeedContentList.get(index - 1).isNativeView();
+        NativeViewContent nativeViewContent = (NativeViewContent) mFeedContentList.get(index - 1);
+        return nativeViewContent.getNativeView();
+    }
+
+    @Override
+    public void bindNativeView(int index, View v) {
+        // TODO(jianli): to be implemented.
+    }
+
+    @Override
+    public int getItemCount() {
+        return mFeedContentList.size();
+    }
+
+    @Override
+    public void addObserver(ListContentManagerObserver observer) {
+        mObservers.add(observer);
+    }
+
+    @Override
+    public void removeObserver(ListContentManagerObserver observer) {
+        mObservers.remove(observer);
+    }
+}

chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/v2/FeedStreamSurface.java

@@ -11,6 +11,8 @@ import org.chromium.chrome.browser.ChromeActivity;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tab.TabLaunchType;
 import org.chromium.chrome.browser.tabmodel.TabModelSelector;
+import org.chromium.chrome.browser.xsurface.FeedActionsHandler;
+import org.chromium.chrome.browser.xsurface.SurfaceActionsHandler;
 import org.chromium.components.feed.proto.FeedUiProto.StreamUpdate;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.ui.base.PageTransition;
@@ -24,7 +26,7 @@ import java.util.List;
  * Created once for each StreamSurfaceMediator corresponding to each NTP/start surface.
  */
 @JNINamespace("feed")
-public class FeedStreamSurface implements FeedActionHandler {
+public class FeedStreamSurface implements SurfaceActionsHandler, FeedActionsHandler {
     private final long mNativeFeedStreamSurface;
     private final ChromeActivity mActivity;
 
@@ -35,6 +37,11 @@ public class FeedStreamSurface implements FeedActionHandler {
     public FeedStreamSurface(ChromeActivity activity) {
         mNativeFeedStreamSurface = FeedStreamSurfaceJni.get().init(FeedStreamSurface.this);
         mActivity = activity;
+
+        FeedListContentManager manager = new FeedListContentManager(this, this);
+
+        // TODO(jianli): Get HybridListRender in order to bind FeedListContentManager to it.
+        // Then add the returned RecyclerView to NTP layout.
     }
 
     /**
@@ -50,7 +57,7 @@ public class FeedStreamSurface implements FeedActionHandler {
     }
 
     @Override
-    public void navigate(String url) {
+    public void navigateTab(String url) {
         LoadUrlParams loadUrlParams = new LoadUrlParams(url);
         loadUrlParams.setTransitionType(PageTransition.AUTO_BOOKMARK);
         mActivity.getActivityTabProvider().get().loadUrl(loadUrlParams);
@@ -59,7 +66,7 @@ public class FeedStreamSurface implements FeedActionHandler {
     }
 
     @Override
-    public void navigateInNewTab(String url) {
+    public void navigateNewTab(String url) {
         TabModelSelector tabModelSelector = mActivity.getTabModelSelector();
         Tab tab = mActivity.getActivityTabProvider().get();
         tabModelSelector.openNewTab(
@@ -73,6 +80,12 @@ public class FeedStreamSurface implements FeedActionHandler {
         FeedStreamSurfaceJni.get().loadMore(mNativeFeedStreamSurface, FeedStreamSurface.this);
     }
 
+    @Override
+    public void processThereAndBackAgainData(byte[] data) {
+        FeedStreamSurfaceJni.get().processThereAndBackAgain(
+                mNativeFeedStreamSurface, FeedStreamSurface.this, data);
+    }
+
     @Override
     public int requestDismissal() {
         // TODO(jianli): may need to pass parameters from UI.
@@ -94,14 +107,6 @@ public class FeedStreamSurface implements FeedActionHandler {
                 mNativeFeedStreamSurface, FeedStreamSurface.this, changeId);
     }
 
-    /**
-     * Handles uploading data for ThereAndBackAgain.
-     */
-    public void processThereAndBackAgain(byte[] data) {
-        FeedStreamSurfaceJni.get().processThereAndBackAgain(
-                mNativeFeedStreamSurface, FeedStreamSurface.this, data);
-    }
-
     /**
      * Informs that the surface is opened. We can request the initial set of content now. Once
      * the content is available, onStreamUpdated will be called.

chrome/android/feed/feed_java_sources.gni

@@ -378,7 +378,7 @@ if (enable_feed_in_chrome) {
     "//chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/tooltip/BasicTooltipApi.java",
     "//chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/tooltip/BasicTooltipSupportedApi.java",
     "//chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/tooltip/FeedTooltipUtils.java",
-    "//chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/v2/FeedActionHandler.java",
+    "//chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/v2/FeedListContentManager.java",
     "//chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/v2/FeedServiceBridge.java",
     "//chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/v2/FeedStreamSurface.java",
   ]

chrome/browser/xsurface/android/java/src/org/chromium/chrome/browser/xsurface/FeedActionsHandler.java

@@ -10,8 +10,30 @@ package org.chromium.chrome.browser.xsurface;
 public interface FeedActionsHandler {
     String KEY = "FeedActions";
 
+    /**
+     * Requests additional content to be loaded. Once the load is completed, onStreamUpdated will be
+     * called.
+     */
+    void loadMore();
+
     /**
      * Sends data back to the server when content is clicked.
      */
     void processThereAndBackAgainData(byte[] data);
+
+    /**
+     * Requests to dismiss a card. A change ID will be returned and it can be used to commit or
+     * discard the change.
+     */
+    int requestDismissal();
+
+    /**
+     * Commits a previous requested dismissal denoted by change ID.
+     */
+    void commitDismissal(int changeId);
+
+    /**
+     * Discards a previous requested dismissal denoted by change ID.
+     */
+    void discardDismissal(int changeId);
 }