Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkUndoController.java

+// Copyright 2015 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.enhancedbookmarks;
+
+import android.content.Context;
+
+import com.google.android.apps.chrome.R;
+
+import org.chromium.chrome.browser.BookmarksBridge.BookmarkItem;
+import org.chromium.chrome.browser.BookmarksBridge.BookmarkModelObserver;
+import org.chromium.chrome.browser.enhanced_bookmarks.EnhancedBookmarksModel;
+import org.chromium.chrome.browser.enhanced_bookmarks.EnhancedBookmarksModel.EnhancedBookmarkDeleteObserver;
+import org.chromium.chrome.browser.snackbar.SnackbarManager;
+
+import java.util.Locale;
+
+/**
+ * Shows an undo bar when the user modifies enhanced bookmarks,
+ * allowing them to undo their changes.
+ * TODO(danduong): Add move undo
+ */
+public class EnhancedBookmarkUndoController extends BookmarkModelObserver implements
+        SnackbarManager.SnackbarController, EnhancedBookmarkDeleteObserver {
+
+    private final EnhancedBookmarksModel mBookmarksModel;
+    private final SnackbarManager mSnackbarManager;
+    private final Context mContext;
+
+    /**
+     * Creates an instance of {@link EnhancedBookmarkUndoController}.
+     * @param context The {@link Context} in which snackbar is shown.
+     * @param model The enhanced bookmark model.
+     * @param snackbarManager SnackManager passed from activity.
+     */
+    public EnhancedBookmarkUndoController(Context context, EnhancedBookmarksModel model,
+            SnackbarManager snackbarManager) {
+        mBookmarksModel = model;
+        mBookmarksModel.addDeleteObserver(this);
+        mSnackbarManager = snackbarManager;
+        mContext = context;
+    }
+
+    /**
+     * Cleans up this class, unregistering for application notifications from bookmark model.
+     */
+    public void destroy() {
+        mBookmarksModel.removeDeleteObserver(this);
+    }
+
+    @Override
+    public void onAction(Object actionData) {
+        mBookmarksModel.undo();
+        mSnackbarManager.dismissSnackbar(false);
+    }
+
+    @Override
+    public void onDismissNoAction(Object actionData) {
+    }
+
+    @Override
+    public void onDismissForEachType(boolean isTimeout) {
+    }
+
+    // Overriding BookmarkModelObserver
+    @Override
+    public void bookmarkModelChanged() {
+        // TODO(danduong): dismiss snackbar only when needed
+        mSnackbarManager.dismissSnackbar(false);
+    }
+
+    @Override
+    public void bookmarkNodeChanged(BookmarkItem node) {
+        // Title/url change of a bookmark should not affect undo.
+    }
+
+    @Override
+    public void bookmarkNodeAdded(BookmarkItem parent, int index) {
+        // Adding a new bookmark should not affect undo.
+    }
+
+    // Implement EnhancedBookmarkDeleteObserver
+    @Override
+    public void onDeleteBookmarks(String[] titles, boolean isUndoable) {
+        assert titles != null && titles.length >= 1;
+
+        if (!isUndoable) return;
+
+        if (titles.length == 1) {
+            mSnackbarManager.showSnackbar(mContext.getString(R.string.undo_bar_delete_message),
+                    titles[0], mContext.getString(R.string.undo_bar_button_text),
+                    null, this);
+        } else {
+            mSnackbarManager.showSnackbar(
+                    mContext.getString(R.string.undo_bar_multiple_delete_message),
+                    String.format(Locale.getDefault(), "%d", titles.length),
+                    mContext.getString(R.string.undo_bar_button_text), null, this);
+        }
+    }
+}