Extract NotificationBuilderBase for holding the arguments.

chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationBuilderBase.java

-// Copyright 2015 The Chromium Authors. All rights reserved.
+// Copyright 2016 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.notifications;
 
 import android.app.Notification;
 import android.app.PendingIntent;
 import android.graphics.Bitmap;
+import android.support.v4.app.NotificationCompat.Action;
+
+import org.chromium.base.VisibleForTesting;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 
 import javax.annotation.Nullable;
 
 /**
- * Builds a notification using the given inputs.
+ * Abstract base class for building a notification. Stores all given arguments for later use.
  */
-public interface NotificationBuilder {
+public abstract class NotificationBuilderBase {
+    /**
+     * Maximum length of CharSequence inputs to prevent excessive memory consumption. At current
+     * screen sizes we display about 500 characters at most, so this is a pretty generous limit, and
+     * it matches what the Notification class does.
+     */
+    @VisibleForTesting
+    static final int MAX_CHARSEQUENCE_LENGTH = 5 * 1024;
+
+    /**
+     * The maximum number of action buttons. One is for the settings button, and two more slots are
+     * for developer provided buttons.
+     */
+    private static final int MAX_ACTION_BUTTONS = 3;
+
+    protected CharSequence mTitle;
+    protected CharSequence mBody;
+    protected CharSequence mOrigin;
+    protected CharSequence mTickerText;
+    protected Bitmap mLargeIcon;
+    protected int mSmallIconId;
+    protected PendingIntent mContentIntent;
+    protected PendingIntent mDeleteIntent;
+    protected List<Action> mActions = new ArrayList<>(MAX_ACTION_BUTTONS);
+    protected Action mSettingsAction;
+    protected int mDefaults = Notification.DEFAULT_ALL;
+    protected long[] mVibratePattern;
 
     /**
      * Combines all of the options that have been set and returns a new Notification object.
      */
-    Notification build();
+    public abstract Notification build();
 
     /**
-     * Sets the title text (first row) of the notification.
+     * Sets the title text of the notification.
      */
-    NotificationBuilder setTitle(@Nullable CharSequence title);
+    public NotificationBuilderBase setTitle(@Nullable CharSequence title) {
+        mTitle = limitLength(title);
+        return this;
+    }
 
     /**
-     * Sets the body text (second row) of the notification.
+     * Sets the body text of the notification.
      */
-    NotificationBuilder setBody(@Nullable CharSequence body);
+    public NotificationBuilderBase setBody(@Nullable CharSequence body) {
+        mBody = limitLength(body);
+        return this;
+    }
 
     /**
-     * Sets the origin text (bottom row) of the notification.
+     * Sets the origin text of the notification.
      */
-    NotificationBuilder setOrigin(@Nullable CharSequence origin);
+    public NotificationBuilderBase setOrigin(@Nullable CharSequence origin) {
+        mOrigin = limitLength(origin);
+        return this;
+    }
 
     /**
      * Sets the text that is displayed in the status bar when the notification first arrives.
      */
-    NotificationBuilder setTicker(@Nullable CharSequence tickerText);
+    public NotificationBuilderBase setTicker(@Nullable CharSequence tickerText) {
+        mTickerText = limitLength(tickerText);
+        return this;
+    }
 
     /**
      * Sets the large icon that is shown in the notification.
      */
-    NotificationBuilder setLargeIcon(@Nullable Bitmap icon);
+    public NotificationBuilderBase setLargeIcon(@Nullable Bitmap icon) {
+        mLargeIcon = icon;
+        return this;
+    }
 
     /**
      * Sets the the small icon that is shown in the notification and in the status bar.
      */
-    NotificationBuilder setSmallIcon(int iconId);
+    public NotificationBuilderBase setSmallIcon(int iconId) {
+        mSmallIconId = iconId;
+        return this;
+    }
 
     /**
      * Sets the PendingIntent to send when the notification is clicked.
      */
-    NotificationBuilder setContentIntent(@Nullable PendingIntent intent);
+    public NotificationBuilderBase setContentIntent(@Nullable PendingIntent intent) {
+        mContentIntent = intent;
+        return this;
+    }
 
     /**
      * Sets the PendingIntent to send when the notification is cleared by the user directly from the
      * notification panel.
      */
-    NotificationBuilder setDeleteIntent(@Nullable PendingIntent intent);
+    public NotificationBuilderBase setDeleteIntent(@Nullable PendingIntent intent) {
+        mDeleteIntent = intent;
+        return this;
+    }
 
     /**
      * Adds an action to the notification. Actions are typically displayed as a button adjacent to
      * the notification content.
      */
-    NotificationBuilder addAction(
-            int iconId, @Nullable CharSequence title, @Nullable PendingIntent intent);
+    public NotificationBuilderBase addAction(
+            int iconId, @Nullable CharSequence title, @Nullable PendingIntent intent) {
+        if (mActions.size() == MAX_ACTION_BUTTONS) {
+            throw new IllegalStateException(
+                    "Cannot add more than " + MAX_ACTION_BUTTONS + " actions.");
+        }
+        mActions.add(new Action(iconId, limitLength(title), intent));
+        return this;
+    }
 
     /**
      * Adds an action to the notification for opening the settings screen.
      */
-    NotificationBuilder addSettingsAction(int iconId, CharSequence title, PendingIntent intent);
+    public NotificationBuilderBase addSettingsAction(
+            int iconId, @Nullable CharSequence title, @Nullable PendingIntent intent) {
+        mSettingsAction = new Action(iconId, limitLength(title), intent);
+        return this;
+    }
 
     /**
      * Sets the default notification options that will be used.
      * <p>
      * The value should be one or more of the following fields combined with
      * bitwise-or:
      * {@link Notification#DEFAULT_SOUND}, {@link Notification#DEFAULT_VIBRATE},
      * {@link Notification#DEFAULT_LIGHTS}.
      * <p>
      * For all default values, use {@link Notification#DEFAULT_ALL}.
      */
-    NotificationBuilder setDefaults(int defaults);
+    public NotificationBuilderBase setDefaults(int defaults) {
+        mDefaults = defaults;
+        return this;
+    }
 
     /**
      * Sets the vibration pattern to use.
      */
-    NotificationBuilder setVibrate(@Nullable long[] pattern);
+    public NotificationBuilderBase setVibrate(long[] pattern) {
+        mVibratePattern = Arrays.copyOf(pattern, pattern.length);
+        return this;
+    }
+
+    @Nullable
+    private static CharSequence limitLength(@Nullable CharSequence input) {
+        if (input == null) {
+            return input;
+        }
+        if (input.length() > MAX_CHARSEQUENCE_LENGTH) {
+            return input.subSequence(0, MAX_CHARSEQUENCE_LENGTH);
+        }
+        return input;
+    }
 }