Refactor ShortcutHelper and merge in BookmarkUtils

chrome/android/java/src/org/chromium/chrome/browser/webapps/AddToHomescreenHelper.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.webapps;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.chrome.browser.BookmarkUtils;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.content_public.browser.WebContents;
+
+/**
+ * This is a helper class to create shortcuts on the Android home screen.

[gone, 2015/08/13 21:43:15]

Change the comment to better describe what this thing does post-split.

[Lalit Maganti, 2015/08/26 13:57:07]

Done in https://codereview.chromium.org/1321463002

+ */
+public class AddToHomescreenHelper {
+
+    /** Observes the data fetching pipeline. */
+    public interface AddToHomescreenHelperObserver {
+        /** Called when the title of the page is available. */
+        void onUserTitleAvailable(String title);
+
+        /** Called when the icon to use in the launcher is available. */
+        void onIconAvailable(Bitmap icon);
+    }
+
+    private final Context mAppContext;
+    private final Tab mTab;
+
+    private AddToHomescreenHelperObserver mObserver;
+    private boolean mIsInitialized;
+    private long mNativeAddToHomescreenHelper;
+
+    public AddToHomescreenHelper(Context appContext, Tab tab) {
+        mAppContext = appContext;
+        mTab = tab;
+    }
+
+    /**
+     * Gets all the information required to initialize the UI.  The observer will be notified as
+     * information required for the shortcut become available.
+     * @param observer Observer to notify.
+     */
+    public void initialize(AddToHomescreenHelperObserver observer) {
+        mObserver = observer;
+        mNativeAddToHomescreenHelper = nativeInitialize(mTab.getWebContents());
+    }
+
+    /**
+     * Returns whether the object is initialized.
+     */
+    public boolean isInitialized() {
+        return mIsInitialized;
+    }
+
+    /**
+     * Puts the object in a state where it is safe to be destroyed.
+     */
+    public void destroy() {
+        nativeDestroy(mNativeAddToHomescreenHelper);
+
+        // Make sure the callback isn't run if the tear down happens before
+        // onInitialized() is called.
+        mObserver = null;
+        mNativeAddToHomescreenHelper = 0;
+    }
+
+    @CalledByNative
+    private void onUserTitleAvailable(String title) {
+        mObserver.onUserTitleAvailable(title);
+    }
+
+    @CalledByNative
+    private void onIconAvailable(Bitmap icon) {
+        mObserver.onIconAvailable(icon);
+        mIsInitialized = true;
+    }
+
+    /**
+     * Adds a shortcut for the current Tab.
+     * @param userRequestedTitle Updated title for the shortcut.

[gone, 2015/08/13 21:43:15]

nit: Not sure what an "Updated title for the shortcut" means without any context
from places where this function is called.

[Lalit Maganti, 2015/08/26 13:57:07]

Done in https://codereview.chromium.org/1321463002

+     */
+    public void addShortcut(String userRequestedTitle) {
+        nativeAddShortcut(mNativeAddToHomescreenHelper, userRequestedTitle);
+    }
+
+    /**
+     * Creates an icon that is acceptable to show on the launcher.
+     */
+    @CalledByNative
+    private static Bitmap finalizeLauncherIcon(
+            String url, Bitmap icon, int red, int green, int blue) {
+        return BookmarkUtils.createLauncherIcon(
+                ApplicationStatus.getApplicationContext(), icon, url, red, green, blue);
+    }
+
+    private native long nativeInitialize(WebContents webContents);
+    private native void nativeAddShortcut(long nativeAddToHomescreenHelper,
+            String userRequestedTitle);
+    private native void nativeDestroy(long nativeAddToHomescreenHelper);
+}