webapps: introduce helper class to store extended set of data

chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.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;
 
 import android.app.ActivityManager;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Path;
 import android.graphics.PorterDuff;
 import android.graphics.PorterDuffXfermode;
 import android.graphics.Rect;
 import android.graphics.RectF;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.Handler;
 import android.os.Looper;
+import android.text.TextUtils;
 import android.util.Base64;
 import android.util.DisplayMetrics;
 import android.util.TypedValue;
 
 import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.base.ApplicationStatus;
 import org.chromium.base.Log;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.chrome.R;
@@ skipping 76 matching lines @@
      * homescreen as soon as the shortcut is created.
      */
     @SuppressWarnings("unused")
     @CalledByNative
     private static void addShortcut(Context context, String url, String userTitle, String name,
             String shortName, Bitmap icon, boolean isWebappCapable, int orientation, int source,
             long themeColor, long backgroundColor) {
         Intent shortcutIntent;
         if (isWebappCapable) {
             // Encode the icon as a base64 string (Launcher drops Bitmaps in the Intent).
-            String encodedIcon = "";
-            if (icon != null) {
-                ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
-                icon.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream);
-                byte[] byteArray = byteArrayOutputStream.toByteArray();
-                encodedIcon = Base64.encodeToString(byteArray, Base64.DEFAULT);
-            }
+            String encodedIcon = icon == null ? "" : encodeBitmapAsString(icon);

[gone, 2015/08/27 18:24:20]

nit: This icon == null check should be at the beginning of encodeBitmapAsString
for the same reason that decodeBitmapFromString checks for an empty string.

[Lalit Maganti, 2015/08/27 18:36:56]

Done.

 
             // Add the shortcut as a launcher icon for a full-screen Activity.
             shortcutIntent = new Intent();
             shortcutIntent.setAction(sDelegate.getFullscreenAction());
             shortcutIntent.putExtra(EXTRA_ICON, encodedIcon);
             shortcutIntent.putExtra(EXTRA_ID, UUID.randomUUID().toString());
             shortcutIntent.putExtra(EXTRA_NAME, name);
             shortcutIntent.putExtra(EXTRA_SHORT_NAME, shortName);
             shortcutIntent.putExtra(EXTRA_URL, url);
             shortcutIntent.putExtra(EXTRA_ORIENTATION, orientation);
@@ skipping 111 matching lines @@
                 drawWidgetBackgroundToCanvas(context, canvas, iconDensity, url,
                         Color.rgb(rValue, gValue, bValue));
             }
             canvas.setBitmap(null);
         } catch (OutOfMemoryError e) {
             Log.w(TAG, "OutOfMemoryError while trying to draw bitmap on canvas.");
         }
         return bitmap;
     }
 
+    /**
+     * Compresses a bitmap into a PNG and converts into a Base64 encoded string.
+     * The encoded string can be decoded using {@link decodeBitmapFromString(String)}.
+     * @param bitmap The Bitmap to compress and encode.
+     * @return the String encoding the Bitmap.
+     */
+    public static String encodeBitmapAsString(Bitmap bitmap) {
+        ByteArrayOutputStream output = new ByteArrayOutputStream();
+        bitmap.compress(Bitmap.CompressFormat.PNG, 100, output);
+        return Base64.encodeToString(output.toByteArray(), Base64.DEFAULT);
+    }
+
+    /**
+     * Decodes a Base64 string into a Bitmap. Used to decode Bitmaps encoded by
+     * {@link encodeBitmapAsString(Bitmap)}.
+     * @param encodedString the Base64 String to decode.
+     * @return the Bitmap which was encoded by the String.
+     */
+    public static Bitmap decodeBitmapFromString(String encodedString) {
+        if (TextUtils.isEmpty(encodedString)) return null;
+        byte[] decoded = Base64.decode(encodedString, Base64.DEFAULT);
+        return BitmapFactory.decodeByteArray(decoded, 0, decoded.length);
+    }
+
     private static Bitmap getBitmapFromResourceId(Context context, int id, int density) {
         Drawable drawable = ApiCompatibilityUtils.getDrawableForDensity(
                 context.getResources(), id, density);
 
         if (drawable instanceof BitmapDrawable) {
             BitmapDrawable bd = (BitmapDrawable) drawable;
             return bd.getBitmap();
         }
         assert false : "The drawable was not a bitmap drawable as expected";
         return null;
@@ skipping 57 matching lines @@
      * @return String that can be used to verify that a WebappActivity is being started by Chrome.
      */
     public static String getEncodedMac(Context context, String url) {
         // The only reason we convert to a String here is because Android inexplicably eats a
         // byte[] when adding the shortcut -- the Bundle received by the launched Activity even
         // lacks the key for the extra.
         byte[] mac = WebappAuthenticator.getMacForUrl(context, url);
         return Base64.encodeToString(mac, Base64.DEFAULT);
     }
 }