michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko.favicons.decoders;
michael@0: 
michael@0: import android.graphics.Bitmap;
michael@0: import android.util.Log;
michael@0: 
michael@0: import java.io.ByteArrayOutputStream;
michael@0: import java.util.Iterator;
michael@0: 
michael@0: /**
michael@0:  * Class representing the result of loading a favicon.
michael@0:  * This operation will produce either a collection of favicons, a single favicon, or no favicon.
michael@0:  * It is necessary to model single favicons differently to a collection of one favicon (An entity
michael@0:  * that may not exist with this scheme) since the in-database representation of these things differ.
michael@0:  * (In particular, collections of favicons are stored in encoded ICO format, whereas single icons are
michael@0:  * stored as decoded bitmap blobs.)
michael@0:  */
michael@0: public class LoadFaviconResult {
michael@0:     private static final String LOGTAG = "LoadFaviconResult";
michael@0: 
michael@0:     byte[] faviconBytes;
michael@0:     int offset;
michael@0:     int length;
michael@0: 
michael@0:     boolean isICO;
michael@0:     Iterator<Bitmap> bitmapsDecoded;
michael@0: 
michael@0:     public Iterator<Bitmap> getBitmaps() {
michael@0:         return bitmapsDecoded;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Return a representation of this result suitable for storing in the database.
michael@0:      *
michael@0:      * @return A byte array containing the bytes from which this result was decoded,
michael@0:      *         or null if re-encoding failed.
michael@0:      */
michael@0:     public byte[] getBytesForDatabaseStorage() {
michael@0:         // Begin by normalising the buffer.
michael@0:         if (offset != 0 || length != faviconBytes.length) {
michael@0:             final byte[] normalised = new byte[length];
michael@0:             System.arraycopy(faviconBytes, offset, normalised, 0, length);
michael@0:             offset = 0;
michael@0:             faviconBytes = normalised;
michael@0:         }
michael@0: 
michael@0:         // For results containing multiple images, we store the result verbatim. (But cutting the
michael@0:         // buffer to size first).
michael@0:         // We may instead want to consider re-encoding the entire ICO as a collection of efficiently
michael@0:         // encoded PNGs. This may not be worth the CPU time (Indeed, the encoding of single-image
michael@0:         // favicons may also not be worth the time/space tradeoff.).
michael@0:         if (isICO) {
michael@0:             return faviconBytes;
michael@0:         }
michael@0: 
michael@0:         // For results containing a single image, we re-encode the
michael@0:         // result as a PNG in an effort to save space.
michael@0:         final Bitmap favicon = ((FaviconDecoder.SingleBitmapIterator) bitmapsDecoded).peek();
michael@0:         final ByteArrayOutputStream stream = new ByteArrayOutputStream();
michael@0: 
michael@0:         try {
michael@0:             if (favicon.compress(Bitmap.CompressFormat.PNG, 100, stream)) {
michael@0:                 return stream.toByteArray();
michael@0:             }
michael@0:         } catch (OutOfMemoryError e) {
michael@0:             Log.w(LOGTAG, "Out of memory re-compressing favicon.");
michael@0:         }
michael@0: 
michael@0:         Log.w(LOGTAG, "Favicon re-compression failed.");
michael@0:         return null;
michael@0:     }
michael@0: 
michael@0: }