/**
* Decode and return the bitmap represented by the given index in the Icon Directory, if valid.
*
* @param index The index into the Icon Directory of the image of interest.
* @return The decoded Bitmap object for this image, or null if the entry is invalid or decoding
* fails.
*/
public Bitmap decodeBitmapAtIndex(int index) {
final IconDirectoryEntry iconDirEntry = iconDirectory[index];
if (iconDirEntry.payloadIsPNG) {
// PNG payload. Simply extract it and decode it.
return BitmapUtils.decodeByteArray(
decodand, offset + iconDirEntry.payloadOffset, iconDirEntry.payloadSize);
}
// The payload is a BMP, so we need to do some magic to get the decoder to do what we want.
// We construct an ICO containing just the image we want, and let Android do the rest.
byte[] decodeTarget =
new byte
[ICO_HEADER_LENGTH_BYTES + ICO_ICONDIRENTRY_LENGTH_BYTES + iconDirEntry.payloadSize];
// Set the type field in the ICO header.
decodeTarget[2] = 1;
// Set the num-images field in the header to 1.
decodeTarget[4] = 1;
// Copy the ICONDIRENTRY we need into the new buffer.
System.arraycopy(
decodand,
offset + iconDirEntry.getOffset(),
decodeTarget,
ICO_HEADER_LENGTH_BYTES,
ICO_ICONDIRENTRY_LENGTH_BYTES);
// Copy the payload into the new buffer.
final int singlePayloadOffset = ICO_HEADER_LENGTH_BYTES + ICO_ICONDIRENTRY_LENGTH_BYTES;
System.arraycopy(
decodand,
offset + iconDirEntry.payloadOffset,
decodeTarget,
singlePayloadOffset,
iconDirEntry.payloadSize);
// Update the offset field of the ICONDIRENTRY to make the new ICO valid.
decodeTarget[ICO_HEADER_LENGTH_BYTES + 12] = (byte) singlePayloadOffset;
decodeTarget[ICO_HEADER_LENGTH_BYTES + 13] = (byte) (singlePayloadOffset >>> 8);
decodeTarget[ICO_HEADER_LENGTH_BYTES + 14] = (byte) (singlePayloadOffset >>> 16);
decodeTarget[ICO_HEADER_LENGTH_BYTES + 15] = (byte) (singlePayloadOffset >>> 24);
// Decode the newly-constructed singleton-ICO.
return BitmapUtils.decodeByteArray(decodeTarget);
}
private static void storeFaviconsInMemCache(Cursor c) {
if (c == null || !c.moveToFirst()) {
return;
}
final Favicons favicons = Favicons.getInstance();
do {
final String url = c.getString(c.getColumnIndexOrThrow(URLColumns.URL));
final byte[] b = c.getBlob(c.getColumnIndexOrThrow(URLColumns.FAVICON));
if (b == null) {
continue;
}
Bitmap favicon = BitmapUtils.decodeByteArray(b);
if (favicon == null) {
continue;
}
favicon = favicons.scaleImage(favicon);
favicons.putFaviconInMemCache(url, favicon);
} while (c.moveToNext());
}