DecodeThread.java

/**
 * Copyright (C) 2013 Eesti Vabariigi Valimiskomisjon 
 * (Estonian National Electoral Committee), www.vvk.ee
 *
 * Written in 2013 by AS Finestmedia, www.finestmedia.ee
 *
 * Vote-verification application for Estonian Internet voting system
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * This file incorporates work covered by the following copyright and  
 * permission notice:  
 * 
 * Copyright (C) 2008 ZXing authors
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/

package ee.vvk.ivotingverification.qr;

import java.util.Collection;
import java.util.EnumMap;
import java.util.EnumSet;
import java.util.Map;
import java.util.concurrent.CountDownLatch;

import android.content.SharedPreferences;
import android.os.Handler;
import android.os.Looper;
import android.preference.PreferenceManager;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
import com.google.zxing.ResultPointCallback;

import ee.vvk.ivotingverification.QRScannerActivity;

/**
 * This thread does all the heavy lifting of decoding the images.
 * 
 * @author dswitkin@google.com (Daniel Switkin)
 */
final class DecodeThread extends Thread {

	public static final String BARCODE_BITMAP = "barcode_bitmap";

	private final QRScannerActivity activity;
	private final Map<DecodeHintType, Object> hints;
	private Handler handler;
	private final CountDownLatch handlerInitLatch;

	DecodeThread(QRScannerActivity activity,
			Collection<BarcodeFormat> decodeFormats, String characterSet,
			ResultPointCallback resultPointCallback) {

		this.activity = activity;
		handlerInitLatch = new CountDownLatch(1);

		hints = new EnumMap<DecodeHintType, Object>(DecodeHintType.class);

		if (decodeFormats == null || decodeFormats.isEmpty()) {
			SharedPreferences prefs = PreferenceManager
					.getDefaultSharedPreferences(activity);
			decodeFormats = EnumSet.noneOf(BarcodeFormat.class);
			if (prefs.getBoolean(PreferencesActivity.KEY_DECODE_1D, false)) {
				decodeFormats.addAll(DecodeFormatManager.ONE_D_FORMATS);
			}
			if (prefs.getBoolean(PreferencesActivity.KEY_DECODE_QR, false)) {
				decodeFormats.addAll(DecodeFormatManager.QR_CODE_FORMATS);
			}
			if (prefs.getBoolean(PreferencesActivity.KEY_DECODE_DATA_MATRIX,
					false)) {
				decodeFormats.addAll(DecodeFormatManager.DATA_MATRIX_FORMATS);
			}
		}
		hints.put(DecodeHintType.POSSIBLE_FORMATS, decodeFormats);

		if (characterSet != null) {
			hints.put(DecodeHintType.CHARACTER_SET, characterSet);
		}
		hints.put(DecodeHintType.NEED_RESULT_POINT_CALLBACK,
				resultPointCallback);
	}

	Handler getHandler() {
		try {
			handlerInitLatch.await();
		} catch (InterruptedException ie) {
		}
		return handler;
	}

	@Override
	public void run() {
		Looper.prepare();
		handler = new DecodeHandler(activity, hints);
		handlerInitLatch.countDown();
		Looper.loop();
	}
}