DecodeThread.java

package com.google.zxing.client.android.fragment;

import android.os.Handler;
import android.os.Looper;
import android.util.Log;

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

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

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

    public static final String BARCODE_BITMAP = "barcode_bitmap";
    public static final String BARCODE_SCALED_FACTOR = "barcode_scaled_factor";

    private final BarCodeScannerFragment fragment;
    private final Map<DecodeHintType, Object> hints;
    private Handler handler;
    private final CountDownLatch handlerInitLatch;

    public DecodeThread(BarCodeScannerFragment fragment,
                        Collection<BarcodeFormat> decodeFormats,
                        Map<DecodeHintType, ?> baseHints,
                        String characterSet,
                        ResultPointCallback resultPointCallback) {

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

        hints = new EnumMap<>(DecodeHintType.class);
        if (baseHints != null) {
            hints.putAll(baseHints);
        }

        hints.put(DecodeHintType.POSSIBLE_FORMATS, decodeFormats);

        if (characterSet != null) {
            hints.put(DecodeHintType.CHARACTER_SET, characterSet);
        }
        hints.put(DecodeHintType.NEED_RESULT_POINT_CALLBACK, resultPointCallback);
        Log.i("DecodeThread", "Hints: " + hints);
    }

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

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

}