/*
* Copyright 2007 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 com.google.zxing;
import com.google.zxing.datamatrix.DataMatrixReader;
import com.google.zxing.maxicode.MaxiCodeReader;
import com.google.zxing.oned.MultiFormatOneDReader;
import com.google.zxing.qrcode.QRCodeReader;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Map;
/**
* MultiFormatReader is a convenience class and the main entry point into the
* library for most uses. By default it attempts to decode all barcode formats
* that the library supports. Optionally, you can provide a hints object to
* request different behavior, for example only decoding QR codes.
*
* @author Sean Owen
* @author dswitkin@google.com (Daniel Switkin)
*/
public final class MultiFormatReader implements Reader {
private Map<DecodeHintType, ?> hints;
private Reader[] readers;
/**
* This version of decode honors the intent of Reader.decode(BinaryBitmap)
* in that it passes null as a hint to the decoders. However, that makes it
* inefficient to call repeatedly. Use setHints() followed by
* decodeWithState() for continuous scan applications.
*
* @param image
* The pixel data to decode
* @return The contents of the image
* @throws NotFoundException
* Any errors which occurred
*/
@Override
public Result decode(BinaryBitmap image) throws NotFoundException {
setHints(null);
return decodeInternal(image);
}
/**
* Decode an image using the hints provided. Does not honor existing state.
*
* @param image
* The pixel data to decode
* @param hints
* The hints to use, clearing the previous state.
* @return The contents of the image
* @throws NotFoundException
* Any errors which occurred
*/
@Override
public Result decode(BinaryBitmap image, Map<DecodeHintType, ?> hints)
throws NotFoundException {
setHints(hints);
return decodeInternal(image);
}
/**
* Decode an image using the state set up by calling setHints() previously.
* Continuous scan clients will get a <b>large</b> speed increase by using
* this instead of decode().
*
* @param image
* The pixel data to decode
* @return The contents of the image
* @throws NotFoundException
* Any errors which occurred
*/
public Result decodeWithState(BinaryBitmap image) throws NotFoundException {
// Make sure to set up the default state so we don't crash
if (readers == null) {
setHints(null);
}
return decodeInternal(image);
}
/**
* This method adds state to the MultiFormatReader. By setting the hints
* once, subsequent calls to decodeWithState(image) can reuse the same set
* of readers without reallocating memory. This is important for performance
* in continuous scan clients.
*
* @param hints
* The set of hints to use for subsequent calls to decode(image)
*/
public void setHints(Map<DecodeHintType, ?> hints) {
this.hints = hints;
boolean tryHarder = hints != null
&& hints.containsKey(DecodeHintType.TRY_HARDER);
@SuppressWarnings("unchecked")
Collection<BarcodeFormat> formats = hints == null ? null
: (Collection<BarcodeFormat>) hints
.get(DecodeHintType.POSSIBLE_FORMATS);
Collection<Reader> readers = new ArrayList<>();
if (formats != null) {
boolean addOneDReader = formats.contains(BarcodeFormat.UPC_A)
|| formats.contains(BarcodeFormat.UPC_E)
|| formats.contains(BarcodeFormat.EAN_13)
|| formats.contains(BarcodeFormat.EAN_8)
|| formats.contains(BarcodeFormat.CODABAR)
|| formats.contains(BarcodeFormat.CODE_39)
|| formats.contains(BarcodeFormat.CODE_93)
|| formats.contains(BarcodeFormat.CODE_128)
|| formats.contains(BarcodeFormat.ITF)
|| formats.contains(BarcodeFormat.RSS_14)
|| formats.contains(BarcodeFormat.RSS_EXPANDED);
// Put 1D readers upfront in "normal" mode
if (addOneDReader && !tryHarder) {
readers.add(new MultiFormatOneDReader(hints));
}
if (formats.contains(BarcodeFormat.QR_CODE)) {
readers.add(new QRCodeReader());
}
if (formats.contains(BarcodeFormat.DATA_MATRIX)) {
readers.add(new DataMatrixReader());
}
if (formats.contains(BarcodeFormat.MAXICODE)) {
readers.add(new MaxiCodeReader());
}
// At end in "try harder" mode
if (addOneDReader && tryHarder) {
readers.add(new MultiFormatOneDReader(hints));
}
}
if (readers.isEmpty()) {
if (!tryHarder) {
readers.add(new MultiFormatOneDReader(hints));
}
readers.add(new QRCodeReader());
readers.add(new DataMatrixReader());
readers.add(new MaxiCodeReader());
if (tryHarder) {
readers.add(new MultiFormatOneDReader(hints));
}
}
this.readers = readers.toArray(new Reader[readers.size()]);
}
@Override
public void reset() {
if (readers != null) {
for (Reader reader : readers) {
reader.reset();
}
}
}
private Result decodeInternal(BinaryBitmap image) throws NotFoundException {
if (readers != null) {
for (Reader reader : readers) {
try {
return reader.decode(image, hints);
} catch (ReaderException re) {
// continue
}
}
}
throw NotFoundException.getNotFoundInstance();
}
}