BarcodeDecoder.cpp Example File

    /* Copyright (c) 2012, 2013  BlackBerry Limited.
     *
     * 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.
     */
    #include "BarcodeDecoder.hpp"

    #include <bb/cascades/DisplayDirection>
    #include <bb/cascades/StackLayout>
    #include <bb/cascades/multimedia/CameraTypes.hpp>

    #include <QSharedPointer>

    #include <zxing/common/GreyscaleLuminanceSource.h>
    #include <zxing/common/HybridBinarizer.h>

    using namespace bb::cascades;
    using namespace bb::cascades::multimedia;
    using namespace bb::community::barcode;
    using namespace zxing;

    BarcodeDecoderControl::BarcodeDecoderControl(Container *parent)
        : CustomControl(parent)
        , m_camera(new Camera(parent))
        , m_cameraSettings(new CameraSettings(this))
        , m_landscapePreviewFrames(false)
        , m_nbuffers(2)
    {
        setRoot(m_camera);

        bool ok = connect(m_camera, SIGNAL(cameraOpened()),
                          this, SLOT(onCameraOpened()));
        Q_ASSERT(ok);

        ok = connect(m_camera, SIGNAL(viewfinderStopped()),
                     this, SLOT(onViewfinderStopped()));
        Q_ASSERT(ok);

        //Prepare the camera
        m_camera->open(CameraUnit::Rear);

        //Configure camera settings
        m_camera->getSettings(m_cameraSettings);
        m_cameraSettings->setCameraMode(CameraMode::Photo);
        m_cameraSettings->setFocusMode(CameraFocusMode::ContinuousMacro);

        if (m_camera->applySettings(m_cameraSettings))
            qDebug() << "settings applied successfully";

        //Prepare the decoder
        m_reader = Ref<MultiFormatReader>(new MultiFormatReader());
        DecodeHints *hints = new DecodeHints();
        hints->addFormat(BarcodeFormat_QR_CODE);
        hints->addFormat(BarcodeFormat_EAN_8);
        hints->addFormat(BarcodeFormat_EAN_13);
        hints->addFormat(BarcodeFormat_UPC_A);
        hints->addFormat(BarcodeFormat_UPC_E);
        hints->addFormat(BarcodeFormat_DATA_MATRIX);
        hints->addFormat(BarcodeFormat_CODE_128);
        hints->addFormat(BarcodeFormat_CODE_39);
        hints->addFormat(BarcodeFormat_ITF);
        hints->addFormat(BarcodeFormat_AZTEC);
        m_reader.object_->setHints(*hints);
    }

    void BarcodeDecoderControl::onPreviewFrameAvailable(
            SharedUCharPointer previewBuffer, quint64 size, unsigned int width,
            unsigned int height, unsigned int stride)
    {
        try {
            Ref<LuminanceSource> source(
                    new GreyscaleLuminanceSource(previewBuffer.data(), stride,
                            size / stride, 0, 0, width, height));
            Ref<Binarizer> binarizer(new HybridBinarizer(source));
            Ref<BinaryBitmap> bitmap(new BinaryBitmap(binarizer));
            Ref<Result> result;

            // If the preview buffer is in landscape, we can rotate out bitmap to let us scan 1D codes
            if (m_landscapePreviewFrames) {
                Ref<BinaryBitmap> rotated = bitmap->rotateCounterClockwise();
                result = m_reader->decode(rotated);
            } else {
                result = m_reader->decode(bitmap);

            }

            const QString newBarcodeData = QString::fromStdString(result->getText()->getText().data());

            if (newBarcodeData != m_barcodeData) {
                m_barcodeData = newBarcodeData;
                emit newBarcodeDetected(m_barcodeData);
            }

        } catch (std::exception &e) {
            qDebug() << "+++++++ ERROR: " << e.what() << endl;
        }

        m_camera->addPreviewBuffer(previewBuffer, size);
    }

    void BarcodeDecoderControl::onCameraOpened()
    {
        const quint64 bufferSize = m_camera->previewBufferSize();
        //Use two buffers for double buffering goodness.
        for (int i = 0; i < m_nbuffers; i++)
            m_camera->addPreviewBuffer(QSharedPointer<unsigned char>(new unsigned char[bufferSize]), bufferSize);

        bool ok = connect(m_camera, SIGNAL(previewFrameAvailable(bb::cascades::multimedia::SharedUCharPointer, quint64, unsigned int, unsigned int, unsigned int)),
                          this, SLOT(onPreviewFrameAvailable(bb::cascades::multimedia::SharedUCharPointer, quint64, unsigned int, unsigned int, unsigned int)));
        Q_ASSERT(ok);
        Q_UNUSED(ok);

        // If the preview frames are oriented East or West, it means we will have to rotate them 90 degrees to reliably detect 1D barcodes
        if (m_camera->devicePreviewFrameDirection() == DisplayDirection::East || m_camera->devicePreviewFrameDirection() == DisplayDirection::West)
            m_landscapePreviewFrames = true;

        m_camera->startViewfinder();
    }

    void BarcodeDecoderControl::startScanning() const
    {
        m_camera->startViewfinder();
    }

    void BarcodeDecoderControl::stopScanning() const
    {
        m_camera->stopViewfinder();
    }

    void BarcodeDecoderControl::onViewfinderStopped()
    {
        m_barcodeData.clear();
    }