barcode_scanner.py 文件源码

def main():
    global main_view
    delegate = MetadataDelegate.new()
    main_view = ui.View(frame=(0, 0, 400, 400))
    main_view.name = 'Barcode Scanner'
    session = AVCaptureSession.alloc().init()
    device = AVCaptureDevice.defaultDeviceWithMediaType_('vide')
    _input = AVCaptureDeviceInput.deviceInputWithDevice_error_(device, None)
    if _input:
        session.addInput_(_input)
    else:
        print('Failed to create input')
        return
    output = AVCaptureMetadataOutput.alloc().init()
    queue = ObjCInstance(dispatch_get_current_queue())
    output.setMetadataObjectsDelegate_queue_(delegate, queue)
    session.addOutput_(output)
    output.setMetadataObjectTypes_(output.availableMetadataObjectTypes())
    prev_layer = AVCaptureVideoPreviewLayer.layerWithSession_(session)
    prev_layer.frame = ObjCInstance(main_view).bounds()
    prev_layer.setVideoGravity_('AVLayerVideoGravityResizeAspectFill')
    ObjCInstance(main_view).layer().addSublayer_(prev_layer)
    label = ui.Label(frame=(0, 0, 400, 30), flex='W', name='label')
    label.background_color = (0, 0, 0, 0.5)
    label.text_color = 'white'
    label.text = 'Nothing scanned yet'
    label.alignment = ui.ALIGN_CENTER
    main_view.add_subview(label)
    session.startRunning()
    main_view.present('sheet')
    main_view.wait_modal()
    session.stopRunning()
    delegate.release()
    session.release()
    output.release()
    if found_codes:
        print 'All scanned codes:\n' + '\n'.join(found_codes)