Cascades Development

[Bluenoser]

I am trying to adapt the code from one of the cascade samples. barcodereader. When I compile my app, all I get is a black screen. This tells me it is failing on the QML code. I have compared the code for what I used and I don't see any QML errors. Can someone take a look?

I have added LIBS += -lbbcascadesmultimedia to the project file as that was the only thing that the barcodereader added and it works fine.

import bb.cascades 1.0
import bb.cascades.multimedia 1.0
import bb.multimedia 1.0

Page {
    Container {
        
        Camera {
            id: qrcodeCamera
            
            onCameraOpened: {
                getSettings(qrcodeCameraSettings)
                qrcodeCameraSettings.focusMode = CameraFocusMode.ContinuousAuto
                qrcodeCameraSettings.shootingMode = CameraShootingMode.Stabilization
                applySettings(qrcodeCameraSettings)
                
                qrcodeCamera.startViewfinder()
            }
            
            onViewFinderStarted: {
                qrcodeDetector.camera = qrcodeCamera
            }
            
            attachedObjects: [
                CameraSettings {
                    id: qrcodeCameraSettings
                }
            ]
        }
        Label {
            id: resultLabel
        }
    }
    attachedObjects: [
        BarcodeDetector {
            id: qrcodeDetector
                
            formats: BarcodeFormat.QrCode
            onBarcodeDetected: {
                if(resultLabel.text != data) {
                    resultLabel = data;
                }
           }
        }
    ]
}

[javayoung]

Yes, this situation is sometimes happened. You can close the black screen then build and run it on device again. The application will be running properly. I can see the barcode reader line in the middle of screen after run it again.

[Bluenoser]

I have gotten the sample that I took the code from to work, but the code I posted does not work and I don't know why so I asking for help.

Thanks

[PBernhardt]

You need to call camera.open() at some point. For example:

    Page {
        onCreationCompleted: {
            if (camera.allCamerasAccessible) {
                camera.open(CameraUnit.Rear);
            }
        }

[oniongarlic]

Have you checked that you request the required permissions in your bar file ?

[Bluenoser]

Making Progress

Camera works, but it never detects the QRCode.

import bb.cascades 1.0
import bb.cascades.multimedia 1.0
import bb.multimedia 1.0

Page {

    Container {
        
        Camera {
            id: qrcodeCamera
//            objectName: "qrcodeCamera"
            preferredWidth: 768.0
            preferredHeight: 768.0

            onCameraOpened: {
                getSettings(qrcodeCameraSettings)
                qrcodeCameraSettings.focusMode = CameraFocusMode.ContinuousAuto
                qrcodeCameraSettings.shootingMode = CameraShootingMode.Stabilization
                applySettings(qrcodeCameraSettings)
                
                qrcodeCamera.startViewfinder()
            }
            
            onViewfinderStarted: {
                qrcodeDetector.camera = qrcodeCamera
            }
            
            attachedObjects: [
                CameraSettings {
                    id: qrcodeCameraSettings
                }
            ]
        }
        Label {
            text: "QRCode Results"
        }
        Label {
            id: resultData
            multiline: true
         }
        
    }
    onCreationCompleted: {
        // Check to see if any cameras are currently accessible.
        if (qrcodeCamera.allCamerasAccessible) {
            // Open the rear camera.
            qrcodeCamera.open(CameraUnit.Rear);
        }
    }
    attachedObjects: [
        BarcodeDetector {
            id: qrcodeDetector
            formats: BarcodeFormat.Any
            onBarcodeDetected: {
                if (resultData.text != data) {
                    resultData.text = data;
                    scannedSound.play()
                }
           }
        },
        SystemSound {
            id: scannedSound
            sound: SystemSound.GeneralNotification
        }
    ]
}

[Bluenoser]

I cannot figure out the problem. The camera works, but it never detects the bar code. I even just copied to code as much as possible from the app that does work. I used the cascades sample barcodereader. I even copied the all the make files and the permissions are identical.

Here is the code that works.

/* Copyright (c) 2012 Research In Motion 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.
*/

import bb.cascades 1.0
import bb.cascades.multimedia 1.0
import bb.multimedia 1.0

Page {
    id: page

    Container {
        background: Color.Black

        layout: DockLayout {}

        //! [0]
        // The camera preview control
        Camera {
            id: camera
            preferredWidth: 768.0
            preferredHeight: 768.0


//            horizontalAlignment: HorizontalAlignment.Fill
//            verticalAlignment: VerticalAlignment.Fill

            onCameraOpened: {
                // Apply some settings after the camera was opened successfully
                getSettings(cameraSettings)
                cameraSettings.focusMode = CameraFocusMode.ContinuousAuto
                cameraSettings.shootingMode = CameraShootingMode.Stabilization
                applySettings(cameraSettings)

                // Start the view finder as it is needed by the barcode detector
                camera.startViewfinder()
            }

            onViewfinderStarted: {
                // Setup the barcode detector with the camera object now
                barcodeDetector.camera = camera
            }

            attachedObjects: [
                CameraSettings {
                    id: cameraSettings
                }
            ]
        }
        //! [0]

        // The overlay image
        ImageView {
            horizontalAlignment: HorizontalAlignment.Fill
            verticalAlignment: VerticalAlignment.Fill

            imageSource: "asset:///images/overlay.png"
        }

        // The area at the top that shows the results
        Container {
            id: resultArea

            horizontalAlignment: HorizontalAlignment.Fill
            verticalAlignment: VerticalAlignment.Top

            layout: DockLayout {}

            visible: false

            ImageView {
                horizontalAlignment: HorizontalAlignment.Fill
                verticalAlignment: VerticalAlignment.Fill

                imageSource: "asset:///images/result_background.png"
            }

            Label {
                id: resultLabel

                horizontalAlignment: HorizontalAlignment.Center
                verticalAlignment: VerticalAlignment.Center

                textStyle {
                    base: SystemDefaults.TextStyles.TitleText
                    color: Color.White
                    textAlign: TextAlign.Center
                }

                multiline: true
            }
        }

        // The upper cover image
        ImageView {
            id: topCover

            horizontalAlignment: HorizontalAlignment.Center
            verticalAlignment: VerticalAlignment.Top

            imageSource: "asset:///images/top_cover.png"

            onTouch: {
                if (event.isDown())
                    startupAnimation.play()
            }
        }

        // The lower cover image
        ImageView {
            id: bottomCover

            horizontalAlignment: HorizontalAlignment.Center
            verticalAlignment: VerticalAlignment.Bottom

            imageSource: "asset:///images/bottom_cover.png"

            onTouch: {
                if (event.isDown())
                    startupAnimation.play()
            }
        }

        // The startup animation that slides out the cover images
        animations: ParallelAnimation {
            id: startupAnimation

            SequentialAnimation {
                target: topCover
                TranslateTransition {
                    fromY: 0
                    toY: -640
                    duration: 1250
                    easingCurve: StockCurve.QuarticInOut
                }
            }
            SequentialAnimation {
                target: bottomCover
                TranslateTransition {
                    fromY: 0
                    toY: 680
                    duration: 1250
                    easingCurve: StockCurve.QuarticInOut
                }
            }

            //! [1]
            onStarted: {
                camera.open()
            }
            //! [1]

            onEnded: {
                // Work around a bug temporarily
                camera.open()
            }
        }
    }

    //! [2]
    attachedObjects: [
        BarcodeDetector {
            id: barcodeDetector
            
            formats: BarcodeFormat.Any
            onBarcodeDetected: {
                if (resultLabel.text != data) {
                    resultLabel.text = data;
                    resultArea.visible = true;
                    scannedSound.play()
                }
            }
        },
        SystemSound {
            id: scannedSound

            sound: SystemSound.GeneralNotification
        }
    ]
    //! [2]
}

 Here is my code which doesn't work. I copied the code directly from the working example.

import bb.cascades 1.0
import bb.cascades.multimedia 1.0
import bb.multimedia 1.0

Page {

    Container {
        
        Camera {
            id: camera
            preferredWidth: 768.0
            preferredHeight: 768.0


//            horizontalAlignment: HorizontalAlignment.Fill
//            verticalAlignment: VerticalAlignment.Fill

            onCameraOpened: {
                // Apply some settings after the camera was opened successfully
                getSettings(cameraSettings)
                cameraSettings.focusMode = CameraFocusMode.ContinuousAuto
                cameraSettings.shootingMode = CameraShootingMode.Stabilization
                applySettings(cameraSettings)

                // Start the view finder as it is needed by the barcode detector
                camera.startViewfinder()
            }

            onViewfinderStarted: {
                // Setup the barcode detector with the camera object now
                barcodeDetector.camera = camera
            }

            attachedObjects: [
                CameraSettings {
                    id: cameraSettings
                }
            ]
        }
        Container {
            id: resultArea
            visible: false
            horizontalAlignment: HorizontalAlignment.Fill
            Label {
                    text: "QRCode Results"
            }
            Label {
                id: resultLabel
                multiline: true
            }
        }
        
    }
    onCreationCompleted: {
        // Check to see if any cameras are currently accessible.
        if (camera.allCamerasAccessible) {
            // Open the rear camera.
            camera.open();
        }
    }
    attachedObjects: [
        BarcodeDetector {
            id: barcodeDetector
            
            formats: BarcodeFormat.Any
            onBarcodeDetected: {
                if (resultLabel.text != data) {
                    resultLabel.text = data;
                    resultArea.visible = true;
                    scannedSound.play()
                }
            }
        },
        SystemSound {
            id: scannedSound

            sound: SystemSound.GeneralNotification
        }
    ]
}

 I just don't get it..

[Bluenoser]

OK. I was able to get it working.. sort of.. You have to open the camera twice to get it to scan a qrcode. And the second camera open cannot be with the onCreationCompleted. I had to do a camera.open() on the onCreationCompleted and another camera.open() in a button. This has to be a bug.