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  4. How to set the camera flash on

How to set the camera flash on

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  • M Offline
    M Offline
    mismail
    wrote on last edited by
    #4

    Hi,
    please look at this link

    "http://www.developer.nokia.com/Community/Discussion/showthread.php?226102-How-can-I-use-camera-flash-as-a-tourch&p=851607#post851607":http://www.developer.nokia.com/Community/Discussion/showthread.php?226102-How-can-I-use-camera-flash-as-a-tourch&p=851607#post851607

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    • A Offline
      A Offline
      alfah
      wrote on last edited by
      #5

      :)

      i did . . i does not give any solutions. . Theres gotta be some way to turn on the flash right??

      regards,

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      • L Offline
        L Offline
        lgeyer
        wrote on last edited by
        #6

        [quote author="alfah" date="1310534091"]The thing is, i couldn get how to use QcameraExposure::Flashmode. I found "QCameraExposure::FlashOn 0x4 Flash is On." in the docs but how do you use it?[/quote]

        For every enum in Qt there is usually a getter called enumName() and a setter setEnumName(). For the "QCameraExposure::FlashMode":http://doc.qt.nokia.com/qtmobility-1.1-tp/qcameraexposure.html#FlashMode-enum enum this will be "QCameraExposure::flashMode()":http://doc.qt.nokia.com/qtmobility-1.1-tp/qcameraexposure.html#flashMode and "QCameraExposure::setFlashMode()":http://doc.qt.nokia.com/qtmobility-1.1-tp/qcameraexposure.html#setFlashMode.

        You will find a list of the possible flash modes in the same document:

        bq. QCameraExposure::FlashOff
        QCameraExposure::FlashOn
        QCameraExposure::FlashAuto
        QCameraExposure::FlashRedEyeReduction
        QCameraExposure::FlashFill
        QCameraExposure::FlashTorch
        QCameraExposure::FlashSlowSyncFrontCurtain
        QCameraExposure::FlashSlowSyncRearCurtain
        QCameraExposure::FlashManual

        To get the current flash mode use
        @
        QCamera* camera = new QCamera;
        QCameraExposure* cameraExposure = camera.exposure();

        FlashModes flashMode = cameraExposure->flashMode();
        @
        To set a flash mode (for example always on) use
        @
        QCamera* camera = new QCamera;
        QCameraExposure* cameraExposure = camera.exposure();

        cameraExposure->setFlashMode(QCameraExposure::FlashTorch);
        @
        Hint: see also "QCameraExposure::isAvailable()":http://doc.qt.nokia.com/qtmobility-1.1-tp/qcameraexposure.html#isAvailable.

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        • A Offline
          A Offline
          alfah
          wrote on last edited by
          #7

          Thanks Lukas.

          That was indeed informative and the precisely what i needed .
          But now there is a small problem. When i run the prog, i get this error
          "QCameraExposure::QcameraExposure(Qcamera*) " is private!!!.. :(
          Wat does it mean?, tht i've created an instance of QCameraExposure it as private??? of i should declare it as private??

          Thank you.

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          • L Offline
            L Offline
            lgeyer
            wrote on last edited by
            #8

            There is no public constructor for the QCameraExposure object, which means that you cannot directly create an object of the QCameraExposure class (which itself is a design decision taken by the creator of the QCameraExposure class).

            You will have to use "QCamera::exposure()":http://doc.qt.nokia.com/qtmobility-1.1-tp/qcamera.html#exposure instead to retrieve a QCameraExposure object.

            The example might be a bit misleading - I corrected it so it should reflect real world code.

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            • K Offline
              K Offline
              kkrzewniak
              wrote on last edited by
              #9

              @QCameraExposure * QCamera::exposure () const@
              Returns the camera exposure control object.
              Sorry I'm a bit late :)

              Me, Grimlock, not "nice dino". ME BASH BRAINS!

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              • A Offline
                A Offline
                alfah
                wrote on last edited by
                #10

                :) thanks lukas

                bein a newbie am i dealin with tough stuff????? :(

                cuz now i get jus one error and it says "

                "request for member setFlashMode in cameraexpo, which is of non class type 'QCameraExposure' "

                this is the code ive used in the function

                { QCamera *camera = new QCamera;
                QCameraExposure *cameraexpo = camera->exposure();
                cameraexpo.setFlashMode(QCameraExposure::FlashOn);

                }

                regards,

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                • A Offline
                  A Offline
                  alfah
                  wrote on last edited by
                  #11

                  hey kkrzewniak

                  thank you, but i could not make head or tail of that oneliner code. :)

                  It returns a camera exposure ctrl obj? meanin?

                  regards,

                  P.S one basic question, is it necessary to switch on the camera to set flash on??

                  regards,

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                  • L Offline
                    L Offline
                    lgeyer
                    wrote on last edited by
                    #12

                    Have you included the QCameraExposure header?
                    @
                    #include <QCameraExposure>
                    @

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                    • L Offline
                      L Offline
                      loladiro
                      wrote on last edited by
                      #13

                      It's
                      @
                      cameraexpo->setFlashMode(QCameraExposure::FlashOn);
                      @
                      not
                      @
                      cameraexpo.setFlashMode(QCameraExposure::FlashOn);
                      @

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                      • A Offline
                        A Offline
                        alfah
                        wrote on last edited by
                        #14

                        @loladiro,
                        thanks! -> did the trick!! i finally got the prog running on c7 with out errors.

                        @lukas, loladiro, kkrzewniak

                        :( but then, when FlashOn was used i got the following msg
                        [Qt Message] camera error: "failed to set flash mode" :( :(

                        When i tried to use FlashTorch, i got
                        [Qt Message] Camera error: "Requested flash mode is not supported." :( :(

                        so wat next???

                        but there are apps which run in c7 which uses flash as torch!!!!!

                        thanks a lot for the help;

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                        • S Offline
                          S Offline
                          slava.chernikoff
                          wrote on last edited by
                          #15

                          Did anyone found a solution how to use camera LED as torch in Qt applications?

                          All suggested solutions like using setFlashMode(bla-bla-bla) doesn't work. But there are a lot of torches for Symbian and Meego... There are should be low-level platform for that trick I guess. But how to find it?

                          there.is.no.right.way

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                          • S Offline
                            S Offline
                            singaporeseo
                            wrote on last edited by
                            #16

                            take shot in bright place so that you don't need flash

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                            • S Offline
                              S Offline
                              slava.chernikoff
                              wrote on last edited by
                              #17

                              It's not about taking pictures. It about - how to use phone as torch.

                              there.is.no.right.way

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                              • J Offline
                                J Offline
                                jim_kaiser
                                wrote on last edited by
                                #18

                                To set the camera flash mode, you need to wait until the camera is initialized. So, connect a slot to the QCamera::statusChanged(QCamera::Status) and in your slot, set the flash mode when the camera is in QCamera::ActiveStatus. I don't know if the torch thingy would work but flash should.
                                The other app with the torch thingy could probably be using native Symbian code to do it.

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