Solved: Mobile App Camera Choice - 'cycle button'

swanders · ‎10-05-2022

Hello everyone,

been browsing around the forums to try and find a solution (or a pointer in the right direction) in the following question.

My app has a camera control, phones that will be using the app have more than 3 camera's (Some have 4 or more camera's). I get the select camera to work with a dropdown, however I would like to 'cycle' trough the different camera options by just pressing a button. If all options have been had, it will jump back to first option. This to create a bit of a 'friendlier' mobile 'take a picture' expierence.

Is this possible? I've been trying to look into different directions:

How to swap Camera to front and back in Power Apps Canvas Apps - Debajit's Power Apps & Dynamics 365...

This comes pretty close I think, but it doesn't capture the camera ID:
Solved: Re: Change dropdown values with button - Power Platform Community (microsoft.com)

To sum it up, is it possible to cycle trough the Camera.AvailableDevices.ID somehow, and automatically go back to the first option when all options have been cycled trough.

I do not expect a solution, though it would be nice, but a push in the right direction would be greatly appreciated!

BCBuizer · ‎10-10-2022

Hi @swanders,

One last idea I had is to use a global variable instead of a context variable. This can then be initiated in App.Onstart:

Set(gblCamera, 0)

Of course the Camera1.Camera property needs to be changed to match the identifier of the global variable.

Also the code for cycling cameras needs to be changed:

Set(
    gblCamera,
    If(
        gblCamera + 1 > Last(Camera1.AvailableDevices).Id,
        First(Camera1.AvailableDevices).Id,
        gblCamera + 1
    )
)

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View solution in original post

BCBuizer · ‎10-05-2022

Hi @swanders,

My first try would look something like the below, using two icons that change a context variable (varCamera). The Camera property of the Camera control then needs to be set to reference the variable:

The code for the left icon is:

UpdateContext(
    {
        varCamera: If(
            varCamera - 1 < First(Camera2.AvailableDevices).Id,
            Last(Camera2.AvailableDevices).Id,
            varCamera - 1
        )
    }
)

And the code for the right icon is:

UpdateContext(
    {
        varCamera: If(
            varCamera + 1 > Last(Camera2.AvailableDevices).Id,
            First(Camera2.AvailableDevices).Id,
            varCamera + 1
        )
    }
)

Since my laptop only has one camera my abilities to test are very limited, but so far it works 🙂

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swanders · ‎10-05-2022

Hi @BCBuizer ,

thank you so much for the fast reply. I will give this a spin first thing I'm able to; I'll keep you updated!

swanders · ‎10-06-2022

Hello @BCBuizer ,

finally gotten home (long day at the office), had some food and much to the pleasure of my girlfriend (ahum) I dove straight into your suggestion.

Seems to work pretty good! There's a little something going on tho (testing on my phone, since yes, my laptop has only one camera as well ;). When I browse to the screen that has the camera control, it tells me that the camera has not been setup correctly. I go over the buttons left and right, and they work perfect! I can even keep on cycling trough all the camera modes with just one button (left or right) and it will cycle trough all the (4) modes of the camera.

On one specific camera mode, when I browse back to the home screen of the app and return to the camera control screen, it will again give me the warning that the camera has not been setup correctly.

It's interesting since with 3 out of 4 modes, browsing back to the home screen, browse back to camera screen, the camera remains active at the position it was left.

I feel a bit shy to ask for more since you've already helped me out a great deal and I'm very thankful for your help so far.

BCBuizer · ‎10-07-2022

Hi @swanders,

What I wasn't sure of when writing the code, is what the possible values are. For testing purposes, can you please add a gallery to the app with Camera.AvailableDevices as the Items property. The gallery should show ThisItem.Id and ThisItem.Name. Please share a screenshot of the gallery when running the app on the phone.

If this shows the camera Ids don't have subsequent values, that will turn out to be the issue with the cycling, since trying to reference a device that doesn't exisit.

For the initial error, try adding the below code to the Onvisible property of the screen that has the camera control in it:

If(IsBlank(varCamera),Updatecontext({varCamera:First(Camera2.AvailableDevices).Id}))

This should "initialise" the variable an hopefully fix the issue.

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swanders · ‎10-07-2022

Pure awesomeness! I know exactly what you're talking about and what it is that you require (starting to get the hang of this Power Apps thing #yay).

Currently at work, will let you know asap, once again many thanks.

swanders · ‎10-07-2022

Hi @BCBuizer ,

here's the update and some screenshots. It seems that the cameras have a logical follow-up from 0 to 3.

Furthermore, I've put in the formula you proposed in the OnVisible property of the screen that has the Camera control in it. Does not seem to give me any extra information. Could it be because of it starting at 0, thus thinking it's blank or empty?

Let me know if any additional information is required.

BCBuizer · ‎10-07-2022

Hi @swanders,

Thank you for posting the screenshots. Very insightfull.

For some reason I couldn't get my previous solution to work, so I tried to tweak the navigate function when navigating to the CameraScreen which did work for me:

Navigate(
    CameraScreen,
    ScreenTransition.None,
    {varCamera: First(Camera2.AvailableDevices).Id}
)

Downside of this is that the selected camera is always reset when moving away from the CameraScreen.

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swanders · ‎10-08-2022

Good morning @BCBuizer ,

still no change on my end. On the laptop it works like a charm, screenshot below. It has the same starting ID as camera as the phone. I'm more or less concerned it's not PowerApps, but the (Samsung) phone. When I open the app and navigate to the camera screen, you can see that the light of the camera goes green for like 2 seconds and then turns of. Selecting the next Camera ID, it turns back on and works like a charm and I can cycle through all the modes.

I have some different model phones laying around from work; I will get some chargers, get them running and setup and test the App on working.

Screenshot of laptop camera, which instantly works when navigating to the screen

swanders · ‎10-10-2022

Hello @BCBuizer ,

finally gotten around to test multiple devices, including a tablet (all Android tho). Every device stumbled upon the same problem: upon navigating to the screen with the camera control, it's black. Cycling trough works perfectly fine for the different modes.

You think it would be wise to 'hardcode' camera "0" into the app? So far, all devices had a camera mode "0".