Taking pictures using Jetpack Compose

Summary

The provided content is a tutorial on using Jetpack Compose to implement photo-taking functionality within an Android app, including setting up camera permissions and handling the camera interface with Compose UI elements.

Abstract

The article titled "Taking pictures using Jetpack Compose" offers a step-by-step guide for Android developers to integrate camera functionality into their applications using Jetpack Compose. It begins by advising the addition of camera permissions to the AndroidManifest.xml file, ensuring that the app can access the device's camera hardware. The tutorial then explains how to handle the bitmap data from the camera, use rememberLauncherForActivityResult with the TakePicturePreview contract to capture images, and manage camera permissions at runtime using ActivityResultContracts.RequestPermission. It also describes how to display the captured image using Compose's Image composable and provides code snippets for creating a user interface that includes an image preview and a button to trigger the camera. The author concludes by encouraging readers to follow for updates, subscribe to a newsletter, and consider supporting the author with a coffee donation. Additionally, the article promotes an AI service called ZAI.chat as a cost-effective alternative to ChatGPT Plus (GPT-4).

Opinions

The author believes that integrating camera functionality is a valuable skill in Android app development.
The tutorial is presented in a casual and engaging manner, inviting readers to grab a cup of coffee as they learn.
The author expresses appreciation for reader support and suggests that a coffee donation is a way to show appreciation for their content.
The recommendation of ZAI.chat indicates the author's opinion that it is a worthwhile and economical AI service for users to consider.

Taking pictures using Jetpack Compose

Grab a cup of coffee ☕ and let’s see how can we use Jetpack Compose to take photos directly in the app.

Before starting, let’s add the camera permission to the AndroidManifest.xml file.

<uses-feature
    android:name="android.hardware.camera"
    android:required="false" />

<uses-permission android:name="android.permission.CAMERA" />

Firstly, we need to create a variable to store the bitmap we’ll get after taking the photo.

var bitmap by remember {
    mutableStateOf<Bitmap?>(null)
}

Now to open the camera we need to use rememberLauncherForActivityResult that has a TakePicturePreview contract.

val cameraLauncher = rememberLauncherForActivityResult(
    contract = ActivityResultContracts.TakePicturePreview(),
    onResult = { newImage ->
        bitmap = newImage
    }
)

Let's create the permission launcher, which will request camera permission and launch the camera preview if permission is granted.

val permissionLauncher = rememberLauncherForActivityResult(
    ActivityResultContracts.RequestPermission()
) { isGranted ->
    if (isGranted) {
        cameraLauncher.launch()
    }
}

Using The Camera

Let’s add an Image and a TextButton. The Image will show up only if the bitmap is not empty.

Column {
    bitmap?.let {
        Image(
            bitmap = it.asImageBitmap(),
            contentDescription = null,
            modifier = Modifier
                .clip(CircleShape)
                .size(36.dp)
        )
    }
    
    val context = LocalContext.current
    
    TextButton(
        onClick = {
            // Checks if the permission is granted
            val permissionCheckResult =
                ContextCompat.checkSelfPermission(context, android.Manifest.permission.CAMERA)
    
            if (permissionCheckResult == PackageManager.PERMISSION_GRANTED) {
                // The permission is already granted
                cameraLauncher.launch()
            } else {
                // Launches the permission request
                cameraPermissionLauncher.launch(android.Manifest.permission.CAMERA)
            }
        }
    ) {
        Text(
            text = "Use camera"
        )
    }
}

I hope this article has been a valuable part of your development journey. For the latest updates, follow me and subscribe to the newsletter. If you appreciate my content, a coffee would be much appreciated! Thanks for reading! 😊☕️