capitalex / MainActivity.kt

package com.ogletree.composecameraexample import android.content.ContentResolver import android.content.ContentValues import android.graphics.Bitmap import android.graphics.BitmapFactory import android.graphics.Matrix import android.net.Uri import android.os.Bundle import android.provider.MediaStore import androidx.activity.ComponentActivity import androidx.activity.compose.setContent import androidx.activity.result.ActivityResultLauncher import androidx.activity.result.contract.ActivityResultContracts import androidx.compose.foundation.Image import androidx.compose.foundation.background import androidx.compose.foundation.clickable import androidx.compose.foundation.layout.* import androidx.compose.material.MaterialTheme import androidx.compose.material.OutlinedButton import androidx.compose.material.Surface import androidx.compose.material.Text import androidx.compose.runtime.* import androidx.compose.ui.Alignment import androidx.compose.ui.Modifier import androidx.compose.ui.graphics.ImageBitmap import androidx.compose.ui.graphics.asImageBitmap import androidx.compose.ui.text.font.FontWeight import androidx.compose.ui.tooling.preview.Preview import androidx.compose.ui.unit.dp import com.ogletree.composecameraexample.ui.theme.ComposeCameraExampleTheme import java.text.SimpleDateFormat import java.util.* import kotlin.math.min class MainActivity : ComponentActivity() { enum class CameraPermissionStatus { NoPermission, PermissionGranted, PermissionDenied } override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) val cameraPermissionStatusState = mutableStateOf(CameraPermissionStatus.NoPermission) val photoUriState: MutableState<Uri?> = mutableStateOf(null) val hasPhotoState = mutableStateOf(value = false) val resolver = applicationContext.contentResolver val requestPermissionLauncher = registerForActivityResult(ActivityResultContracts.RequestPermission()){ isGranted: Boolean -> if (isGranted) { cameraPermissionStatusState.value = CameraPermissionStatus.PermissionGranted } else { cameraPermissionStatusState.value = CameraPermissionStatus.PermissionDenied } } val takePhotoLauncher = registerForActivityResult(ActivityResultContracts.TakePicture()) { isSaved -> hasPhotoState.value = isSaved } val takePhoto: () -> Unit = { hasPhotoState.value = false val values = ContentValues().apply { val title = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.US).format(Date()) put(MediaStore.Images.Media.TITLE, "Compose Camera Example Image - $title") put(MediaStore.Images.Media.DISPLAY_NAME, title) put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg") put(MediaStore.Images.Media.DATE_TAKEN, System.currentTimeMillis()) } val uri = resolver.insert( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values ) takePhotoLauncher.launch(uri) photoUriState.value = uri } // Ideally these would be cached instead of reloaded val getThumbnail: (Uri?) -> ImageBitmap? = { uri -> val targetSize = 256f println("URI is $uri") uri?.let { println("Opening Input Stream") resolver.openInputStream(it) }?.let { BitmapFactory.decodeStream(it) }?.let { val height = it.height.toFloat() val width = it.width.toFloat() val scaleFactor = min(targetSize / height, targetSize / width) Bitmap.createScaledBitmap(it, (scaleFactor * width).toInt() , (scaleFactor * height).toInt(), true) }?.let { val rotation = getImageRotation(resolver, uri) Bitmap.createBitmap(it, 0, 0, it.width, it.height, Matrix().apply { postRotate(rotation.toFloat()) }, true) }?.asImageBitmap() } val getFullImage: (Uri?) -> ImageBitmap? = { uri -> uri?.let { resolver.openInputStream(it) }?.let { BitmapFactory.decodeStream(it) }?.let { val rotation = getImageRotation(resolver, uri) Bitmap.createBitmap(it, 0, 0, it.width, it.height, Matrix().apply { postRotate(rotation.toFloat()) }, true) }?.asImageBitmap() } setContent { val cameraPermissionStatus by remember { cameraPermissionStatusState } val hasPhoto by remember { hasPhotoState } var shouldShowFullImage by remember { mutableStateOf(false) } ComposeCameraExampleTheme { Box(modifier = Modifier.fillMaxSize()) { Column( modifier = Modifier.fillMaxSize(), verticalArrangement = Arrangement.Center, horizontalAlignment = Alignment.CenterHorizontally ) { TakePhotoButton( cameraPermissionStatus = cameraPermissionStatus, requestPermissionLauncher = requestPermissionLauncher, takePhoto = takePhoto ) if (hasPhoto) { val bitmap = getThumbnail(photoUriState.value) println("Is bitmap null: $bitmap") if (bitmap != null) { Image( bitmap = bitmap, contentDescription = "Thumbnail of Save Photo", modifier = Modifier.clickable { shouldShowFullImage = true } ) } } } if (shouldShowFullImage && hasPhoto) { val bitmap =getFullImage(photoUriState.value) if (bitmap != null){ Box(modifier = Modifier.fillMaxSize().clickable { shouldShowFullImage = false }){ Image( bitmap = bitmap, contentDescription = "Full image of Save Photo", modifier = Modifier.align(Alignment.Center) ) Surface( modifier = Modifier .background(MaterialTheme.colors.background) .align(Alignment.Center) .padding(8.dp) ) { Text( text = "Click to Close", style = MaterialTheme.typography.h4.copy( fontWeight = FontWeight.ExtraBold ) ) } } } else { shouldShowFullImage = false } } } } } } private fun getImageRotation(resolver: ContentResolver, uri: Uri): Int { val cursor = resolver.query(uri, arrayOf(MediaStore.Images.Media.ORIENTATION), null, null, null) var result = 0 cursor?.apply { moveToFirst() val index = getColumnIndex(MediaStore.Images.Media.ORIENTATION) result = getInt(index) close() } println("Rotation = $result") return result } } @Composable fun TakePhotoButton( cameraPermissionStatus: MainActivity.CameraPermissionStatus, requestPermissionLauncher: ActivityResultLauncher<String>, takePhoto: () -> Unit ) { OutlinedButton( onClick = { when (cameraPermissionStatus) { MainActivity.CameraPermissionStatus.NoPermission -> requestPermissionLauncher.launch(android.Manifest.permission.CAMERA) MainActivity.CameraPermissionStatus.PermissionGranted -> takePhoto() MainActivity.CameraPermissionStatus.PermissionDenied -> {} } } ) { when (cameraPermissionStatus) { MainActivity.CameraPermissionStatus.NoPermission -> Text(text = "Request Camera Permissions") MainActivity.CameraPermissionStatus.PermissionDenied -> Text(text = "Camera Permissions Have Been Denied") MainActivity.CameraPermissionStatus.PermissionGranted -> Text(text = "Take Photo") } } } @Composable fun Greeting(name: String) { Text(text = "Hello $name!") } @Preview(showBackground = true) @Composable fun DefaultPreview() { ComposeCameraExampleTheme { Greeting("Android") } }