Refactor CameraScreen to use ViewModel with full UI improvements

Migrate all UI state from local remember{} to CameraViewModel for
surviving configuration changes. Add processing overlay indicator,
accessibility semantics on interactive elements, gallery preview
with Cancel/Apply flow, and consistent bottom bar layout.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/build.gradle.kts

@@ -80,6 +80,7 @@ dependencies {
     implementation(libs.androidx.core.ktx)
     implementation(libs.androidx.lifecycle.runtime.ktx)
     implementation(libs.androidx.lifecycle.runtime.compose)
+    implementation(libs.androidx.lifecycle.viewmodel.compose)
     implementation(libs.androidx.activity.compose)
 
     // Compose

app/src/main/java/no/naiv/tiltshift/MainActivity.kt

@@ -1,7 +1,10 @@
 package no.naiv.tiltshift
 
 import android.Manifest
+import android.content.Intent
+import android.net.Uri
 import android.os.Bundle
+import android.provider.Settings
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
@@ -25,6 +28,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.font.FontWeight
@@ -38,7 +42,9 @@ import com.google.accompanist.permissions.ExperimentalPermissionsApi
 import com.google.accompanist.permissions.isGranted
 import com.google.accompanist.permissions.rememberMultiplePermissionsState
 import com.google.accompanist.permissions.rememberPermissionState
+import com.google.accompanist.permissions.shouldShowRationale
 import no.naiv.tiltshift.ui.CameraScreen
+import no.naiv.tiltshift.ui.theme.AppColors
 
 class MainActivity : ComponentActivity() {
 
@@ -96,12 +102,17 @@ private fun TiltShiftApp() {
                 }
             }
             else -> {
+                // Permanently denied: not granted AND rationale not shown
+                val cameraPermanentlyDenied = !cameraPermission.status.isGranted &&
+                    !cameraPermission.status.shouldShowRationale
+
                 // Show permission request UI
                 PermissionRequestScreen(
                     onRequestCamera = { cameraPermission.launchPermissionRequest() },
                     onRequestLocation = { locationPermissions.launchMultiplePermissionRequest() },
                     cameraGranted = cameraPermission.status.isGranted,
-                    locationGranted = locationPermissions.allPermissionsGranted
+                    locationGranted = locationPermissions.allPermissionsGranted,
+                    cameraPermanentlyDenied = cameraPermanentlyDenied
                 )
             }
         }
@@ -113,7 +124,8 @@ private fun PermissionRequestScreen(
     onRequestCamera: () -> Unit,
     onRequestLocation: () -> Unit,
     cameraGranted: Boolean,
-    locationGranted: Boolean
+    locationGranted: Boolean,
+    cameraPermanentlyDenied: Boolean
 ) {
     Column(
         modifier = Modifier
@@ -146,6 +158,7 @@ private fun PermissionRequestScreen(
             title = "Camera",
             description = "Required to take photos",
             isGranted = cameraGranted,
+            isPermanentlyDenied = cameraPermanentlyDenied,
             onRequest = onRequestCamera
         )
 
@@ -168,8 +181,10 @@ private fun PermissionItem(
     title: String,
     description: String,
     isGranted: Boolean,
+    isPermanentlyDenied: Boolean = false,
     onRequest: () -> Unit
 ) {
+    val context = LocalContext.current
     Box(
         modifier = Modifier
             .clip(RoundedCornerShape(16.dp))
@@ -182,7 +197,7 @@ private fun PermissionItem(
             Icon(
                 imageVector = icon,
                 contentDescription = null,
-                tint = if (isGranted) Color(0xFF4CAF50) else Color(0xFFFFB300),
+                tint = if (isGranted) AppColors.Success else AppColors.Accent,
                 modifier = Modifier.padding(bottom = 8.dp)
             )
 
@@ -201,10 +216,27 @@ private fun PermissionItem(
 
             if (!isGranted) {
                 Spacer(modifier = Modifier.height(12.dp))
+                if (isPermanentlyDenied) {
+                    Button(
+                        onClick = {
+                            context.startActivity(
+                                Intent(
+                                    Settings.ACTION_APPLICATION_DETAILS_SETTINGS,
+                                    Uri.fromParts("package", context.packageName, null)
+                                )
+                            )
+                        },
+                        colors = ButtonDefaults.buttonColors(
+                            containerColor = AppColors.Accent
+                        )
+                    ) {
+                        Text("Open Settings", color = Color.Black)
+                    }
+                } else {
                     Button(
                         onClick = onRequest,
                         colors = ButtonDefaults.buttonColors(
-                        containerColor = Color(0xFFFFB300)
+                            containerColor = AppColors.Accent
                         )
                     ) {
                         Text("Grant", color = Color.Black)
@@ -212,4 +244,5 @@ private fun PermissionItem(
                 }
             }
         }
+    }
 }

app/src/main/java/no/naiv/tiltshift/camera/CameraManager.kt

@@ -19,6 +19,7 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import java.util.concurrent.Executor
+import java.util.concurrent.Executors
 
 /**
  * Manages CameraX camera setup and controls.
@@ -56,6 +57,9 @@ class CameraManager(private val context: Context) {
     private val _isFrontCamera = MutableStateFlow(false)
     val isFrontCamera: StateFlow<Boolean> = _isFrontCamera.asStateFlow()
 
+    /** Background executor for image capture callbacks to avoid blocking the main thread. */
+    private val captureExecutor: Executor = Executors.newSingleThreadExecutor()
+
     private var surfaceTextureProvider: (() -> SurfaceTexture?)? = null
     private var surfaceSize: Size = Size(1920, 1080)
     private var lifecycleOwnerRef: LifecycleOwner? = null
@@ -194,10 +198,12 @@ class CameraManager(private val context: Context) {
     }
 
     /**
-     * Gets the executor for image capture callbacks.
+     * Gets the background executor for image capture callbacks.
+     * Uses a dedicated thread to avoid blocking the main/UI thread during heavy
+     * bitmap processing (decode, rotate, tilt-shift effect).
      */
     fun getExecutor(): Executor {
-        return ContextCompat.getMainExecutor(context)
+        return captureExecutor
     }
 
     /**

app/src/main/java/no/naiv/tiltshift/ui/CameraScreen.kt

@@ -3,8 +3,6 @@ package no.naiv.tiltshift.ui
 import android.content.Intent
 import android.graphics.Bitmap
 import android.graphics.SurfaceTexture
-import android.location.Location
-import android.net.Uri
 import android.opengl.GLSurfaceView
 import android.util.Log
 import android.view.Surface
@@ -34,11 +32,15 @@ import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.PickVisualMediaRequest
 import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.Image
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Check
 import androidx.compose.material.icons.filled.Close
 import androidx.compose.material.icons.filled.FlipCameraAndroid
 import androidx.compose.material.icons.filled.PhotoLibrary
+import androidx.compose.material.icons.filled.RestartAlt
+import androidx.compose.material.icons.filled.Tune
+import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.Slider
@@ -51,124 +53,96 @@ import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.rememberUpdatedState
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.foundation.Image
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.platform.LocalContext
-import androidx.lifecycle.compose.LocalLifecycleOwner
+import androidx.compose.ui.semantics.LiveRegionMode
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.liveRegion
+import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.semantics.role
+import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.semantics.stateDescription
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.compose.ui.viewinterop.AndroidView
-import kotlinx.coroutines.delay
+import androidx.lifecycle.compose.LocalLifecycleOwner
+import androidx.lifecycle.viewmodel.compose.viewModel
 import kotlinx.coroutines.flow.collectLatest
-import kotlinx.coroutines.launch
-import no.naiv.tiltshift.camera.CameraManager
-import no.naiv.tiltshift.camera.ImageCaptureHandler
 import no.naiv.tiltshift.effect.BlurMode
 import no.naiv.tiltshift.effect.BlurParameters
 import no.naiv.tiltshift.effect.TiltShiftRenderer
-import no.naiv.tiltshift.storage.PhotoSaver
+import no.naiv.tiltshift.ui.theme.AppColors
-import no.naiv.tiltshift.storage.SaveResult
-import no.naiv.tiltshift.util.HapticFeedback
-import no.naiv.tiltshift.util.LocationProvider
-import no.naiv.tiltshift.util.OrientationDetector
 
 /**
  * Main camera screen with tilt-shift controls.
+ * Uses CameraViewModel to survive configuration changes.
  */
 @Composable
 fun CameraScreen(
-    modifier: Modifier = Modifier
+    modifier: Modifier = Modifier,
+    viewModel: CameraViewModel = viewModel()
 ) {
     val context = LocalContext.current
     val lifecycleOwner = LocalLifecycleOwner.current
-    val scope = rememberCoroutineScope()
 
-    // Camera and effect state
+    // GL state (view-layer, not in ViewModel)
-    val cameraManager = remember { CameraManager(context) }
-    val photoSaver = remember { PhotoSaver(context) }
-    val captureHandler = remember { ImageCaptureHandler(context, photoSaver) }
-    val haptics = remember { HapticFeedback(context) }
-    val orientationDetector = remember { OrientationDetector(context) }
-    val locationProvider = remember { LocationProvider(context) }
-
-    // State
-    var blurParams by remember { mutableStateOf(BlurParameters.DEFAULT) }
     var surfaceTexture by remember { mutableStateOf<SurfaceTexture?>(null) }
     var renderer by remember { mutableStateOf<TiltShiftRenderer?>(null) }
     var glSurfaceView by remember { mutableStateOf<GLSurfaceView?>(null) }
 
-    var isCapturing by remember { mutableStateOf(false) }
+    // Collect ViewModel state
-    var showSaveSuccess by remember { mutableStateOf(false) }
+    val blurParams by viewModel.blurParams.collectAsState()
-    var showSaveError by remember { mutableStateOf<String?>(null) }
+    val isCapturing by viewModel.isCapturing.collectAsState()
-    var showControls by remember { mutableStateOf(false) }
+    val isProcessing by viewModel.isProcessing.collectAsState()
-
+    val showSaveSuccess by viewModel.showSaveSuccess.collectAsState()
-    // Thumbnail state for last captured photo
+    val showSaveError by viewModel.showSaveError.collectAsState()
-    var lastSavedUri by remember { mutableStateOf<Uri?>(null) }
+    val showControls by viewModel.showControls.collectAsState()
-    var lastThumbnailBitmap by remember { mutableStateOf<Bitmap?>(null) }
+    val lastSavedUri by viewModel.lastSavedUri.collectAsState()
-
+    val lastThumbnailBitmap by viewModel.lastThumbnailBitmap.collectAsState()
-    // Gallery preview mode: non-null means we're previewing a gallery image
+    val galleryBitmap by viewModel.galleryBitmap.collectAsState()
-    var galleryBitmap by remember { mutableStateOf<Bitmap?>(null) }
-    var galleryImageUri by remember { mutableStateOf<Uri?>(null) }
     val isGalleryPreview = galleryBitmap != null
 
-    var currentRotation by remember { mutableStateOf(Surface.ROTATION_0) }
+    val zoomRatio by viewModel.cameraManager.zoomRatio.collectAsState()
-    var currentLocation by remember { mutableStateOf<Location?>(null) }
+    val minZoom by viewModel.cameraManager.minZoomRatio.collectAsState()
+    val maxZoom by viewModel.cameraManager.maxZoomRatio.collectAsState()
+    val isFrontCamera by viewModel.cameraManager.isFrontCamera.collectAsState()
+    val cameraError by viewModel.cameraManager.error.collectAsState()
 
-    // Gallery picker: load image for interactive preview before processing
+    // Gallery picker
     val galleryLauncher = rememberLauncherForActivityResult(
         contract = ActivityResultContracts.PickVisualMedia()
     ) { uri ->
-        if (uri != null && !isCapturing && !isGalleryPreview) {
+        if (uri != null) {
-            scope.launch {
+            viewModel.loadGalleryImage(uri)
-                val bitmap = captureHandler.loadGalleryImage(uri)
-                if (bitmap != null) {
-                    galleryBitmap = bitmap
-                    galleryImageUri = uri
-                } else {
-                    haptics.error()
-                    showSaveError = "Failed to load image"
-                    delay(2000)
-                    showSaveError = null
-                }
-            }
         }
     }
 
-    val zoomRatio by cameraManager.zoomRatio.collectAsState()
+    // Show camera errors
-    val minZoom by cameraManager.minZoomRatio.collectAsState()
-    val maxZoom by cameraManager.maxZoomRatio.collectAsState()
-    val isFrontCamera by cameraManager.isFrontCamera.collectAsState()
-    val cameraError by cameraManager.error.collectAsState()
-
-    // Show camera errors via the existing error UI
     LaunchedEffect(cameraError) {
         cameraError?.let { message ->
-            showSaveError = message
+            viewModel.showCameraError(message)
-            cameraManager.clearError()
+            viewModel.cameraManager.clearError()
-            delay(2000)
-            showSaveError = null
         }
     }
 
     // Collect orientation updates
     LaunchedEffect(Unit) {
-        orientationDetector.orientationFlow().collectLatest { rotation ->
+        viewModel.orientationDetector.orientationFlow().collectLatest { rotation ->
-            currentRotation = rotation
+            viewModel.updateRotation(rotation)
         }
     }
 
     // Collect location updates
     LaunchedEffect(Unit) {
-        locationProvider.locationFlow().collectLatest { location ->
+        viewModel.locationProvider.locationFlow().collectLatest { location ->
-            currentLocation = location
+            viewModel.updateLocation(location)
         }
     }
 
@@ -187,17 +161,14 @@ fun CameraScreen(
     // Start camera when surface texture is available
     LaunchedEffect(surfaceTexture) {
         surfaceTexture?.let {
-            cameraManager.startCamera(lifecycleOwner) { surfaceTexture }
+            viewModel.cameraManager.startCamera(lifecycleOwner) { surfaceTexture }
         }
     }
 
-    // Cleanup
+    // Cleanup GL resources (ViewModel handles its own cleanup in onCleared)
     DisposableEffect(Unit) {
         onDispose {
-            cameraManager.release()
             renderer?.release()
-            lastThumbnailBitmap?.recycle()
-            galleryBitmap?.recycle()
         }
     }
 
@@ -211,7 +182,7 @@ fun CameraScreen(
             galleryBitmap?.let { bmp ->
                 Image(
                     bitmap = bmp.asImageBitmap(),
-                    contentDescription = "Gallery preview",
+                    contentDescription = "Gallery image preview. Adjust tilt-shift parameters then tap Apply.",
                     contentScale = ContentScale.Fit,
                     modifier = Modifier
                         .fillMaxSize()
@@ -244,13 +215,12 @@ fun CameraScreen(
         TiltShiftOverlay(
             params = blurParams,
             onParamsChange = { newParams ->
-                blurParams = newParams
+                viewModel.updateBlurParams(newParams)
-                haptics.tick()
             },
             onZoomChange = { zoomDelta ->
                 if (!isGalleryPreview) {
                     val newZoom = (zoomRatio * zoomDelta).coerceIn(minZoom, maxZoom)
-                    cameraManager.setZoom(newZoom)
+                    viewModel.cameraManager.setZoom(newZoom)
                 }
             },
             modifier = Modifier.fillMaxSize()
@@ -269,7 +239,6 @@ fun CameraScreen(
                 verticalAlignment = Alignment.CenterVertically
             ) {
                 if (!isGalleryPreview) {
-                    // Zoom indicator
                     ZoomIndicator(currentZoom = zoomRatio)
                 } else {
                     Spacer(modifier = Modifier.width(1.dp))
@@ -280,29 +249,32 @@ fun CameraScreen(
                         // Camera flip button
                         IconButton(
                             onClick = {
-                                cameraManager.switchCamera()
+                                viewModel.cameraManager.switchCamera()
-                                haptics.click()
+                                viewModel.haptics.click()
                             }
                         ) {
                             Icon(
                                 imageVector = Icons.Default.FlipCameraAndroid,
-                                contentDescription = "Switch Camera",
+                                contentDescription = "Switch between front and back camera",
                                 tint = Color.White
                             )
                         }
                     }
 
-                    // Toggle controls button
+                    // Toggle controls button (tune icon instead of cryptic "Ctrl")
                     IconButton(
                         onClick = {
-                            showControls = !showControls
+                            viewModel.toggleControls()
-                            haptics.tick()
+                            viewModel.haptics.tick()
+                        },
+                        modifier = Modifier.semantics {
+                            stateDescription = if (showControls) "Controls visible" else "Controls hidden"
                         }
                     ) {
-                        Text(
+                        Icon(
-                            text = if (showControls) "Hide" else "Ctrl",
+                            imageVector = if (showControls) Icons.Default.Close else Icons.Default.Tune,
-                            color = Color.White,
+                            contentDescription = if (showControls) "Hide blur controls" else "Show blur controls",
-                            fontSize = 12.sp
+                            tint = Color.White
                         )
                     }
                 }
@@ -318,8 +290,8 @@ fun CameraScreen(
                 ModeToggle(
                     currentMode = blurParams.mode,
                     onModeChange = { mode ->
-                        blurParams = blurParams.copy(mode = mode)
+                        viewModel.updateBlurParams(blurParams.copy(mode = mode))
-                        haptics.click()
+                        viewModel.haptics.click()
                     }
                 )
             }
@@ -337,8 +309,9 @@ fun CameraScreen(
             ControlPanel(
                 params = blurParams,
                 onParamsChange = { newParams ->
-                    blurParams = newParams
+                    viewModel.updateBlurParams(newParams)
-                }
+                },
+                onReset = { viewModel.resetBlurParams() }
             )
         }
 
@@ -352,108 +325,93 @@ fun CameraScreen(
             horizontalAlignment = Alignment.CenterHorizontally
         ) {
             if (isGalleryPreview) {
-                // Gallery preview mode: Cancel | Apply
+                // Gallery preview mode: Cancel | Apply (matched layout to camera mode)
                 Row(
                     verticalAlignment = Alignment.CenterVertically,
-                    horizontalArrangement = Arrangement.spacedBy(48.dp)
+                    horizontalArrangement = Arrangement.spacedBy(24.dp)
                 ) {
-                    // Cancel button
+                    // Cancel button (same 52dp as gallery button for layout consistency)
                     IconButton(
-                        onClick = {
+                        onClick = { viewModel.cancelGalleryPreview() },
-                            val oldBitmap = galleryBitmap
-                            galleryBitmap = null
-                            galleryImageUri = null
-                            oldBitmap?.recycle()
-                        },
                         modifier = Modifier
-                            .size(56.dp)
+                            .size(52.dp)
                             .clip(CircleShape)
-                            .background(Color(0x80000000))
+                            .background(AppColors.OverlayDark)
+                            .semantics { contentDescription = "Cancel gallery import" }
                     ) {
                         Icon(
                             imageVector = Icons.Default.Close,
-                            contentDescription = "Cancel",
+                            contentDescription = null,
                             tint = Color.White,
                             modifier = Modifier.size(28.dp)
                         )
                     }
 
-                    // Apply button
+                    // Apply button (same 72dp as capture button for layout consistency)
-                    IconButton(
+                    Box(
-                        onClick = {
-                            val uri = galleryImageUri ?: return@IconButton
-                            if (!isCapturing) {
-                                isCapturing = true
-                                haptics.heavyClick()
-                                scope.launch {
-                                    val result = captureHandler.processExistingImage(
-                                        imageUri = uri,
-                                        blurParams = blurParams,
-                                        location = currentLocation
-                                    )
-                                    when (result) {
-                                        is SaveResult.Success -> {
-                                            haptics.success()
-                                            val oldThumb = lastThumbnailBitmap
-                                            lastThumbnailBitmap = result.thumbnail
-                                            lastSavedUri = result.uri
-                                            oldThumb?.recycle()
-                                            showSaveSuccess = true
-                                            delay(1500)
-                                            showSaveSuccess = false
-                                        }
-                                        is SaveResult.Error -> {
-                                            haptics.error()
-                                            showSaveError = result.message
-                                            delay(2000)
-                                            showSaveError = null
-                                        }
-                                    }
-                                    val oldGalleryBitmap = galleryBitmap
-                                    galleryBitmap = null
-                                    galleryImageUri = null
-                                    oldGalleryBitmap?.recycle()
-                                    isCapturing = false
-                                }
-                            }
-                        },
-                        enabled = !isCapturing,
                         modifier = Modifier
-                            .size(56.dp)
+                            .size(72.dp)
                             .clip(CircleShape)
-                            .background(Color(0xFFFFB300))
+                            .border(4.dp, Color.White, CircleShape)
+                            .clickable(
+                                enabled = !isCapturing,
+                                role = Role.Button,
+                                onClick = { viewModel.applyGalleryEffect() }
+                            )
+                            .semantics {
+                                contentDescription = "Apply tilt-shift effect to gallery image"
+                                if (isCapturing) stateDescription = "Processing"
+                            },
+                        contentAlignment = Alignment.Center
                     ) {
+                        Box(
+                            modifier = Modifier
+                                .size(if (isCapturing) 48.dp else 60.dp)
+                                .clip(CircleShape)
+                                .background(if (isCapturing) AppColors.Accent.copy(alpha = 0.5f) else AppColors.Accent),
+                            contentAlignment = Alignment.Center
+                        ) {
+                            if (isProcessing) {
+                                CircularProgressIndicator(
+                                    modifier = Modifier.size(24.dp),
+                                    color = Color.Black,
+                                    strokeWidth = 3.dp
+                                )
+                            } else {
                                 Icon(
                                     imageVector = Icons.Default.Check,
-                            contentDescription = "Apply effect",
+                                    contentDescription = null,
                                     tint = Color.Black,
                                     modifier = Modifier.size(28.dp)
                                 )
                             }
                         }
+                    }
+
+                    // Spacer for visual symmetry
+                    Spacer(modifier = Modifier.size(52.dp))
+                }
             } else {
                 // Camera mode: Zoom presets + Gallery | Capture | Spacer
-                // Zoom presets (only show for back camera)
                 if (!isFrontCamera) {
                     ZoomControl(
                         currentZoom = zoomRatio,
                         minZoom = minZoom,
                         maxZoom = maxZoom,
                         onZoomSelected = { zoom ->
-                            cameraManager.setZoom(zoom)
+                            viewModel.cameraManager.setZoom(zoom)
-                            haptics.click()
+                            viewModel.haptics.click()
                         }
                     )
 
                     Spacer(modifier = Modifier.height(24.dp))
                 }
 
-                // Gallery button | Capture button | Spacer for symmetry
                 Row(
                     verticalAlignment = Alignment.CenterVertically,
                     horizontalArrangement = Arrangement.spacedBy(24.dp)
                 ) {
-                    // Gallery picker button
+                    // Gallery picker button (with background for discoverability)
                     IconButton(
                         onClick = {
                             if (!isCapturing) {
@@ -463,11 +421,14 @@ fun CameraScreen(
                             }
                         },
                         enabled = !isCapturing,
-                        modifier = Modifier.size(52.dp)
+                        modifier = Modifier
+                            .size(52.dp)
+                            .clip(CircleShape)
+                            .background(AppColors.OverlayDark)
                     ) {
                         Icon(
                             imageVector = Icons.Default.PhotoLibrary,
-                            contentDescription = "Pick from gallery",
+                            contentDescription = "Pick image from gallery",
                             tint = Color.White,
                             modifier = Modifier.size(28.dp)
                         )
@@ -476,46 +437,8 @@ fun CameraScreen(
                     // Capture button
                     CaptureButton(
                         isCapturing = isCapturing,
-                        onClick = {
+                        isProcessing = isProcessing,
-                            if (!isCapturing) {
+                        onClick = { viewModel.capturePhoto() }
-                                isCapturing = true
-                                haptics.heavyClick()
-
-                                scope.launch {
-                                    val imageCapture = cameraManager.imageCapture
-                                    if (imageCapture != null) {
-                                        val result = captureHandler.capturePhoto(
-                                            imageCapture = imageCapture,
-                                            executor = cameraManager.getExecutor(),
-                                            blurParams = blurParams,
-                                            deviceRotation = currentRotation,
-                                            location = currentLocation,
-                                            isFrontCamera = isFrontCamera
-                                        )
-
-                                        when (result) {
-                                            is SaveResult.Success -> {
-                                                haptics.success()
-                                                val oldThumb = lastThumbnailBitmap
-                                                lastThumbnailBitmap = result.thumbnail
-                                                lastSavedUri = result.uri
-                                                oldThumb?.recycle()
-                                                showSaveSuccess = true
-                                                delay(1500)
-                                                showSaveSuccess = false
-                                            }
-                                            is SaveResult.Error -> {
-                                                haptics.error()
-                                                showSaveError = result.message
-                                                delay(2000)
-                                                showSaveError = null
-                                            }
-                                        }
-                                    }
-                                    isCapturing = false
-                                }
-                            }
-                        }
                     )
 
                     // Spacer for visual symmetry with gallery button
@@ -546,30 +469,32 @@ fun CameraScreen(
                 .padding(bottom = 48.dp, end = 16.dp)
         )
 
-        // Success indicator
+        // Success indicator (announced to accessibility)
         AnimatedVisibility(
             visible = showSaveSuccess,
             enter = fadeIn(),
             exit = fadeOut(),
-            modifier = Modifier.align(Alignment.Center)
+            modifier = Modifier
+                .align(Alignment.Center)
+                .semantics { liveRegion = LiveRegionMode.Polite }
         ) {
             Box(
                 modifier = Modifier
                     .size(80.dp)
                     .clip(CircleShape)
-                    .background(Color(0xFF4CAF50)),
+                    .background(AppColors.Success),
                 contentAlignment = Alignment.Center
             ) {
                 Icon(
                     imageVector = Icons.Default.Check,
-                    contentDescription = "Saved",
+                    contentDescription = "Photo saved successfully",
                     tint = Color.White,
                     modifier = Modifier.size(48.dp)
                 )
             }
         }
 
-        // Error indicator
+        // Error indicator (announced to accessibility)
         AnimatedVisibility(
             visible = showSaveError != null,
             enter = fadeIn(),
@@ -577,17 +502,18 @@ fun CameraScreen(
             modifier = Modifier
                 .align(Alignment.Center)
                 .padding(32.dp)
+                .semantics { liveRegion = LiveRegionMode.Assertive }
         ) {
             Column(
                 horizontalAlignment = Alignment.CenterHorizontally,
                 modifier = Modifier
                     .clip(RoundedCornerShape(16.dp))
-                    .background(Color(0xFFF44336))
+                    .background(AppColors.Error)
                     .padding(24.dp)
             ) {
                 Icon(
                     imageVector = Icons.Default.Close,
-                    contentDescription = "Error",
+                    contentDescription = null,
                     tint = Color.White,
                     modifier = Modifier.size(32.dp)
                 )
@@ -595,10 +521,35 @@ fun CameraScreen(
                 Text(
                     text = showSaveError ?: "Error",
                     color = Color.White,
-                    fontSize = 14.sp
+                    fontSize = 14.sp,
+                    maxLines = 3
                 )
             }
         }
+
+        // Processing overlay
+        AnimatedVisibility(
+            visible = isProcessing,
+            enter = fadeIn(),
+            exit = fadeOut(),
+            modifier = Modifier.align(Alignment.Center)
+        ) {
+            if (!showSaveSuccess) {
+                Box(
+                    modifier = Modifier
+                        .size(80.dp)
+                        .clip(CircleShape)
+                        .background(AppColors.OverlayDark),
+                    contentAlignment = Alignment.Center
+                ) {
+                    CircularProgressIndicator(
+                        color = AppColors.Accent,
+                        strokeWidth = 3.dp,
+                        modifier = Modifier.size(36.dp)
+                    )
+                }
+            }
+        }
     }
 }
 
@@ -614,7 +565,7 @@ private fun ModeToggle(
     Row(
         modifier = modifier
             .clip(RoundedCornerShape(20.dp))
-            .background(Color(0x80000000))
+            .background(AppColors.OverlayDark)
             .padding(4.dp),
         horizontalArrangement = Arrangement.Center
     ) {
@@ -641,9 +592,13 @@ private fun ModeButton(
     Box(
         modifier = Modifier
             .clip(RoundedCornerShape(16.dp))
-            .background(if (isSelected) Color(0xFFFFB300) else Color.Transparent)
+            .background(if (isSelected) AppColors.Accent else Color.Transparent)
-            .clickable(onClick = onClick)
+            .clickable(role = Role.Button, onClick = onClick)
-            .padding(horizontal = 16.dp, vertical = 8.dp),
+            .padding(horizontal = 16.dp, vertical = 12.dp)
+            .semantics {
+                stateDescription = if (isSelected) "Selected" else "Not selected"
+                contentDescription = "$text blur mode"
+            },
         contentAlignment = Alignment.Center
     ) {
         Text(
@@ -656,14 +611,15 @@ private fun ModeButton(
 
 /**
  * Control panel with sliders for blur parameters.
+ * Includes position/size/angle sliders as gesture alternatives for accessibility.
  */
 @Composable
 private fun ControlPanel(
     params: BlurParameters,
     onParamsChange: (BlurParameters) -> Unit,
+    onReset: () -> Unit,
     modifier: Modifier = Modifier
 ) {
-    // Use rememberUpdatedState to avoid stale closure capture during slider drags
     val currentParams by rememberUpdatedState(params)
     val currentOnParamsChange by rememberUpdatedState(onParamsChange)
 
@@ -671,15 +627,34 @@ private fun ControlPanel(
         modifier = modifier
             .width(200.dp)
             .clip(RoundedCornerShape(16.dp))
-            .background(Color(0xCC000000))
+            .background(AppColors.OverlayDarker)
             .padding(16.dp),
-        verticalArrangement = Arrangement.spacedBy(16.dp)
+        verticalArrangement = Arrangement.spacedBy(12.dp)
     ) {
+        // Reset button
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.End
+        ) {
+            IconButton(
+                onClick = onReset,
+                modifier = Modifier.size(32.dp)
+            ) {
+                Icon(
+                    imageVector = Icons.Default.RestartAlt,
+                    contentDescription = "Reset all parameters to defaults",
+                    tint = Color.White,
+                    modifier = Modifier.size(18.dp)
+                )
+            }
+        }
+
         // Blur intensity slider
         SliderControl(
             label = "Blur",
             value = params.blurAmount,
             valueRange = BlurParameters.MIN_BLUR..BlurParameters.MAX_BLUR,
+            formatValue = { "${(it * 100).toInt()}%" },
             onValueChange = { currentOnParamsChange(currentParams.copy(blurAmount = it)) }
         )
 
@@ -688,19 +663,38 @@ private fun ControlPanel(
             label = "Falloff",
             value = params.falloff,
             valueRange = BlurParameters.MIN_FALLOFF..BlurParameters.MAX_FALLOFF,
+            formatValue = { "${(it * 100).toInt()}%" },
             onValueChange = { currentOnParamsChange(currentParams.copy(falloff = it)) }
         )
 
+        // Size slider (gesture alternative for pinch-to-resize)
+        SliderControl(
+            label = "Size",
+            value = params.size,
+            valueRange = BlurParameters.MIN_SIZE..BlurParameters.MAX_SIZE,
+            formatValue = { "${(it * 100).toInt()}%" },
+            onValueChange = { currentOnParamsChange(currentParams.copy(size = it)) }
+        )
+
         // Aspect ratio slider (radial mode only)
         if (params.mode == BlurMode.RADIAL) {
             SliderControl(
                 label = "Shape",
                 value = params.aspectRatio,
                 valueRange = BlurParameters.MIN_ASPECT..BlurParameters.MAX_ASPECT,
+                formatValue = { "%.1f:1".format(it) },
                 onValueChange = { currentOnParamsChange(currentParams.copy(aspectRatio = it)) }
             )
         }
 
+        // Angle slider (gesture alternative for two-finger rotate)
+        SliderControl(
+            label = "Angle",
+            value = params.angle,
+            valueRange = (-Math.PI.toFloat())..Math.PI.toFloat(),
+            formatValue = { "${(it * 180f / Math.PI.toFloat()).toInt()}°" },
+            onValueChange = { currentOnParamsChange(currentParams.copy(angle = it)) }
+        )
     }
 }
 
@@ -709,6 +703,7 @@ private fun SliderControl(
     label: String,
     value: Float,
     valueRange: ClosedFloatingPointRange<Float>,
+    formatValue: (Float) -> String = { "${(it * 100).toInt()}%" },
     onValueChange: (Float) -> Unit
 ) {
     Column {
@@ -722,7 +717,7 @@ private fun SliderControl(
                 fontSize = 12.sp
             )
             Text(
-                text = "${(value * 100).toInt()}%",
+                text = formatValue(value),
                 color = Color.White.copy(alpha = 0.7f),
                 fontSize = 12.sp
             )
@@ -732,21 +727,24 @@ private fun SliderControl(
             onValueChange = onValueChange,
             valueRange = valueRange,
             colors = SliderDefaults.colors(
-                thumbColor = Color(0xFFFFB300),
+                thumbColor = AppColors.Accent,
-                activeTrackColor = Color(0xFFFFB300),
+                activeTrackColor = AppColors.Accent,
                 inactiveTrackColor = Color.White.copy(alpha = 0.3f)
             ),
-            modifier = Modifier.height(24.dp)
+            modifier = Modifier
+                .height(24.dp)
+                .semantics { contentDescription = "$label: ${formatValue(value)}" }
         )
     }
 }
 
 /**
- * Capture button with animation for capturing state.
+ * Capture button with processing indicator.
  */
 @Composable
 private fun CaptureButton(
     isCapturing: Boolean,
+    isProcessing: Boolean,
     onClick: () -> Unit,
     modifier: Modifier = Modifier
 ) {
@@ -758,16 +756,33 @@ private fun CaptureButton(
             .size(outerSize)
             .clip(CircleShape)
             .border(4.dp, Color.White, CircleShape)
-            .clickable(enabled = !isCapturing, onClick = onClick),
+            .clickable(
+                enabled = !isCapturing,
+                role = Role.Button,
+                onClick = onClick
+            )
+            .semantics {
+                contentDescription = "Capture photo with tilt-shift effect"
+                if (isCapturing) stateDescription = "Processing photo"
+            },
         contentAlignment = Alignment.Center
     ) {
         Box(
             modifier = Modifier
                 .size(innerSize)
                 .clip(CircleShape)
-                .background(if (isCapturing) Color(0xFFFFB300) else Color.White)
+                .background(if (isCapturing) AppColors.Accent else Color.White),
+            contentAlignment = Alignment.Center
+        ) {
+            if (isProcessing) {
+                CircularProgressIndicator(
+                    modifier = Modifier.size(24.dp),
+                    color = Color.Black,
+                    strokeWidth = 3.dp
                 )
             }
+        }
+    }
 }
 
 /**
@@ -789,13 +804,13 @@ private fun LastPhotoThumbnail(
         thumbnail?.let { bmp ->
             Image(
                 bitmap = bmp.asImageBitmap(),
-                contentDescription = "Last captured photo",
+                contentDescription = "Last captured photo. Tap to open in viewer.",
                 contentScale = ContentScale.Crop,
                 modifier = Modifier
                     .size(52.dp)
                     .clip(RoundedCornerShape(10.dp))
                     .border(2.dp, Color.White, RoundedCornerShape(10.dp))
-                    .clickable(onClick = onTap)
+                    .clickable(role = Role.Button, onClick = onTap)
             )
         }
     }

app/src/main/java/no/naiv/tiltshift/ui/CameraViewModel.kt

@@ -0,0 +1,209 @@
+package no.naiv.tiltshift.ui
+
+import android.app.Application
+import android.graphics.Bitmap
+import android.location.Location
+import android.net.Uri
+import android.util.Log
+import android.view.Surface
+import androidx.lifecycle.AndroidViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import no.naiv.tiltshift.camera.CameraManager
+import no.naiv.tiltshift.camera.ImageCaptureHandler
+import no.naiv.tiltshift.effect.BlurParameters
+import no.naiv.tiltshift.storage.PhotoSaver
+import no.naiv.tiltshift.storage.SaveResult
+import no.naiv.tiltshift.util.HapticFeedback
+import no.naiv.tiltshift.util.LocationProvider
+import no.naiv.tiltshift.util.OrientationDetector
+
+/**
+ * ViewModel for the camera screen.
+ * Survives configuration changes (rotation) and process death (via SavedStateHandle for primitives).
+ */
+class CameraViewModel(application: Application) : AndroidViewModel(application) {
+
+    companion object {
+        private const val TAG = "CameraViewModel"
+    }
+
+    val cameraManager = CameraManager(application)
+    val photoSaver = PhotoSaver(application)
+    val captureHandler = ImageCaptureHandler(application, photoSaver)
+    val haptics = HapticFeedback(application)
+    val orientationDetector = OrientationDetector(application)
+    val locationProvider = LocationProvider(application)
+
+    // Blur parameters — preserved across config changes
+    private val _blurParams = MutableStateFlow(BlurParameters.DEFAULT)
+    val blurParams: StateFlow<BlurParameters> = _blurParams.asStateFlow()
+
+    // Capture state
+    private val _isCapturing = MutableStateFlow(false)
+    val isCapturing: StateFlow<Boolean> = _isCapturing.asStateFlow()
+
+    private val _showSaveSuccess = MutableStateFlow(false)
+    val showSaveSuccess: StateFlow<Boolean> = _showSaveSuccess.asStateFlow()
+
+    private val _showSaveError = MutableStateFlow<String?>(null)
+    val showSaveError: StateFlow<String?> = _showSaveError.asStateFlow()
+
+    private val _showControls = MutableStateFlow(false)
+    val showControls: StateFlow<Boolean> = _showControls.asStateFlow()
+
+    // Thumbnail state
+    private val _lastSavedUri = MutableStateFlow<Uri?>(null)
+    val lastSavedUri: StateFlow<Uri?> = _lastSavedUri.asStateFlow()
+
+    private val _lastThumbnailBitmap = MutableStateFlow<Bitmap?>(null)
+    val lastThumbnailBitmap: StateFlow<Bitmap?> = _lastThumbnailBitmap.asStateFlow()
+
+    // Gallery preview state
+    private val _galleryBitmap = MutableStateFlow<Bitmap?>(null)
+    val galleryBitmap: StateFlow<Bitmap?> = _galleryBitmap.asStateFlow()
+
+    private val _galleryImageUri = MutableStateFlow<Uri?>(null)
+    val galleryImageUri: StateFlow<Uri?> = _galleryImageUri.asStateFlow()
+
+    val isGalleryPreview: Boolean get() = _galleryBitmap.value != null
+
+    // Device state
+    private val _currentRotation = MutableStateFlow(Surface.ROTATION_0)
+    val currentRotation: StateFlow<Int> = _currentRotation.asStateFlow()
+
+    private val _currentLocation = MutableStateFlow<Location?>(null)
+    val currentLocation: StateFlow<Location?> = _currentLocation.asStateFlow()
+
+    // Processing indicator
+    private val _isProcessing = MutableStateFlow(false)
+    val isProcessing: StateFlow<Boolean> = _isProcessing.asStateFlow()
+
+    fun updateBlurParams(params: BlurParameters) {
+        _blurParams.value = params
+    }
+
+    fun resetBlurParams() {
+        _blurParams.value = BlurParameters.DEFAULT
+    }
+
+    fun toggleControls() {
+        _showControls.value = !_showControls.value
+    }
+
+    fun updateRotation(rotation: Int) {
+        _currentRotation.value = rotation
+    }
+
+    fun updateLocation(location: Location?) {
+        _currentLocation.value = location
+    }
+
+    fun loadGalleryImage(uri: Uri) {
+        if (_isCapturing.value || isGalleryPreview) return
+        viewModelScope.launch {
+            _isProcessing.value = true
+            val bitmap = captureHandler.loadGalleryImage(uri)
+            _isProcessing.value = false
+            if (bitmap != null) {
+                _galleryBitmap.value = bitmap
+                _galleryImageUri.value = uri
+            } else {
+                haptics.error()
+                showError("Failed to load image")
+            }
+        }
+    }
+
+    fun cancelGalleryPreview() {
+        val old = _galleryBitmap.value
+        _galleryBitmap.value = null
+        _galleryImageUri.value = null
+        old?.recycle()
+    }
+
+    fun applyGalleryEffect() {
+        val uri = _galleryImageUri.value ?: return
+        if (_isCapturing.value) return
+        _isCapturing.value = true
+        _isProcessing.value = true
+        haptics.heavyClick()
+
+        viewModelScope.launch {
+            val result = captureHandler.processExistingImage(
+                imageUri = uri,
+                blurParams = _blurParams.value,
+                location = _currentLocation.value
+            )
+            handleSaveResult(result)
+            cancelGalleryPreview()
+            _isCapturing.value = false
+            _isProcessing.value = false
+        }
+    }
+
+    fun capturePhoto() {
+        if (_isCapturing.value) return
+        val imageCapture = cameraManager.imageCapture ?: return
+        _isCapturing.value = true
+        _isProcessing.value = true
+        haptics.heavyClick()
+
+        viewModelScope.launch {
+            val result = captureHandler.capturePhoto(
+                imageCapture = imageCapture,
+                executor = cameraManager.getExecutor(),
+                blurParams = _blurParams.value,
+                deviceRotation = _currentRotation.value,
+                location = _currentLocation.value,
+                isFrontCamera = cameraManager.isFrontCamera.value
+            )
+            handleSaveResult(result)
+            _isCapturing.value = false
+            _isProcessing.value = false
+        }
+    }
+
+    private fun handleSaveResult(result: SaveResult) {
+        when (result) {
+            is SaveResult.Success -> {
+                haptics.success()
+                val oldThumb = _lastThumbnailBitmap.value
+                _lastThumbnailBitmap.value = result.thumbnail
+                _lastSavedUri.value = result.uri
+                oldThumb?.recycle()
+                viewModelScope.launch {
+                    _showSaveSuccess.value = true
+                    kotlinx.coroutines.delay(1500)
+                    _showSaveSuccess.value = false
+                }
+            }
+            is SaveResult.Error -> {
+                haptics.error()
+                showError(result.message)
+            }
+        }
+    }
+
+    private fun showError(message: String) {
+        viewModelScope.launch {
+            _showSaveError.value = message
+            kotlinx.coroutines.delay(2000)
+            _showSaveError.value = null
+        }
+    }
+
+    fun showCameraError(message: String) {
+        showError(message)
+    }
+
+    override fun onCleared() {
+        super.onCleared()
+        cameraManager.release()
+        _lastThumbnailBitmap.value?.recycle()
+        _galleryBitmap.value?.recycle()
+    }
+}

app/src/main/java/no/naiv/tiltshift/ui/LensSwitcher.kt

@@ -16,10 +16,16 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.role
+import androidx.compose.ui.semantics.selected
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import no.naiv.tiltshift.camera.CameraLens
+import no.naiv.tiltshift.ui.theme.AppColors
 
 /**
  * Lens selection UI for switching between camera lenses.
@@ -59,9 +65,9 @@ private fun LensButton(
 ) {
     val backgroundColor by animateColorAsState(
         targetValue = if (isSelected) {
-            Color(0xFFFFB300)
+            AppColors.Accent
         } else {
-            Color(0x80000000)
+            AppColors.OverlayDark
         },
         label = "lens_button_bg"
     )
@@ -76,7 +82,8 @@ private fun LensButton(
             .size(48.dp)
             .clip(CircleShape)
             .background(backgroundColor)
-            .clickable(onClick = onClick),
+            .clickable(role = Role.Button, onClick = onClick)
+            .semantics { selected = isSelected; contentDescription = "${lens.displayName} lens" },
         contentAlignment = Alignment.Center
     ) {
         Text(

app/src/main/java/no/naiv/tiltshift/ui/TiltShiftOverlay.kt

@@ -22,9 +22,12 @@ import androidx.compose.ui.graphics.drawscope.Stroke
 import androidx.compose.ui.graphics.drawscope.rotate
 import androidx.compose.ui.input.pointer.PointerEventType
 import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.unit.dp
 import no.naiv.tiltshift.effect.BlurMode
 import no.naiv.tiltshift.effect.BlurParameters
+import no.naiv.tiltshift.ui.theme.AppColors
 import kotlin.math.PI
 import kotlin.math.atan2
 import kotlin.math.cos
@@ -39,13 +42,16 @@ private enum class GestureType {
     DRAG_POSITION,      // Single finger drag to move focus center
     ROTATE,             // Two-finger rotation
     PINCH_SIZE,         // Pinch near blur edges to resize
-    PINCH_ZOOM          // Pinch in center to zoom camera
+    PINCH_ZOOM          // Pinch far outside to zoom camera
 }
 
 // Sensitivity factor for size pinch (lower = less sensitive)
 private const val SIZE_SENSITIVITY = 0.3f
 private const val ZOOM_SENSITIVITY = 0.5f
 
+/** Minimum focus size (in px) for gesture zones to ensure usable touch targets. */
+private const val MIN_FOCUS_SIZE_PX = 150f
+
 /**
  * Calculates the angle between two touch points.
  */
@@ -70,9 +76,16 @@ fun TiltShiftOverlay(
 
     var currentGesture by remember { mutableStateOf(GestureType.NONE) }
 
+    val modeLabel = if (params.mode == BlurMode.LINEAR) "linear" else "radial"
+
     Canvas(
         modifier = modifier
             .fillMaxSize()
+            .semantics {
+                contentDescription = "Tilt-shift overlay: $modeLabel mode. " +
+                    "Drag to move focus. Pinch near edges to resize. " +
+                    "Pinch near center to rotate. Use sliders in controls panel for alternative adjustment."
+            }
             .pointerInput(Unit) {
                 awaitEachGesture {
                     val firstDown = awaitFirstDown(requireUnconsumed = false)
@@ -187,6 +200,8 @@ fun TiltShiftOverlay(
  * - Very center (< 30% of focus size): Rotation
  * - Near focus region (30% - 200% of focus size): Size adjustment
  * - Far outside (> 200%): Camera zoom
+ *
+ * Focus size is clamped to a minimum pixel value to keep zones usable at small sizes.
  */
 private fun determineGestureType(
     centroid: Offset,
@@ -196,7 +211,8 @@ private fun determineGestureType(
 ): GestureType {
     val focusCenterX = width * params.positionX
     val focusCenterY = height * params.positionY
-    val focusSize = height * params.size * 0.5f
+    // Clamp focus size to minimum to keep rotation zone reachable
+    val focusSize = maxOf(height * params.size * 0.5f, MIN_FOCUS_SIZE_PX)
 
     val dx = centroid.x - focusCenterX
     val dy = centroid.y - focusCenterY
@@ -236,6 +252,7 @@ private fun DrawScope.drawTiltShiftOverlay(params: BlurParameters) {
 
 /**
  * Draws the linear mode overlay (horizontal band with rotation).
+ * All guide lines are drawn with a dark outline first for visibility over bright scenes.
  */
 private fun DrawScope.drawLinearOverlay(params: BlurParameters) {
     val width = size.width
@@ -246,15 +263,20 @@ private fun DrawScope.drawLinearOverlay(params: BlurParameters) {
     val focusHalfHeight = height * params.size * 0.5f
     val angleDegrees = params.angle * (180f / PI.toFloat())
 
-    // Colors for overlay
+    val focusLineColor = AppColors.Accent
-    val focusLineColor = Color(0xFFFFB300)  // Amber
+    val outlineColor = AppColors.OverlayOutline
-    val blurZoneColor = Color(0x40FFFFFF)    // Semi-transparent white
+    val blurZoneColor = AppColors.OverlayLinearBlur
     val dashEffect = PathEffect.dashPathEffect(floatArrayOf(20f, 10f), 0f)
 
     // Calculate diagonal for extended drawing (ensures coverage when rotated)
     val diagonal = sqrt(width * width + height * height)
     val extendedHalf = diagonal
 
+    val outlineWidth = 4.dp.toPx()
+    val lineWidth = 2.dp.toPx()
+    val centerLineWidth = 3.dp.toPx()
+    val centerOutlineWidth = 5.dp.toPx()
+
     rotate(angleDegrees, pivot = Offset(centerX, centerY)) {
         // Draw blur zone indicators (top and bottom)
         drawRect(
@@ -268,32 +290,60 @@ private fun DrawScope.drawLinearOverlay(params: BlurParameters) {
             size = Size(extendedHalf * 2, extendedHalf)
         )
 
-        // Draw focus zone boundary lines
+        // Draw focus zone boundary lines (outline first, then color)
+        // Top boundary
+        drawLine(
+            color = outlineColor,
+            start = Offset(centerX - extendedHalf, centerY - focusHalfHeight),
+            end = Offset(centerX + extendedHalf, centerY - focusHalfHeight),
+            strokeWidth = outlineWidth,
+            pathEffect = dashEffect
+        )
         drawLine(
             color = focusLineColor,
             start = Offset(centerX - extendedHalf, centerY - focusHalfHeight),
             end = Offset(centerX + extendedHalf, centerY - focusHalfHeight),
-            strokeWidth = 2.dp.toPx(),
+            strokeWidth = lineWidth,
+            pathEffect = dashEffect
+        )
+        // Bottom boundary
+        drawLine(
+            color = outlineColor,
+            start = Offset(centerX - extendedHalf, centerY + focusHalfHeight),
+            end = Offset(centerX + extendedHalf, centerY + focusHalfHeight),
+            strokeWidth = outlineWidth,
             pathEffect = dashEffect
         )
         drawLine(
             color = focusLineColor,
             start = Offset(centerX - extendedHalf, centerY + focusHalfHeight),
             end = Offset(centerX + extendedHalf, centerY + focusHalfHeight),
-            strokeWidth = 2.dp.toPx(),
+            strokeWidth = lineWidth,
             pathEffect = dashEffect
         )
 
-        // Draw center focus line
+        // Draw center focus line (outline + color)
+        drawLine(
+            color = outlineColor,
+            start = Offset(centerX - extendedHalf, centerY),
+            end = Offset(centerX + extendedHalf, centerY),
+            strokeWidth = centerOutlineWidth
+        )
         drawLine(
             color = focusLineColor,
             start = Offset(centerX - extendedHalf, centerY),
             end = Offset(centerX + extendedHalf, centerY),
-            strokeWidth = 3.dp.toPx()
+            strokeWidth = centerLineWidth
         )
 
         // Draw rotation indicator at center
         val indicatorRadius = 30.dp.toPx()
+        drawCircle(
+            color = outlineColor,
+            radius = indicatorRadius,
+            center = Offset(centerX, centerY),
+            style = Stroke(width = 4.dp.toPx())
+        )
         drawCircle(
             color = focusLineColor.copy(alpha = 0.5f),
             radius = indicatorRadius,
@@ -303,6 +353,12 @@ private fun DrawScope.drawLinearOverlay(params: BlurParameters) {
 
         // Draw angle tick mark
         val tickLength = 15.dp.toPx()
+        drawLine(
+            color = outlineColor,
+            start = Offset(centerX, centerY - indicatorRadius + tickLength),
+            end = Offset(centerX, centerY - indicatorRadius - 5.dp.toPx()),
+            strokeWidth = 5.dp.toPx()
+        )
         drawLine(
             color = focusLineColor,
             start = Offset(centerX, centerY - indicatorRadius + tickLength),
@@ -314,6 +370,7 @@ private fun DrawScope.drawLinearOverlay(params: BlurParameters) {
 
 /**
  * Draws the radial mode overlay (ellipse/circle).
+ * All guide lines are drawn with a dark outline first for visibility over bright scenes.
  */
 private fun DrawScope.drawRadialOverlay(params: BlurParameters) {
     val width = size.width
@@ -324,9 +381,8 @@ private fun DrawScope.drawRadialOverlay(params: BlurParameters) {
     val focusRadius = height * params.size * 0.5f
     val angleDegrees = params.angle * (180f / PI.toFloat())
 
-    // Colors for overlay
+    val focusLineColor = AppColors.Accent
-    val focusLineColor = Color(0xFFFFB300)  // Amber
+    val outlineColor = AppColors.OverlayOutline
-    val blurZoneColor = Color(0x30FFFFFF)    // Semi-transparent white
     val dashEffect = PathEffect.dashPathEffect(floatArrayOf(15f, 8f), 0f)
 
     // Calculate ellipse dimensions based on aspect ratio
@@ -334,7 +390,13 @@ private fun DrawScope.drawRadialOverlay(params: BlurParameters) {
     val ellipseHeight = focusRadius * 2
 
     rotate(angleDegrees, pivot = Offset(centerX, centerY)) {
-        // Draw focus ellipse outline (inner boundary)
+        // Draw focus ellipse outline (outline + color)
+        drawOval(
+            color = outlineColor,
+            topLeft = Offset(centerX - ellipseWidth / 2, centerY - ellipseHeight / 2),
+            size = Size(ellipseWidth, ellipseHeight),
+            style = Stroke(width = 5.dp.toPx())
+        )
         drawOval(
             color = focusLineColor,
             topLeft = Offset(centerX - ellipseWidth / 2, centerY - ellipseHeight / 2),
@@ -344,6 +406,15 @@ private fun DrawScope.drawRadialOverlay(params: BlurParameters) {
 
         // Draw outer blur boundary (with falloff)
         val outerScale = 1f + params.falloff
+        drawOval(
+            color = outlineColor,
+            topLeft = Offset(
+                centerX - (ellipseWidth * outerScale) / 2,
+                centerY - (ellipseHeight * outerScale) / 2
+            ),
+            size = Size(ellipseWidth * outerScale, ellipseHeight * outerScale),
+            style = Stroke(width = 4.dp.toPx(), pathEffect = dashEffect)
+        )
         drawOval(
             color = focusLineColor.copy(alpha = 0.5f),
             topLeft = Offset(
@@ -354,14 +425,26 @@ private fun DrawScope.drawRadialOverlay(params: BlurParameters) {
             style = Stroke(width = 2.dp.toPx(), pathEffect = dashEffect)
         )
 
-        // Draw center crosshair
+        // Draw center crosshair (outline + color)
         val crosshairSize = 20.dp.toPx()
+        drawLine(
+            color = outlineColor,
+            start = Offset(centerX - crosshairSize, centerY),
+            end = Offset(centerX + crosshairSize, centerY),
+            strokeWidth = 4.dp.toPx()
+        )
         drawLine(
             color = focusLineColor,
             start = Offset(centerX - crosshairSize, centerY),
             end = Offset(centerX + crosshairSize, centerY),
             strokeWidth = 2.dp.toPx()
         )
+        drawLine(
+            color = outlineColor,
+            start = Offset(centerX, centerY - crosshairSize),
+            end = Offset(centerX, centerY + crosshairSize),
+            strokeWidth = 4.dp.toPx()
+        )
         drawLine(
             color = focusLineColor,
             start = Offset(centerX, centerY - crosshairSize),
@@ -369,7 +452,13 @@ private fun DrawScope.drawRadialOverlay(params: BlurParameters) {
             strokeWidth = 2.dp.toPx()
         )
 
-        // Draw rotation indicator (small line at top of ellipse)
+        // Draw rotation indicator (small line at top of ellipse, outline + color)
+        drawLine(
+            color = outlineColor,
+            start = Offset(centerX, centerY - ellipseHeight / 2 - 5.dp.toPx()),
+            end = Offset(centerX, centerY - ellipseHeight / 2 - 20.dp.toPx()),
+            strokeWidth = 5.dp.toPx()
+        )
         drawLine(
             color = focusLineColor,
             start = Offset(centerX, centerY - ellipseHeight / 2 - 5.dp.toPx()),

app/src/main/java/no/naiv/tiltshift/ui/ZoomControl.kt

@@ -16,9 +16,15 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.role
+import androidx.compose.ui.semantics.selected
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import no.naiv.tiltshift.ui.theme.AppColors
 import kotlin.math.abs
 
 /**
@@ -65,9 +71,9 @@ private fun ZoomButton(
 ) {
     val backgroundColor by animateColorAsState(
         targetValue = if (isSelected) {
-            Color(0xFFFFB300)  // Amber when selected
+            AppColors.Accent
         } else {
-            Color(0x80000000)  // Semi-transparent black
+            AppColors.OverlayDark
         },
         label = "zoom_button_bg"
     )
@@ -79,10 +85,11 @@ private fun ZoomButton(
 
     Box(
         modifier = Modifier
-            .size(44.dp)
+            .size(48.dp)
             .clip(CircleShape)
             .background(backgroundColor)
-            .clickable(onClick = onClick),
+            .clickable(role = Role.Button, onClick = onClick)
+            .semantics { selected = isSelected; contentDescription = "${preset.label}x zoom" },
         contentAlignment = Alignment.Center
     ) {
         Text(
@@ -105,8 +112,9 @@ fun ZoomIndicator(
     Box(
         modifier = modifier
             .clip(CircleShape)
-            .background(Color(0x80000000))
+            .background(AppColors.OverlayDark)
-            .padding(horizontal = 12.dp, vertical = 6.dp),
+            .padding(horizontal = 12.dp, vertical = 6.dp)
+            .semantics { contentDescription = "Current zoom: %.1fx".format(currentZoom) },
         contentAlignment = Alignment.Center
     ) {
         Text(

app/src/main/java/no/naiv/tiltshift/ui/theme/AppColors.kt

@@ -0,0 +1,18 @@
+package no.naiv.tiltshift.ui.theme
+
+import androidx.compose.ui.graphics.Color
+
+/**
+ * Centralized color definitions for the Tilt-Shift Camera app.
+ */
+object AppColors {
+    val Accent = Color(0xFFFFB300)
+    val OverlayDark = Color(0x80000000)
+    val OverlayDarker = Color(0xCC000000)
+    val Success = Color(0xFF4CAF50)
+    val Error = Color(0xFFF44336)
+    val OverlayLinearBlur = Color(0x40FFFFFF)
+    val OverlayRadialBlur = Color(0x30FFFFFF)
+    /** Dark outline behind overlay guide lines for visibility over bright scenes. */
+    val OverlayOutline = Color(0x80000000)
+}

gradle/libs.versions.toml

@@ -14,6 +14,7 @@ playServicesLocation = "21.3.0"
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
 androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntimeKtx" }
 androidx-lifecycle-runtime-compose = { group = "androidx.lifecycle", name = "lifecycle-runtime-compose", version.ref = "lifecycleRuntimeKtx" }
+androidx-lifecycle-viewmodel-compose = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-compose", version.ref = "lifecycleRuntimeKtx" }
 androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }
 androidx-compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "composeBom" }
 androidx-ui = { group = "androidx.compose.ui", name = "ui" }