Type-safe capture pipeline and image dimension bounds

- Replace unsafe as Any / as SaveResult casts with a sealed
  CaptureOutcome class for type-safe continuation handling
- Catch SecurityException separately with permission-specific messages
- Replace raw e.message with generic user-friendly error strings
- Add inJustDecodeBounds pre-check in loadBitmapFromUri to downsample
  images exceeding 4096px, preventing OOM from huge gallery images

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

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

@@ -34,17 +34,18 @@ class ImageCaptureHandler(
 
     companion object {
         private const val TAG = "ImageCaptureHandler"
+        /** Maximum decoded image dimension to prevent OOM from huge gallery images. */
+        private const val MAX_IMAGE_DIMENSION = 4096
     }
 
     /**
-     * Holds the processed bitmap ready for saving, produced inside the
+     * Type-safe outcome of the camera capture callback.
-     * camera callback (synchronous CPU work) and consumed afterwards
+     * Eliminates unsafe `as Any` / `as SaveResult` casts.
-     * in the caller's coroutine context.
      */
-    private class ProcessedCapture(
+    private sealed class CaptureOutcome {
-        val originalBitmap: Bitmap,
+        class Processed(val original: Bitmap, val processed: Bitmap) : CaptureOutcome()
-        val processedBitmap: Bitmap
+        class Failed(val result: SaveResult.Error) : CaptureOutcome()
-    )
+    }
 
     /**
      * Captures a photo and applies the tilt-shift effect.
@@ -64,7 +65,7 @@ class ImageCaptureHandler(
         isFrontCamera: Boolean
     ): SaveResult {
         // Phase 1: capture and process the image synchronously in the callback
-        val captureResult = suspendCancellableCoroutine { continuation ->
+        val captureResult = suspendCancellableCoroutine<CaptureOutcome> { continuation ->
             imageCapture.takePicture(
                 executor,
                 object : ImageCapture.OnImageCapturedCallback() {
@@ -78,7 +79,7 @@ class ImageCaptureHandler(
 
                             if (currentBitmap == null) {
                                 continuation.resume(
-                                    SaveResult.Error("Failed to convert image") as Any
+                                    CaptureOutcome.Failed(SaveResult.Error("Failed to convert image"))
                                 )
                                 return
                             }
@@ -86,25 +87,23 @@ class ImageCaptureHandler(
                             currentBitmap = rotateBitmap(currentBitmap, imageRotation, isFrontCamera)
 
                             val processedBitmap = applyTiltShiftEffect(currentBitmap, blurParams)
-                            // Keep originalBitmap alive — both are recycled after saving
                             val original = currentBitmap
                             currentBitmap = null
 
-                            continuation.resume(ProcessedCapture(original, processedBitmap))
+                            continuation.resume(CaptureOutcome.Processed(original, processedBitmap))
                         } catch (e: Exception) {
                             Log.e(TAG, "Image processing failed", e)
                             currentBitmap?.recycle()
                             continuation.resume(
-                                SaveResult.Error("Capture failed: ${e.message}", e) as Any
+                                CaptureOutcome.Failed(SaveResult.Error("Failed to process image. Please try again.", e))
                             )
                         }
                     }
 
                     override fun onError(exception: ImageCaptureException) {
+                        Log.e(TAG, "Image capture failed", exception)
                         continuation.resume(
-                            SaveResult.Error(
+                            CaptureOutcome.Failed(SaveResult.Error("Failed to capture photo. Please try again.", exception))
-                                "Capture failed: ${exception.message}", exception
-                            ) as Any
                         )
                     }
                 }
@@ -112,12 +111,14 @@ class ImageCaptureHandler(
         }
 
         // Phase 2: save both original and processed to disk (suspend-safe)
-        if (captureResult is ProcessedCapture) {
+        return when (captureResult) {
-            return try {
+            is CaptureOutcome.Failed -> captureResult.result
-                val thumbnail = createThumbnail(captureResult.processedBitmap)
+            is CaptureOutcome.Processed -> {
+                try {
+                    val thumbnail = createThumbnail(captureResult.processed)
                     val result = photoSaver.saveBitmapPair(
-                    original = captureResult.originalBitmap,
+                        original = captureResult.original,
-                    processed = captureResult.processedBitmap,
+                        processed = captureResult.processed,
                         orientation = ExifInterface.ORIENTATION_NORMAL,
                         location = location
                     )
@@ -128,12 +129,11 @@ class ImageCaptureHandler(
                         result
                     }
                 } finally {
-                captureResult.originalBitmap.recycle()
+                    captureResult.original.recycle()
-                captureResult.processedBitmap.recycle()
+                    captureResult.processed.recycle()
+                }
             }
         }
-
-        return captureResult as SaveResult
     }
 
     /**
@@ -238,9 +238,12 @@ class ImageCaptureHandler(
                 thumbnail?.recycle()
                 result
             }
+        } catch (e: SecurityException) {
+            Log.e(TAG, "Permission denied while processing gallery image", e)
+            SaveResult.Error("Permission denied. Please grant access and try again.", e)
         } catch (e: Exception) {
             Log.e(TAG, "Gallery image processing failed", e)
-            SaveResult.Error("Processing failed: ${e.message}", e)
+            SaveResult.Error("Failed to process image. Please try again.", e)
         } finally {
             originalBitmap?.recycle()
             processedBitmap?.recycle()
@@ -248,13 +251,33 @@ class ImageCaptureHandler(
     }
 
     /**
-     * Loads a bitmap from a content URI.
+     * Loads a bitmap from a content URI with dimension bounds checking
+     * to prevent OOM from extremely large images.
      */
     private fun loadBitmapFromUri(uri: Uri): Bitmap? {
         return try {
+            // First pass: read dimensions without decoding pixels
+            val options = BitmapFactory.Options().apply { inJustDecodeBounds = true }
             context.contentResolver.openInputStream(uri)?.use { stream ->
-                BitmapFactory.decodeStream(stream)
+                BitmapFactory.decodeStream(stream, null, options)
             }
+
+            // Calculate sample size to stay within MAX_IMAGE_DIMENSION
+            val maxDim = maxOf(options.outWidth, options.outHeight)
+            val sampleSize = if (maxDim > MAX_IMAGE_DIMENSION) {
+                var sample = 1
+                while (maxDim / sample > MAX_IMAGE_DIMENSION) sample *= 2
+                sample
+            } else 1
+
+            // Second pass: decode with sample size
+            val decodeOptions = BitmapFactory.Options().apply { inSampleSize = sampleSize }
+            context.contentResolver.openInputStream(uri)?.use { stream ->
+                BitmapFactory.decodeStream(stream, null, decodeOptions)
+            }
+        } catch (e: SecurityException) {
+            Log.e(TAG, "Permission denied loading bitmap from URI", e)
+            null
         } catch (e: Exception) {
             Log.e(TAG, "Failed to load bitmap from URI", e)
             null