Multi-page step 1: PageValidationDialog

app/src/main/java/org/mydomain/myscan/MainViewModel.kt

@@ -3,7 +3,6 @@ package org.mydomain.myscan
 import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.Matrix
-import android.util.Log
 import androidx.camera.core.ImageProxy
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
@@ -68,13 +67,10 @@ class MainViewModel(private val imageSegmentationService: ImageSegmentationServi
         _currentScreen.value = screen
     }
 
-    fun processCapturedImageAndNavigate(imageProxy: ImageProxy) {
+    fun processCapturedImageThen(imageProxy: ImageProxy, onResult: (Bitmap?) -> Unit) {
         viewModelScope.launch {
-            Log.d("MyScan", "Navigating to spinner")
-            navigateTo(Screen.PagePreview(image = null, isProcessing = true))
             val processedImage = processCapturedImage(imageProxy)
-            Log.d("MyScan", "Navigating to result image")
-            navigateTo(Screen.PagePreview(image = processedImage, isProcessing = false))
+            onResult(processedImage)
         }
     }
 
@@ -98,4 +94,8 @@ class MainViewModel(private val imageSegmentationService: ImageSegmentationServi
         val matrix = Matrix().apply { postRotate(degrees.toFloat()) }
         return Bitmap.createBitmap(this, 0, 0, width, height, matrix, true)
     }
+
+    fun addPage(bitmap: Bitmap) {
+        // TODO
+    }
 }

app/src/main/java/org/mydomain/myscan/view/Camera.kt

@@ -64,6 +64,12 @@ fun CameraScreen(
     uiState: CameraScreenState,
     onImageAnalyzed: (ImageProxy) -> Unit,
 ) {
+    // TODO Should we move those variables to ViewModel?
+    // TODO pause the live analysis when displaying the PageValidationDialogs
+    val showPageDialog = remember { mutableStateOf(false) }
+    val isProcessing = remember { mutableStateOf(false) }
+    val processedPage = remember { mutableStateOf<Bitmap?>(null) }
+
     val context = LocalContext.current
     val requestPermissionLauncher = rememberLauncherForActivityResult(
         ActivityResultContracts.RequestPermission()
@@ -101,10 +107,15 @@ fun CameraScreen(
         MessageBox(uiState.inferenceTime)
         Button(
             onClick = {
+                showPageDialog.value = true
+                isProcessing.value = true
                 captureController.takePicture(
                     onImageCaptured = { imageProxy ->
                         if (imageProxy != null) {
-                            viewModel.processCapturedImageAndNavigate(imageProxy)
+                            viewModel.processCapturedImageThen(imageProxy) { result ->
+                                processedPage.value = result
+                                isProcessing.value = false
+                            }
                         } else {
                             Log.e("MyScan", "Error during image capture")
                         }
@@ -115,6 +126,23 @@ fun CameraScreen(
             Text("Capture")
         }
     }
+
+    if (showPageDialog.value) {
+        PageValidationDialog(
+            isProcessing = isProcessing.value,
+            pageBitmap = processedPage.value,
+            onConfirm = {
+                viewModel.addPage(processedPage.value!!)
+                showPageDialog.value = false
+            },
+            onReject = {
+                showPageDialog.value = false
+            },
+            onDismiss = {
+                showPageDialog.value = false
+            }
+        )
+    }
 }
 
 @Composable

app/src/main/java/org/mydomain/myscan/view/PageValidation.kt

@@ -0,0 +1,84 @@
+package org.mydomain.myscan.view
+
+import android.graphics.Bitmap
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.aspectRatio
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.Button
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.window.Dialog
+
+@Composable
+fun PageValidationDialog(
+    isProcessing: Boolean,
+    pageBitmap: Bitmap?,
+    onConfirm: () -> Unit,
+    onReject: () -> Unit,
+    onDismiss: () -> Unit
+) {
+    Dialog (onDismissRequest = onDismiss) {
+        Surface (
+            shape = RoundedCornerShape(16.dp),
+            color = MaterialTheme.colorScheme.surface,
+            tonalElevation = 8.dp,
+            modifier = Modifier
+                .fillMaxSize()
+                .aspectRatio(3f / 4f)
+        ) {
+            if (isProcessing) {
+                Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
+                    CircularProgressIndicator()
+                }
+            } else {
+                Column (
+                    Modifier
+                        .fillMaxSize()
+                        .padding(16.dp),
+                    verticalArrangement = Arrangement.SpaceBetween
+                ) {
+                    if (pageBitmap == null) {
+                        Text("Failed to process image")
+                    } else {
+                        Image(
+                            bitmap = pageBitmap.asImageBitmap(),
+                            contentDescription = null,
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .weight(1f),
+                            contentScale = ContentScale.Fit
+                        )
+                    }
+
+                    Row (
+                        horizontalArrangement = Arrangement.SpaceEvenly,
+                        modifier = Modifier.fillMaxWidth()
+                    ) {
+                        OutlinedButton (onClick = onReject) {
+                            Text("Reject")
+                        }
+                        Button (onClick = onConfirm) {
+                            Text("OK")
+                        }
+                    }
+                }
+            }
+        }
+    }
+}