Multi-page step 2: FinalizeDocumentScreen

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

@@ -4,6 +4,7 @@ import android.graphics.Bitmap
 import androidx.compose.runtime.Immutable
 
 @Immutable
+// TODO Rename to LiveAnalysisState
 data class CameraScreenState(
     val detectionMessage: String? = null,
     val inferenceTime: Long = 0L,

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

@@ -22,7 +22,7 @@ import androidx.core.content.FileProvider
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import org.mydomain.myscan.ui.theme.MyScanTheme
 import org.mydomain.myscan.view.CameraScreen
-import org.mydomain.myscan.view.PagePreviewScreen
+import org.mydomain.myscan.view.FinalizeDocumentScreen
 import org.opencv.android.OpenCVLoader
 import java.io.File
 import java.io.FileOutputStream
@@ -38,22 +38,24 @@ class MainActivity : ComponentActivity() {
         setContent {
             val currentScreen by viewModel.currentScreen.collectAsStateWithLifecycle()
             val cameraScreenState by viewModel.cameraScreenState.collectAsStateWithLifecycle()
+            val pages by viewModel.pages.collectAsStateWithLifecycle()
             val context = LocalContext.current
             MyScanTheme {
                 Scaffold { innerPadding ->
                     Column (modifier = Modifier.padding(innerPadding)) {
-                        when (val screen = currentScreen) {
+                        when (currentScreen) {
                             is Screen.Camera -> {
                                 CameraScreen(viewModel, cameraScreenState,
-                                    onImageAnalyzed = { image -> viewModel.segment(image) } )
+                                    onImageAnalyzed = { image -> viewModel.segment(image) },
+                                    onFinalizePressed = { viewModel.navigateTo(Screen.FinalizeDocument) }
+                                )
                             }
-                            is Screen.PagePreview -> {
-                                PagePreviewScreen (
-                                    image = screen.image,
-                                    isProcessing = screen.isProcessing,
+                            is Screen.FinalizeDocument -> {
+                                FinalizeDocumentScreen (
+                                    viewModel,
                                     onBackPressed = { viewModel.navigateTo(Screen.Camera) },
-                                    onSavePressed = createPdfAndSave(context),
-                                    onSharePressed = createPdfAndShare(context),
+                                    onSavePressed = savePdf(pages, context),
+                                    // TODO "on share"
                                 )
                             }
                         }
@@ -93,8 +95,11 @@ class MainActivity : ComponentActivity() {
         }
     }
 
-    fun createPdfAndSave(context: Context): (Bitmap) -> Unit = { bitmap ->
-        val document = createPdfFromBitmaps(listOf(bitmap))
+    private fun savePdf(
+        pages: List<Bitmap>,
+        context: Context
+    ): () -> Unit = {
+        val document = createPdfFromBitmaps(pages)
         try {
             val downloadsDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
             if (!downloadsDir.exists()) downloadsDir.mkdirs()

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

@@ -4,6 +4,7 @@ import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.Matrix
 import androidx.camera.core.ImageProxy
+import androidx.compose.runtime.mutableStateListOf
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
@@ -14,6 +15,7 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 
@@ -33,6 +35,10 @@ class MainViewModel(private val imageSegmentationService: ImageSegmentationServi
     private val _currentScreen = MutableStateFlow<Screen>(Screen.Camera)
     val currentScreen: StateFlow<Screen> = _currentScreen.asStateFlow()
 
+    // TODO store images on disk
+    private val _pages = MutableStateFlow<List<Bitmap>>(listOf())
+    val pages: StateFlow<List<Bitmap>> = _pages
+
     init {
         viewModelScope.launch {
             imageSegmentationService.initialize()
@@ -96,6 +102,8 @@ class MainViewModel(private val imageSegmentationService: ImageSegmentationServi
     }
 
     fun addPage(bitmap: Bitmap) {
-        // TODO
+        _pages.update { list -> list.plus(bitmap) }
     }
+
+    fun pageCount(): Int = _pages.value.size
 }

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

@@ -1,11 +1,6 @@
 package org.mydomain.myscan
 
-import android.graphics.Bitmap
-
 sealed class Screen {
     object Camera : Screen()
-    data class PagePreview(
-        val image: Bitmap? = null,
-        val isProcessing: Boolean = true
-    ) : Screen()
+    object FinalizeDocument : Screen()
 }

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

@@ -19,14 +19,17 @@ import androidx.camera.core.resolutionselector.ResolutionSelector
 import androidx.camera.lifecycle.ProcessCameraProvider
 import androidx.camera.view.PreviewView
 import androidx.compose.foundation.Canvas
+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.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.width
 import androidx.compose.material3.Button
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
@@ -58,11 +61,14 @@ import org.mydomain.myscan.scaledTo
 import java.util.concurrent.ExecutorService
 import java.util.concurrent.Executors
 
+// TODO Split this big file
+
 @Composable
 fun CameraScreen(
     viewModel: MainViewModel,
     uiState: CameraScreenState,
     onImageAnalyzed: (ImageProxy) -> Unit,
+    onFinalizePressed: () -> Unit
 ) {
     // TODO Should we move those variables to ViewModel?
     // TODO pause the live analysis when displaying the PageValidationDialogs
@@ -91,19 +97,8 @@ fun CameraScreen(
         }
     }
 
-    Column {
-        val width = LocalConfiguration.current.screenWidthDp
-        val height = width / 3 * 4
-        Box(
-            modifier = Modifier
-                .width(width.dp)
-                .height(height.dp)
-        ) {
-            CameraPreview(
-                onImageAnalyzed = onImageAnalyzed,
-                captureController = captureController)
-            AnalysisOverlay(uiState)
-        }
+    Box(modifier = Modifier.fillMaxSize()) {
+        CameraPreviewWithOverlay(onImageAnalyzed, captureController, uiState)
         MessageBox(uiState.inferenceTime)
         Button(
             onClick = {
@@ -121,10 +116,14 @@ fun CameraScreen(
                         }
                     }
                 )},
-            modifier = Modifier.align(Alignment.CenterHorizontally),
+            modifier = Modifier.align(Alignment.BottomCenter).padding(bottom = 96.dp),
         ) {
             Text("Capture")
         }
+        CameraScreenFooter(
+            pageCount = viewModel.pageCount(),
+            onFinalizePressed = onFinalizePressed,
+            modifier = Modifier.align(Alignment.BottomCenter))
     }
 
     if (showPageDialog.value) {
@@ -145,6 +144,27 @@ fun CameraScreen(
     }
 }
 
+@Composable
+private fun CameraPreviewWithOverlay(
+    onImageAnalyzed: (ImageProxy) -> Unit,
+    captureController: CameraCaptureController,
+    uiState: CameraScreenState
+) {
+    val width = LocalConfiguration.current.screenWidthDp
+    val height = width / 3 * 4
+    Box(
+        modifier = Modifier
+            .width(width.dp)
+            .height(height.dp)
+    ) {
+        CameraPreview(
+            onImageAnalyzed = onImageAnalyzed,
+            captureController = captureController
+        )
+        AnalysisOverlay(uiState)
+    }
+}
+
 @Composable
 fun CameraPreview(
     modifier: Modifier = Modifier,
@@ -299,3 +319,36 @@ fun MessageBox(inferenceTime: Long) {
         color = Color.Gray,
     )
 }
+
+@Composable
+fun CameraScreenFooter(
+    pageCount: Int,
+    onFinalizePressed: () -> Unit,
+    modifier: Modifier,
+) {
+    Surface (
+        color = MaterialTheme.colorScheme.inverseOnSurface,
+        tonalElevation = 4.dp,
+        modifier = modifier.fillMaxWidth().height(56.dp)
+    ) {
+        Row (
+            modifier = Modifier
+                .padding(horizontal = 16.dp, vertical = 8.dp)
+                .fillMaxWidth(),
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.SpaceBetween
+        ) {
+            Text(
+                text = "Pages : $pageCount",
+                style = MaterialTheme.typography.bodyMedium
+            )
+
+            Button (
+                onClick = onFinalizePressed,
+                enabled = pageCount > 0
+            ) {
+                Text("Finish")
+            }
+        }
+    }
+}

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

@@ -0,0 +1,87 @@
+package org.mydomain.myscan.view
+
+import android.graphics.Bitmap
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.PaddingValues
+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.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material3.Button
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.lifecycle.viewmodel.compose.viewModel
+import org.mydomain.myscan.MainViewModel
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun FinalizeDocumentScreen(
+    viewModel: MainViewModel = viewModel(),
+    onBackPressed: () -> Unit,
+    onSavePressed: () -> Unit
+) {
+    val pages: List<Bitmap> by viewModel.pages.collectAsStateWithLifecycle()
+    Scaffold (
+        topBar = {
+            TopAppBar(
+                title = { Text("Finalize document") },
+                navigationIcon = {
+                    IconButton(onClick = onBackPressed) {
+                        Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = "Back")
+                    }
+                },
+                actions = {
+                    Button(onClick = onSavePressed) {
+                        Text(text = "Save PDF")
+                    }
+                }
+            )
+        }
+    ) { padding ->
+        LazyColumn (
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(padding)
+                .background(Color(0xFFF0F0F0)),
+            verticalArrangement = Arrangement.spacedBy(16.dp),
+            contentPadding = PaddingValues(16.dp)
+        ) {
+            items(pages) { bitmap ->
+                Card(
+                    shape = RoundedCornerShape(12.dp),
+                    elevation = CardDefaults.cardElevation(4.dp),
+                    modifier = Modifier.fillMaxWidth()
+                ) {
+                    Image(
+                        bitmap = bitmap.asImageBitmap(),
+                        contentDescription = "Page",
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .aspectRatio(bitmap.width.toFloat() / bitmap.height)
+                            .background(Color.White)
+                    )
+                }
+            }
+        }
+    }
+}

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

@@ -1,82 +0,0 @@
-package org.mydomain.myscan.view
-
-import android.graphics.Bitmap
-import androidx.compose.foundation.Image
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.width
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.automirrored.filled.ArrowBack
-import androidx.compose.material3.Button
-import androidx.compose.material3.CircularProgressIndicator
-import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
-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
-
-@Composable
-fun PagePreviewScreen(
-    image: Bitmap?,
-    isProcessing: Boolean,
-    onBackPressed: () -> Unit,
-    onSavePressed: (Bitmap) -> Unit,
-    onSharePressed: (Bitmap) -> Unit,
-) {
-    Box(modifier = Modifier.fillMaxSize()) {
-        when {
-            isProcessing -> {
-                CircularProgressIndicator(
-                    modifier = Modifier
-                        .align(Alignment.Center)
-                )
-            }
-            image != null -> {
-                Image(
-                    bitmap = image.asImageBitmap(),
-                    contentDescription = "Document preview",
-                    modifier = Modifier.fillMaxSize(),
-                    contentScale = ContentScale.Fit
-                )
-                Row(
-                    modifier = Modifier
-                        .align(Alignment.BottomCenter)
-                        .padding(16.dp)
-                ) {
-                    Button (onClick = { onSavePressed(image) }) {
-                        Text("Save PDF")
-                    }
-                    Spacer(modifier = Modifier.width(8.dp))
-                    Button (onClick = { onSharePressed(image) }) {
-                        Text("Share PDF")
-                    }
-                }
-            }
-            else -> {
-                Text(
-                    text = "No image is available.",
-                    modifier = Modifier.align(Alignment.Center)
-                )
-            }
-        }
-
-        IconButton (
-            onClick = onBackPressed,
-            modifier = Modifier
-                .align(Alignment.TopStart)
-                .padding(16.dp)
-        ) {
-            Icon(
-                imageVector = Icons.AutoMirrored.Filled.ArrowBack,
-                contentDescription = "Back"
-            )
-        }
-    }
-}