improvement(Desktop): Scan QR codes by loading them from an image file

common/src/androidMain/kotlin/com/artemchep/keyguard/feature/qr/ScanQrScreen.kt

@@ -27,6 +27,7 @@ import androidx.compose.ui.viewinterop.AndroidView
 import androidx.core.content.ContextCompat
 import com.artemchep.keyguard.feature.navigation.NavigationIcon
 import com.artemchep.keyguard.feature.navigation.RouteResultTransmitter
+import com.artemchep.keyguard.res.Res
 import com.artemchep.keyguard.ui.CollectedEffect
 import com.artemchep.keyguard.ui.ScaffoldColumn
 import com.artemchep.keyguard.ui.theme.Dimens
@@ -37,6 +38,7 @@ import com.google.accompanist.permissions.rememberPermissionState
 import com.google.mlkit.vision.barcode.BarcodeScanning
 import com.google.mlkit.vision.barcode.common.Barcode
 import com.google.mlkit.vision.common.InputImage
+import dev.icerock.moko.resources.compose.stringResource
 import java.util.concurrent.Executors
 
 @Composable
@@ -71,7 +73,7 @@ fun ScanQrScreen(
                 modifier = Modifier
                     .statusBarsPadding(),
                 title = {
-                    Text("Scan QR code")
+                    Text(stringResource(Res.strings.scanqr_title))
                 },
                 navigationIcon = {
                     NavigationIcon()

common/src/commonMain/resources/MR/base/strings.xml

@@ -481,6 +481,9 @@
     <string name="error_failed_open_uri">Failed to open a URI</string>
     <string name="error_failed_format_placeholder">Failed to format the placeholder</string>
 
+    <string name="scanqr_title">Scan QR code</string>
+    <string name="scanqr_load_from_image_note">Load and parse a QR code from an image file.</string>
+
     <!-- Title of the 'Show as Barcode' dialog -->
     <string name="barcodetype_title">Barcode</string>
     <string name="barcodetype_action_show_in_barcode_title">Show as Barcode</string>

common/src/desktopMain/kotlin/com/artemchep/keyguard/feature/filepicker/FilePickerEffect.kt

@@ -41,6 +41,8 @@ actual fun FilePickerEffect(
                         when {
                             mimeType == "text/plain" -> "txt"
                             mimeType == "text/wordlist" -> "wordlist"
+                            mimeType == "image/png" -> "png"
+                            mimeType == "image/jpg" -> "jpg"
                             else -> null
                         }
                     }

common/src/desktopMain/kotlin/com/artemchep/keyguard/feature/qr/ScanQrRoute.kt

@@ -7,5 +7,8 @@ import com.artemchep.keyguard.feature.navigation.RouteResultTransmitter
 actual object ScanQrRoute : RouteForResult<String> {
     @Composable
     override fun Content(transmitter: RouteResultTransmitter<String>) {
+        ScanQrScreen(
+            transmitter = transmitter,
+        )
     }
 }

common/src/desktopMain/kotlin/com/artemchep/keyguard/feature/qr/ScanQrScreen.kt

@@ -0,0 +1,96 @@
+package com.artemchep.keyguard.feature.qr
+
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.Button
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBarDefaults
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.input.nestedscroll.nestedScroll
+import com.artemchep.keyguard.common.model.Loadable
+import com.artemchep.keyguard.feature.filepicker.FilePickerEffect
+import com.artemchep.keyguard.feature.navigation.NavigationIcon
+import com.artemchep.keyguard.feature.navigation.RouteResultTransmitter
+import com.artemchep.keyguard.res.Res
+import com.artemchep.keyguard.ui.CollectedEffect
+import com.artemchep.keyguard.ui.ScaffoldColumn
+import com.artemchep.keyguard.ui.theme.Dimens
+import com.artemchep.keyguard.ui.toolbar.LargeToolbar
+import dev.icerock.moko.resources.compose.stringResource
+
+@Composable
+fun ScanQrScreen(
+    modifier: Modifier = Modifier,
+    transmitter: RouteResultTransmitter<String>,
+) {
+    val loadableState = produceScanQrState()
+    when (loadableState) {
+        is Loadable.Ok -> {
+            val state = loadableState.value
+            CollectedEffect(state.onSuccessFlow) { rawValue ->
+                // Notify that we have successfully logged in, and that
+                // the caller can now decide what to do.
+                transmitter.invoke(rawValue)
+            }
+            FilePickerEffect(
+                flow = state.filePickerIntentFlow,
+            )
+        }
+
+        else -> {
+            // Do nothing.
+        }
+    }
+
+    val scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior()
+    ScaffoldColumn(
+        modifier = modifier
+            .nestedScroll(scrollBehavior.nestedScrollConnection),
+        topAppBarScrollBehavior = scrollBehavior,
+        topBar = {
+            LargeToolbar(
+                title = {
+                    Text(stringResource(Res.strings.scanqr_title))
+                },
+                navigationIcon = {
+                    NavigationIcon()
+                },
+                scrollBehavior = scrollBehavior,
+            )
+        },
+    ) {
+        when (loadableState) {
+            is Loadable.Ok -> {
+                val contentState = loadableState.value.contentFlow
+                    .collectAsState()
+                Text(
+                    modifier = Modifier
+                        .padding(horizontal = Dimens.horizontalPadding),
+                    text = stringResource(Res.strings.scanqr_load_from_image_note),
+                )
+                Spacer(
+                    modifier = Modifier
+                        .height(Dimens.verticalPadding),
+                )
+                Button(
+                    modifier = Modifier
+                        .padding(horizontal = Dimens.horizontalPadding),
+                    onClick = {
+                        contentState.value.onSelectFile()
+                    },
+                ) {
+                    Text(
+                        text = stringResource(Res.strings.select_file),
+                    )
+                }
+            }
+
+            is Loadable.Loading -> {
+                // Do nothing
+            }
+        }
+    }
+}

common/src/desktopMain/kotlin/com/artemchep/keyguard/feature/qr/ScanQrState.kt

@@ -0,0 +1,18 @@
+package com.artemchep.keyguard.feature.qr
+
+import androidx.compose.runtime.Immutable
+import com.artemchep.keyguard.feature.filepicker.FilePickerIntent
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.emptyFlow
+
+@Immutable
+data class ScanQrState(
+    val contentFlow: StateFlow<Content>,
+    val onSuccessFlow: Flow<String>,
+    val filePickerIntentFlow: Flow<FilePickerIntent<*>> = emptyFlow(),
+) {
+    data class Content(
+        val onSelectFile: () -> Unit,
+    )
+}

common/src/desktopMain/kotlin/com/artemchep/keyguard/feature/qr/ScanQrStateProducer.kt

@@ -0,0 +1,101 @@
+package com.artemchep.keyguard.feature.qr
+
+import androidx.compose.runtime.Composable
+import com.artemchep.keyguard.common.io.effectMap
+import com.artemchep.keyguard.common.io.flatMap
+import com.artemchep.keyguard.common.io.handleErrorWith
+import com.artemchep.keyguard.common.io.io
+import com.artemchep.keyguard.common.io.ioRaise
+import com.artemchep.keyguard.common.io.launchIn
+import com.artemchep.keyguard.common.model.Loadable
+import com.artemchep.keyguard.common.usecase.WindowCoroutineScope
+import com.artemchep.keyguard.common.util.flow.EventFlow
+import com.artemchep.keyguard.feature.filepicker.FilePickerIntent
+import com.artemchep.keyguard.feature.navigation.state.produceScreenState
+import com.google.zxing.ChecksumException
+import com.google.zxing.FormatException
+import com.google.zxing.NotFoundException
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.flowOf
+import org.kodein.di.compose.localDI
+import org.kodein.di.direct
+import org.kodein.di.instance
+import java.net.URL
+import javax.imageio.ImageIO
+
+@Composable
+fun produceScanQrState(): Loadable<ScanQrState> = with(localDI().direct) {
+    produceScanQrState(
+        windowCoroutineScope = instance(),
+    )
+}
+
+@Composable
+fun produceScanQrState(
+    windowCoroutineScope: WindowCoroutineScope,
+): Loadable<ScanQrState> = produceScreenState(
+    key = "scan_qr",
+    initial = Loadable.Loading,
+    args = arrayOf(
+    ),
+) {
+    val onSuccessSink = EventFlow<String>()
+    val filePickerIntentSink = EventFlow<FilePickerIntent<*>>()
+
+    fun onSelect(uri: String) = io(uri)
+        .effectMap(Dispatchers.IO) {
+            val url = URL(it)
+            val image = ImageIO.read(url)
+            requireNotNull(image) {
+                "Failed to read a file as an image"
+            }
+        }
+        .flatMap { image ->
+            io(image)
+                .effectMap(Dispatchers.Default) {
+                    ScanQrUtil.qrDecodeFromImage(it)
+                }
+                .handleErrorWith { e ->
+                    val msg = when (e) {
+                        is NotFoundException -> "Failed to find a barcode in the image"
+                        is FormatException -> "Failed to parse a barcode"
+                        is ChecksumException -> "Failed to parse a barcode"
+                        else -> return@handleErrorWith ioRaise(e)
+                    }
+                    ioRaise(RuntimeException(msg))
+                }
+        }
+        .effectMap { text ->
+            onSuccessSink.emit(text)
+        }
+        .launchIn(screenScope)
+
+    fun onClick() {
+        val intent = FilePickerIntent.OpenDocument(
+            mimeTypes = arrayOf(
+                "image/png",
+                "image/jpg",
+            ),
+        ) { info ->
+            if (info != null) {
+                val uri = info.uri.toString()
+                onSelect(uri)
+            }
+        }
+        filePickerIntentSink.emit(intent)
+    }
+
+    val content = ScanQrState.Content(
+        onSelectFile = ::onClick,
+    )
+    val contentFlow = MutableStateFlow(content)
+
+    val state = ScanQrState(
+        contentFlow = contentFlow,
+        onSuccessFlow = onSuccessSink,
+        filePickerIntentFlow = filePickerIntentSink,
+    )
+    val success = Loadable.Ok(state)
+    flowOf(success)
+}

common/src/desktopMain/kotlin/com/artemchep/keyguard/feature/qr/ScanQrUtil.kt

@@ -0,0 +1,18 @@
+package com.artemchep.keyguard.feature.qr
+
+import com.google.zxing.BinaryBitmap
+import com.google.zxing.client.j2se.BufferedImageLuminanceSource
+import com.google.zxing.common.HybridBinarizer
+import com.google.zxing.qrcode.QRCodeReader
+import java.awt.image.BufferedImage
+
+object ScanQrUtil {
+    fun qrDecodeFromImage(
+        bufferedImage: BufferedImage,
+    ): String {
+        val bfImgLuminanceSource = BufferedImageLuminanceSource(bufferedImage)
+        val binaryBmp = BinaryBitmap(HybridBinarizer(bfImgLuminanceSource))
+        val qrReader = QRCodeReader()
+        return qrReader.decode(binaryBmp).text
+    }
+}