[#312] Scan QR Screen Scaffold

* [#312] [#309] Scaffold Scan QR Screen

- Screen scaffolding.
- Model classes.
- Screen states handling.
- Needed dependencies added.
- Camera permission handling. Redirect to Settings.
- Added SettingsUtilTest class.
- Added view classes tests.
- Renamed tag class in update package.
- Fix the scan frame size while changing the screen orientation.
- Suppress Lint warning
Co-authored-by: Carter Jernigan <git@carterjernigan.com>

gradle.properties

@@ -81,9 +81,11 @@ PLAY_PUBLISHER_PLUGIN_VERSION=3.7.0
 ANDROIDX_ACTIVITY_VERSION=1.4.0
 ANDROIDX_ANNOTATION_VERSION=1.3.0
 ANDROIDX_APPCOMPAT_VERSION=1.4.1
+ANDROIDX_CAMERA_VERSION=1.1.0-beta03
 ANDROIDX_COMPOSE_COMPILER_VERSION=1.2.0-alpha08
 ANDROIDX_COMPOSE_MATERIAL3_VERSION=1.0.0-alpha09
 ANDROIDX_COMPOSE_VERSION=1.1.1
+ANDROIDX_CONSTRAINTLAYOUT_VERSION=1.0.0
 ANDROIDX_CORE_VERSION=1.7.0
 ANDROIDX_ESPRESSO_VERSION=3.4.0
 ANDROIDX_LIFECYCLE_VERSION=2.4.1

settings.gradle.kts

@@ -114,9 +114,11 @@ dependencyResolutionManagement {
             val androidxActivityVersion = extra["ANDROIDX_ACTIVITY_VERSION"].toString()
             val androidxAnnotationVersion = extra["ANDROIDX_ANNOTATION_VERSION"].toString()
             val androidxAppcompatVersion = extra["ANDROIDX_APPCOMPAT_VERSION"].toString()
+            val androidxCameraVersion = extra["ANDROIDX_CAMERA_VERSION"].toString()
             val androidxComposeCompilerVersion = extra["ANDROIDX_COMPOSE_COMPILER_VERSION"].toString()
             val androidxComposeMaterial3Version = extra["ANDROIDX_COMPOSE_MATERIAL3_VERSION"].toString()
             val androidxComposeVersion = extra["ANDROIDX_COMPOSE_VERSION"].toString()
+            val androidxConstraintlayoutVersion = extra["ANDROIDX_CONSTRAINTLAYOUT_VERSION"].toString()
             val androidxCoreVersion = extra["ANDROIDX_CORE_VERSION"].toString()
             val androidxEspressoVersion = extra["ANDROIDX_ESPRESSO_VERSION"].toString()
             val androidxLifecycleVersion = extra["ANDROIDX_LIFECYCLE_VERSION"].toString()
@@ -152,6 +154,9 @@ dependencyResolutionManagement {
             library("androidx-activity-compose", "androidx.activity:activity-compose:$androidxActivityVersion")
             library("androidx-annotation", "androidx.annotation:annotation:$androidxAnnotationVersion")
             library("androidx-appcompat", "androidx.appcompat:appcompat:$androidxAppcompatVersion")
+            library("androidx-camera", "androidx.camera:camera-camera2:$androidxCameraVersion")
+            library("androidx-camera-lifecycle", "androidx.camera:camera-lifecycle:$androidxCameraVersion")
+            library("androidx-camera-view", "androidx.camera:camera-view:$androidxCameraVersion")
             library("androidx-compose-foundation", "androidx.compose.foundation:foundation:$androidxComposeVersion")
             library("androidx-compose-material3", "androidx.compose.material3:material3:$androidxComposeMaterial3Version")
             library("androidx-compose-material-icons-core", "androidx.compose.material:material-icons-core:$androidxComposeVersion")
@@ -160,6 +165,7 @@ dependencyResolutionManagement {
             library("androidx-compose-ui", "androidx.compose.ui:ui:$androidxComposeVersion")
             library("androidx-compose-compiler", "androidx.compose.compiler:compiler:$androidxComposeCompilerVersion")
             library("androidx-core", "androidx.core:core-ktx:$androidxCoreVersion")
+            library("androidx-constraintlayout", "androidx.constraintlayout:constraintlayout-compose:$androidxConstraintlayoutVersion")
             library("androidx-lifecycle-livedata", "androidx.lifecycle:lifecycle-livedata-ktx:$androidxLifecycleVersion")
             library("androidx-navigation-compose", "androidx.navigation:navigation-compose:$androidxNavigationComposeVersion")
             library("androidx-security-crypto", "androidx.security:security-crypto-ktx:$androidxSecurityCryptoVersion")
@@ -172,6 +178,7 @@ dependencyResolutionManagement {
             library("kotlin-test", "org.jetbrains.kotlin:kotlin-test:$kotlinVersion")
             library("kotlinx-coroutines-android", "org.jetbrains.kotlinx:kotlinx-coroutines-android:$kotlinxCoroutinesVersion")
             library("kotlinx-coroutines-core", "org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlinxCoroutinesVersion")
+            library("kotlinx-coroutines-guava", "org.jetbrains.kotlinx:kotlinx-coroutines-guava:$kotlinxCoroutinesVersion")
             library("kotlinx-datetime", "org.jetbrains.kotlinx:kotlinx-datetime:$kotlinxDateTimeVersion")
             library("play-core", "com.google.android.play:core:$playCoreVersion")
             library("play-core-ktx", "com.google.android.play:core-ktx:$playCoreKtxVersion")
@@ -195,6 +202,14 @@ dependencyResolutionManagement {
             library("kotlinx-coroutines-test", "org.jetbrains.kotlinx:kotlinx-coroutines-test:$kotlinxCoroutinesVersion")
 
             // Bundles
+            bundle(
+                "androidx-camera",
+                listOf(
+                    "androidx-camera",
+                    "androidx-camera-lifecycle",
+                    "androidx-camera-view"
+                )
+            )
             bundle(
                 "androidx-compose-core",
                 listOf(

ui-lib/build.gradle.kts

@@ -34,6 +34,7 @@ android {
                     "src/main/res/ui/home",
                     "src/main/res/ui/onboarding",
                     "src/main/res/ui/profile",
+                    "src/main/res/ui/scan",
                     "src/main/res/ui/restore",
                     "src/main/res/ui/request",
                     "src/main/res/ui/seed",
@@ -54,16 +55,19 @@ dependencies {
     implementation(libs.androidx.activity)
     implementation(libs.androidx.appcompat)
     implementation(libs.androidx.annotation)
+    implementation(libs.androidx.constraintlayout)
     implementation(libs.androidx.core)
     implementation(libs.androidx.lifecycle.livedata)
     implementation(libs.androidx.splash)
     implementation(libs.androidx.workmanager)
+    implementation(libs.bundles.androidx.camera)
     implementation(libs.bundles.androidx.compose.core)
     implementation(libs.bundles.androidx.compose.extended)
     implementation(libs.bundles.play.core)
     implementation(libs.kotlin.stdlib)
     implementation(libs.kotlinx.coroutines.android)
     implementation(libs.kotlinx.coroutines.core)
+    implementation(libs.kotlinx.coroutines.guava)
     implementation(libs.kotlinx.datetime)
     implementation(libs.zcash.sdk)
     implementation(libs.zcash.bip39)

ui-lib/src/androidTest/AndroidManifest.xml

@@ -14,6 +14,9 @@
         <activity
             android:name="co.electriccoin.zcash.ui.screen.update.TestUpdateActivity"
             android:exported="false" />
+        <activity
+            android:name="co.electriccoin.zcash.ui.screen.scan.TestScanActivity"
+            android:exported="false" />
     </application>
 
 </manifest>

ui-lib/src/androidTest/java/co/electriccoin/zcash/ui/screen/scan/TestScanActivity.kt

@@ -0,0 +1,35 @@
+package co.electriccoin.zcash.ui.screen.scan
+
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.ui.Modifier
+import co.electriccoin.zcash.ui.design.component.GradientSurface
+import co.electriccoin.zcash.ui.design.theme.ZcashTheme
+
+class TestScanActivity : ComponentActivity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setupUiContent()
+    }
+
+    private fun setupUiContent() {
+        setContent {
+            ZcashTheme {
+                GradientSurface(
+                    Modifier
+                        .fillMaxWidth()
+                        .fillMaxHeight()
+                ) {
+                    WrapScan(
+                        this,
+                        goBack = {}
+                    )
+                }
+            }
+        }
+    }
+}

ui-lib/src/androidTest/java/co/electriccoin/zcash/ui/screen/scan/util/SettingsUtilTest.kt

@@ -0,0 +1,30 @@
+package co.electriccoin.zcash.ui.screen.scan.util
+
+import android.content.Context
+import android.content.Intent
+import android.provider.Settings
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.filters.SmallTest
+import org.junit.Test
+import kotlin.test.assertContains
+import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
+
+class SettingsUtilTest {
+
+    companion object {
+        val SETTINGS_URI = SettingsUtil.SETTINGS_URI_PREFIX +
+            ApplicationProvider.getApplicationContext<Context>().packageName
+    }
+
+    @Test
+    @SmallTest
+    fun check_intent_to_settings() {
+        val intent = SettingsUtil.newSettingsIntent(ApplicationProvider.getApplicationContext<Context>().packageName)
+        assertNotNull(intent)
+        assertEquals(Settings.ACTION_APPLICATION_DETAILS_SETTINGS, intent.action)
+        assertContains(intent.categories, Intent.CATEGORY_DEFAULT)
+        assertEquals(SettingsUtil.FLAGS, intent.flags)
+        assertEquals(SETTINGS_URI, intent.data.toString())
+    }
+}

ui-lib/src/androidTest/java/co/electriccoin/zcash/ui/screen/scan/view/ScanPermissionGrantedViewTest.kt

@@ -0,0 +1,73 @@
+package co.electriccoin.zcash.ui.screen.scan.view
+
+import android.Manifest
+import androidx.compose.ui.test.assertIsDisplayed
+import androidx.compose.ui.test.junit4.ComposeContentTestRule
+import androidx.compose.ui.test.junit4.createAndroidComposeRule
+import androidx.compose.ui.test.onNodeWithContentDescription
+import androidx.compose.ui.test.onNodeWithTag
+import androidx.compose.ui.test.onNodeWithText
+import androidx.compose.ui.test.performClick
+import androidx.test.filters.MediumTest
+import androidx.test.rule.GrantPermissionRule
+import co.electriccoin.zcash.test.UiTestPrerequisites
+import co.electriccoin.zcash.ui.R
+import co.electriccoin.zcash.ui.screen.scan.ScanTag
+import co.electriccoin.zcash.ui.screen.scan.TestScanActivity
+import co.electriccoin.zcash.ui.test.getStringResource
+import org.junit.Assert.assertEquals
+import org.junit.Rule
+import org.junit.Test
+
+// TODO [#313]: https://github.com/zcash/secant-android-wallet/issues/313
+class ScanPermissionGrantedViewTest : UiTestPrerequisites() {
+
+    @get:Rule
+    val composeTestRule = createAndroidComposeRule<TestScanActivity>()
+
+    // To automatically have CAMERA permission granted for all test in the class. Note, there is no
+    // way to revoke the granted permission after it's granted.
+    @get:Rule
+    val grantPermissionRule: GrantPermissionRule = GrantPermissionRule.grant(Manifest.permission.CAMERA)
+
+    @Test
+    @MediumTest
+    fun back() {
+        val testSetup = newTestSetup()
+
+        assertEquals(0, testSetup.getOnBackCount())
+
+        composeTestRule.clickBack()
+
+        assertEquals(1, testSetup.getOnBackCount())
+    }
+
+    @Test
+    @MediumTest
+    fun check_all_ui_elements_displayed() {
+        composeTestRule.waitForIdle()
+
+        composeTestRule.onNodeWithText(getStringResource(R.string.scan_header)).also {
+            it.assertIsDisplayed()
+        }
+        composeTestRule.onNodeWithTag(ScanTag.CAMERA_VIEW).also {
+            it.assertIsDisplayed()
+        }
+        composeTestRule.onNodeWithTag(ScanTag.QR_FRAME).also {
+            it.assertIsDisplayed()
+        }
+        composeTestRule.onNodeWithTag(ScanTag.TEXT_STATE).also {
+            it.assertIsDisplayed()
+        }
+    }
+
+    private fun newTestSetup() = ScanViewTestSetup(composeTestRule).apply {
+        setDefaultContent()
+    }
+
+    private fun ComposeContentTestRule.clickBack() {
+        onNodeWithContentDescription(getStringResource(R.string.scan_back_content_description)).also {
+            it.performClick()
+        }
+    }
+}

ui-lib/src/androidTest/java/co/electriccoin/zcash/ui/screen/scan/view/ScanViewTestSetup.kt

@@ -0,0 +1,63 @@
+package co.electriccoin.zcash.ui.screen.scan.view
+
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.test.junit4.ComposeContentTestRule
+import co.electriccoin.zcash.ui.design.theme.ZcashTheme
+import co.electriccoin.zcash.ui.screen.scan.model.ScanState
+import java.util.concurrent.atomic.AtomicInteger
+import java.util.concurrent.atomic.AtomicReference
+
+// TODO [#313]: https://github.com/zcash/secant-android-wallet/issues/313
+class ScanViewTestSetup(
+    private val composeTestRule: ComposeContentTestRule
+) {
+    private val onScanCount = AtomicInteger(0)
+    private val onOpenSettingsCount = AtomicInteger(0)
+    private val onBackCount = AtomicInteger(0)
+    private val scanState = AtomicReference(ScanState.Permission)
+
+    fun getOnScanCount(): Int {
+        composeTestRule.waitForIdle()
+        return onScanCount.get()
+    }
+
+    fun getOnOpenSettingsCount(): Int {
+        composeTestRule.waitForIdle()
+        return onOpenSettingsCount.get()
+    }
+
+    fun getOnBackCount(): Int {
+        composeTestRule.waitForIdle()
+        return onBackCount.get()
+    }
+
+    fun getScanState(): ScanState {
+        composeTestRule.waitForIdle()
+        return scanState.get()
+    }
+
+    @Composable
+    fun getDefaultContent() {
+        Scan(
+            snackbarHostState = SnackbarHostState(),
+            onBack = {
+                onBackCount.incrementAndGet()
+            },
+            onScan = {
+                onScanCount.incrementAndGet()
+            },
+            onOpenSettings = {
+                onOpenSettingsCount.incrementAndGet()
+            }
+        )
+    }
+
+    fun setDefaultContent() {
+        composeTestRule.setContent {
+            ZcashTheme {
+                getDefaultContent()
+            }
+        }
+    }
+}

ui-lib/src/androidTest/java/co/electriccoin/zcash/ui/screen/update/view/UpdateViewTest.kt

@@ -7,10 +7,11 @@ import androidx.compose.ui.test.onNodeWithText
 import androidx.compose.ui.test.onRoot
 import androidx.compose.ui.test.performClick
 import androidx.test.filters.MediumTest
+import co.electriccoin.zcash.test.UiTestPrerequisites
 import co.electriccoin.zcash.ui.R
 import co.electriccoin.zcash.ui.screen.update.AppUpdateChecker
-import co.electriccoin.zcash.ui.screen.update.RestoreTag
 import co.electriccoin.zcash.ui.screen.update.TestUpdateActivity
+import co.electriccoin.zcash.ui.screen.update.UpdateTag
 import co.electriccoin.zcash.ui.screen.update.fixture.UpdateInfoFixture
 import co.electriccoin.zcash.ui.screen.update.model.UpdateInfo
 import co.electriccoin.zcash.ui.screen.update.model.UpdateState
@@ -20,7 +21,7 @@ import org.junit.Assert.assertEquals
 import org.junit.Rule
 import org.junit.Test
 
-class UpdateViewTest {
+class UpdateViewTest : UiTestPrerequisites() {
 
     @get:Rule
     val composeTestRule = createAndroidComposeRule<TestUpdateActivity>()
@@ -122,7 +123,7 @@ class UpdateViewTest {
 
         assertEquals(0, testSetup.getOnDownloadCount())
 
-        composeTestRule.onNodeWithText(RestoreTag.PROGRESSBAR_DOWNLOADING).also {
+        composeTestRule.onNodeWithText(UpdateTag.PROGRESSBAR_DOWNLOADING).also {
             it.assertDoesNotExist()
         }
 
@@ -158,13 +159,13 @@ class UpdateViewTest {
 }
 
 private fun ComposeContentTestRule.clickLater() {
-    onNodeWithTag(RestoreTag.BTN_LATER).also {
+    onNodeWithTag(UpdateTag.BTN_LATER).also {
         it.performClick()
     }
 }
 
 private fun ComposeContentTestRule.clickDownload() {
-    onNodeWithTag(RestoreTag.BTN_DOWNLOAD).also {
+    onNodeWithTag(UpdateTag.BTN_DOWNLOAD).also {
         it.performClick()
     }
 }

ui-lib/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="co.electriccoin.zcash.ui">
 
+    <uses-permission android:name="android.permission.CAMERA" />
+
     <application
         android:icon="@mipmap/ic_launcher_square"
         android:roundIcon="@mipmap/ic_launcher_round"

ui-lib/src/main/java/co/electriccoin/zcash/ui/MainActivity.kt

@@ -47,6 +47,7 @@ import co.electriccoin.zcash.ui.screen.request.view.Request
 import co.electriccoin.zcash.ui.screen.restore.view.RestoreWallet
 import co.electriccoin.zcash.ui.screen.restore.viewmodel.CompleteWordSetState
 import co.electriccoin.zcash.ui.screen.restore.viewmodel.RestoreViewModel
+import co.electriccoin.zcash.ui.screen.scan.WrapScan
 import co.electriccoin.zcash.ui.screen.seed.view.Seed
 import co.electriccoin.zcash.ui.screen.send.view.Send
 import co.electriccoin.zcash.ui.screen.settings.view.Settings
@@ -253,7 +254,7 @@ class MainActivity : ComponentActivity() {
         NavHost(navController = navController, startDestination = NAV_HOME) {
             composable(NAV_HOME) {
                 WrapHome(
-                    goScan = {},
+                    goScan = { navController.navigate(NAV_SCAN) },
                     goProfile = { navController.navigate(NAV_PROFILE) },
                     goSend = { navController.navigate(NAV_SEND) },
                     goRequest = { navController.navigate(NAV_REQUEST) }
@@ -307,6 +308,9 @@ class MainActivity : ComponentActivity() {
             composable(NAV_ABOUT) {
                 WrapAbout(goBack = { navController.popBackStack() })
             }
+            composable(NAV_SCAN) {
+                WrapScan(goBack = { navController.popBackStack() })
+            }
         }
     }
 
@@ -491,6 +495,9 @@ class MainActivity : ComponentActivity() {
 
         @VisibleForTesting
         const val NAV_ABOUT = "about"
+
+        @VisibleForTesting
+        const val NAV_SCAN = "scan"
     }
 }
 

ui-lib/src/main/java/co/electriccoin/zcash/ui/screen/scan/AndroidScan.kt

@@ -0,0 +1,47 @@
+package co.electriccoin.zcash.ui.screen.scan
+
+import androidx.activity.ComponentActivity
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import co.electriccoin.zcash.ui.MainActivity
+import co.electriccoin.zcash.ui.R
+import co.electriccoin.zcash.ui.screen.scan.util.SettingsUtil
+import co.electriccoin.zcash.ui.screen.scan.view.Scan
+import kotlinx.coroutines.launch
+
+@Composable
+internal fun MainActivity.WrapScan(
+    goBack: () -> Unit
+) {
+    WrapScan(this, goBack)
+}
+
+@Composable
+fun WrapScan(
+    activity: ComponentActivity,
+    goBack: () -> Unit
+) {
+    val snackbarHostState = remember { SnackbarHostState() }
+    val scope = rememberCoroutineScope()
+
+    Scan(
+        snackbarHostState,
+        onBack = goBack,
+        onScan = {},
+        onOpenSettings = {
+            runCatching {
+                activity.startActivity(SettingsUtil.newSettingsIntent(activity.packageName))
+            }.onFailure {
+                // This case should not really happen, as the Settings app should be available on every
+                // Android device, but we need to handle it somehow.
+                scope.launch {
+                    snackbarHostState.showSnackbar(
+                        message = activity.getString(R.string.scan_settings_open_failed)
+                    )
+                }
+            }
+        }
+    )
+}

ui-lib/src/main/java/co/electriccoin/zcash/ui/screen/scan/ScanTag.kt

@@ -0,0 +1,10 @@
+package co.electriccoin.zcash.ui.screen.scan
+
+/**
+ * These are only used for automated testing.
+ */
+object ScanTag {
+    const val TEXT_STATE = "text_state"
+    const val CAMERA_VIEW = "camera_view"
+    const val QR_FRAME = "frame"
+}

ui-lib/src/main/java/co/electriccoin/zcash/ui/screen/scan/model/ScanState.kt

@@ -0,0 +1,8 @@
+package co.electriccoin.zcash.ui.screen.scan.model
+
+enum class ScanState {
+    Failed,
+    Permission,
+    Scanning,
+    Success
+}

ui-lib/src/main/java/co/electriccoin/zcash/ui/screen/scan/util/SettingsUtil.kt

@@ -0,0 +1,31 @@
+package co.electriccoin.zcash.ui.screen.scan.util
+
+import android.content.Intent
+import android.net.Uri
+import android.provider.Settings
+
+object SettingsUtil {
+
+    internal const val SETTINGS_URI_PREFIX = "package:"
+
+    internal const val FLAGS = Intent.FLAG_ACTIVITY_NEW_TASK or
+        Intent.FLAG_ACTIVITY_NO_HISTORY or
+        Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS
+
+    /**
+     * Returns an intent to the system Settings page of the app given by packageName parameter.
+     *
+     * @param packageName of the app, which should be opened in the Settings
+     *
+     * @return Intent for launching the system Settings app
+     */
+    internal fun newSettingsIntent(
+        packageName: String
+    ): Intent {
+        return Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS).apply {
+            addCategory(Intent.CATEGORY_DEFAULT)
+            data = Uri.parse("$SETTINGS_URI_PREFIX$packageName")
+            flags = FLAGS
+        }
+    }
+}

ui-lib/src/main/java/co/electriccoin/zcash/ui/screen/scan/view/ScanView.kt

@@ -0,0 +1,333 @@
+package co.electriccoin.zcash.ui.screen.scan.view
+
+import android.Manifest
+import android.content.pm.PackageManager
+import android.content.res.Configuration
+import android.view.ViewGroup
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.camera.core.CameraSelector
+import androidx.camera.lifecycle.ProcessCameraProvider
+import androidx.camera.view.PreviewView
+import androidx.compose.foundation.BorderStroke
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SmallTopAppBar
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
+import androidx.compose.material3.SnackbarResult
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Alignment.Companion.CenterHorizontally
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.layout.onSizeChanged
+import androidx.compose.ui.platform.LocalConfiguration
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.platform.LocalLifecycleOwner
+import androidx.compose.ui.platform.testTag
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.IntSize
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import androidx.compose.ui.viewinterop.AndroidView
+import androidx.constraintlayout.compose.ConstraintLayout
+import androidx.constraintlayout.compose.Dimension
+import androidx.core.content.ContextCompat
+import androidx.lifecycle.LifecycleOwner
+import co.electriccoin.zcash.ui.R
+import co.electriccoin.zcash.ui.design.component.GradientSurface
+import co.electriccoin.zcash.ui.design.component.SecondaryButton
+import co.electriccoin.zcash.ui.design.theme.ZcashTheme
+import co.electriccoin.zcash.ui.screen.scan.ScanTag
+import co.electriccoin.zcash.ui.screen.scan.model.ScanState
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.guava.await
+import kotlinx.coroutines.launch
+import java.util.UUID
+import kotlin.math.roundToInt
+
+// TODO [#423]: https://github.com/zcash/secant-android-wallet/issues/423
+// TODO [#313]: https://github.com/zcash/secant-android-wallet/issues/313
+@Preview("Scan")
+@Composable
+fun PreviewScan() {
+    ZcashTheme(darkTheme = true) {
+        GradientSurface {
+            Scan(
+                snackbarHostState = SnackbarHostState(),
+                onBack = {},
+                onScan = {},
+                onOpenSettings = {}
+            )
+        }
+    }
+}
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Suppress("UNUSED_VARIABLE")
+@Composable
+fun Scan(
+    snackbarHostState: SnackbarHostState,
+    onBack: () -> Unit,
+    onScan: (String) -> Unit,
+    onOpenSettings: () -> Unit,
+) {
+    Scaffold(
+        topBar = { ScanTopAppBar(onBack = onBack) },
+        snackbarHost = { SnackbarHost(snackbarHostState) },
+    ) {
+        ScanMainContent(
+            onScan,
+            onOpenSettings,
+            onBack,
+            snackbarHostState
+        )
+    }
+}
+
+@Composable
+fun ScanBottomItems(
+    scanState: ScanState,
+    onOpenSettings: () -> Unit
+) {
+    Column(modifier = Modifier.fillMaxWidth()) {
+        Text(
+            text = stringResource(id = R.string.scan_hint),
+            color = Color.White,
+            fontSize = 18.sp,
+            fontWeight = FontWeight.Bold,
+            modifier = Modifier
+                .fillMaxWidth()
+                .align(CenterHorizontally)
+                .padding(horizontal = 24.dp, vertical = 8.dp)
+        )
+
+        Text(
+            text = when (scanState) {
+                ScanState.Permission -> stringResource(id = R.string.scan_state_permission)
+                ScanState.Scanning -> stringResource(id = R.string.scan_state_scanning)
+                ScanState.Success -> stringResource(id = R.string.scan_state_success)
+                ScanState.Failed -> stringResource(id = R.string.scan_state_failed)
+            },
+            color = Color.White,
+            fontSize = 16.sp,
+            modifier = Modifier
+                .fillMaxWidth()
+                .align(CenterHorizontally)
+                .padding(horizontal = 24.dp, vertical = 8.dp)
+                .testTag(ScanTag.TEXT_STATE)
+        )
+
+        if (scanState == ScanState.Permission) {
+            SecondaryButton(
+                onClick = onOpenSettings,
+                text = stringResource(id = R.string.scan_settings_button),
+                modifier = Modifier
+                    .padding(horizontal = 24.dp, vertical = 12.dp)
+            )
+        }
+    }
+}
+
+@Composable
+private fun ScanTopAppBar(onBack: () -> Unit) {
+    SmallTopAppBar(
+        title = { Text(text = stringResource(id = R.string.scan_header)) },
+        navigationIcon = {
+            IconButton(
+                onClick = onBack
+            ) {
+                Icon(
+                    imageVector = Icons.Filled.ArrowBack,
+                    contentDescription = stringResource(R.string.scan_back_content_description)
+                )
+            }
+        }
+    )
+}
+
+@Suppress("UNUSED_VARIABLE", "UNUSED_PARAMETER", "MagicNumber", "LongMethod")
+@Composable
+private fun ScanMainContent(
+    onScan: (String) -> Unit,
+    onOpenSettings: () -> Unit,
+    onBack: () -> Unit,
+    snackbarHostState: SnackbarHostState
+) {
+    val context = LocalContext.current
+    val lifecycleOwner = LocalLifecycleOwner.current
+
+    val (scanState, setScanState) = rememberSaveable {
+        mutableStateOf(
+            if (ContextCompat.checkSelfPermission(context, Manifest.permission.CAMERA) ==
+                PackageManager.PERMISSION_GRANTED
+            ) {
+                ScanState.Scanning
+            } else {
+                ScanState.Permission
+            }
+        )
+    }
+
+    val (scanResult, setScanResult) = rememberSaveable { mutableStateOf("") }
+
+    val launcher = rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.RequestPermission(),
+        onResult = { granted ->
+            if (granted) {
+                setScanState(ScanState.Scanning)
+            } else {
+                setScanState(ScanState.Permission)
+            }
+        }
+    )
+
+    // We use a random value to show the permission popup after a user grants the CAMERA permission
+    // outside of the app (in Settings).
+    LaunchedEffect(key1 = UUID.randomUUID()) {
+        launcher.launch(Manifest.permission.CAMERA)
+    }
+
+    val cameraProviderFlow = remember {
+        flow<ProcessCameraProvider> { emit(ProcessCameraProvider.getInstance(context).await()) }
+    }
+
+    // we calculate the best frame size for the current device screen
+    val framePossibleSize = remember { mutableStateOf(IntSize.Zero) }
+
+    val configuration = LocalConfiguration.current
+    val frameActualSize = if (configuration.orientation == Configuration.ORIENTATION_LANDSCAPE) {
+        (framePossibleSize.value.height * 0.85).roundToInt()
+    } else {
+        (framePossibleSize.value.width * 0.7).roundToInt()
+    }
+
+    ConstraintLayout(modifier = Modifier.fillMaxSize()) {
+        val (frame, bottomItems) = createRefs()
+
+        if (scanState == ScanState.Scanning) {
+            ScanCameraView(
+                onBack,
+                cameraProviderFlow,
+                lifecycleOwner,
+                snackbarHostState
+            )
+
+            Box(
+                modifier = Modifier
+                    .constrainAs(frame) {
+                        top.linkTo(parent.top)
+                        bottom.linkTo(bottomItems.top)
+                        start.linkTo(parent.start)
+                        end.linkTo(parent.end)
+                        width = Dimension.fillToConstraints
+                        height = Dimension.fillToConstraints
+                    }.onSizeChanged { coordinates ->
+                        framePossibleSize.value = coordinates
+                    },
+                contentAlignment = Alignment.Center
+            ) {
+                ScanFrame(frameActualSize)
+            }
+        }
+
+        Box(modifier = Modifier.constrainAs(bottomItems) { bottom.linkTo(parent.bottom) }) {
+            ScanBottomItems(scanState, onOpenSettings)
+        }
+    }
+}
+
+@Suppress("MagicNumber")
+@Composable
+fun ScanFrame(frameSize: Int) {
+    Box(
+        modifier = Modifier
+            .size(with(LocalDensity.current) { frameSize.toDp() })
+            .background(Color.Transparent)
+            .border(BorderStroke(10.dp, Color.White), RoundedCornerShape(10))
+            .testTag(ScanTag.QR_FRAME)
+    )
+}
+
+@Composable
+fun ScanCameraView(
+    onBack: () -> Unit,
+    cameraProviderFlow: Flow<ProcessCameraProvider>,
+    lifecycleOwner: LifecycleOwner,
+    snackbarHostState: SnackbarHostState
+) {
+    val context = LocalContext.current
+    val scope = rememberCoroutineScope()
+
+    val cameraProvider = cameraProviderFlow.collectAsState(initial = null).value
+    if (null == cameraProvider) {
+        // Show loading indicator
+    } else {
+        AndroidView(
+            factory = { factoryContext ->
+                val previewView = PreviewView(factoryContext).apply {
+                    this.scaleType = PreviewView.ScaleType.FILL_CENTER
+                    layoutParams = ViewGroup.LayoutParams(
+                        ViewGroup.LayoutParams.MATCH_PARENT,
+                        ViewGroup.LayoutParams.MATCH_PARENT
+                    )
+                }
+                val preview = androidx.camera.core.Preview.Builder().build()
+                val selector = CameraSelector.Builder()
+                    .requireLensFacing(CameraSelector.LENS_FACING_BACK)
+                    .build()
+                preview.setSurfaceProvider(previewView.surfaceProvider)
+
+                runCatching {
+                    // we must unbind the use-cases before rebinding them
+                    cameraProvider.unbindAll()
+                    cameraProvider.bindToLifecycle(
+                        lifecycleOwner,
+                        selector,
+                        preview
+                    )
+                }.onFailure {
+                    scope.launch {
+                        val snackbarResult = snackbarHostState.showSnackbar(
+                            message = context.getString(R.string.scan_setup_failed),
+                            actionLabel = context.getString(R.string.scan_setup_back),
+                        )
+                        if (snackbarResult == SnackbarResult.ActionPerformed) {
+                            onBack()
+                        }
+                    }
+                }
+
+                previewView
+            },
+            Modifier
+                .fillMaxSize()
+                .testTag(ScanTag.CAMERA_VIEW),
+        )
+    }
+}

ui-lib/src/main/java/co/electriccoin/zcash/ui/screen/support/model/EnvironmentInfo.kt

@@ -1,5 +1,6 @@
 package co.electriccoin.zcash.ui.screen.support.model
 
+import android.annotation.SuppressLint
 import android.content.Context
 import cash.z.ecc.sdk.ext.ui.model.MonetarySeparators
 import co.electriccoin.zcash.spackle.AndroidApiVersion
@@ -22,6 +23,7 @@ class EnvironmentInfo(val locale: Locale, val monetarySeparators: MonetarySepara
             currentLocaleLegacy(context)
         }
 
+        @SuppressLint("NewApi")
         private fun currentLocaleNPlus(context: Context) = context.resources.configuration.locales[0]
 
         @Suppress("Deprecation")

ui-lib/src/main/java/co/electriccoin/zcash/ui/screen/update/UpdateTag.kt

@@ -3,7 +3,7 @@ package co.electriccoin.zcash.ui.screen.update
 /**
  * These are only used for automated testing.
  */
-object RestoreTag {
+object UpdateTag {
     const val BTN_LATER = "btn_later"
     const val BTN_DOWNLOAD = "btn_download"
     const val PROGRESSBAR_DOWNLOADING = "progressbar_downloading"

ui-lib/src/main/java/co/electriccoin/zcash/ui/screen/update/view/UpdateView.kt

@@ -31,7 +31,7 @@ import co.electriccoin.zcash.ui.design.component.PrimaryButton
 import co.electriccoin.zcash.ui.design.component.Reference
 import co.electriccoin.zcash.ui.design.component.TertiaryButton
 import co.electriccoin.zcash.ui.design.theme.ZcashTheme
-import co.electriccoin.zcash.ui.screen.update.RestoreTag
+import co.electriccoin.zcash.ui.screen.update.UpdateTag
 import co.electriccoin.zcash.ui.screen.update.fixture.UpdateInfoFixture
 import co.electriccoin.zcash.ui.screen.update.model.UpdateInfo
 import co.electriccoin.zcash.ui.screen.update.model.UpdateState
@@ -96,7 +96,7 @@ fun UpdateOverlayRunning(updateInfo: UpdateInfo) {
                 .background(ZcashTheme.colors.overlay.copy(0.5f))
                 .fillMaxWidth()
                 .fillMaxHeight()
-                .testTag(RestoreTag.PROGRESSBAR_DOWNLOADING),
+                .testTag(UpdateTag.PROGRESSBAR_DOWNLOADING),
             horizontalAlignment = Alignment.CenterHorizontally,
             verticalArrangement = Arrangement.Center
         ) {
@@ -136,7 +136,7 @@ private fun UpdateBottomAppBar(
             text = stringResource(R.string.update_download_button),
             modifier = Modifier
                 .fillMaxWidth()
-                .testTag(RestoreTag.BTN_DOWNLOAD),
+                .testTag(UpdateTag.BTN_DOWNLOAD),
             enabled = updateInfo.state != UpdateState.Running
         )
 
@@ -153,7 +153,7 @@ private fun UpdateBottomAppBar(
             ),
             modifier = Modifier
                 .fillMaxWidth()
-                .testTag(RestoreTag.BTN_LATER),
+                .testTag(UpdateTag.BTN_LATER),
             enabled = !updateInfo.isForce && updateInfo.state != UpdateState.Running
         )
     }

ui-lib/src/main/res/ui/scan/values/strings.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="scan_header">Scan a Zcash QR</string>
+    <string name="scan_back_content_description">Back</string>
+
+    <string name="scan_hint">We will validate any Zcash URI and take you to the appropriate action.</string>
+
+    <string name="scan_settings_button">Enable camera permission</string>
+    <string name="scan_settings_open_failed">Unable to launch Settings app.</string>
+
+    <string name="scan_setup_failed">Unable to run QR scanner.</string>
+    <string name="scan_setup_back">Back</string>
+
+    <string name="scan_state_permission">Permission for camera is necessary.</string>
+    <string name="scan_state_scanning">Scanning…</string>
+    <string name="scan_state_success">Successfully scanned.</string>
+    <string name="scan_state_failed">Scanning failed.</string>
+</resources>