PM-26594: Move the QrCodeAnalyzer to the UI module (#5980)

ui/build.gradle.kts

@@ -57,6 +57,7 @@ dependencies {
     implementation(platform(libs.androidx.compose.bom))
     implementation(libs.androidx.activity.compose)
     implementation(libs.androidx.browser)
+    implementation(libs.androidx.camera.camera2)
     implementation(libs.androidx.compose.animation)
     implementation(libs.androidx.compose.material3)
     implementation(libs.androidx.compose.material3.adaptive)
@@ -72,6 +73,7 @@ dependencies {
     implementation(libs.kotlinx.serialization)
     implementation(libs.kotlinx.coroutines.core)
     implementation(libs.kotlinx.collections.immutable)
+    implementation(libs.zxing.zxing.core)
 
     // For now we are restricted to running Compose tests for debug builds only
     debugImplementation(libs.androidx.compose.ui.test.manifest)
@@ -86,6 +88,7 @@ dependencies {
     testImplementation(libs.androidx.compose.ui.test)
 
     testFixturesImplementation(libs.androidx.activity.compose)
+    testFixturesImplementation(libs.androidx.camera.camera2)
     testFixturesImplementation(libs.androidx.compose.ui.test)
     testFixturesImplementation(libs.androidx.navigation.compose)
     testFixturesImplementation(libs.google.hilt.android.testing)

ui/src/main/kotlin/com/bitwarden/ui/platform/feature/qrcodescan/util/QrCodeAnalyzer.kt

@@ -0,0 +1,16 @@
+package com.bitwarden.ui.platform.feature.qrcodescan.util
+
+import androidx.camera.core.ImageAnalysis
+import androidx.compose.runtime.Stable
+
+/**
+ * An interface that is used to help scan QR codes.
+ */
+@Stable
+interface QrCodeAnalyzer : ImageAnalysis.Analyzer {
+
+    /**
+     * The method that is called once the code is scanned.
+     */
+    var onQrCodeScanned: (String) -> Unit
+}

ui/src/main/kotlin/com/bitwarden/ui/platform/feature/qrcodescan/util/QrCodeAnalyzerImpl.kt

@@ -0,0 +1,69 @@
+package com.bitwarden.ui.platform.feature.qrcodescan.util
+
+import androidx.camera.core.ImageProxy
+import com.bitwarden.annotation.OmitFromCoverage
+import com.google.zxing.BarcodeFormat
+import com.google.zxing.BinaryBitmap
+import com.google.zxing.DecodeHintType
+import com.google.zxing.MultiFormatReader
+import com.google.zxing.NotFoundException
+import com.google.zxing.PlanarYUVLuminanceSource
+import com.google.zxing.common.HybridBinarizer
+import java.nio.ByteBuffer
+
+/**
+ * A class setup to handle image analysis so that we can use the Zxing library
+ * to scan QR codes and convert them to a string.
+ */
+@OmitFromCoverage
+class QrCodeAnalyzerImpl : QrCodeAnalyzer {
+
+    /**
+     * This will ensure the result is only sent once as multiple images with a valid
+     * QR code can be sent for analysis.
+     */
+    private var qrCodeRead = false
+
+    override lateinit var onQrCodeScanned: (String) -> Unit
+
+    override fun analyze(image: ImageProxy) {
+        if (qrCodeRead) {
+            return
+        }
+
+        val source = PlanarYUVLuminanceSource(
+            image.planes[0].buffer.toByteArray(),
+            image.width,
+            image.height,
+            0,
+            0,
+            image.width,
+            image.height,
+            false,
+        )
+        val binaryBitmap = BinaryBitmap(HybridBinarizer(source))
+        try {
+            val result = MultiFormatReader().decode(
+                binaryBitmap,
+                mapOf(
+                    DecodeHintType.POSSIBLE_FORMATS to arrayListOf(BarcodeFormat.QR_CODE),
+                    DecodeHintType.ALSO_INVERTED to true,
+                ),
+            )
+
+            qrCodeRead = true
+            onQrCodeScanned(result.text)
+        } catch (_: NotFoundException) {
+            return
+        } finally {
+            image.close()
+        }
+    }
+}
+
+/**
+ * This function helps us prepare the byte buffer to be read.
+ */
+@OmitFromCoverage
+private fun ByteBuffer.toByteArray(): ByteArray =
+    ByteArray(rewind().remaining()).also { get(it) }

ui/src/testFixtures/kotlin/com/bitwarden/ui/platform/feature/qrcodescan/util/FakeQrCodeAnalyzer.kt

@@ -0,0 +1,21 @@
+package com.bitwarden.ui.platform.feature.qrcodescan.util
+
+import androidx.camera.core.ImageProxy
+
+/**
+ * A helper class that helps test scan outcomes.
+ */
+class FakeQrCodeAnalyzer : QrCodeAnalyzer {
+
+    override lateinit var onQrCodeScanned: (String) -> Unit
+
+    /**
+     * The result of the scan that will be sent to the ViewModel (or `null` to indicate a
+     * scanning error.
+     */
+    var scanResult: String? = null
+
+    override fun analyze(image: ImageProxy) {
+        scanResult?.let { onQrCodeScanned.invoke(it) }
+    }
+}