QR code Generation Component (EXPOSUREAPP-5961) (#2689)

* added qr code generator component

* linting

* updated error handling

* linting

* updated exception handling in view model

Co-authored-by: harambasicluka <64483219+harambasicluka@users.noreply.github.com>

Corona-Warn-App/src/deviceForTesters/java/de/rki/coronawarnapp/test/eventregistration/ui/qrcode/QrCodeCreationTestViewModel.kt

@@ -2,17 +2,12 @@ package de.rki.coronawarnapp.test.eventregistration.ui.qrcode
 
 import android.content.Context
 import android.graphics.Bitmap
-import android.graphics.Color.BLACK
-import android.graphics.Color.WHITE
 import android.graphics.pdf.PdfDocument
 import android.view.View
-import com.google.zxing.BarcodeFormat
-import com.google.zxing.EncodeHintType
-import com.google.zxing.MultiFormatWriter
-import com.google.zxing.common.BitMatrix
 import dagger.assisted.AssistedFactory
 import dagger.assisted.AssistedInject
 import de.rki.coronawarnapp.appconfig.AppConfigProvider
+import de.rki.coronawarnapp.ui.eventregistration.organizer.details.QrCodeGenerator
 import de.rki.coronawarnapp.util.coroutine.DispatcherProvider
 import de.rki.coronawarnapp.util.di.AppContext
 import de.rki.coronawarnapp.util.files.FileSharing
@@ -26,6 +21,7 @@ import java.io.FileOutputStream
 class QrCodeCreationTestViewModel @AssistedInject constructor(
     private val dispatcher: DispatcherProvider,
     private val fileSharing: FileSharing,
+    private val qrCodeGenerator: QrCodeGenerator,
     @AppContext private val context: Context,
     private val appConfigProvider: AppConfigProvider,
 ) : CWAViewModel(dispatcher) {
@@ -38,7 +34,13 @@ class QrCodeCreationTestViewModel @AssistedInject constructor(
      * Creates a QR Code [Bitmap] ,result is delivered by [qrCodeBitmap]
      */
     fun createQrCode(input: String) = launch(context = dispatcher.IO) {
-        qrCodeBitmap.postValue(encodeAsBitmap(input))
+
+        try {
+            qrCodeBitmap.postValue(qrCodeGenerator.createQrCode(input))
+        } catch (e: Exception) {
+            Timber.d(e, "Qr code creation failed")
+            errorMessage.postValue(e.localizedMessage ?: "QR code creation failed")
+        }
     }
 
     /**
@@ -83,48 +85,6 @@ class QrCodeCreationTestViewModel @AssistedInject constructor(
         return File(dir, "CoronaWarnApp-Event.pdf")
     }
 
-    private suspend fun encodeAsBitmap(input: String, size: Int = 1000): Bitmap? {
-        return try {
-            val qrCodeErrorCorrectionLevel = appConfigProvider
-                .getAppConfig()
-                .presenceTracing
-                .qrCodeErrorCorrectionLevel
-            Timber.i("QrCodeErrorCorrectionLevel: $qrCodeErrorCorrectionLevel")
-            val hints = mapOf(
-                EncodeHintType.ERROR_CORRECTION to qrCodeErrorCorrectionLevel
-                // This is not required in the specs and it should not be enabled
-                // it is causing crash on older Android versions ex:API 23
-                // EncodeHintType.CHARACTER_SET to Charsets.UTF_8
-            )
-            MultiFormatWriter().encode(
-                input,
-                BarcodeFormat.QR_CODE,
-                size,
-                size,
-                hints
-            ).toBitmap()
-        } catch (e: Exception) {
-            Timber.d(e, "Qr code creation failed")
-            errorMessage.postValue(e.localizedMessage ?: "QR code creation failed")
-            null
-        }
-    }
-
-    private fun BitMatrix.toBitmap() =
-        Bitmap.createBitmap(
-            context.resources.displayMetrics,
-            width,
-            height,
-            Bitmap.Config.ARGB_8888
-        ).apply {
-            for (x in 0 until width) {
-                for (y in 0 until height) {
-                    val color = if (get(x, y)) BLACK else WHITE
-                    setPixel(x, y, color)
-                }
-            }
-        }
-
     @AssistedFactory
     interface Factory : SimpleCWAViewModelFactory<QrCodeCreationTestViewModel>
 }

Corona-Warn-App/src/main/java/de/rki/coronawarnapp/eventregistration/checkins/qrcode/QrCodeGenerator.kt

@@ -0,0 +1,58 @@
+package de.rki.coronawarnapp.ui.eventregistration.organizer.details
+
+import android.content.Context
+import android.graphics.Bitmap
+import android.graphics.Color
+import com.google.zxing.BarcodeFormat
+import com.google.zxing.EncodeHintType
+import com.google.zxing.MultiFormatWriter
+import com.google.zxing.common.BitMatrix
+import dagger.Reusable
+import de.rki.coronawarnapp.appconfig.AppConfigProvider
+import de.rki.coronawarnapp.util.di.AppContext
+import timber.log.Timber
+import javax.inject.Inject
+
+@Reusable
+class QrCodeGenerator @Inject constructor(
+    private val appConfigProvider: AppConfigProvider,
+    @AppContext private val context: Context,
+) {
+
+    suspend fun createQrCode(input: String, size: Int = 1000): Bitmap? {
+
+        val qrCodeErrorCorrectionLevel = appConfigProvider
+            .getAppConfig()
+            .presenceTracing
+            .qrCodeErrorCorrectionLevel
+        Timber.i("QrCodeErrorCorrectionLevel: $qrCodeErrorCorrectionLevel")
+        val hints = mapOf(
+            EncodeHintType.ERROR_CORRECTION to qrCodeErrorCorrectionLevel
+        )
+
+        return MultiFormatWriter().encode(
+            input,
+            BarcodeFormat.QR_CODE,
+            size,
+            size,
+            hints
+        ).toBitmap()
+    }
+
+    private fun BitMatrix.toBitmap(): Bitmap {
+        val bitmap = Bitmap.createBitmap(
+            context.resources.displayMetrics,
+            width,
+            height,
+            Bitmap.Config.ARGB_8888
+        )
+
+        for (x in 0 until width) {
+            for (y in 0 until height) {
+                val color = if (get(x, y)) Color.BLACK else Color.WHITE
+                bitmap.setPixel(x, y, color)
+            }
+        }
+        return bitmap
+    }
+}