Add QR Code Scanner

app/build.gradle

@@ -128,4 +128,10 @@ dependencies {
 
     // Image viewer
     implementation 'com.github.stfalcon-studio:StfalconImageViewer:v1.0.1'
+
+    // QR Scanning
+    implementation 'com.google.mlkit:barcode-scanning:17.3.0'
+    implementation "androidx.camera:camera-camera2:1.2.3"
+    implementation "androidx.camera:camera-lifecycle:1.2.3"
+    implementation "androidx.camera:camera-view:1.2.3"
 }

app/src/main/AndroidManifest.xml

@@ -2,7 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="io.heckel.ntfy">
 
-    <!-- Permissions -->
+
+
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/> <!-- For instant delivery foregrounds service -->
     <uses-permission android:name="android.permission.WAKE_LOCK"/> <!-- To keep foreground service awake; soon not needed anymore -->
@@ -11,7 +12,12 @@
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="28"/> <!-- Only required on SDK <= 28 -->
     <uses-permission android:name="android.permission.SCHEDULE_EXACT_ALARM"/> <!-- To reschedule the websocket retry -->
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/> <!-- As of Android 13, we need to ask for permission to post notifications -->
+    <uses-permission android:name="android.permission.CAMERA" /> <!-- To Scan QR Codes -->
 
+    <!-- Permissions -->
+    <uses-feature
+        android:name="android.hardware.camera"
+        android:required="false" />
     <!--
         Permission REQUEST_INSTALL_PACKAGES (F-Droid only!):
           - Permission is used to install .apk files that were received as attachments
@@ -94,6 +100,9 @@
                 android:exported="false">
         </activity>
 
+        <!-- Scan QR code -->
+        <activity android:name=".ui.QrScannerActivity" />
+
         <!-- Subscriber foreground service for hosts other than ntfy.sh -->
         <service android:name=".service.SubscriberService"/>
 

app/src/main/java/io/heckel/ntfy/ui/AddFragment.kt

@@ -4,11 +4,14 @@ import android.app.Activity
 import android.app.AlertDialog
 import android.app.Dialog
 import android.content.Context
+import android.content.Intent
 import android.os.Bundle
 import android.view.View
 import android.view.WindowManager
 import android.view.inputmethod.InputMethodManager
 import android.widget.*
+import androidx.activity.result.ActivityResultLauncher
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.fragment.app.DialogFragment
 import androidx.lifecycle.lifecycleScope
 import com.google.android.material.textfield.TextInputEditText
@@ -34,6 +37,7 @@ class AddFragment : DialogFragment() {
     private lateinit var loginView: View
     private lateinit var positiveButton: Button
     private lateinit var negativeButton: Button
+    private lateinit var qrButton: Button
 
     // Subscribe page
     private lateinit var subscribeTopicText: TextInputEditText
@@ -56,6 +60,26 @@ class AddFragment : DialogFragment() {
     private lateinit var loginErrorText: TextView
     private lateinit var loginErrorTextImage: View
 
+    // QR Codes
+    private var qrActivityResultLauncher: ActivityResultLauncher<Intent> = registerForActivityResult(
+        ActivityResultContracts.StartActivityForResult()) { result ->
+        if (result.resultCode == Activity.RESULT_OK) {
+            val data: Intent? = result.data
+            //receive data from firstActivity
+            val topic = data?.getStringExtra(QrScannerActivity.QR_CODE_DATA_TOPIC)
+            val url = data?.getStringExtra(QrScannerActivity.QR_CODE_DATA_SERVER_URL)
+            subscribeTopicText.setText(topic)
+            if (url != getDefaultBaseUrl()) {
+                subscribeBaseUrlText.setText(url)
+                subscribeUseAnotherServerCheckbox.isChecked = true
+            } else {
+                subscribeUseAnotherServerCheckbox.isChecked = false
+            }
+        } else if (result.resultCode == Activity.RESULT_CANCELED) {
+            Toast.makeText(requireContext(),"Unable to scan QR Code",Toast.LENGTH_SHORT).show()
+        }
+    }
+
     interface SubscribeListener {
         fun onSubscribe(topic: String, baseUrl: String, instant: Boolean)
     }
@@ -152,6 +176,9 @@ class AddFragment : DialogFragment() {
             .setNegativeButton(R.string.add_dialog_button_cancel) { _, _ ->
                 // This will be overridden below
             }
+            .setNeutralButton("Scan QR") {_, _ ->
+                // This will be overridden below
+            }
             .create()
 
         // Show keyboard when the dialog is shown (see https://stackoverflow.com/a/19573049/1440785)
@@ -168,6 +195,11 @@ class AddFragment : DialogFragment() {
             negativeButton.setOnClickListener {
                 negativeButtonClick()
             }
+
+            qrButton = dialog.getButton(AlertDialog.BUTTON_NEUTRAL)
+            qrButton.setOnClickListener {
+                qrButtonClick()
+            }
             val subscribeTextWatcher = AfterChangedTextWatcher {
                 validateInputSubscribeView()
             }
@@ -288,6 +320,12 @@ class AddFragment : DialogFragment() {
         }
     }
 
+    private fun qrButtonClick() {
+        Log.d(TAG, "Entering QR scanner mode")
+        val intent = Intent(this.context, QrScannerActivity::class.java)
+        qrActivityResultLauncher.launch(intent)
+    }
+
     private fun validateInputSubscribeView() {
         if (!this::positiveButton.isInitialized) return // As per crash seen in Google Play
 
@@ -366,10 +404,15 @@ class AddFragment : DialogFragment() {
         return if (subscribeUseAnotherServerCheckbox.isChecked) {
             subscribeBaseUrlText.text.toString()
         } else {
-            return defaultBaseUrl ?: appBaseUrl
+            return getDefaultBaseUrl()
         }
     }
 
+    private fun getDefaultBaseUrl(): String {
+        return defaultBaseUrl ?: appBaseUrl
+    }
+
+
     private fun showSubscribeView() {
         resetSubscribeView()
         positiveButton.text = getString(R.string.add_dialog_button_subscribe)

app/src/main/java/io/heckel/ntfy/ui/QrScannerActivity.kt

@@ -0,0 +1,172 @@
+package io.heckel.ntfy.ui
+
+import android.Manifest
+import android.app.Activity
+import android.app.AlertDialog
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
+import androidx.camera.core.CameraSelector
+import androidx.camera.core.ImageAnalysis
+import androidx.camera.core.Preview
+import androidx.camera.lifecycle.ProcessCameraProvider
+import androidx.camera.view.PreviewView
+import androidx.core.app.ActivityCompat
+import androidx.core.content.ContextCompat
+import io.heckel.ntfy.R
+import io.heckel.ntfy.util.Log
+import io.heckel.ntfy.util.QrCodeAnalyzer
+import java.util.concurrent.ExecutorService
+import java.util.concurrent.Executors
+
+
+class QrScannerActivity : AppCompatActivity(R.layout.activity_qr_scanner) {
+    private lateinit var cameraExecutor: ExecutorService
+    private final val ntfyQrDataPrefix = "ntfy://"
+    private final val ntfyQrDataTopicSeperator = ";"
+
+
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        cameraExecutor = Executors.newSingleThreadExecutor()
+
+        checkCameraPermission()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        cameraExecutor.shutdown()
+    }
+
+    /**
+     * 1. This function is responsible to request the required CAMERA permission
+     */
+    private fun checkCameraPermission() {
+        try {
+            val requiredPermissions = arrayOf(Manifest.permission.CAMERA)
+            ActivityCompat.requestPermissions(this, requiredPermissions, 0)
+        } catch (e: IllegalArgumentException) {
+            checkIfCameraPermissionIsGranted()
+        }
+    }
+
+    /**
+     * 2. This function will check if the CAMERA permission has been granted.
+     * If so, it will call the function responsible to initialize the camera preview.
+     * Otherwise, it will raise an alert.
+     */
+    private fun checkIfCameraPermissionIsGranted() {
+        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
+            // Permission granted: start the preview
+            startCamera()
+        } else {
+            // Permission denied
+            AlertDialog.Builder(this)
+                .setTitle("Permission required")
+                .setMessage("This application needs to access the camera to process barcodes")
+                .setPositiveButton("Ok") { _, _ ->
+                    // Keep asking for permission until granted
+                    checkCameraPermission()
+                }
+                .setCancelable(false)
+                .create()
+                .apply {
+                    setCanceledOnTouchOutside(false)
+                    show()
+                }
+        }
+    }
+
+    /**
+     * 3. This function is executed once the user has granted or denied the missing permission
+     */
+    override fun onRequestPermissionsResult(
+        requestCode: Int,
+        permissions: Array<out String>,
+        grantResults: IntArray
+    ) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
+        checkIfCameraPermissionIsGranted()
+    }
+
+    /**
+     * This function is responsible for the setup of the camera preview and the image analyzer.
+     */
+    private fun startCamera() {
+        val cameraProviderFuture = ProcessCameraProvider.getInstance(this)
+        cameraProviderFuture.addListener({
+            val cameraProvider = cameraProviderFuture.get()
+
+            // Preview
+            val preview = Preview.Builder()
+                .build()
+                .also {
+                    it.setSurfaceProvider(this.findViewById<PreviewView>(R.id.preview_view).surfaceProvider)
+                }
+
+            // Image analyzer
+            val imageAnalyzer = ImageAnalysis.Builder()
+                .setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
+                .build()
+                .also {
+                    it.setAnalyzer(cameraExecutor, QrCodeAnalyzer { data ->
+                        Log.d(TAG, "Found URL with value $data")
+                        val intent = Intent()
+                        try {
+                            val (qrUrl, qrTopic) = parseQrCodeData(data)
+                            intent.putExtra(QR_CODE_DATA_SERVER_URL, qrUrl)
+                            intent.putExtra(QR_CODE_DATA_TOPIC, qrTopic)
+                            setResult(Activity.RESULT_OK, intent)
+                        } catch (e: Exception) {
+                            Log.e(TAG, "QR reading failed with message ${e.message.toString()}")
+                            setResult(Activity.RESULT_CANCELED, intent)
+                        }
+                        finish()
+
+                    })
+                }
+
+            // Select back camera as a default
+            val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA
+
+            try {
+                // Unbind use cases before rebinding
+                cameraProvider.unbindAll()
+
+                // Bind use cases to camera
+                cameraProvider.bindToLifecycle(
+                    this, cameraSelector, preview, imageAnalyzer
+                )
+
+            } catch (exc: Exception) {
+                exc.printStackTrace()
+            }
+        }, ContextCompat.getMainExecutor(this))
+    }
+
+    private fun parseQrCodeData(data: String?): Pair<String, String> {
+        if (data == null || !data.startsWith(ntfyQrDataPrefix)) {
+            throw Exception("Bad QR code data format")
+        }
+
+        val startIndex = ntfyQrDataPrefix.length
+        val seperatorIndex = data.indexOf(ntfyQrDataTopicSeperator)
+
+        if (seperatorIndex == -1) {
+            throw Exception("Bad QR code data format")
+        }
+
+        val url = data.substring(startIndex, seperatorIndex)
+        val topicName = data.substring(seperatorIndex + 1)
+
+        return Pair(url, topicName)
+    }
+
+    companion object {
+        const val TAG = "NtfyQrScannerActivity"
+        const val QR_CODE_DATA_SERVER_URL = "qrServerUrls"
+        const val QR_CODE_DATA_TOPIC = "qrTopic"
+    }
+}

app/src/main/java/io/heckel/ntfy/util/QrCodeAnalyzer.kt

@@ -0,0 +1,43 @@
+package io.heckel.ntfy.util
+
+import androidx.annotation.OptIn
+import androidx.camera.core.ExperimentalGetImage
+import androidx.camera.core.ImageAnalysis
+import androidx.camera.core.ImageProxy
+import com.google.mlkit.vision.barcode.BarcodeScannerOptions
+import com.google.mlkit.vision.barcode.BarcodeScanning
+import com.google.mlkit.vision.barcode.common.Barcode
+import com.google.mlkit.vision.common.InputImage
+
+class QrCodeAnalyzer(private val onBarcodeScanned: (String?) -> Unit): ImageAnalysis.Analyzer {
+
+    @OptIn(ExperimentalGetImage::class) override fun analyze(imageProxy: ImageProxy) {
+        val mediaImage = imageProxy.image
+
+        if (mediaImage != null) {
+            val image = InputImage.fromMediaImage(mediaImage, imageProxy.imageInfo.rotationDegrees)
+            val options = BarcodeScannerOptions.Builder()
+                .setBarcodeFormats(Barcode.FORMAT_QR_CODE)
+                .build()
+            val scanner = BarcodeScanning.getClient(options);
+
+            scanner.process(image)
+                .addOnSuccessListener { barcodes ->
+                    for (barcode in barcodes) {
+                        Log.d("QR Analyzer", "${barcode.valueType}")
+                        val valueType = barcode.valueType
+                        when (valueType) {
+                            Barcode.TYPE_TEXT -> {
+                                onBarcodeScanned(barcode.rawValue)
+                                break
+                            }
+                        }
+                    }
+                }
+                .addOnFailureListener {}
+                .addOnCompleteListener {
+                    imageProxy.close()
+                }
+        }
+    }
+}

app/src/main/res/layout/activity_qr_scanner.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".ui.QrScannerActivity">
+
+    <androidx.camera.view.PreviewView
+        android:id="@+id/preview_view"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>