Scan QR code from gallery image

app/src/main/java/app/grapheneos/camera/CamConfig.kt

@@ -1476,7 +1476,13 @@ class CamConfig(private val mActivity: MainActivity) {
 
         if (isQRMode) {
             mActivity.qrOverlay.visibility = View.VISIBLE
-            mActivity.thirdOption.visibility = View.INVISIBLE
+
+            mActivity.thirdOption.visibility = View.VISIBLE
+            mActivity.whiteOptionCircle.visibility = View.INVISIBLE
+            mActivity.imagePreview.visibility = View.INVISIBLE
+            mActivity.thirdCircle.visibility = View.INVISIBLE
+            mActivity.playPreview.visibility = View.INVISIBLE
+            mActivity.qrImageImport.visibility = View.VISIBLE
 
             if (scanAllCodes) {
                 mActivity.flipCamIcon.setImageResource(
@@ -1499,6 +1505,12 @@ class CamConfig(private val mActivity: MainActivity) {
         } else {
             mActivity.qrOverlay.visibility = View.INVISIBLE
             mActivity.thirdOption.visibility = View.VISIBLE
+
+            mActivity.qrImageImport.visibility = View.GONE
+            mActivity.whiteOptionCircle.visibility = View.VISIBLE
+            mActivity.imagePreview.visibility = View.VISIBLE
+            mActivity.thirdCircle.visibility = View.VISIBLE
+
             mActivity.flipCamIcon.setImageResource(R.drawable.flip_camera)
             mActivity.cancelButtonView.visibility = View.VISIBLE
 

app/src/main/java/app/grapheneos/camera/analyzer/QRAnalyzer.kt

@@ -1,5 +1,6 @@
 package app.grapheneos.camera.analyzer
 
+import android.graphics.Bitmap
 import android.util.Log
 import androidx.camera.core.ImageAnalysis.Analyzer
 import androidx.camera.core.ImageProxy
@@ -9,6 +10,7 @@ import com.google.zxing.BinaryBitmap
 import com.google.zxing.DecodeHintType
 import com.google.zxing.MultiFormatReader
 import com.google.zxing.PlanarYUVLuminanceSource
+import com.google.zxing.RGBLuminanceSource
 import com.google.zxing.ReaderException
 import com.google.zxing.common.HybridBinarizer
 import java.util.EnumMap
@@ -17,6 +19,32 @@ import kotlin.math.roundToInt
 class QRAnalyzer(private val mActivity: MainActivity) : Analyzer {
     companion object {
         private const val TAG = "QRCodeImageAnalyzer"
+
+        fun scanStillImage(bitmap: Bitmap, possibleFormats: List<BarcodeFormat>): String? {
+            val width = bitmap.width
+            val height = bitmap.height
+            val pixels = IntArray(width * height)
+            bitmap.getPixels(pixels, 0, width, 0, 0, width, height)
+
+            val hints: MutableMap<DecodeHintType, Any> = EnumMap(DecodeHintType::class.java)
+            hints[DecodeHintType.POSSIBLE_FORMATS] = possibleFormats
+            hints[DecodeHintType.TRY_HARDER] = true
+
+            val reader = MultiFormatReader().apply { setHints(hints) }
+
+            val source = RGBLuminanceSource(width, height, pixels)
+            decodeOrNull(reader, BinaryBitmap(HybridBinarizer(source)))?.let { return it }
+            return decodeOrNull(reader, BinaryBitmap(HybridBinarizer(source.invert())))
+        }
+
+        private fun decodeOrNull(reader: MultiFormatReader, binaryBitmap: BinaryBitmap): String? {
+            reader.reset()
+            return try {
+                reader.decodeWithState(binaryBitmap).text
+            } catch (e: ReaderException) {
+                null
+            }
+        }
     }
 
     private var frameCounter = 0

app/src/main/java/app/grapheneos/camera/ui/activities/MainActivity.kt

@@ -45,6 +45,7 @@ import android.widget.ProgressBar
 import android.widget.RelativeLayout
 import android.widget.TextView
 import androidx.activity.enableEdgeToEdge
+import androidx.activity.result.PickVisualMediaRequest
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.activity.result.contract.ActivityResultContracts.RequestMultiplePermissions
 import androidx.annotation.StringRes
@@ -70,6 +71,7 @@ import app.grapheneos.camera.CameraMode
 import app.grapheneos.camera.ITEM_TYPE_IMAGE
 import app.grapheneos.camera.ITEM_TYPE_VIDEO
 import app.grapheneos.camera.R
+import app.grapheneos.camera.analyzer.QRAnalyzer
 import app.grapheneos.camera.capturer.ImageCapturer
 import app.grapheneos.camera.capturer.VideoCapturer
 import app.grapheneos.camera.capturer.getVideoThumbnail
@@ -156,6 +158,9 @@ open class MainActivity : AppCompatActivity(),
     lateinit var thirdOption: View
     lateinit var imagePreview: ShapeableImageView
     lateinit var previewLoader: ProgressBar
+    lateinit var whiteOptionCircle: ImageView
+    lateinit var playPreview: ImageView
+    lateinit var qrImageImport: ImageButton
     private var isZooming = false
 
     lateinit var zoomBar: ZoomBar
@@ -315,6 +320,42 @@ open class MainActivity : AppCompatActivity(),
         Log.i(TAG, "Selected location: ${data?.encodedPath!!}")
     }
 
+    private val qrImagePickerLauncher = registerForActivityResult(
+        ActivityResultContracts.PickVisualMedia()
+    ) { uri: Uri? ->
+        if (uri != null) {
+            scanQRFromImage(uri)
+        }
+    }
+
+    private fun scanQRFromImage(uri: Uri) {
+        val bitmap = try {
+            val source = ImageDecoder.createSource(contentResolver, uri)
+            ImageDecoder.decodeBitmap(source) { decoder, _, _ ->
+                decoder.allocator = ImageDecoder.ALLOCATOR_SOFTWARE
+            }
+        } catch (e: Exception) {
+            Log.w(TAG, "Unable to decode picked image for QR scan", e)
+            showMessage(R.string.could_not_read_image)
+            return
+        }
+
+        val possibleFormats = if (camConfig.scanAllCodes) {
+            BarcodeFormat.values().asList()
+        } else {
+            camConfig.allowedFormats
+        }
+
+        val result = QRAnalyzer.scanStillImage(bitmap, possibleFormats)
+        bitmap.recycle()
+
+        if (result != null) {
+            onScanResultSuccess(result)
+        } else {
+            showMessage(R.string.no_code_found_in_image)
+        }
+    }
+
     private fun showAudioPermissionDeniedDialog(onDisableAudio: () -> Unit = {}) {
         val builder = MaterialAlertDialogBuilder(this)
             .setTitle(R.string.audio_permission_dialog_title)
@@ -606,6 +647,15 @@ open class MainActivity : AppCompatActivity(),
         thirdOption = binding.thirdOption
         previewLoader = binding.previewLoading
         imagePreview = binding.imagePreview
+        whiteOptionCircle = binding.whiteOptionCircle
+        playPreview = binding.playPreview
+        qrImageImport = binding.qrImageImport
+        qrImageImport.setOnClickListener {
+            resetAutoSleep()
+            qrImagePickerLauncher.launch(
+                PickVisualMediaRequest(ActivityResultContracts.PickVisualMedia.ImageOnly)
+            )
+        }
         previewView = binding.preview
         previewView.scaleType = PreviewView.ScaleType.FIT_START
         previewContainer = binding.previewContainer

app/src/main/java/app/grapheneos/camera/ui/activities/VideoCaptureActivity.kt

@@ -5,22 +5,15 @@ import android.net.Uri
 import android.os.Bundle
 import android.provider.MediaStore.EXTRA_OUTPUT
 import android.view.View
-import android.widget.ImageView
 import app.grapheneos.camera.R
 
 class VideoCaptureActivity : CaptureActivity() {
 
-    private lateinit var whiteOptionCircle: ImageView
-    private lateinit var playPreview: ImageView
-
     private var savedUri: Uri? = null
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        whiteOptionCircle = findViewById(R.id.white_option_circle)
-        playPreview = findViewById(R.id.play_preview)
-
         captureButton.setImageResource(R.drawable.recording)
 
         captureButton.setOnClickListener OnClickListener@{

app/src/main/res/drawable/scan_from_image.xml

@@ -0,0 +1,12 @@
+<vector
+    android:height="24dp"
+    android:width="24dp"
+    android:viewportHeight="24"
+    android:viewportWidth="24"
+    xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M21,19V5c0,-1.1 -0.9,-2 -2,-2H5c-1.1,0 -2,0.9 -2,2v14c0,1.1 0.9,2 2,2h14c1.1,0 2,-0.9 2,-2zM8.5,13.5l2.5,3.01L14.5,12l4.5,6H5l3.5,-4.5z"/>
+
+</vector>

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

@@ -365,6 +365,18 @@
                     android:layout_gravity="center"
                     android:contentDescription="@string/play_preview"/>
 
+                <ImageButton
+                    android:id="@+id/qr_image_import"
+                    android:layout_width="64dp"
+                    android:layout_height="64dp"
+                    android:layout_gravity="center"
+                    android:padding="16dp"
+                    android:scaleType="fitCenter"
+                    android:src="@drawable/scan_from_image"
+                    android:background="@drawable/option_circle"
+                    android:visibility="gone"
+                    android:contentDescription="@string/scan_from_image"/>
+
             </FrameLayout>
 
         </LinearLayout>

app/src/main/res/values/strings.xml

@@ -61,6 +61,9 @@
     <string name="rec_without_audio">Start recording without audio</string>
     <string name="qr_scan_toggle">QR Scan toggle</string>
     <string name="qr_scan">QR Code</string>
+    <string name="scan_from_image">Scan code from an image</string>
+    <string name="no_code_found_in_image">No code found in the selected image.</string>
+    <string name="could_not_read_image">Could not read the selected image.</string>
     <string name="data_matrix">Data Matrix</string>
     <string name="aztec_code">Aztec Code</string>
     <string name="more_options">More Options</string>