add zoom QR and flashlight button

app/src/main/java/sh/sar/basedbank/ui/home/QrScannerActivity.kt

@@ -13,6 +13,12 @@ import android.provider.Settings
 import android.widget.Toast
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
+import android.content.res.ColorStateList
+import android.graphics.Color
+import android.graphics.drawable.Animatable
+import android.view.ScaleGestureDetector
+import androidx.appcompat.content.res.AppCompatResources
+import androidx.camera.core.Camera
 import androidx.camera.core.CameraSelector
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowCompat
@@ -52,6 +58,8 @@ class QrScannerActivity : AppCompatActivity() {
         textMode = ZxingCpp.TextMode.PLAIN
     )
 
+    private var camera: Camera? = null
+    private var torchEnabled = false
     private var cameraStarted = false
 
     private val permissionLauncher = registerForActivityResult(
@@ -104,8 +112,36 @@ class QrScannerActivity : AppCompatActivity() {
             }
             insets
         }
-        binding.btnCancel.setOnClickListener { finish() }
         binding.btnPickImage.setOnClickListener { pickImageLauncher.launch("image/*") }
+        binding.zoomSlider.addOnChangeListener { _, value, fromUser ->
+            if (fromUser) camera?.cameraControl?.setLinearZoom(value)
+        }
+        val scaleDetector = ScaleGestureDetector(this,
+            object : ScaleGestureDetector.SimpleOnScaleGestureListener() {
+                override fun onScale(detector: ScaleGestureDetector): Boolean {
+                    val state = camera?.cameraInfo?.zoomState?.value ?: return true
+                    camera?.cameraControl?.setZoomRatio(
+                        (state.zoomRatio * detector.scaleFactor)
+                            .coerceIn(state.minZoomRatio, state.maxZoomRatio)
+                    )
+                    return true
+                }
+            })
+        binding.previewView.setOnTouchListener { _, event ->
+            scaleDetector.onTouchEvent(event)
+            true
+        }
+        binding.btnFlashlight.setOnClickListener {
+            torchEnabled = !torchEnabled
+            camera?.cameraControl?.enableTorch(torchEnabled)
+            val drawableRes = if (torchEnabled) R.drawable.ic_flashlight_to_on else R.drawable.ic_flashlight_to_off
+            val drawable = AppCompatResources.getDrawable(this, drawableRes)
+            binding.btnFlashlight.icon = drawable
+            (drawable as? Animatable)?.start()
+            binding.btnFlashlight.iconTint = ColorStateList.valueOf(
+                if (torchEnabled) Color.parseColor("#FFEB3B") else Color.WHITE
+            )
+        }
 
         if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
             == PackageManager.PERMISSION_GRANTED
@@ -179,9 +215,12 @@ class QrScannerActivity : AppCompatActivity() {
 
             try {
                 provider.unbindAll()
-                provider.bindToLifecycle(
+                camera = provider.bindToLifecycle(
                     this, CameraSelector.DEFAULT_BACK_CAMERA, preview, analysis
                 )
+                camera?.cameraInfo?.zoomState?.observe(this@QrScannerActivity) { state ->
+                    binding.zoomSlider.value = state.linearZoom
+                }
             } catch (_: Exception) {
                 finish()
             }