camera permissions routine

app/src/main/java/com/geeksville/mesh/MainActivity.kt

@@ -42,6 +42,7 @@ import com.geeksville.android.Logging
 import com.geeksville.android.ServiceClient
 import com.geeksville.concurrent.handledLaunch
 import com.geeksville.mesh.android.getBackgroundPermissions
+import com.geeksville.mesh.android.getCameraPermissions
 import com.geeksville.mesh.android.getMissingPermissions
 import com.geeksville.mesh.database.entity.Packet
 import com.geeksville.mesh.databinding.ActivityMainBinding
@@ -247,6 +248,8 @@ class MainActivity : AppCompatActivity(), Logging,
         return getMissingPermissions(perms)
     }
 
+    /** Ask the user to grant camera permission */
+    fun requestCameraPermission() = requestPermission(getCameraPermissions(), false)
 
     /** Ask the user to grant background location permission */
     fun requestBackgroundPermission() = requestPermission(getBackgroundPermissions(), false)

app/src/main/java/com/geeksville/mesh/android/ContextServices.kt

@@ -28,6 +28,18 @@ fun Context.getMissingPermissions(perms: List<String>) = perms.filter {
     ) != PackageManager.PERMISSION_GRANTED
 }
 
+/**
+ * Camera permission (or empty if we already have what we need)
+ */
+fun Context.getCameraPermissions(): List<String> {
+    val perms = mutableListOf(Manifest.permission.CAMERA)
+
+    return getMissingPermissions(perms)
+}
+
+/** @return true if the user already has camera permission */
+fun Context.hasCameraPermission() = getCameraPermissions().isEmpty()
+
 /**
  * A list of missing background location permissions (or empty if we already have what we need)
  */

app/src/main/java/com/geeksville/mesh/ui/ChannelFragment.kt

@@ -20,7 +20,9 @@ import com.geeksville.android.Logging
 import com.geeksville.android.hideKeyboard
 import com.geeksville.mesh.AppOnlyProtos
 import com.geeksville.mesh.ChannelProtos
+import com.geeksville.mesh.MainActivity
 import com.geeksville.mesh.R
+import com.geeksville.mesh.android.hasCameraPermission
 import com.geeksville.mesh.databinding.ChannelFragmentBinding
 import com.geeksville.mesh.model.Channel
 import com.geeksville.mesh.model.ChannelOption
@@ -208,12 +210,16 @@ class ChannelFragment : ScreenFragment("Channel"), Logging {
         }
 
         binding.scanButton.setOnClickListener {
-            val zxingScan = IntentIntegrator.forSupportFragment(this)
-            zxingScan.setCameraId(0)
-            zxingScan.setPrompt("")
-            zxingScan.setBeepEnabled(false)
-            zxingScan.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE)
-            zxingScan.initiateScan()
+            if ((requireActivity() as MainActivity).hasCameraPermission()) {
+                val zxingScan = IntentIntegrator.forSupportFragment(this)
+                zxingScan.setCameraId(0)
+                zxingScan.setPrompt("")
+                zxingScan.setBeepEnabled(false)
+                zxingScan.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE)
+                zxingScan.initiateScan()
+            } else {
+                (requireActivity() as MainActivity).requestCameraPermission()
+            }
         }
 
         // Note: Do not use setOnCheckedChanged here because we don't want to be called when we programmatically disable editing