Camera permission behaviour (#505)

* Remove unused else

* Remove SDK version check since we are on minimum 24 already

* Add intent key about missing camera permission

* Add boolean value to show error dialog

- always true for the beginning to keep current behaviour

* Make displaying an error dialog for missing camera permissions optional

* Add intent extras for Intent initialisation

* Initialise camera permission dialog visibility from Intent

* Add original intent to IntentResult

* Use original intent in IntentResult

* Make onRequestPermissionResult public again

* Forward onRequestPermissionResult

* React on Intent information

- for example on the missing camera permission

* Revert "Remove SDK version check since we are on minimum 24 already"

This reverts commit 8f79f56a

* Add missing imports

2 files changed, 16 insertions, 2 deletions

diff --git a/sample/src/main/java/example/zxing/CustomScannerActivity.java b/sample/src/main/java/example/zxing/CustomScannerActivity.java
index 70f2df9b..ef41f1c5 100644
--- a/sample/src/main/java/example/zxing/CustomScannerActivity.java
+++ b/sample/src/main/java/example/zxing/CustomScannerActivity.java
@@ -8,6 +8,8 @@ import android.view.KeyEvent;
 import android.view.View;
 import android.widget.Button;
 
+import androidx.annotation.NonNull;
+
 import com.journeyapps.barcodescanner.CaptureManager;
 import com.journeyapps.barcodescanner.DecoratedBarcodeView;
 import com.journeyapps.barcodescanner.ViewfinderView;
@@ -45,6 +47,7 @@ public class CustomScannerActivity extends Activity implements
 
         capture = new CaptureManager(this, barcodeScannerView);
         capture.initializeFromIntent(getIntent(), savedInstanceState);
+        capture.setShowMissingCameraPermissionDialog(false);
         capture.decode();
 
         changeMaskColor(null);
@@ -116,4 +119,9 @@ public class CustomScannerActivity extends Activity implements
     public void onTorchOff() {
         switchFlashlightButton.setText(R.string.turn_on_flashlight);
     }
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
+        capture.onRequestPermissionsResult(requestCode, permissions, grantResults);
+    }
 }
diff --git a/sample/src/main/java/example/zxing/MainActivity.java b/sample/src/main/java/example/zxing/MainActivity.java
index 9c879278..99a3b620 100644
--- a/sample/src/main/java/example/zxing/MainActivity.java
+++ b/sample/src/main/java/example/zxing/MainActivity.java
@@ -128,8 +128,14 @@ public class MainActivity extends AppCompatActivity {
         IntentResult result = IntentIntegrator.parseActivityResult(resultCode, data);
 
         if(result.getContents() == null) {
-            Log.d("MainActivity", "Cancelled scan");
-            Toast.makeText(this, "Cancelled", Toast.LENGTH_LONG).show();
+            Intent originalIntent = result.getOriginalIntent();
+            if (originalIntent == null) {
+                Log.d("MainActivity", "Cancelled scan");
+                Toast.makeText(this, "Cancelled", Toast.LENGTH_LONG).show();
+            } else if(originalIntent.hasExtra(Intents.Scan.MISSING_CAMERA_PERMISSION)) {
+                Log.d("MainActivity", "Cancelled scan due to missing camera permission");
+                Toast.makeText(this, "Cancelled due to missing camera permission", Toast.LENGTH_LONG).show();
+            }
         } else {
             Log.d("MainActivity", "Scanned");
             Toast.makeText(this, "Scanned: " + result.getContents(), Toast.LENGTH_LONG).show();