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

1 files changed, 8 insertions, 2 deletions

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();