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 8f79f56

* Add missing imports

sample/src/main/java/example/zxing/CustomScannerActivity.java

@@ -8,6 +8,8 @@
 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 @@ protected void onCreate(Bundle savedInstanceState) {
 
         capture = new CaptureManager(this, barcodeScannerView);
         capture.initializeFromIntent(getIntent(), savedInstanceState);
+        capture.setShowMissingCameraPermissionDialog(false);
         capture.decode();
 
         changeMaskColor(null);
@@ -116,4 +119,9 @@ public void onTorchOn() {
     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);
+    }
 }

sample/src/main/java/example/zxing/MainActivity.java

@@ -128,8 +128,14 @@ protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         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();

zxing-android-embedded/src/com/google/zxing/client/android/Intents.java

@@ -115,6 +115,21 @@ public static final class Scan {
          */
         public static final String TIMEOUT = "TIMEOUT";
 
+        /**
+         * Set the time to finish the scan screen.
+         */
+        public static final String MISSING_CAMERA_PERMISSION = "MISSING_CAMERA_PERMISSION";
+
+        /**
+         * Set the time to finish the scan screen.
+         */
+        public static final String SHOW_MISSING_CAMERA_PERMISSION_DIALOG = "SHOW_MISSING_CAMERA_PERMISSION_DIALOG";
+
+        /**
+         * Set the time to finish the scan screen.
+         */
+        public static final String MISSING_CAMERA_PERMISSION_DIALOG_MESSAGE = "MISSING_CAMERA_PERMISSION_DIALOG_MESSAGE";
+
         /**
          * Whether or not the orientation should be locked when the activity is first started.
          * Defaults to true.

zxing-android-embedded/src/com/google/zxing/integration/android/IntentIntegrator.java

@@ -383,9 +383,10 @@ public static IntentResult parseActivityResult(int resultCode, Intent intent) {
                     rawBytes,
                     orientation,
                     errorCorrectionLevel,
-                    barcodeImagePath);
+                    barcodeImagePath,
+                    intent);
         }
-        return new IntentResult();
+        return new IntentResult(intent);
     }
 
     private static List<String> list(String... values) {

zxing-android-embedded/src/com/google/zxing/integration/android/IntentResult.java

@@ -16,6 +16,8 @@
 
 package com.google.zxing.integration.android;
 
+import android.content.Intent;
+
 /**
  * <p>Encapsulates the result of a barcode scan invoked through {@link IntentIntegrator}.</p>
  *
@@ -29,23 +31,30 @@ public final class IntentResult {
     private final Integer orientation;
     private final String errorCorrectionLevel;
     private final String barcodeImagePath;
+    private final Intent originalIntent;
 
     IntentResult() {
-        this(null, null, null, null, null, null);
+        this(null, null, null, null, null, null, null);
+    }
+
+    IntentResult(Intent intent) {
+        this(null, null, null, null, null, null, intent);
     }
 
     IntentResult(String contents,
                  String formatName,
                  byte[] rawBytes,
                  Integer orientation,
                  String errorCorrectionLevel,
-                 String barcodeImagePath) {
+                 String barcodeImagePath,
+                 Intent originalIntent) {
         this.contents = contents;
         this.formatName = formatName;
         this.rawBytes = rawBytes;
         this.orientation = orientation;
         this.errorCorrectionLevel = errorCorrectionLevel;
         this.barcodeImagePath = barcodeImagePath;
+        this.originalIntent = originalIntent;
     }
 
     /**
@@ -90,6 +99,13 @@ public String getBarcodeImagePath() {
         return barcodeImagePath;
     }
 
+    /**
+     * @return the original intent
+     */
+    public Intent getOriginalIntent() {
+        return originalIntent;
+    }
+
     @Override
     public String toString() {
         int rawBytesLength = rawBytes == null ? 0 : rawBytes.length;
@@ -98,6 +114,7 @@ public String toString() {
             "Raw bytes: (" + rawBytesLength + " bytes)\n" +
             "Orientation: " + orientation + '\n' +
             "EC level: " + errorCorrectionLevel + '\n' +
-            "Barcode image: " + barcodeImagePath + '\n';
+            "Barcode image: " + barcodeImagePath + '\n' +
+            "Original intent: " + originalIntent + '\n';
     }
 }

zxing-android-embedded/src/com/journeyapps/barcodescanner/CaptureManager.java

@@ -4,7 +4,6 @@
 import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.AlertDialog;
-import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.pm.ActivityInfo;
 import android.content.pm.PackageManager;
@@ -13,14 +12,15 @@
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
-import androidx.core.app.ActivityCompat;
-import androidx.core.content.ContextCompat;
 import android.util.Log;
 import android.view.Display;
 import android.view.Surface;
 import android.view.Window;
 import android.view.WindowManager;
 
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+
 import com.google.zxing.ResultMetadataType;
 import com.google.zxing.ResultPoint;
 import com.google.zxing.client.android.BeepManager;
@@ -61,6 +61,9 @@ public class CaptureManager {
     private static final String SAVED_ORIENTATION_LOCK = "SAVED_ORIENTATION_LOCK";
     private boolean returnBarcodeImagePath = false;
 
+    private boolean showDialogIfMissingCameraPermission = true;
+    private String missingCameraPermissionDialogMessage = "";
+
     private boolean destroyed = false;
 
     private InactivityTimer inactivityTimer;
@@ -103,7 +106,9 @@ public void previewStopped() {
 
         @Override
         public void cameraError(Exception error) {
-            displayFrameworkBugMessageAndExit();
+            displayFrameworkBugMessageAndExit(
+                    activity.getString(R.string.zxing_msg_camera_framework_bug)
+            );
         }
 
         @Override
@@ -162,6 +167,13 @@ public void initializeFromIntent(Intent intent, Bundle savedInstanceState) {
                 beepManager.setBeepEnabled(false);
             }
 
+            if (intent.hasExtra(Intents.Scan.SHOW_MISSING_CAMERA_PERMISSION_DIALOG)) {
+                setShowMissingCameraPermissionDialog(
+                        intent.getBooleanExtra(Intents.Scan.SHOW_MISSING_CAMERA_PERMISSION_DIALOG, true),
+                        intent.getStringExtra(Intents.Scan.MISSING_CAMERA_PERMISSION_DIALOG_MESSAGE)
+                );
+            }
+
             if (intent.hasExtra(Intents.Scan.TIMEOUT)) {
                 handler.postDelayed(this::returnResultTimeout, intent.getLongExtra(Intents.Scan.TIMEOUT, 0L));
             }
@@ -234,9 +246,7 @@ private void openCameraWithPermission() {
                     new String[]{Manifest.permission.CAMERA},
                     cameraPermissionReqCode);
             askedPermission = true;
-        } else {
-            // Wait for permission result
-        }
+        } // else wait for permission result
     }
 
     /**
@@ -253,8 +263,13 @@ public void onRequestPermissionsResult(int requestCode, String permissions[], in
                 // permission was granted
                 barcodeView.resume();
             } else {
-                // TODO: display better error message.
-                displayFrameworkBugMessageAndExit();
+                setMissingCameraPermissionResult();
+
+                if (showDialogIfMissingCameraPermission) {
+                    displayFrameworkBugMessageAndExit(missingCameraPermissionDialogMessage);
+                } else {
+                    closeAndFinish();
+                }
             }
         }
     }
@@ -369,6 +384,12 @@ protected void closeAndFinish() {
         inactivityTimer.cancel();
     }
 
+    private void setMissingCameraPermissionResult() {
+        Intent intent = new Intent(Intents.Scan.ACTION);
+        intent.putExtra(Intents.Scan.MISSING_CAMERA_PERMISSION, true);
+        activity.setResult(Activity.RESULT_CANCELED, intent);
+    }
+
     protected void returnResultTimeout() {
         Intent intent = new Intent(Intents.Scan.ACTION);
         intent.putExtra(Intents.Scan.TIMEOUT, true);
@@ -382,25 +403,20 @@ protected void returnResult(BarcodeResult rawResult) {
         closeAndFinish();
     }
 
-    protected void displayFrameworkBugMessageAndExit() {
+    protected void displayFrameworkBugMessageAndExit(String message) {
         if (activity.isFinishing() || this.destroyed || finishWhenClosed) {
             return;
         }
+
+        if (message.isEmpty()) {
+            message = activity.getString(R.string.zxing_msg_camera_framework_bug);
+        }
+
         AlertDialog.Builder builder = new AlertDialog.Builder(activity);
         builder.setTitle(activity.getString(R.string.zxing_app_name));
-        builder.setMessage(activity.getString(R.string.zxing_msg_camera_framework_bug));
-        builder.setPositiveButton(R.string.zxing_button_ok, new DialogInterface.OnClickListener() {
-            @Override
-            public void onClick(DialogInterface dialog, int which) {
-                finish();
-            }
-        });
-        builder.setOnCancelListener(new DialogInterface.OnCancelListener() {
-            @Override
-            public void onCancel(DialogInterface dialog) {
-                finish();
-            }
-        });
+        builder.setMessage(message);
+        builder.setPositiveButton(R.string.zxing_button_ok, (dialog, which) -> finish());
+        builder.setOnCancelListener(dialog -> finish());
         builder.show();
     }
 
@@ -411,4 +427,29 @@ public static int getCameraPermissionReqCode() {
     public static void setCameraPermissionReqCode(int cameraPermissionReqCode) {
         CaptureManager.cameraPermissionReqCode = cameraPermissionReqCode;
     }
+
+    /**
+     * If set to true, shows the default error dialog if camera permission is missing.
+     * <p>
+     * If set to false, instead the capture manager just finishes.
+     * <p>
+     * In both cases, the activity result is set to {@link Intents.Scan#MISSING_CAMERA_PERMISSION}
+     * and cancelled
+     */
+    public void setShowMissingCameraPermissionDialog(boolean visible) {
+        setShowMissingCameraPermissionDialog(visible, "");
+    }
+
+    /**
+     * If set to true, shows the specified error dialog message if camera permission is missing.
+     * <p>
+     * If set to false, instead the capture manager just finishes.
+     * <p>
+     * In both cases, the activity result is set to {@link Intents.Scan#MISSING_CAMERA_PERMISSION}
+     * and cancelled
+     */
+    public void setShowMissingCameraPermissionDialog(boolean visible, String message) {
+        showDialogIfMissingCameraPermission = visible;
+        missingCameraPermissionDialogMessage = message != null ? message : "";
+    }
 }