[tests][android] added android O permission prompts

tests/android/app/src/main/java/com/reactnativefirebasedemo/MainActivity.java

@@ -1,15 +1,80 @@
 package com.reactnativefirebasedemo;
 
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.net.Uri;
+import android.os.Build;
+import android.os.Bundle;
+import android.provider.Settings;
+
 import com.facebook.react.ReactActivity;
 
 public class MainActivity extends ReactActivity {
 
-    /**
-     * Returns the name of the main component registered from JavaScript.
-     * This is used to schedule rendering of the component.
-     */
-    @Override
-    protected String getMainComponentName() {
-        return "ReactNativeFirebaseDemo";
+  public static final int PERMISSION_REQ_CODE = 1234;
+  public static final int OVERLAY_PERMISSION_REQ_CODE = 1235;
+
+  String[] perms = {
+    "android.permission.READ_EXTERNAL_STORAGE",
+    "android.permission.WRITE_EXTERNAL_STORAGE"
+  };
+
+  /**
+   * Returns the name of the main component registered from JavaScript.
+   * This is used to schedule rendering of the component.
+   */
+  @Override
+  protected String getMainComponentName() {
+    return "ReactNativeFirebaseDemo";
+  }
+
+  @Override
+  public void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    checkWindowPerms();
+  }
+
+  public void checkWindowPerms() {
+    // Checking if device version > 22 and we need to use new permission model
+    if (Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP_MR1) {
+      // Checking if we can draw window overlay
+      if (!Settings.canDrawOverlays(this)) {
+        // Requesting permission for window overlay(needed for all react-native apps)
+        Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
+          Uri.parse("package:" + getPackageName()));
+        startActivityForResult(intent, OVERLAY_PERMISSION_REQ_CODE);
+      }
+      for (String perm : perms) {
+        // Checking each permission and if denied then requesting permissions
+        if (checkSelfPermission(perm) == PackageManager.PERMISSION_DENIED) {
+          requestPermissions(perms, PERMISSION_REQ_CODE);
+          break;
+        }
+      }
     }
+  }
+
+  // Window overlay permission intent result
+  @Override
+  public void onActivityResult(int requestCode, int resultCode, Intent data) {
+    super.onActivityResult(requestCode, resultCode, data);
+    if (requestCode == OVERLAY_PERMISSION_REQ_CODE) {
+      checkWindowPerms();
+    }
+  }
+
+  // Permission results
+  @Override
+  public void onRequestPermissionsResult(int permsRequestCode, String[] permissions, int[] grantResults) {
+    switch (permsRequestCode) {
+      case PERMISSION_REQ_CODE:
+        // example how to get result of permissions requests (there can be more then one permission dialog)
+        // boolean readAccepted = grantResults[0]==PackageManager.PERMISSION_GRANTED;
+        // boolean writeAccepted = grantResults[1]==PackageManager.PERMISSION_GRANTED;
+        // checking permissions to prevent situation when user denied some permission
+        checkWindowPerms();
+        break;
+
+    }
+  }
 }