Tango: added asking Motion Tracking permission

app/android/src/com/introlab/rtabmap/RTABMapActivity.java

@@ -35,6 +35,8 @@ import android.widget.LinearLayout;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import com.google.atap.tangoservice.Tango;
+
 // The main activity of the application. This activity shows debug information
 // and a glSurfaceView that renders graphic content.
 public class RTABMapActivity extends Activity implements OnClickListener {
@@ -150,9 +152,27 @@ public class RTABMapActivity extends Activity implements OnClickListener {
     RTABMapLib.openDatabase(mTempDatabasePath);
   }
   
+  @Override
+  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+  	// Check which request we're responding to
+  	if (requestCode == Tango.TANGO_INTENT_ACTIVITYCODE) {
+  		// Make sure the request was successful
+  		if (resultCode == RESULT_CANCELED) {
+  			Toast.makeText(this, "Motion Tracking Permissions Required!",
+  					Toast.LENGTH_SHORT).show();
+  			finish();
+  		}
+  	}
+  }
+
   @Override
   protected void onResume() {
     super.onResume();
+    
+    Log.i(TAG, String.format("onResume()"));
+    
+    if (Tango.hasPermission(this, Tango.PERMISSIONTYPE_MOTION_TRACKING)) {
+
     	mGLView.onResume();
         
         mTotalLoopClosures = 0;
@@ -163,7 +183,19 @@ public class RTABMapActivity extends Activity implements OnClickListener {
     	    mItemSave.setEnabled(false);
     		mItemExport.setEnabled(false);
         }
-   RTABMapLib.onResume();
+
+        if(RTABMapLib.onResume()!=0)
+        {
+        	Toast.makeText(getApplicationContext(), 
+    				String.format("Failed to connect with Tango!"), Toast.LENGTH_SHORT).show();
+        }
+
+    } else {
+    	Log.i(TAG, String.format("Asking for motion tracking permission"));
+        startActivityForResult(
+                Tango.getRequestPermissionIntent(Tango.PERMISSIONTYPE_MOTION_TRACKING),
+                Tango.TANGO_INTENT_ACTIVITYCODE);
+    }
   }
 
   @Override