added call to canvas.setFocusTraversalKeysEnabled() in initSurface() to

make sure that the TAB key is detected (issue #1967)

core/src/processing/opengl/PGL.java

@@ -604,6 +604,8 @@ public class PGL {
       window.addGLEventListener(listener);
     }
 
+    canvas.setFocusTraversalKeysEnabled(false);
+
     fboLayerCreated = false;
     fboLayerInUse = false;
     firstFrame = true;