Method windowClosing

app/src/processing/app/AbstractMonitor.java:31–39

(WindowEvent event)

    addWindowListener(new WindowAdapter() {
      @Override
      public void windowClosing(WindowEvent event) {
        try {
          closed = true;
          close();
        } catch (Exception e) {
          // ignore
        }
      }
    });

    // obvious, no?