Пример # 1
public void mouseClicked(MouseEvent e) {
if (isShowParameters)
isShowParameters = false;
else
isShowParameters = true;
ParametersWindows.getInstance().setVisible(isShowParameters);
}
Пример № 2
public void mouseClicked(MouseEvent e) {
isShowParameters = !isShowParameters;
ParametersWindows.getInstance().setVisible(isShowParameters);
}