connect(ui.x_value, SIGNAL(valueChanged(int)), this, SLOT(widgetHasChanged()));
connect(ui.y_value, SIGNAL(valueChanged(int)), this, SLOT(widgetHasChanged()));
connect(ui.x_value, SIGNAL(valueChanged(int)), this, SLOT(widgetHasChanged()));
connect(ui.y_value, SIGNAL(valueChanged(int)), this, SLOT(widgetHasChanged()));