_x_offset->Bind (wxEVT_SPINCTRL, boost::bind (&TextPanel::x_offset_changed, this));
_y_offset->Bind (wxEVT_SPINCTRL, boost::bind (&TextPanel::y_offset_changed, this));
_x_scale->Bind (wxEVT_SPINCTRL, boost::bind (&TextPanel::x_scale_changed, this));
_x_offset->Bind (wxEVT_SPINCTRL, boost::bind (&TextPanel::x_offset_changed, this));
_y_offset->Bind (wxEVT_SPINCTRL, boost::bind (&TextPanel::y_offset_changed, this));
_x_scale->Bind (wxEVT_SPINCTRL, boost::bind (&TextPanel::x_scale_changed, this));