NAME

XtAddEventHandler, XtAddRawEventHandler, XtRemoveEventHandler, XtRemoveRawEventHandler, XtInsertEventHandler, XtInsertRawEventHandler - add and remove event handlers

SYNTAX

void XtAddEventHandler(Widget _w, EventMask _e_v_e_n_t___m_a_s_k, Boolean _n_o_n_m_a_s_k_a_b_l_e, XtEventHandler _p_r_o_c, XtPointer _c_l_i_e_n_t___d_a_t_a); void XtAddRawEventHandler(Widget _w, EventMask _e_v_e_n_t___m_a_s_k, Boolean _n_o_n_m_a_s_k_a_b_l_e, XtEventHandler _p_r_o_c, XtPointer _c_l_i_e_n_t___d_a_t_a); void XtRemoveEventHandler(Widget _w, EventMask _e_v_e_n_t___m_a_s_k, Boolean _n_o_n_m_a_s_k_a_b_l_e, XtEventHandler _p_r_o_c, XtPointer _c_l_i_e_n_t___d_a_t_a); void XtRemoveRawEventHandler(Widget _w, EventMask _e_v_e_n_t___m_a_s_k, Boolean _n_o_n_m_a_s_k_a_b_l_e, XtEventHandler _p_r_o_c, XtPointer _c_l_i_e_n_t___d_a_t_a); void XtInsertEventHandler(Widget _w, EventMask _e_v_e_n_t___m_a_s_k, Boolean _n_o_n_m_a_s_k_a_b_l_e, XtEventHandler _p_r_o_c, XtPointer _c_l_i_e_n_t___d_a_t_a, XtListPosition _p_o_s_i_t_i_o_n); void XtInsertRawEventHandler(Widget _w, EventMask _e_v_e_n_t___m_a_s_k, Boolean _n_o_n_m_a_s_k_a_b_l_e, XtEventHandler _p_r_o_c, XtPointer _c_l_i_e_n_t___d_a_t_a, XtListPosition _p_o_s_i_t_i_o_n); typedef enum { XtListHead, XtListTail } XtListPosition;

ARGUMENTS

_c_l_i_e_n_t___d_a_t_a Specifies additional data to be passed to the client's event handler.
_e_v_e_n_t___m_a_s_k Specifies the event mask for which to call or unregister this procedure.
_n_o_n_m_a_s_k_a_b_l_e Specifies a Boolean value that indicates whether this procedure should be
called or removed on the nonmaskable events (_G_r_a_p_h_i_c_s_E_x_p_o_s_e, _N_o_E_x_p_o_s_e, _S_e_l_e_c_t_i_o_n_C_l_e_a_r, _S_e_l_e_c_t_i_o_n_R_e_q_u_e_s_t, _S_e_l_e_c_t_i_o_n_N_o_t_i_f_y, _C_l_i_e_n_t_M_e_s_s_a_g_e, and _M_a_p_p_i_n_g_N_o_t_i_f_y).
_p_r_o_c Specifies the procedure that is to be added or removed.
_w Specifies the widget for which this event handler is being registered.
_p_o_s_i_t_i_o_n Specifies when the event handler is to be called relative to other
previously registered handlers.

DESCRIPTION

The _X_t_A_d_d_E_v_e_n_t_H_a_n_d_l_e_r function registers a procedure with the dispatch mechanism that is to be called when an event that matches the mask occurs on the specified widget. If the procedure is already registered with the same client_data, the specified mask is ORed into the existing mask. If the widget is realized, _X_t_A_d_d_E_v_e_n_t_H_a_n_d_l_e_r calls _X_S_e_l_e_c_t_I_n_p_u_t, if necessary.

The _X_t_A_d_d_R_a_w_E_v_e_n_t_H_a_n_d_l_e_r function is similar to _X_t_A_d_d_E_v_e_n_t_H_a_n_d_l_e_r except that it does not affect the widget's mask and never causes an _X_S_e_l_e_c_t_I_n_p_u_t for its events. Note that the widget might already have those mask bits set because of other nonraw event handlers registered on it.

The _X_t_R_e_m_o_v_e_R_a_w_E_v_e_n_t_H_a_n_d_l_e_r function stops the specified procedure from receiving the specified events. Because the procedure is a raw event handler, this does not affect the widget's mask and never causes a call on _X_S_e_l_e_c_t_I_n_p_u_t.

_X_t_I_n_s_e_r_t_E_v_e_n_t_H_a_n_d_l_e_r is identical to _X_t_A_d_d_E_v_e_n_t_H_a_n_d_l_e_r with the additional _p_o_s_i_t_i_o_n argument. if _p_o_s_i_t_i_o_n is _X_t_L_i_s_t_H_e_a_d, the event handler is registered to that it will be called before any event handlers that were previously registered for the same widget. If _p_o_s_i_t_i_o_n is _X_t_L_i_s_t_T_a_i_l, the event handler is registered to be called after any previously registered event handlers. If the procedure is already registered with the same _c_l_i_e_n_t___d_a_t_a value, the specified mask augments the existing mask and the procedure is repositioned in the list.

_X_t_I_n_s_e_r_t_R_a_w_E_v_e_n_t_H_a_n_d_l_e_r is similar to _X_t_I_n_s_e_r_t_E_v_e_n_t_H_a_n_d_l_e_r except that it does not modify the widget's event mask and never causes an _X_S_e_l_e_c_t_I_n_p_u_t for the specified events. If the procedure is already registered with the same _c_l_i_e_n_t___d_a_t_a value, the specified mask augments the existing mask and the procedure is repositioned in the list.

SEE ALSO

XtAppNextEvent(3Xt), XtBuildEventMask(3Xt)
_X _T_o_o_l_k_i_t _I_n_t_r_i_n_s_i_c_s _- _C _L_a_n_g_u_a_g_e _I_n_t_e_r_f_a_c_e
_X_l_i_b _- _C _L_a_n_g_u_a_g_e _X _I_n_t_e_r_f_a_c_e