cdk_binding man page

cdk_binding — Curses Development Kit Character Binding Capabilities.


cc [ flag ... ] file ... -lcdk [ library ... ]

#include <cdk.h>
    void bindCDKObject (
EObjectType cdkType,
void *object,
chtype key,
BINDFN function,
void *data);
    int checkCDKObjectBind (
EObjectType cdkType,
void *object,
chtype key);
    void cleanCDKObjectBindings (
EObjectType cdkType,
void *object);
    bool isCDKObjectBind (
EObjectType cdkType,
void *object,
chtype key);
    void unbindCDKObject (
EObjectType cdkType,
void *object,
chtype key);
    int getcCDKObject (
CDKOBJS *object);
    int getchCDKObject (
CDKOBJS *object,
boolean *functionKey);


Cdk has the ability to create user definable key bindings. This ability makes Cdk more dynamic and usable for a wide variety of tasks. The following section outlines the binding functions, their use, and their purpose.


creates a key binding between a specific Cdk widget (object) given key (key). The parameter cdkType is of type EObjectType which is one of the following values.

vALPHALIST Alphalist Widgetcdk_alphalist (3)
vBUTTON Button Widget cdk_button (3)
vBUTTONBOX Buttonbox Widget cdk_buttonbox (3)
vCALENDAR Calendar Widget cdk_calendar (3)
vDIALOG Dialog Widget cdk_dialog (3)
vDSCALE DoubleFloat Widget cdk_dscale (3)
vENTRY Entry Widget cdk_entry (3)
vFSCALE Floating Scale Widget cdk_fscale (3)
vFSELECT File Selector Widget cdk_fselect (3)
vFSLIDER Floating Slider Widget cdk_fslider (3)
vGRAPH Graph Widget cdk_graph (3)
vHISTOGRAM Histogram Widget cdk_histogram (3)
vITEMLIST Item List Widget cdk_itemlist (3)
vLABEL Label Widget cdk_label (3)
vMARQUEE Marquee Widget cdk_marquee (3)
vMATRIX Matrix Widget cdk_matrix (3)
vMENTRY Multiple Line Entry Widget cdk_mentry (3)
vMENU Menu Widget cdk_menu (3)
vRADIO Radio List Widget cdk_radio (3)
vSCALE Integer Scale Widget cdk_scale (3)
vSCROLL Scrolling List Widget cdk_scroll (3)
vSELECTION Selection List Widget cdk_selection (3)
vSLIDER Slider Widget cdk_slider (3)
vSWINDOW Scrolling Window Widget cdk_swindow (3)
vTEMPLATE Template Entry Widget cdk_template (3)
vUSCALE Unsigned Scale Widget cdk_uscale (3)
vUSLIDER Unsigned Slider Widget cdk_uslider (3)
vVIEWER Viewer Widget cdk_viewer (3)

The parameter function is the callback function. The parameter data points to data passed to the callback function. The parameter key is the key hit which triggered this callback.


check to see if a binding for the given key exists. If it does, Cdk runs the associated command and returns its value, normally TRUE.  If no binding exists, return FALSE.

The widgets which accept input, e.g., via "inject" methods, use this to check if the injected character is bound to a function. If that returns TRUE, the widget may update its exitType value: if earlyExit value is set (not equal to vNEVER_ACTIVATED), the widget sets exitType to that value.


removes all user defined key bindings from the given widget.


check to see if a binding for the given key exists. If it does return TRUE. If no binding exists, return FALSE.


removes a specific binding to an object. The parameter are the same as for bindCDKObject.


reads a keycode from the given widget. This is depcrecated: use getchCDKObject.


reads a keycode from the given widget. It sets a flag to indicate if the result is a function key. If the keycode has been bound to the special function getcCDKBind, then it will be translated to the value which was given for the binding data. Otherwise, a few special cases are performed:

Key Result
CTRL-N tab
carriage return KEY_ENTER
newline KEY_ENTER

All of the widgets use getchCDKObject internally for consistency.


To help demonstrate how to use the key bindings I will demonstrate a simple dialog box widget with help for each button. The following code segment creates a dialog box and a callback function named dialogHelpCB.


#include <cdk.h>

char *XCursesProgramName="bind_ex";

static int dialogHelpCB (EObjectType cdktype GCC_UNUSED, void *object, void *clientData GCC_UNUSED, chtype key GCC_UNUSED)
   CDKDIALOG *dialog = (CDKDIALOG *)object;
   char *mesg[5];

   /* Check which button we are on. */
   if (dialog->currentButton == 0)
      mesg[0] = "<C></U>Help for </U>Who<!U>.";
      mesg[1] = "<C>When this button is picked the name of the current";
      mesg[2] = "<C>user is displayed on the screen in a popup window.";
      popupLabel (ScreenOf(dialog), mesg, 3);
   else if (dialog->currentButton == 1)
      mesg[0] = "<C></U>Help for </U>Time<!U>.";
      mesg[1] = "<C>When this button is picked the current time is";
      mesg[2] = "<C>displayed on the screen in a popup window.";
      popupLabel (ScreenOf(dialog), mesg, 3);
   else if (dialog->currentButton == 2)
      mesg[0] = "<C></U>Help for </U>Date<!U>.";
      mesg[1] = "<C>When this button is picked the current date is";
      mesg[2] = "<C>displayed on the screen in a popup window.";
      popupLabel (ScreenOf(dialog), mesg, 3);
   else if (dialog->currentButton == 3)
      mesg[0] = "<C></U>Help for </U>Quit<!U>.";
      mesg[1] = "<C>When this button is picked the dialog box is exited.";
      popupLabel (ScreenOf(dialog), mesg, 2);
   return (FALSE);

int main (void)
   /* Declare variables. */
   CDKSCREEN	*cdkscreen;
   CDKDIALOG	*question;
   WINDOW	*cursesWin;
   char		*buttons[40];
   char		*message[40], *info[5], *loginName;
   char		temp[256];
   int		selection;
   time_t	clck;
   struct tm	*currentTime;

   /* Set up CDK. */
   cursesWin = initscr();
   cdkscreen = initCDKScreen (cursesWin);

   /* Start color. */

   /* Set up the dialog box. */
   message[0] = "<C></U>Simple Command Interface";
   message[1] = "Pick the command you wish to run.";
   message[2] = "<C>Press </R>?<!R> for help.";
   buttons[0] = "Who";
   buttons[1] = "Time";
   buttons[2] = "Date";
   buttons[3] = "Quit";

   /* Create the dialog box. */
   question	= newCDKDialog (cdkscreen, CENTER, CENTER,
				message, 3, buttons, 4, A_REVERSE,

   /* Check if we got a null value back. */
   if (question == (CDKDIALOG *)0)
      destroyCDKScreen (cdkscreen);

      /* End curses... */

      /* Spit out a message. */
      printf ("Oops. Can't seem to create the dialog box. Is the window too small?\n");
      exit (1);

   /* Create the key binding. */
   bindCDKObject (vDIALOG, question, '?', dialogHelpCB, 0);

   /* Activate the dialog box. */
   selection = 0;
   while (selection != 3)
      /* Get the users button selection. */
      selection = activateCDKDialog (question, (chtype *)0);

      /* Check the results. */
      if (selection == 0)
	 /* Get the users login name. */
	 info[0] = "<C>     </U>Login Name<!U>     ";
	 loginName = getlogin();
	 if (loginName == (char *)0)
	    strcpy (temp, "<C></R>Unknown");
	     sprintf (temp, "<C><%s>", loginName);
	 info[1] = copyChar (temp);
	 popupLabel (ScreenOf(question), info, 2);
	 freeChar (info[1]);
      else if (selection == 1)
	 /* Print out the time. */
	 currentTime = localtime(&clck);
	 sprintf (temp, "<C>%d:%d:%d", currentTime->tm_hour,
	 info[0] = "<C>   </U>Current Time<!U>   ";
	 info[1] = copyChar (temp);
	 popupLabel (ScreenOf(question), info, 2);
	 freeChar (info[1]);
      else if (selection == 2)
	 /* Print out the date. */
	 currentTime = localtime(&clck);
	 sprintf (temp, "<C>%d/%d/%02d", currentTime->tm_mday,
					currentTime->tm_year % 100);
	 info[0] = "<C>   </U>Current Date<!U>   ";
	 info[1] = copyChar (temp);
	 popupLabel (ScreenOf(question), info, 2);
	 freeChar (info[1]);

   /* Clean up. */
   destroyCDKDialog (question);
   destroyCDKScreen (cdkscreen);
   delwin (cursesWin);
   exit (0);


See Also

cdk(3), cdk_display(3), cdk_screen(3)

Referenced By

cdk(3), cdk_alphalist(3), cdk_button(3), cdk_buttonbox(3), cdk_calendar(3), cdk_dialog(3), cdk_display(3), cdk_dscale(3), cdk_entry(3), cdk_fscale(3), cdk_fselect(3), cdk_fslider(3), cdk_graph(3), cdk_histogram(3), cdk_itemlist(3), cdk_label(3), cdk_marquee(3), cdk_matrix(3), cdk_mentry(3), cdk_menu(3), cdk_misc(3), cdk_objs(3), cdk_position(3), cdk_process(3), cdk_radio(3), cdk_scale(3), cdk_screen(3), cdk_scroll(3), cdk_selection(3), cdk_slider(3), cdk_swindow(3), cdk_template(3), cdk_traverse(3), cdk_uscale(3), cdk_uslider(3), cdk_viewer(3).