cdk_binding(3)

NAME
cdk_binding - Curses Development Kit Character Binding Capabilities.

SYNOPSIS

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);

DESCRIPTION
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.

bindCDKObject
    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.

EObjectType_Value | Corresponding_Widget | Widget_Manual_Page
vALPHALIST | Alphalist Widget | cdk_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.

checkCDKObjectBind
    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.

cleanCDKObjectBindings
    removes all user defined key bindings from the given widget.

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

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

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

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-A | KEY_HOME
    CTRL-B | KEY_LEFT
    CTRL-E | KEY_END
    CTRL-F | KEY_RIGHT
    CTRL-N | tab
    CTRL-P | KEY_BTAB
    DEL | KEY_DC
    backspace | KEY_BACKSPACE
    carriage return | KEY_ENTER
    newline | KEY_ENTER

All of the widgets use getchCDKObject internally for consistency.

EXAMPLE
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>

#ifdef HAVE_XCURSES
char *XCursesProgramName="bind_ex";
#endif

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. */
   initCDKColor();

   /* 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,
				TRUE, TRUE, FALSE);

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

      /* End curses... */
      endCDK();

      /* 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");
	 }
	 else
	 {
	     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. */
	 time(&clck);
	 currentTime = localtime(&clck);
	 sprintf (temp, "<C>%d:%d:%d", currentTime->tm_hour,
					currentTime->tm_min,
					currentTime->tm_sec);
	 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. */
	 time(&clck);
	 currentTime = localtime(&clck);
	 sprintf (temp, "<C>%d/%d/%02d", currentTime->tm_mday,
					currentTime->tm_mon,
					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);
   endCDK();
   exit (0);
}
________________________________________

SEE ALSO
cdk(3), cdk_display(3), cdk_screen(3)