Scroll in CDK

[Fu Steve X]

Tom,

A couple of things about the Scroll widget are illustrated in the test program at the end of this message. The test program is based on the sample scroll_ex.c.

1. I invoke the function deleteCDKScrollItem( ) to delete an item then re-draw the Scroll. The numbers do not get re-set when re-drawing the Scroll if the Boolean numbers is turned on, They are now 1,2,4... since 3 is deleted.

2. The following line is needed to avoid a core dump when deleting all items and reset the scroll with new items.
        scrollList->item = 0;
I think it is because the function call CDKfreeChtypes at line #846 in createCDKScrollItemList. Not sure why it is needed to be freed. If it is really needed, probably the scrollp->item should be set to NULL in deleteCDKScrollItem when the listSize==0.

Thanks.

Steve

---------------------------------   cut here ------------------------------------------------------------------

/* $Id: scroll_ex.c,v 1.16 2004/08/28 01:02:30 tom Exp $ */

#include <cdk.h>

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

/*
 * This program demonstrates the Cdk scrolling list widget.
 */
int main(int argc, char **argv)
{
   /* Declare variables. */
   CDKSCREEN *cdkscreen         = 0;
   CDKSCROLL *scrollList        = 0;
   WINDOW *cursesWin            = 0;
   char *title                  = "<C></5>Pick a file";
   char **item                  = 0;
   char *mesg[5], temp[256];
   int selection, count, i;

   CDK_PARAMS params;

   CDKparseParams(argc, argv, &params, CDK_CLI_PARAMS);

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

   /* Set up CDK Colors. */
   initCDKColor();

   /* Use the current diretory list to fill the radio list. */
   count = CDKgetDirectoryContents (".", &item);

   /* Create the scrolling list. */
   scrollList = newCDKScroll (cdkscreen,
                              CDKparamValue(&params, 'X', CENTER),
                              CDKparamValue(&params, 'Y', CENTER),
                              RIGHT,
                              CDKparamValue(&params, 'H', 10),
                              CDKparamValue(&params, 'W', 50),
                              title, item, count,
                              TRUE,
                              A_REVERSE,
                              CDKparamValue(&params, 'N', TRUE),
                              CDKparamValue(&params, 'S', FALSE));

   /* Is the scrolling list null? */
   if (scrollList == 0)
   {
      /* Exit CDK. */
      destroyCDKScreen (cdkscreen);
      endCDK();

      /* Print out a message and exit. */
      printf ("Oops. Could not make scrolling list. Is the window too small?\n");
      exit (EXIT_FAILURE);
   }

   drawCDKScroll (scrollList, 1);
       
   sleep (2);
        /*
        * delete one item
        */
        deleteCDKScrollItem(scrollList, 2);
   drawCDKScroll (scrollList, 1);

   sleep (2);
        /*
        * delete all items
        */

        count = scrollList->listSize;

        for (i = 0; i<count; i++ )
        {
                if ( item[i] ) {
                         free ( item[i] );
                }
        deleteCDKScrollItem(scrollList, count-i-1);
        }

/*
* needed to avoid being free again.
*/
        scrollList->item = 0;

   /* Use the parent of current diretory list to fill the radio list. */
   count = CDKgetDirectoryContents ("..", &item);

        setCDKScrollItems(scrollList, item, count, TRUE);

   drawCDKScroll (scrollList, 1);
   setCDKScrollPosition (scrollList, 0);

   /* Activate the scrolling list. */
   selection = activateCDKScroll (scrollList, 0);

   /* Determine how the widget was exited. */
   if (scrollList->exitType == vESCAPE_HIT)
   {
      mesg[0] = "<C>You hit escape. No file selected.";
      mesg[1] = "",
      mesg[2] = "<C>Press any key to continue.";
      popupLabel (cdkscreen, mesg, 3);
   }
   else if (scrollList->exitType == vNORMAL)
   {
      mesg[0] = "<C>You selected the following file";
      sprintf (temp, "<C>%.*s", (int)(sizeof(temp) - 20), item[selection]);
      mesg[1] = copyChar (temp);
      mesg[2] = "<C>Press any key to continue.";
      popupLabel (cdkscreen, mesg, 3);
      freeChar (mesg[1]);
   }

   /* Clean up. */
   CDKfreeStrings (item);
   destroyCDKScroll (scrollList);
   destroyCDKScreen (cdkscreen);
   endCDK();
   exit (EXIT_SUCCESS);
}