Using Segment Editing Functions

You can use editing functions to:

• Create a chained-dynamic segment
  
• Delete a segment
  
• Edit the contents of a segment

The following figure shows an example of how to edit the contents of a segment. In the example, three elements are inserted. The steps required for this task are as follows:

• Set the segment edit mode to insert or replace using GpiSetEditMode.

• Set the drawing mode to retain.

• Open the segment using GpiOpenSegment, passing it the segment identifier from a previous correlation operation.

• Set the element pointer so that it points to the position at which you will replace or insert an element using GpiSetElementPointer, GpiSetElementPointerAtLabel or GpiOffsetElementPointer.

• Insert the new primitives using any of the Gpi primitive functions.

• Delete any unnecessary primitives using GpiDeleteElement or GpiDeleteElementRange.

• Close the segment using GpiCloseSegment.

#define INCL_GPISEGEDITING#define INCL_GPICONTROL
#include <os2.h>
void fncESEG01(void){
    HPS hps;
    LONG idNonChained;
    POINTL ptl;

    GpiSetEditMode(hps, SEGEM_INSERT);

    GpiSetDrawingMode(hps, DM_RETAIN);

    GpiOpenSegment(hps, idNonChained);

    GpiSetElementPointer(hps, 0L);

    GpiSetColor(hps, CLR_YELLOW);

    ptl.x = 100; ptl.y = 100;

    GpiMove(hps, &ptl);

    ptl.x = 150; ptl.y = 150;

    GpiBox(hps, DRO_OUTLINE, &ptl, 40L, 40L);

    ptl.x = 30; ptl.y = 30;

    GpiMove(hps, &ptl);

    GpiSetElementPointer(hps, 5L);

    GpiDeleteElement(hps);

    GpiCloseSegment(hps);

} /* fncESEG01 */

The first element inserted contains the graphics order that sets the color to yellow; the second element moves the current position; and the third element draws an outlined box with rounded corners. After the three elements are inserted, the code deletes the element at position 5 in the segment (this element was previously at positions 1 and 2).