Function TkTextRedrawRegion

micropolis-activity/src/tk/tktxdisp.c:1461–1510

ARGSUSED */

(textPtr, x, y, width, height)

 *	This procedure is invoked to schedule a redisplay for a given
 *	region of a text widget.  The redisplay itself may not occur
 *	immediately:  it's scheduled as a when-idle handler.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Information will eventually be redrawn on the screen.
 *
 *----------------------------------------------------------------------
 */

	/* ARGSUSED */
void
TkTextRedrawRegion(textPtr, x, y, width, height)
    TkText *textPtr;		/* Widget record for text widget. */
    int x, y;			/* Coordinates of upper-left corner of area
				 * to be redrawn, in pixels relative to
				 * textPtr's window. */
    int width, height;		/* Width and height of area to be redrawn. */
{
    register DLine *dlPtr;
    DInfo *dInfoPtr = textPtr->dInfoPtr;
    int maxY;

    /*
     * Find all lines that overlap the given region and mark them for
     * redisplay.
     */

    maxY = y + height;
    for (dlPtr = dInfoPtr->dLinePtr; dlPtr != NULL;
	    dlPtr = dlPtr->nextPtr) {
	if (((dlPtr->y + dlPtr->height) > y) && (dlPtr->y < maxY)) {
	    dlPtr->oldY = -1;
	}
    }
    if (dInfoPtr->topOfEof < maxY) {
	dInfoPtr->topOfEof = maxY;
    }

    /*
     * Schedule the redisplay operation if there isn't one already
     * scheduled.
     */

    if (!(dInfoPtr->flags & REDRAW_PENDING)) {
	dInfoPtr->flags |= REDRAW_PENDING;
//	Tk_DoWhenIdle(DisplayText, (ClientData) textPtr);
	assert(textPtr->updateTimerToken == NULL);
	if (textPtr->updateTimerToken == NULL) {
	    textPtr->updateTimerToken =
	      Tk_CreateTimerHandler(
		TextUpdateTime,