Function DisplayMessage

micropolis-activity/src/tk/tkmsg.c:585–681

(clientData)

 *	None.
 *
 * Side effects:
 *	Information appears on the screen.
 *
 *--------------------------------------------------------------
 */

static void
DisplayMessage(clientData)
    ClientData clientData;	/* Information about window. */
{
    register Message *msgPtr = (Message *) clientData;
    register Tk_Window tkwin = msgPtr->tkwin;
    char *p;
    int x, y, lineLength, numChars, charsLeft;

    msgPtr->flags &= ~REDRAW_PENDING;
    if ((msgPtr->tkwin == NULL) || !Tk_IsMapped(tkwin)) {
	return;
    }
    if (msgPtr->flags & CLEAR_NEEDED) {
	XClearWindow(Tk_Display(tkwin), Tk_WindowId(tkwin));
	msgPtr->flags &= ~CLEAR_NEEDED;
    }

    /*
     * Compute starting y-location for message based on message size
     * and anchor option.
     */

    switch (msgPtr->anchor) {
	case TK_ANCHOR_NW: case TK_ANCHOR_N: case TK_ANCHOR_NE:
	    y = msgPtr->borderWidth + msgPtr->padY;
	    break;
	case TK_ANCHOR_W: case TK_ANCHOR_CENTER: case TK_ANCHOR_E:
	    y = (Tk_Height(tkwin) - msgPtr->msgHeight)/2;
	    break;
	default:
	    y = Tk_Height(tkwin) - msgPtr->borderWidth - msgPtr->padY
		    - msgPtr->msgHeight;
	    break;
    }
    y += msgPtr->fontPtr->ascent;

    /*
     * Work through the string to display one line at a time.
     * Display each line in three steps.  First compute the
     * line's width, then figure out where to display the
     * line to justify it properly, then display the line.
     */

    for (p = msgPtr->string, charsLeft = msgPtr->numChars; *p != 0;
	    y += msgPtr->fontPtr->ascent + msgPtr->fontPtr->descent) {
	if (*p == '\n') {
	    p++;
	    charsLeft--;
	    continue;
	}
	numChars = TkMeasureChars(msgPtr->fontPtr, p, charsLeft, 0,