rem: WArea totalArea, usableArea = scr->totalUsableArea;
add: WArea totalArea, usableArea;
context: wGetUsableAreaForHead(WScreen *scr, int head, WArea *totalAreaPtr){    WArea totalArea, usableArea = scr->totalUsableArea;    WMRect rect = wGetRectForHead(scr, head);    totalArea.x1 = rect.pos.x;    totalArea.y1 = rect.pos.y;    totalArea.x2 = totalArea.x1 + rect.size.width;    totalArea.y2 = totalArea.y1 + rect.size.height;    if (totalAreaPtr != NULL) *totalAreaPtr = totalArea;    usableArea.x1 = WMAX(totalArea.x1, usableArea.x1);    usableArea.y1 = WMAX(totalArea.y1, usableArea.y1);    usableArea.x2 = WMIN(totalArea.x2, usableArea.x2);    usableArea.y2 = WMIN(totalArea.y2, usableArea.y2);    return usableArea;}