* @see #setFillForegroundColor(short)
* @param fp fill pattern (set to {@link org.apache.poi.ss.usermodel.CellStyle#SOLID_FOREGROUND} to fill w/foreground color)
*/
public void setFillPattern(short fp) {
CTFill ct = getCTFill();
CTPatternFill ptrn = ct.isSetPatternFill() ? ct.getPatternFill() : ct.addNewPatternFill();
if(fp == NO_FILL && ptrn.isSetPatternType()) ptrn.unsetPatternType();
else ptrn.setPatternType(STPatternType.Enum.forInt(fp + 1));
int idx = _stylesSource.putFill(new XSSFCellFill(ct));
_cellXf.setFillId(idx);
_cellXf.setApplyFill(true);