Added Christian's Centre Across Selection code.

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@948709 13f79535-47bb-0310-9956-ffa450edef68

src/examples/src/org/apache/poi/xssf/usermodel/examples/AligningCells.java

@@ -14,25 +14,33 @@
 See the License for the specific language governing permissions and
 limitations under the License.
 ==================================================================== */
-
 package org.apache.poi.xssf.usermodel.examples;
 
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import org.apache.poi.ss.usermodel.*;
 import org.apache.poi.xssf.usermodel.*;
+import org.openxmlformats.schemas.spreadsheetml.x2006.main.impl.CTRowImpl;
 
 /**
  * Shows how various alignment options work.
+ *
+ * Modified by Cristian Petrula, Romania on May 26, 2010
+ * New method was added centerAcrossSelection to center a column content over 
+ * one selection using ALIGN_CENTER_SELECTION
+ * To create this method example was change for XSSF only and the previous
+ * AligningCells.java example has been moved into the SS examples folder.
  */
 public class AligningCells {
 
     public static void main(String[] args) throws IOException {
-        Workbook wb = new XSSFWorkbook(); //or new HSSFWorkbook();
+        XSSFWorkbook wb = new XSSFWorkbook();
 
-        Sheet sheet = wb.createSheet();
+        XSSFSheet sheet = wb.createSheet();
-        Row row = sheet.createRow((short) 2);
+        XSSFRow row = sheet.createRow((short) 2);
         row.setHeightInPoints(30);
         for (int i = 0; i < 8; i++) {
             //column width is set in units of 1/256th of a character width
@@ -47,6 +55,10 @@ public class AligningCells {
         createCell(wb, row, (short) 5, XSSFCellStyle.ALIGN_LEFT, XSSFCellStyle.VERTICAL_TOP);
         createCell(wb, row, (short) 6, XSSFCellStyle.ALIGN_RIGHT, XSSFCellStyle.VERTICAL_TOP);
 
+        //center text over B4, C4, D4
+        row = sheet.createRow((short) 3);
+        centerAcrossSelection(wb, row, (short) 1, (short) 3, XSSFCellStyle.VERTICAL_CENTER);
+
         // Write the output to a file
         FileOutputStream fileOut = new FileOutputStream("xssf-align.xlsx");
         wb.write(fileOut);
@@ -61,12 +73,57 @@ public class AligningCells {
      * @param column the column number to create the cell in
      * @param halign the horizontal alignment for the cell.
      */
-    private static void createCell(Workbook wb, Row row, short column, short halign, short valign) {
+    private static void createCell(XSSFWorkbook wb, XSSFRow row, short column,
-        Cell cell = row.createCell(column);
+            short halign, short valign) {
+        XSSFCell cell = row.createCell(column);
         cell.setCellValue(new XSSFRichTextString("Align It"));
         CellStyle cellStyle = wb.createCellStyle();
         cellStyle.setAlignment(halign);
         cellStyle.setVerticalAlignment(valign);
         cell.setCellStyle(cellStyle);
     }
+
+    /**
+     * Center a text over multiple columns using ALIGN_CENTER_SELECTION
+     *
+     * @param wb the workbook
+     * @param row the row to create the cell in
+     * @param start_column  the column number to create the cell in and where the selection starts
+     * @param end_column    the column number where the selection ends
+     * @param valign the horizontal alignment for the cell.
+     *
+     * @author Cristian Petrula, Romania
+     */
+    private static void centerAcrossSelection(XSSFWorkbook wb, XSSFRow row,
+            short start_column, short end_column, short valign) {
+
+        // Create cell style with ALIGN_CENTER_SELECTION
+        XSSFCellStyle cellStyle = wb.createCellStyle();
+        cellStyle.setAlignment(XSSFCellStyle.ALIGN_CENTER_SELECTION);
+        cellStyle.setVerticalAlignment(valign);
+
+        // Create cells over the selected area
+        for (int i = start_column; i <= end_column; i++) {
+            XSSFCell cell = row.createCell(i);
+            cell.setCellStyle(cellStyle);
+        }
+
+        // Set value to the first cell
+        XSSFCell cell = row.getCell(start_column);
+        cell.setCellValue(new XSSFRichTextString("Align It"));
+
+        // Make the selection
+        CTRowImpl ctRow = (CTRowImpl) row.getCTRow();
+        List spanList = new ArrayList();
+
+        // Add object with format start_coll:end_coll. For example 1:3 will span from
+        // cell 1 to cell 3, where the column index starts with 0
+        //
+        // You can add multiple spans for one row
+        Object span = start_column + ":" + end_column;
+        spanList.add(span);
+
+        //add spns to the row
+        ctRow.setSpans(spanList);
+    }
 }