added SpreadsheetVersion enum to hold version-specific properties such as maximum number of rows and columns, etc.

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@761723 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/poi/ss/SpreadsheetVersion.java

@@ -0,0 +1,122 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+
+package org.apache.poi.ss;
+
+import org.apache.poi.ss.util.CellReference;
+
+/**
+ * This enum allows spreadsheets from multiple Excel versions to be handled by the common code.
+ * Properties of this enum correspond to attributes of the <i>spreadsheet</i> that are easily
+ * discernable to the user.  It is not intended to deal with low-level issues like file formats.  
+ * <p/>
+ * 
+ * For internal POI use only
+ * 
+ * @author Josh Micich
+ * @author Yegor Kozlov
+ */
+public enum SpreadsheetVersion {
+    /**
+     * Excel97 format aka BIFF8
+     * <ul>
+     * <li>The total number of available columns is 256 (2^8)</li>
+     * <li>The total number of available rows is 64k (2^16)</li>
+     * <li>The maximum number of arguments to a function is 30</li>
+     * <li>Number of conditional format conditions on a cell is 3</li>
+     * </ul>
+     */
+	EXCEL97(0x10000, 0x0100, 30, 3),
+
+    /**
+     * Excel2007
+     *
+     * <ul>
+     * <li>The total number of available columns is 16K (2^14)</li>
+     * <li>The total number of available rows is 1M (2^20)</li>
+     * <li>The maximum number of arguments to a function is 255</li>
+     * <li>Number of conditional format conditions on a cell is unlimited
+     *  (actually limited by available memory in Excel)</li>
+     * <ul>
+     */
+    EXCEL2007(0x100000, 0x4000, 255, Integer.MAX_VALUE);
+
+	private final int _maxRows;
+	private final int _maxColumns;
+	private final int _maxFunctionArgs;
+    private final int _maxCondFormats;
+
+	private SpreadsheetVersion(int maxRows, int maxColumns, int maxFunctionArgs, int maxCondFormats) {
+		_maxRows = maxRows;
+		_maxColumns = maxColumns;
+		_maxFunctionArgs = maxFunctionArgs;
+        _maxCondFormats = maxCondFormats;
+	}
+
+	/**
+	 * @return the maximum number of usable rows in each spreadsheet
+	 */
+	public int getMaxRows() {
+		return _maxRows;
+	}
+
+    /**
+     * @return the last (maximum) valid row index, equals to <code> getMaxRows() - 1 </code>
+     */
+    public int getLastRowIndex() {
+        return _maxRows - 1;
+    }
+
+	/**
+	 * @return the maximum number of usable columns in each spreadsheet
+	 */
+	public int getMaxColumns() {
+		return _maxColumns;
+	}
+
+    /**
+     * @return the last (maximum) valid column index, equals to <code> getMaxColumns() - 1 </code>
+     */
+    public int getLastColumnIndex() {
+        return _maxColumns - 1;
+    }
+
+	/**
+	 * @return the maximum number arguments that can be passed to a multi-arg
+	 *         function (e.g. COUNTIF)
+	 */
+	public int getMaxFunctionArgs() {
+		return _maxFunctionArgs;
+	}
+
+    /**
+     *
+     * @return the maximum number of conditional format conditions on a cell
+     */
+    public int getMaxConditionalFormats() {
+        return _maxCondFormats;
+    }
+
+    /**
+     * 
+     * @return the last valid column index in a ALPHA-26 representation
+     *   ( <code>IV</code> or <code>XFD</code>).
+     */
+    public String getLastColumnName() {
+        return CellReference.convertNumToColString(getLastColumnIndex());
+    }
+}

src/java/org/apache/poi/ss/util/CellReference.java

@@ -388,7 +388,7 @@ public class CellReference {
 	 *  representation.
 	 * eg column #3 -> D
 	 */
-	protected static String convertNumToColString(int col) {
+	public static String convertNumToColString(int col) {
 		// Excel counts column A as the 1st column, we
 		//  treat it as the 0th one
 		int excelColNum = col + 1;

src/testcases/org/apache/poi/ss/TestSpreadsheetVersion.java

@@ -0,0 +1,49 @@
+/* ====================================================================
+   Licensed to the Apache Software Foundation (ASF) under one or more
+   contributor license agreements.  See the NOTICE file distributed with
+   this work for additional information regarding copyright ownership.
+   The ASF licenses this file to You under the Apache License, Version 2.0
+   (the "License"); you may not use this file except in compliance with
+   the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+==================================================================== */
+package org.apache.poi.ss;
+
+import junit.framework.TestCase;
+
+/**
+ * Check that all enum values are properly set
+ *
+ * @author Yegor Kozlov
+ */
+public class TestSpreadsheetVersion extends TestCase {
+
+    public void testExcel97(){
+        SpreadsheetVersion v = SpreadsheetVersion.EXCEL97;
+        assertEquals(1 << 8, v.getMaxColumns());
+        assertEquals(v.getMaxColumns() - 1, v.getLastColumnIndex());
+        assertEquals(1 << 16, v.getMaxRows());
+        assertEquals(v.getMaxRows() - 1, v.getLastRowIndex());
+        assertEquals(30, v.getMaxFunctionArgs());
+        assertEquals(3, v.getMaxConditionalFormats());
+        assertEquals("IV", v.getLastColumnName());
+    }
+
+    public void testExcel2007(){
+        SpreadsheetVersion v = SpreadsheetVersion.EXCEL2007;
+        assertEquals(1 << 14, v.getMaxColumns());
+        assertEquals(v.getMaxColumns() - 1, v.getLastColumnIndex());
+        assertEquals(1 << 20, v.getMaxRows());
+        assertEquals(v.getMaxRows() - 1, v.getLastRowIndex());
+        assertEquals(255, v.getMaxFunctionArgs());
+        assertEquals(Integer.MAX_VALUE, v.getMaxConditionalFormats());
+        assertEquals("XFD", v.getLastColumnName());
+    }
+}