add copy constructor

git-svn-id: https://svn.apache.org/repos/asf/poi/branches/ss_border_property_template@1748072 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -197,6 +197,30 @@ public final class BorderPropertyTemplate {
         _propertyTemplate = new HashMap<CellAddress, Map<String, Object>>();
     }
 
+    /**
+     * Copy constructor
+     *
+     * Create a template from an existing template.
+     * Changes made to either template do not affect the other template.
+     * @since 3.15 beta 2
+     */
+    public BorderPropertyTemplate(BorderPropertyTemplate prototype) {
+        this();
+        // deep copy the _propertyTemplate map from prototype
+        for (Entry<CellAddress, Map<String, Object>> other : prototype._propertyTemplate.entrySet()) {
+            CellAddress cell = other.getKey();
+            Map<String, Object> otherMap = other.getValue();
+
+            // The keys in otherMap are immutable Strings
+            // The values in otherMap are immutable Shorts or BorderStyles
+            // Therefore, this map's data cannot be modified through protoype
+            Map<String, Object> map = new HashMap<String, Object>(otherMap);
+
+            // CellAddress is an immutable class, therefore it is ok to reference the same instance
+            _propertyTemplate.put(cell, map);
+        }
+    }
+
     /**
      * Add a group of cell borders for a cell range to the border property template.
      * The borders are not applied to the cells at this time, just the template is drawn

src/testcases/org/apache/poi/ss/util/TestBorderPropertyTemplate.java

@@ -18,6 +18,7 @@
 package org.apache.poi.ss.util;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 
 import java.io.IOException;
 
@@ -43,6 +44,37 @@ public final class TestBorderPropertyTemplate {
     private static final short BLUE = IndexedColors.BLUE.getIndex();
     private static final short AUTOMATIC = IndexedColors.AUTOMATIC.getIndex();
 
+    @Test
+    public void createTemplateFromExisting() throws IOException {
+        CellRangeAddress a1a1 = new CellRangeAddress(0, 0, 0, 0); //A1:A1
+        CellRangeAddress b2b2 = new CellRangeAddress(1, 1, 1, 1); //B2:B2
+        CellRangeAddress c3c3 = new CellRangeAddress(2, 2, 2, 2); //C3:C3
+        CellAddress a1 = new CellAddress(0, 0); //A1
+        CellAddress b2 = new CellAddress(1, 1); //B2
+        CellAddress c3 = new CellAddress(2, 2); //C3
+
+        BorderPropertyTemplate pt1 = new BorderPropertyTemplate();
+        pt1.drawBorders(a1a1, BorderStyle.THIN, RED, BorderExtent.TOP);
+
+        // check to make sure borders were copied
+        BorderPropertyTemplate pt2 = new BorderPropertyTemplate(pt1);
+        assertEquals(1, pt2.getNumBorders(a1));
+        assertThin(pt2.getTemplateProperty(a1, CellUtil.BORDER_TOP));
+        assertRed(pt2.getTemplateProperty(a1, CellUtil.TOP_BORDER_COLOR));
+
+        // Changes to original template should not affect copied template.
+        pt1.drawBorders(b2b2, BorderStyle.THIN, RED, BorderExtent.TOP);
+        assertEquals(0, pt2.getNumBorders(b2));
+        assertNull(pt2.getTemplateProperty(b2, CellUtil.BORDER_TOP));
+        assertNull(pt2.getTemplateProperty(b2, CellUtil.TOP_BORDER_COLOR));
+
+        // Changes to copied template should not affect original template
+        pt2.drawBorders(c3c3, BorderStyle.THIN, RED, BorderExtent.TOP);
+        assertEquals(0, pt1.getNumBorders(c3));
+        assertNull(pt1.getTemplateProperty(c3, CellUtil.BORDER_TOP));
+        assertNull(pt1.getTemplateProperty(c3, CellUtil.TOP_BORDER_COLOR));
+    }
+
     @Test
     public void getNumBorders() throws IOException {
         CellRangeAddress a1a1 = new CellRangeAddress(0, 0, 0, 0); //A1:A1