Fix bug 38921, where HSSFPalette.findSimilar() wasn't working properly, and add tests for it

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@629755 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/content/xdocs/changes.xml

@@ -36,6 +36,7 @@
 
 		<!-- Don't forget to update status.xml too! -->
         <release version="3.1-beta1" date="2008-??-??">
+           <action dev="POI-DEVELOPERS" type="fix">38921 - Have HSSFPalette.findSimilar() work properly</action>
            <action dev="POI-DEVELOPERS" type="fix">44456 - Fix the contrib SViewer / SViewerPanel to not fail on sheets with missing rows</action>
            <action dev="POI-DEVELOPERS" type="fix">44403 - Further support for unusual, but valid, arguments to the Mid function</action>
            <action dev="POI-DEVELOPERS" type="fix">44410 - Support for whole-column ranges, such as C:C, in formula strings and the formula evaluator</action>

src/documentation/content/xdocs/status.xml

@@ -33,6 +33,7 @@
 	<!-- Don't forget to update changes.xml too! -->
     <changes>
         <release version="3.1-beta1" date="2008-??-??">
+           <action dev="POI-DEVELOPERS" type="fix">38921 - Have HSSFPalette.findSimilar() work properly</action>
            <action dev="POI-DEVELOPERS" type="fix">44456 - Fix the contrib SViewer / SViewerPanel to not fail on sheets with missing rows</action>
            <action dev="POI-DEVELOPERS" type="fix">44403 - Further support for unusual, but valid, arguments to the Mid function</action>
            <action dev="POI-DEVELOPERS" type="fix">44410 - Support for whole-column ranges, such as C:C, in formula strings and the formula evaluator</action>

src/java/org/apache/poi/hssf/usermodel/HSSFPalette.java

@@ -99,9 +99,11 @@ public class HSSFPalette
         for (short i = (short) PaletteRecord.FIRST_COLOR_INDEX; b != null;
             b = palette.getColor(++i))
         {
-            int colorDistance = red - b[0] + green - b[1] + blue - b[2];
+            int colorDistance = Math.abs(red - b[0]) + 
+            	Math.abs(green - b[1]) + Math.abs(blue - b[2]);
             if (colorDistance < minColorDistance)
             {
+                minColorDistance = colorDistance;
                 result = getColor(i);
             }
         }

src/testcases/org/apache/poi/hssf/usermodel/TestHSSFPalette.java

@@ -160,6 +160,49 @@ public class TestHSSFPalette extends TestCase
         assertEquals("FFFF:0:FFFF", p.getColor((short)14).getHexString());
     }
     
+    public void testFindSimilar() throws Exception {
+    	HSSFWorkbook book = new HSSFWorkbook();
+    	HSSFPalette p = book.getCustomPalette();
+    	
+    	
+    	// Add a few edge colours in
+    	p.setColorAtIndex((short)8, (byte)-1, (byte)0, (byte)0);
+    	p.setColorAtIndex((short)9, (byte)0, (byte)-1, (byte)0);
+    	p.setColorAtIndex((short)10, (byte)0, (byte)0, (byte)-1);
+    	
+    	// And some near a few of them
+    	p.setColorAtIndex((short)11, (byte)-1, (byte)2, (byte)2);
+    	p.setColorAtIndex((short)12, (byte)-2, (byte)2, (byte)10);
+    	p.setColorAtIndex((short)13, (byte)-4, (byte)0, (byte)0);
+    	p.setColorAtIndex((short)14, (byte)-8, (byte)0, (byte)0);
+    	
+    	assertEquals(
+    			"FFFF:0:0", p.getColor((short)8).getHexString()
+    	);
+    	
+    	// Now check we get the right stuff back
+    	assertEquals(
+    			p.getColor((short)8).getHexString(), 
+    			p.findSimilarColor((byte)-1, (byte)0, (byte)0).getHexString()
+    	);
+    	assertEquals(
+    			p.getColor((short)8).getHexString(), 
+    			p.findSimilarColor((byte)-2, (byte)0, (byte)0).getHexString()
+    	);
+    	assertEquals(
+    			p.getColor((short)8).getHexString(), 
+    			p.findSimilarColor((byte)-1, (byte)1, (byte)0).getHexString()
+    	);
+    	assertEquals(
+    			p.getColor((short)11).getHexString(), 
+    			p.findSimilarColor((byte)-1, (byte)2, (byte)1).getHexString()
+    	);
+    	assertEquals(
+    			p.getColor((short)12).getHexString(), 
+    			p.findSimilarColor((byte)-1, (byte)2, (byte)10).getHexString()
+    	);
+    }
+    
     /**
      * Verifies that the generated gnumeric-format string values match the
      * hardcoded values in the HSSFColor default color palette