Parse Dash Pattern

src/com/mxgraph/canvas/mxGraphicsCanvas2D.java

@@ -352,15 +352,7 @@ public void setDashPattern(String value)
 	{
 		if (value != null && value.length() > 0)
 		{
-			String[] tokens = value.split(" ");
-			float[] dashpattern = new float[tokens.length];
-
-			for (int i = 0; i < tokens.length; i++)
-			{
-				dashpattern[i] = (float) (Float.parseFloat(tokens[i]));
-			}
-
-			state.dashPattern = dashpattern;
+			state.dashPattern = mxUtils.parseDashPattern(value);
 		}
 	}
 

src/com/mxgraph/util/mxUtils.java

@@ -1715,6 +1715,45 @@ public static String getHexColorString(Color color)
 	{
 		return mxHtmlColor.getHexColorString(color);
 	}
+
+	/**
+	 * Convert a string representing a dash pattern into a float array.
+	 * A valid dash pattern is a string of dash widths (floating point values)
+	 * separated by space characters.
+	 * 
+	 * @param dashPatternString
+	 *            the string representing the dash pattern
+	 * @return float[]
+	 * @exception NumberFormatException
+	 *                if any of the dash widths cannot be interpreted as a
+	 *                floating point number
+	 */
+	public static float[] parseDashPattern(String dashPatternString)
+			throws NumberFormatException
+	{
+		if (dashPatternString != null && dashPatternString.length() > 0)
+		{
+			String[] tokens = dashPatternString.split(" ");
+			float[] dashpattern = new float[tokens.length];
+			float dashWidth;
+
+			for (int i = 0; i < tokens.length; i++)
+			{
+				dashWidth = (float) (Float.parseFloat(tokens[i]));
+				if (dashWidth > 0)
+				{
+					dashpattern[i] = dashWidth;
+				}
+				else
+				{
+					throw NumberFormatException("Dash width must be positive");
+				}
+			}
+
+			return dashpattern;
+		}
+		return null;
+	}
 
 	/**
 	 * Reads the given filename into a string.