Extracted some often-used XML constants and utility methods into an interface and a class in org.apache.fop.util.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/branches/Temp_AreaTreeNewDesign@685137 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 199 insertions, 1 deletions

diff --git a/src/java/org/apache/fop/util/DOM2SAX.java b/src/java/org/apache/fop/util/DOM2SAX.java
index 04096e053..839cf107f 100644
--- a/src/java/org/apache/fop/util/DOM2SAX.java
+++ b/src/java/org/apache/fop/util/DOM2SAX.java
@@ -232,7 +232,7 @@ public class DOM2SAX {
 
                     // Add attribute to list
                     attrs.addAttribute(attr.getNamespaceURI(),
-                            getLocalName(attr), qnameAttr, "CDATA", attr
+                            getLocalName(attr), qnameAttr, XMLUtil.CDATA, attr
                                     .getNodeValue());
                 }
             }
diff --git a/src/java/org/apache/fop/util/XMLConstants.java b/src/java/org/apache/fop/util/XMLConstants.java
new file mode 100644
index 000000000..1f85c3b07
--- /dev/null
+++ b/src/java/org/apache/fop/util/XMLConstants.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.
+ */
+
+/* $Id$ */
+
+package org.apache.fop.util;
+
+
+/**
+ * A collection of constants for XML handling.
+ */
+public interface XMLConstants {
+
+    /** "CDATA" constant */
+    String CDATA = "CDATA";
+
+    /** XML namespace prefix */
+    String XML_PREFIX = "xml";
+    /** XML namespace URI */
+    String XML_NAMESPACE = "http://www.w3.org/XML/1998/namespace";
+
+    /** XMLNS namespace prefix */
+    String XMLNS_PREFIX = "xmlns";
+    /** XMLNS namespace URI */
+    String XMLNS_NAMESPACE_URI = "http://www.w3.org/2000/xmlns/";
+
+    /** Namespace prefix for XLink */
+    String XLINK_PREFIX = "xlink";
+    /** XML namespace for XLink */
+    String XLINK_NAMESPACE = "http://www.w3.org/1999/xlink";
+    /** xlink:href attribute */
+    org.apache.xmlgraphics.util.QName XLINK_HREF = new org.apache.xmlgraphics.util.QName(
+            XLINK_NAMESPACE, XLINK_PREFIX, "href");
+
+}
diff --git a/src/java/org/apache/fop/util/XMLUtil.java b/src/java/org/apache/fop/util/XMLUtil.java
new file mode 100644
index 000000000..13784ea19
--- /dev/null
+++ b/src/java/org/apache/fop/util/XMLUtil.java
@@ -0,0 +1,149 @@
+/*
+ * 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.
+ */
+
+/* $Id$ */
+
+package org.apache.fop.util;
+
+import java.awt.Rectangle;
+import java.awt.geom.Rectangle2D;
+
+import org.xml.sax.Attributes;
+import org.xml.sax.SAXException;
+
+/**
+ * A collection of utility method for XML handling.
+ */
+public class XMLUtil implements XMLConstants {
+
+    /**
+     * Returns an attribute value as a boolean value.
+     * @param attributes the Attributes object
+     * @param name the name of the attribute
+     * @param defaultValue the default value if the attribute is not specified
+     * @return the attribute value as a boolean
+     */
+    public static boolean getAttributeAsBoolean(Attributes attributes, String name,
+            boolean defaultValue) {
+        String s = attributes.getValue(name);
+        if (s == null) {
+            return defaultValue;
+        } else {
+            return Boolean.valueOf(s).booleanValue();
+        }
+    }
+
+    /**
+     * Returns an attribute value as a int value.
+     * @param attributes the Attributes object
+     * @param name the name of the attribute
+     * @param defaultValue the default value if the attribute is not specified
+     * @return the attribute value as an int
+     */
+    public static int getAttributeAsInt(Attributes attributes, String name,
+            int defaultValue) {
+        String s = attributes.getValue(name);
+        if (s == null) {
+            return defaultValue;
+        } else {
+            return Integer.parseInt(s);
+        }
+    }
+
+    /**
+     * Returns an attribute value as a int value.
+     * @param attributes the Attributes object
+     * @param name the name of the attribute
+     * @return the attribute value as an int
+     * @throws SAXException if the attribute is missing
+     */
+    public static int getAttributeAsInt(Attributes attributes, String name) throws SAXException {
+        String s = attributes.getValue(name);
+        if (s == null) {
+            throw new SAXException("Attribute '" + name + "' is missing");
+        } else {
+            return Integer.parseInt(s);
+        }
+    }
+
+    /**
+     * Returns an attribute value as a Integer value.
+     * @param attributes the Attributes object
+     * @param name the name of the attribute
+     * @return the attribute value as an Integer or null if the attribute is missing
+     */
+    public static Integer getAttributeAsInteger(Attributes attributes, String name) {
+        String s = attributes.getValue(name);
+        if (s == null) {
+            return null;
+        } else {
+            return new Integer(s);
+        }
+    }
+
+    /**
+     * Returns an attribute value as a Rectangle2D value. The string value is expected as 4
+     * double-precision numbers separated by whitespace.
+     * @param attributes the Attributes object
+     * @param name the name of the attribute
+     * @return the attribute value as an Rectangle2D
+     */
+    public static Rectangle2D getAttributeAsRectangle2D(Attributes attributes, String name) {
+        String s = attributes.getValue(name).trim();
+        double[] values = ConversionUtils.toDoubleArray(s, "\\s");
+        if (values.length != 4) {
+            throw new IllegalArgumentException("Rectangle must consist of 4 double values!");
+        }
+        return new Rectangle2D.Double(values[0], values[1], values[2], values[3]);
+    }
+
+    /**
+     * Returns an attribute value as a Rectangle value. The string value is expected as 4
+     * integer numbers separated by whitespace.
+     * @param attributes the Attributes object
+     * @param name the name of the attribute
+     * @return the attribute value as an Rectangle
+     */
+    public static Rectangle getAttributeAsRectangle(Attributes attributes, String name) {
+        String s = attributes.getValue(name);
+        if (s == null) {
+            return null;
+        }
+        int[] values = ConversionUtils.toIntArray(s.trim(), "\\s");
+        if (values.length != 4) {
+            throw new IllegalArgumentException("Rectangle must consist of 4 int values!");
+        }
+        return new Rectangle(values[0], values[1], values[2], values[3]);
+    }
+
+    /**
+     * Returns an attribute value as a integer array. The string value is expected as 4
+     * integer numbers separated by whitespace.
+     * @param attributes the Attributes object
+     * @param name the name of the attribute
+     * @return the attribute value as an int array
+     */
+    public static int[] getAttributeAsIntArray(Attributes attributes, String name) {
+        String s = attributes.getValue(name);
+        if (s == null) {
+            return null;
+        } else {
+            return ConversionUtils.toIntArray(s.trim(), "\\s");
+        }
+    }
+
+}