Adopt commons-jxpath classes to the eclipse codebase

Author: laeubi

bundles/org.eclipse.e4.emf.xpath/src/org/apache/commons/jxpath/AbstractFactory.java

@@ -0,0 +1,68 @@
+/*
+ * 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.commons.jxpath;
+
+/**
+ * The  {@link JXPathContext#createPath JXPathContext.createPath()} method of
+ * JXPathContext can create missing objects as it traverses an XPath; it
+ * utilizes an AbstractFactory for that purpose. Install a factory on
+ * JXPathContext by calling {@link JXPathContext#setFactory JXPathContext.
+ * setFactory()}.
+ * <p>
+ * All  methods of this class return false.  Override any of them to return true
+ * to indicate that the factory has successfully created the described object.
+ */
+public abstract class AbstractFactory {
+
+    /**
+     * The  parameters may describe a collection element or an individual
+     * object. It is up to the factory to infer which one it is. If it is a
+     * collection, the factory should check if the collection exists.  If not,
+     * it should create the collection. Then it should create the index'th
+     * element of the collection and return true.
+     * <p>
+     *
+     * @param context can be used to evaluate other XPaths, get to variables
+     * etc.
+     * @param pointer describes the location of the node to be created
+     * @param parent is the object that will serve as a parent of the new
+     * object
+     * @param name is the name of the child of the parent that needs to be
+     * created. In the case of DOM may be qualified.
+     * @param index is used if the pointer represents a collection element. You
+     * may need to expand or even create the collection to accommodate the new
+     * element.
+     *
+     * @return true if the object was successfully created
+     */
+    public boolean createObject(final JXPathContext context, final Pointer pointer,
+                                final Object parent, final String name, final int index) {
+        return false;
+    }
+
+    /**
+     * Declare the specified variable
+     *
+     * @param context hosts variable pools. See
+     * {@link JXPathContext#getVariables() JXPathContext.getVariables()}
+     * @param name is the name of the variable without the "$" sign
+     * @return true if the variable was successfully defined
+     */
+    public boolean declareVariable(final JXPathContext context, final String name) {
+        return false;
+    }
+}

bundles/org.eclipse.e4.emf.xpath/src/org/apache/commons/jxpath/BasicNodeSet.java

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+/*
+ * 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.commons.jxpath;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A simple implementation of {@link NodeSet} that behaves as a collection
+ * of pointers.
+ */
+public class BasicNodeSet implements NodeSet {
+    private final List pointers = new ArrayList();
+    private List readOnlyPointers;
+    private List nodes;
+    private List values;
+
+    /**
+     * Add a pointer to this NodeSet.
+     * @param pointer to add
+     */
+    public void add(final Pointer pointer) {
+        if (pointers.add(pointer)) {
+            clearCacheLists();
+        }
+    }
+
+    /**
+     * Add the specified NodeSet to this NodeSet.
+     * @param nodeSet to add
+     */
+    public void add(final NodeSet nodeSet) {
+        if (pointers.addAll(nodeSet.getPointers())) {
+            clearCacheLists();
+        }
+    }
+
+    /**
+     * Remove a pointer from this NodeSet.
+     * @param pointer to remove
+     */
+    public void remove(final Pointer pointer) {
+        if (pointers.remove(pointer)) {
+            clearCacheLists();
+        }
+    }
+
+    @Override
+    public synchronized List getPointers() {
+        if (readOnlyPointers == null) {
+            readOnlyPointers = Collections.unmodifiableList(pointers);
+        }
+        return readOnlyPointers;
+    }
+
+    @Override
+    public synchronized List getNodes() {
+        if (nodes == null) {
+            nodes = new ArrayList();
+            for (int i = 0; i < pointers.size(); i++) {
+                final Pointer pointer = (Pointer) pointers.get(i);
+                nodes.add(pointer.getNode());
+            }
+            nodes = Collections.unmodifiableList(nodes);
+        }
+        return nodes;
+    }
+
+    @Override
+    public synchronized List getValues() {
+        if (values == null) {
+            values = new ArrayList();
+            for (int i = 0; i < pointers.size(); i++) {
+                final Pointer pointer = (Pointer) pointers.get(i);
+                values.add(pointer.getValue());
+            }
+            values = Collections.unmodifiableList(values);
+        }
+        return values;
+    }
+
+    @Override
+    public String toString() {
+        return pointers.toString();
+    }
+
+    /**
+     * Clear cache list members.
+     */
+    private synchronized void clearCacheLists() {
+        readOnlyPointers = null;
+        nodes = null;
+        values = null;
+    }
+
+}

bundles/org.eclipse.e4.emf.xpath/src/org/apache/commons/jxpath/BasicVariables.java

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+/*
+ * 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.commons.jxpath;
+
+import java.util.HashMap;
+
+/**
+ * A basic implementation of the Variables interface that uses a HashMap.
+ */
+public class BasicVariables implements Variables {
+    private static final long serialVersionUID = 2708263960832062725L;
+
+    /**
+     * Contains the values of declared variables
+     */
+    private final HashMap vars = new HashMap();
+
+    /**
+     * Returns true if the variable has been defined, even if the
+     * value of the variable is null.
+     *
+     * @param varName is a variable name without the "$" sign
+     * @return true if the variable is declared
+     */
+    @Override
+    public boolean isDeclaredVariable(final String varName) {
+        return vars.containsKey(varName);
+    }
+
+    /**
+     * Returns the value of the variable if it is defined,
+     * otherwise, throws IllegalArgumentException
+     *
+     * @param varName is a variable name without the "$" sign
+     * @return the value of the variable
+     */
+    @Override
+    public Object getVariable(final String varName) {
+        // Note that a variable may be defined with a null value
+
+        if (vars.containsKey(varName)) {
+            return vars.get(varName);
+        }
+
+        throw new IllegalArgumentException(
+            "No such variable: '" + varName + "'");
+    }
+
+    /**
+     * Defines a new variable with the specified value or modifies
+     * the value of an existing variable.
+     *
+     * @param varName is a variable name without the "$" sign
+     * @param value is the new value for the variable, which can be null
+     */
+    @Override
+    public void declareVariable(final String varName, final Object value) {
+        vars.put(varName, value);
+    }
+
+    /**
+     * Removes an existing variable. May throw UnsupportedOperationException.
+     *
+     * @param varName is a variable name without the "$" sign
+     */
+    @Override
+    public void undeclareVariable(final String varName) {
+        vars.remove(varName);
+    }
+
+    @Override
+    public String toString() {
+        return vars.toString();
+    }
+}