Java tutorial
/* * 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 groovy.beans; import org.codehaus.groovy.ast.ASTNode; import org.codehaus.groovy.ast.AnnotatedNode; import org.codehaus.groovy.ast.AnnotationNode; import org.codehaus.groovy.ast.ClassHelper; import org.codehaus.groovy.ast.ClassNode; import org.codehaus.groovy.ast.FieldNode; import org.codehaus.groovy.ast.MethodNode; import org.codehaus.groovy.ast.Parameter; import org.codehaus.groovy.ast.PropertyNode; import org.codehaus.groovy.ast.expr.Expression; import org.codehaus.groovy.ast.stmt.BlockStatement; import org.codehaus.groovy.ast.stmt.Statement; import org.codehaus.groovy.ast.tools.PropertyNodeUtils; import org.codehaus.groovy.control.CompilePhase; import org.codehaus.groovy.control.SourceUnit; import org.codehaus.groovy.control.messages.SimpleMessage; import org.codehaus.groovy.control.messages.SyntaxErrorMessage; import org.codehaus.groovy.syntax.SyntaxException; import org.codehaus.groovy.transform.ASTTransformation; import org.codehaus.groovy.transform.GroovyASTTransformation; import org.objectweb.asm.Opcodes; import java.beans.PropertyChangeListener; import java.beans.PropertyChangeSupport; import static org.apache.groovy.ast.tools.ClassNodeUtils.addGeneratedMethod; import static org.apache.groovy.util.BeanUtils.capitalize; import static org.codehaus.groovy.ast.tools.GeneralUtils.args; import static org.codehaus.groovy.ast.tools.GeneralUtils.assignX; import static org.codehaus.groovy.ast.tools.GeneralUtils.callThisX; import static org.codehaus.groovy.ast.tools.GeneralUtils.callX; import static org.codehaus.groovy.ast.tools.GeneralUtils.constX; import static org.codehaus.groovy.ast.tools.GeneralUtils.ctorX; import static org.codehaus.groovy.ast.tools.GeneralUtils.declS; import static org.codehaus.groovy.ast.tools.GeneralUtils.fieldX; import static org.codehaus.groovy.ast.tools.GeneralUtils.localVarX; import static org.codehaus.groovy.ast.tools.GeneralUtils.param; import static org.codehaus.groovy.ast.tools.GeneralUtils.params; import static org.codehaus.groovy.ast.tools.GeneralUtils.returnS; import static org.codehaus.groovy.ast.tools.GeneralUtils.stmt; import static org.codehaus.groovy.ast.tools.GeneralUtils.varX; /** * Handles generation of code for the {@code @Bindable} annotation when {@code @Vetoable} * is not present. * <p> * Generally, it adds (if needed) a PropertyChangeSupport field and * the needed add/removePropertyChangeListener methods to support the * listeners. * <p> * It also generates the setter and wires the setter through the * PropertyChangeSupport. * <p> * If a {@link Vetoable} annotation is detected it does nothing and * lets the {@link VetoableASTTransformation} handle all the changes. */ @GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION) public class BindableASTTransformation implements ASTTransformation, Opcodes { protected static final ClassNode boundClassNode = ClassHelper.make(Bindable.class); /** * Convenience method to see if an annotated node is {@code @Bindable}. * * @param node the node to check * @return true if the node is bindable */ public static boolean hasBindableAnnotation(AnnotatedNode node) { for (AnnotationNode annotation : node.getAnnotations()) { if (boundClassNode.equals(annotation.getClassNode())) { return true; } } return false; } /** * Handles the bulk of the processing, mostly delegating to other methods. * * @param nodes the ast nodes * @param source the source unit for the nodes */ public void visit(ASTNode[] nodes, SourceUnit source) { if (!(nodes[0] instanceof AnnotationNode) || !(nodes[1] instanceof AnnotatedNode)) { throw new RuntimeException("Internal error: wrong types: $node.class / $parent.class"); } AnnotationNode node = (AnnotationNode) nodes[0]; AnnotatedNode parent = (AnnotatedNode) nodes[1]; if (VetoableASTTransformation.hasVetoableAnnotation(parent)) { // VetoableASTTransformation will handle both @Bindable and @Vetoable return; } ClassNode declaringClass = parent.getDeclaringClass(); if (parent instanceof FieldNode) { if ((((FieldNode) parent).getModifiers() & Opcodes.ACC_FINAL) != 0) { source.getErrorCollector().addErrorAndContinue(new SyntaxErrorMessage(new SyntaxException( "@groovy.beans.Bindable cannot annotate a final property.", node.getLineNumber(), node.getColumnNumber(), node.getLastLineNumber(), node.getLastColumnNumber()), source)); } if (VetoableASTTransformation.hasVetoableAnnotation(parent.getDeclaringClass())) { // VetoableASTTransformation will handle both @Bindable and @Vetoable return; } addListenerToProperty(source, node, declaringClass, (FieldNode) parent); } else if (parent instanceof ClassNode) { addListenerToClass(source, (ClassNode) parent); } } private void addListenerToProperty(SourceUnit source, AnnotationNode node, ClassNode declaringClass, FieldNode field) { String fieldName = field.getName(); for (PropertyNode propertyNode : declaringClass.getProperties()) { if (propertyNode.getName().equals(fieldName)) { if (field.isStatic()) { //noinspection ThrowableInstanceNeverThrown source.getErrorCollector().addErrorAndContinue(new SyntaxErrorMessage(new SyntaxException( "@groovy.beans.Bindable cannot annotate a static property.", node.getLineNumber(), node.getColumnNumber(), node.getLastLineNumber(), node.getLastColumnNumber()), source)); } else { if (needsPropertyChangeSupport(declaringClass, source)) { addPropertyChangeSupport(declaringClass); } createListenerSetter(declaringClass, propertyNode); } return; } } //noinspection ThrowableInstanceNeverThrown source.getErrorCollector().addErrorAndContinue(new SyntaxErrorMessage(new SyntaxException( "@groovy.beans.Bindable must be on a property, not a field. Try removing the private, protected, or public modifier.", node.getLineNumber(), node.getColumnNumber(), node.getLastLineNumber(), node.getLastColumnNumber()), source)); } private void addListenerToClass(SourceUnit source, ClassNode classNode) { if (needsPropertyChangeSupport(classNode, source)) { addPropertyChangeSupport(classNode); } for (PropertyNode propertyNode : classNode.getProperties()) { FieldNode field = propertyNode.getField(); // look to see if per-field handlers will catch this one... if (hasBindableAnnotation(field) || ((field.getModifiers() & Opcodes.ACC_FINAL) != 0) || field.isStatic() || VetoableASTTransformation.hasVetoableAnnotation(field)) { // explicitly labeled properties are already handled, // don't transform final properties // don't transform static properties // VetoableASTTransformation will handle both @Bindable and @Vetoable continue; } createListenerSetter(classNode, propertyNode); } } /* * Wrap an existing setter. */ private static void wrapSetterMethod(ClassNode classNode, String propertyName) { String getterName = "get" + capitalize(propertyName); MethodNode setter = classNode.getSetterMethod("set" + capitalize(propertyName)); if (setter != null) { // Get the existing code block Statement code = setter.getCode(); Expression oldValue = localVarX("$oldValue"); Expression newValue = localVarX("$newValue"); BlockStatement block = new BlockStatement(); // create a local variable to hold the old value from the getter block.addStatement(declS(oldValue, callThisX(getterName))); // call the existing block, which will presumably set the value properly block.addStatement(code); // get the new value to emit in the event block.addStatement(declS(newValue, callThisX(getterName))); // add the firePropertyChange method call block.addStatement( stmt(callThisX("firePropertyChange", args(constX(propertyName), oldValue, newValue)))); // replace the existing code block with our new one setter.setCode(block); } } private void createListenerSetter(ClassNode classNode, PropertyNode propertyNode) { String setterName = "set" + capitalize(propertyNode.getName()); if (classNode.getMethods(setterName).isEmpty()) { Statement setterBlock = createBindableStatement(propertyNode, fieldX(propertyNode.getField())); // create method void <setter>(<type> fieldName) createSetterMethod(classNode, propertyNode, setterName, setterBlock); } else { wrapSetterMethod(classNode, propertyNode.getName()); } } /** * Creates a statement body similar to: * <code>this.firePropertyChange("field", field, field = value)</code> * * @param propertyNode the field node for the property * @param fieldExpression a field expression for setting the property value * @return the created statement */ protected Statement createBindableStatement(PropertyNode propertyNode, Expression fieldExpression) { // create statementBody return stmt(callThisX("firePropertyChange", args(constX(propertyNode.getName()), fieldExpression, assignX(fieldExpression, varX("value"))))); } /** * Creates a setter method with the given body. * * @param declaringClass the class to which we will add the setter * @param propertyNode the field to back the setter * @param setterName the name of the setter * @param setterBlock the statement representing the setter block */ protected void createSetterMethod(ClassNode declaringClass, PropertyNode propertyNode, String setterName, Statement setterBlock) { MethodNode setter = new MethodNode(setterName, PropertyNodeUtils.adjustPropertyModifiersForMethod(propertyNode), ClassHelper.VOID_TYPE, params(param(propertyNode.getType(), "value")), ClassNode.EMPTY_ARRAY, setterBlock); setter.setSynthetic(true); // add it to the class addGeneratedMethod(declaringClass, setter); } /** * Snoops through the declaring class and all parents looking for methods * <code>void addPropertyChangeListener(PropertyChangeListener)</code>, * <code>void removePropertyChangeListener(PropertyChangeListener)</code>, and * <code>void firePropertyChange(String, Object, Object)</code>. If any are defined all * must be defined or a compilation error results. * * @param declaringClass the class to search * @param sourceUnit the source unit, for error reporting. {@code @NotNull}. * @return true if property change support should be added */ protected boolean needsPropertyChangeSupport(ClassNode declaringClass, SourceUnit sourceUnit) { boolean foundAdd = false, foundRemove = false, foundFire = false; ClassNode consideredClass = declaringClass; while (consideredClass != null) { for (MethodNode method : consideredClass.getMethods()) { // just check length, MOP will match it up foundAdd = foundAdd || method.getName().equals("addPropertyChangeListener") && method.getParameters().length == 1; foundRemove = foundRemove || method.getName().equals("removePropertyChangeListener") && method.getParameters().length == 1; foundFire = foundFire || method.getName().equals("firePropertyChange") && method.getParameters().length == 3; if (foundAdd && foundRemove && foundFire) { return false; } } consideredClass = consideredClass.getSuperClass(); } // check if a super class has @Bindable annotations consideredClass = declaringClass.getSuperClass(); while (consideredClass != null) { if (hasBindableAnnotation(consideredClass)) return false; for (FieldNode field : consideredClass.getFields()) { if (hasBindableAnnotation(field)) return false; } consideredClass = consideredClass.getSuperClass(); } if (foundAdd || foundRemove || foundFire) { sourceUnit.getErrorCollector().addErrorAndContinue(new SimpleMessage("@Bindable cannot be processed on " + declaringClass.getName() + " because some but not all of addPropertyChangeListener, removePropertyChange, and firePropertyChange were declared in the current or super classes.", sourceUnit)); return false; } return true; } /** * Adds the necessary field and methods to support property change support. * <p> * Adds a new field: * <pre> * <code>protected final java.beans.PropertyChangeSupport this$PropertyChangeSupport = new java.beans.PropertyChangeSupport(this)</code>" * </pre> * <p> * Also adds support methods: * <pre> * <code>public void addPropertyChangeListener(java.beans.PropertyChangeListener)</code> * <code>public void addPropertyChangeListener(String, java.beans.PropertyChangeListener)</code> * <code>public void removePropertyChangeListener(java.beans.PropertyChangeListener)</code> * <code>public void removePropertyChangeListener(String, java.beans.PropertyChangeListener)</code> * <code>public java.beans.PropertyChangeListener[] getPropertyChangeListeners()</code> * </pre> * * @param declaringClass the class to which we add the support field and methods */ protected void addPropertyChangeSupport(ClassNode declaringClass) { ClassNode pcsClassNode = ClassHelper.make(PropertyChangeSupport.class); ClassNode pclClassNode = ClassHelper.make(PropertyChangeListener.class); //String pcsFieldName = "this$propertyChangeSupport"; // add field: // protected final PropertyChangeSupport this$propertyChangeSupport = new java.beans.PropertyChangeSupport(this) FieldNode pcsField = declaringClass.addField("this$propertyChangeSupport", ACC_FINAL | ACC_PRIVATE | ACC_SYNTHETIC, pcsClassNode, ctorX(pcsClassNode, args(varX("this")))); // add method: // void addPropertyChangeListener(listener) { // this$propertyChangeSupport.addPropertyChangeListener(listener) // } addGeneratedMethod(declaringClass, new MethodNode("addPropertyChangeListener", ACC_PUBLIC, ClassHelper.VOID_TYPE, params(param(pclClassNode, "listener")), ClassNode.EMPTY_ARRAY, stmt(callX(fieldX(pcsField), "addPropertyChangeListener", args(varX("listener", pclClassNode)))))); // add method: // void addPropertyChangeListener(name, listener) { // this$propertyChangeSupport.addPropertyChangeListener(name, listener) // } addGeneratedMethod(declaringClass, new MethodNode("addPropertyChangeListener", ACC_PUBLIC, ClassHelper.VOID_TYPE, params(param(ClassHelper.STRING_TYPE, "name"), param(pclClassNode, "listener")), ClassNode.EMPTY_ARRAY, stmt(callX(fieldX(pcsField), "addPropertyChangeListener", args(varX("name", ClassHelper.STRING_TYPE), varX("listener", pclClassNode)))))); // add method: // boolean removePropertyChangeListener(listener) { // return this$propertyChangeSupport.removePropertyChangeListener(listener); // } addGeneratedMethod(declaringClass, new MethodNode("removePropertyChangeListener", ACC_PUBLIC, ClassHelper.VOID_TYPE, params(param(pclClassNode, "listener")), ClassNode.EMPTY_ARRAY, stmt(callX(fieldX(pcsField), "removePropertyChangeListener", args(varX("listener", pclClassNode)))))); // add method: void removePropertyChangeListener(name, listener) addGeneratedMethod(declaringClass, new MethodNode("removePropertyChangeListener", ACC_PUBLIC, ClassHelper.VOID_TYPE, params(param(ClassHelper.STRING_TYPE, "name"), param(pclClassNode, "listener")), ClassNode.EMPTY_ARRAY, stmt(callX(fieldX(pcsField), "removePropertyChangeListener", args(varX("name", ClassHelper.STRING_TYPE), varX("listener", pclClassNode)))))); // add method: // void firePropertyChange(String name, Object oldValue, Object newValue) { // this$propertyChangeSupport.firePropertyChange(name, oldValue, newValue) // } addGeneratedMethod(declaringClass, new MethodNode("firePropertyChange", ACC_PUBLIC, ClassHelper.VOID_TYPE, params(param(ClassHelper.STRING_TYPE, "name"), param(ClassHelper.OBJECT_TYPE, "oldValue"), param(ClassHelper.OBJECT_TYPE, "newValue")), ClassNode.EMPTY_ARRAY, stmt(callX(fieldX(pcsField), "firePropertyChange", args(varX("name", ClassHelper.STRING_TYPE), varX("oldValue"), varX("newValue")))))); // add method: // PropertyChangeListener[] getPropertyChangeListeners() { // return this$propertyChangeSupport.getPropertyChangeListeners // } addGeneratedMethod(declaringClass, new MethodNode("getPropertyChangeListeners", ACC_PUBLIC, pclClassNode.makeArray(), Parameter.EMPTY_ARRAY, ClassNode.EMPTY_ARRAY, returnS(callX(fieldX(pcsField), "getPropertyChangeListeners")))); // add method: // PropertyChangeListener[] getPropertyChangeListeners(String name) { // return this$propertyChangeSupport.getPropertyChangeListeners(name) // } addGeneratedMethod(declaringClass, new MethodNode("getPropertyChangeListeners", ACC_PUBLIC, pclClassNode.makeArray(), params(param(ClassHelper.STRING_TYPE, "name")), ClassNode.EMPTY_ARRAY, returnS(callX(fieldX(pcsField), "getPropertyChangeListeners", args(varX("name", ClassHelper.STRING_TYPE)))))); } }