org.netbeans.html.json.spi.FunctionBinding Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of net.java.html.json Show documentation
API for smooth representation of JSON objects in Java. Write your application in Java and present it using modern HTML rendering technologies like Knockout.
The newest version!
/**
 * 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.netbeans.html.json.spi;

import java.lang.ref.Reference;
import java.lang.ref.WeakReference;
import net.java.html.BrwsrCtx;
import net.java.html.json.Function;
import net.java.html.json.Model;
import static org.netbeans.html.json.spi.PropertyBinding.weakSupported;

/** Describes a function provided by the {@link Model} and 
 * annotated by {@link Function} annotation.
 *
 * @author Jaroslav Tulach
 */
public abstract class FunctionBinding {
    FunctionBinding() {
    }
    
    /** Returns name of the function.
     * @return function name
     */
    public abstract String getFunctionName();
    
    /**
     * Calls the function provided data associated with current element, as well
     * as information about the event that triggered the event.
     *
     * @param data data associated with selected element
     * @param ev event (with additional properties) that triggered the event
     */
    public abstract void call(Object data, Object ev);
    
    /** Returns identical version of the binding, but one that holds on the
     * original model object via weak reference.
     * 
     * @return binding that uses weak reference
     * @since 1.1
     */
    public abstract FunctionBinding weak();

    static  FunctionBinding registerFunction(String name, int index, M model, Proto.Type access) {
        return new Impl(model, name, index, access);
    }
    
    private static abstract class AImpl extends FunctionBinding {
        final String name;
        final Proto.Type access;
        final int index;

        public AImpl(String name, int index, Proto.Type access) {
            this.name = name;
            this.index = index;
            this.access = access;
        }
        
        protected abstract M model();

        @Override
        public String getFunctionName() {
            return name;
        }

        @Override
        public void call(final Object data, final Object ev) {
            final M model = model();
            if (model == null) {
                return;
            }
            BrwsrCtx ctx = access.protoFor(model).getContext();
            class Dispatch implements Runnable {
                @Override
                public void run() {
                    try {
                        access.call(model, index, data, ev);
                    } catch (Throwable ex) {
                        ex.printStackTrace();
                    }
                }
            }
            ctx.execute(new Dispatch());
        }
    }
    
    private static final class Impl extends AImpl {
        private final M model;

        public Impl(M model, String name, int index, Proto.Type access) {
            super(name, index, access);
            this.model = model;
        }

        @Override
        protected M model() {
            return model;
        }

        @Override
        public FunctionBinding weak() {
            if (weakSupported) {
                return new Weak(model, name, index, access);
            } else {
                return this;
            }
        }
    }
    
    private static final class Weak extends AImpl {
        private final Reference ref;
        
        public Weak(M model, String name, int index, Proto.Type access) {
            super(name, index, access);
            this.ref = new WeakReference(model);
        }

        @Override
        protected M model() {
            return ref.get();
        }

        @Override
        public FunctionBinding weak() {
            return this;
        }
    }
}