setcommand.java

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/**
 *   SetCommand.java
 *   Copyright 2005 Carlos Silva A.
 * 
 *   Licensed 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 jgantt.cmds;

import java.lang.reflect.Method;
import java.text.MessageFormat;
import java.util.Date;

import jgantt.model.Task;

/**
 * SetCommand represents a command that executes a setter for an object. Uses
 * reflextion to invoke the method with diferent attributes. Usage:new
 * SetCommand(Object, "setMethod", executeValue, undoValue));
 * <p>
 * $Date: 2005/07/14 06:16:04 $
 * </p>
 * 
 * @version $Revision: 1.4 $
 * @author Carlos Silva
 */
public class SetCommand implements Command {

    String setter;
    Class[] argType;
    Object oldValue;
    Object newValue;
    Object object;

    private SetCommand(Object object, String setter) {
        this.object = object;
        this.setter = setter;
    }

    /**
     * Asignador de String
     */
    public SetCommand(Object object, String setter, String newVal, String oldVal) {
        this.object = object;
        argType = new Class[] { String.class };
        this.newValue = newVal;
        this.oldValue = oldVal;
    }

    /**
     * Asignador de int
     */
    public SetCommand(Task task, String setter, int newValue, int oldValue) {
        this(task, setter);
        argType = new Class[] { Integer.TYPE };
        this.newValue = new Integer(newValue);
        this.oldValue = new Integer(oldValue);
    }

    /**
     * Asignador de boolean
     * 
     * @param task
     * @param setter
     * @param newValue
     * @param oldValue
     */
    public SetCommand(Task task, String setter, boolean newV, boolean oldV) {
        this(task, setter);
        argType = new Class[] { Boolean.TYPE };
        this.newValue = new Boolean(newV);
        this.oldValue = new Boolean(oldV);
    }

    /**
     * Asignador de boolean
     * 
     * @param task
     * @param setter
     * @param newValue
     * @param oldValue
     */
    public SetCommand(Task task, String setter, Date newV, Date oldV) {
        this(task, setter);
        argType = new Class[] { Boolean.TYPE };
        this.newValue = newV;
        this.oldValue = oldV;
    }

    /**
     * @see jgantt.cmds.TaskCommand#execute()
     */
    public void execute() {
        invoke(newValue);
    }

    /**
     * @see jgantt.cmds.TaskCommand#undo()
     */
    public void undo() {
        invoke(oldValue);
    }

    void invoke(Object value) {
        try {
            Method method = object.getClass().getMethod(setter, argType);
            method.invoke(object, new Object[] { value });
        } catch (Exception e) {
            Object a[] = new Object[] { setter, argType[0], value };
            String spec = MessageFormat.format("invoke ${0}(${1}, ${2})", a);
            System.err.println(spec);
            e.printStackTrace();
        }
    }
}