/*****************************************************************************
 * 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.                                                        *
 *                                                                           *
 * This file is part of the BeanShell Java Scripting distribution.           *
 * Documentation and updates may be found at http://www.beanshell.org/       *
 * Patrick Niemeyer (pat@pat.net)                                            *
 * Author of Learning Java, O'Reilly & Associates                            *
 *                                                                           *
 *****************************************************************************/

package bsh.util;

import java.awt.*;
import javax.swing.*;
import bsh.*;

/**
	Scriptable Canvas with buffered graphics.

	Provides a Component that:
	1) delegates calls to paint() to a bsh method called paint() 
		in a specific NameSpace.
	2) provides a simple buffered image maintained by built in paint() that 
		is useful for simple immediate procedural rendering from scripts...  

*/
public class BshCanvas extends JComponent {
	This ths;
	Image imageBuffer;

	public BshCanvas () { }

	public BshCanvas ( This ths ) {
		this.ths = ths;
	}

	public void paintComponent( Graphics g ) {
		// copy buffered image
		if ( imageBuffer != null )
			g.drawImage(imageBuffer, 0,0, this);

		// Delegate call to scripted paint() method
		if ( ths != null ) {
			try {
				ths.invokeMethod( "paint", new Object[] { g } );
			} catch(EvalError e) {
				if ( Interpreter.DEBUG ) Interpreter.debug(
					"BshCanvas: method invocation error:" + e);
			}
		}
	}

	/**
		Get a buffered (persistent) image for drawing on this component
	*/
	public Graphics getBufferedGraphics() {
		Dimension dim = getSize();
		imageBuffer = createImage( dim.width, dim.height );
		return imageBuffer.getGraphics();
	}

	public void setBounds( int x, int y, int width, int height ) {
		setPreferredSize( new Dimension(width, height) );
		setMinimumSize( new Dimension(width, height) );
		super.setBounds( x, y, width, height );
	}

}

