imagelabel.java

java高级使用教程 全书一共分六章

// ImageLabel - a label with an image instead of a string
//
// Copyright (C)1996,1998 by Jef Poskanzer <[e-mail]>. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
// Visit the ACME Labs Java page for up-to-date versions of this and other
// fine Java utilities: http://www.acme.com/java/

package Acme.Widgets;

import java.awt.*;
import java.awt.image.*;

/// A label with an image instead of a string.
// <P>
// <A HREF="/resources/classes/Acme/Widgets/ImageLabel.java">Fetch the software.</A><BR>
// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>

public class ImageLabel extends Canvas
    {

    private Image image;
    private int width = -1;
    private int height = -1;

    /// Constructor.
    public ImageLabel( Image image )
	{
	setImage( image );
	}

    /// Sets the image.
    public void setImage( Image image )
	{
	invalidate();
	this.image = image;
	width = height = -1;
	changeSize( image.getWidth( this ), image.getHeight( this ) );
	repaint();
	}

    private void changeSize( int w, int h )
	{
	if ( w == -1 || h == -1 )
	    return;
	width = w;
	height = h;
	resize( width, height );
	// setSize( width, height );
	Acme.GuiUtils.packWindow( this );
	}

    public Dimension preferredSize()
	{
	return minimumSize();
	}

    public Dimension minimumSize()
	{
	return new Dimension( width, height );
	}

    public void paint( Graphics graphics )
	{
	graphics.drawImage( image, 0, 0, this );
	}


    public boolean imageUpdate(
	Image img, int infoflags, int x, int y, int w, int h )
	{
        boolean errorFlag = ( infoflags & ERROR ) != 0;
        boolean abortFlag = ( infoflags & ABORT ) != 0;
        boolean widthFlag = ( infoflags & WIDTH ) != 0;
        boolean heightFlag = ( infoflags & HEIGHT ) != 0;
        boolean propertiesFlag = ( infoflags & PROPERTIES ) != 0;
        boolean somebitsFlag = ( infoflags & SOMEBITS ) != 0;
        boolean framebitsFlag = ( infoflags & FRAMEBITS ) != 0;
        boolean allbitsFlag = ( infoflags & ALLBITS ) != 0;
	if ( errorFlag || abortFlag )
	    {
	    setImage( Acme.GuiUtils.brokenIcon( this ) );
	    return false;
	    }
	if ( widthFlag || heightFlag || framebitsFlag || allbitsFlag )
	    changeSize( w, h );
	if ( framebitsFlag || allbitsFlag )
	    {
	    repaint();
	    return false;
	    }
	if ( somebitsFlag )
	    repaint( 100 );
	return true;
	}

    }