buttondialog.java

java高级使用教程 全书一共分六章

// ButtonDialog - a generic modal button box
//
// 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.*;

/// A generic modal button box.
// <P>
// Puts up a dialog with a message and client-specified buttons.
// All user input is locked out.  The program can retrieve the user's
// answer via the getAnswer() method.
// <P>
// NOTE: do not use this inside an event handler call!  With some browsers
// this will cause a deadlock.  Instead, have your event handler start a new
// thread to run the button box.
// <P>
// <A HREF="/resources/classes/Acme/Widgets/ButtonDialog.java">Fetch the software.</A><BR>
// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>

public class ButtonDialog extends Dialog implements Runnable
    {

    private String[] buttons;
    private int[] answers;


    /// Constructor, no title, one button.
    public ButtonDialog( Frame parent, String message, String button1, int answer1 )
	{
	super( parent, true );
	build( message, button1, answer1 );
	}

    /// Constructor, specified title, one button.
    public ButtonDialog( Frame parent, String title, String message, String button1, int answer1 )
	{
	super( parent, title, true );
	build( message, button1, answer1 );
	}

    /// Build routine, one button.
    private void build( String message, String button1, int answer1 )
	{
	buttons = new String[1];
	answers = new int[1];
	buttons[0] = button1;
	answers[0] = answer1;
	build( message );
	}


    /// Constructor, no title, two buttons.
    public ButtonDialog( Frame parent, String message, String button1, int answer1, String button2, int answer2 )
	{
	super( parent, true );
	build( message, button1, answer1, button2, answer2 );
	}

    /// Constructor, specified title, two buttons.
    public ButtonDialog( Frame parent, String title, String message, String button1, int answer1, String button2, int answer2 )
	{
	super( parent, title, true );
	build( message, button1, answer1, button2, answer2 );
	}

    /// Build routine, two buttons.
    private void build( String message, String button1, int answer1, String button2, int answer2 )
	{
	buttons = new String[2];
	answers = new int[2];
	buttons[0] = button1;
	answers[0] = answer1;
	buttons[1] = button2;
	answers[1] = answer2;
	build( message );
	}


    /// Constructor, no title, three buttons.
    public ButtonDialog( Frame parent, String message, String button1, int answer1, String button2, int answer2, String button3, int answer3 )
	{
	super( parent, true );
	build( message, button1, answer1, button2, answer2, button3, answer3 );
	}

    /// Constructor, specified title, three buttons.
    public ButtonDialog( Frame parent, String title, String message, String button1, int answer1, String button2, int answer2, String button3, int answer3 )
	{
	super( parent, title, true );
	build( message, button1, answer1, button2, answer2, button3, answer3 );
	}

    /// Build routine, three buttons.
    private void build( String message, String button1, int answer1, String button2, int answer2, String button3, int answer3 )
	{
	buttons = new String[3];
	answers = new int[3];
	buttons[0] = button1;
	answers[0] = answer1;
	buttons[1] = button2;
	answers[1] = answer2;
	buttons[2] = button3;
	answers[2] = answer3;
	build( message );
	}


    /// Constructor, no title, four buttons.
    public ButtonDialog( Frame parent, String message, String button1, int answer1, String button2, int answer2, String button3, int answer3, String button4, int answer4 )
	{
	super( parent, true );
	build( message, button1, answer1, button2, answer2, button3, answer3, button4, answer4 );
	}

    /// Constructor, specified title, four buttons.
    public ButtonDialog( Frame parent, String title, String message, String button1, int answer1, String button2, int answer2, String button3, int answer3, String button4, int answer4 )
	{
	super( parent, title, true );
	build( message, button1, answer1, button2, answer2, button3, answer3, button4, answer4 );
	}

    /// Build routine, four buttons.
    private void build( String message, String button1, int answer1, String button2, int answer2, String button3, int answer3, String button4, int answer4 )
	{
	buttons = new String[4];
	answers = new int[4];
	buttons[0] = button1;
	answers[0] = answer1;
	buttons[1] = button2;
	answers[1] = answer2;
	buttons[2] = button3;
	answers[2] = answer3;
	buttons[3] = button4;
	answers[3] = answer4;
	build( message );
	}


    /// Common build routine.
    private void build( String message )
	{
	setResizable( false );
	this.setBackground( Acme.GuiUtils.qmarkColor );

	GridBagLayout gb = new GridBagLayout();
	setLayout( gb );
	GridBagConstraints gbc = new GridBagConstraints();
	gbc.insets = new Insets( 5, 5, 5, 5 );


	ImageLabel imageLabel =
	    new ImageLabel( Acme.GuiUtils.qmarkIcon( this ) );
	gb.setConstraints( imageLabel, gbc );
	add( imageLabel );
	Label label = new Label( message );
	gbc.gridwidth = GridBagConstraints.REMAINDER;
	gb.setConstraints( label, gbc );
	add( label );
	Panel buttonPanel = new Panel();
	buttonPanel.setLayout( new FlowLayout( FlowLayout.LEFT ) );
	for ( int i = 0; i < buttons.length; ++i )
	    buttonPanel.add( new Button( buttons[i] ) );
	gb.setConstraints( buttonPanel, gbc );
	add( buttonPanel );
	}


    /// Show the box.
    public void show()
	{
	pack();
	validate();
	// We do the super.show() in another thread, cause for modal dialogs
	// it doesn't return until the dialog goes away.  This isn't strictly
	// a problem for this class, cause we're going to do our own
	// wait-for-done below, but some clients may want to do some
	// processing before waiting.
	(new Thread( this )).start();
	}

    public void run()
	{
	super.show();
	}


    /// Event handler.
    public boolean handleEvent( Event evt )
	{
	switch ( evt.id )
	    {
	    case Event.ACTION_EVENT:
	    for ( int i = 0; i < buttons.length; ++i )
		if ( evt.arg.equals( buttons[i] ) )
		    {
		    click( answers[i] );
		    return true;
		    }
	    break;
	    }
	return super.handleEvent( evt );
	}


    private boolean clicked = false;
    private int answer;

    private synchronized void click( int val )
	{
	clicked = true;
	notify();
	answer = val;
	hide();
	//setVisible( false );
	dispose();
	}

    /// Get the answer.
    public synchronized int getAnswer()
	{
	while ( ! clicked )
	    {
	    try
		{
		wait();
		}
	    catch ( InterruptedException ignore ) {}
	    }
	return answer;
	}

    }