arrowbutton.java

FuncPlotter is a combined Java application and applet for displaying two-dimensional plots of explic

/*====================================================================*\

ArrowButton.java

Arrow button class.

------------------------------------------------------------------------

This file is part of FuncPlotter, a combined Java application and applet
for plotting explicit functions in one variable.
Copyright 2005-2007 Andy Morgan-Richards.

FuncPlotter is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program.  If not, see <http://www.gnu.org/licenses/>.

\*====================================================================*/


// PACKAGE


package gui;

//----------------------------------------------------------------------


// IMPORTS


import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Rectangle;

import javax.swing.JComponent;

//----------------------------------------------------------------------


// ARROW BUTTON CLASS


public class ArrowButton
    extends JComponent
{

////////////////////////////////////////////////////////////////////////
//  Constants
////////////////////////////////////////////////////////////////////////

    public enum Direction
    {
        UP,
        DOWN,
        LEFT,
        RIGHT
    }

    private static final    int MIN_WIDTH   = 1;
    private static final    int MAX_WIDTH   = (1 << 15) - 1;

    private static final    int MIN_HEIGHT  = 1;
    private static final    int MAX_HEIGHT  = (1 << 15) - 1;

    private static final    int MIN_ARROW_SIZE  = 1;
    private static final    int MAX_ARROW_SIZE  = (1 << 15) - 1;

    private static final    Color   BORDER_COLOUR               = new Color( 96, 96, 96 );
    private static final    Color   BACKGROUND_COLOUR           = new Color( 188, 216, 188 );
    private static final    Color   ACTIVE_BACKGROUND_COLOUR    = new Color( 236, 192, 88 );
    private static final    Color   DISABLED_BACKGROUND_COLOUR  = new Color( 208, 208, 208 );
    private static final    Color   FOREGROUND_COLOUR           = Color.BLACK;
    private static final    Color   DISABLED_FOREGROUND_COLOUR  = new Color( 144, 144, 144 );

////////////////////////////////////////////////////////////////////////
//  Constructors
////////////////////////////////////////////////////////////////////////

    public ArrowButton( int       width,
                        int       height,
                        int       arrowSize,
                        Direction direction )
        throws IllegalArgumentException
    {

        // Validate arguments

        if ( (width < MIN_WIDTH) || (width > MAX_WIDTH) || (height < MIN_HEIGHT) || (height > MAX_HEIGHT) ||
             (arrowSize < MIN_ARROW_SIZE) || (arrowSize > MAX_ARROW_SIZE) || (direction == null) )
            throw new IllegalArgumentException( );

        // Initialise instance variables

        this.width = width;
        this.height = height;
        this.arrowSize = arrowSize;
        this.direction = direction;

        // Set attributes

        setOpaque( true );
        setFocusable( false );

    }

    //------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Instance methods : overriding methods
////////////////////////////////////////////////////////////////////////

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

    //------------------------------------------------------------------

    protected void paintComponent( Graphics gr )
    {

        // Fill background

        Rectangle rect = gr.getClipBounds( );
        gr.setColor( isEnabled( ) ? pressed ? ACTIVE_BACKGROUND_COLOUR
                                            : BACKGROUND_COLOUR
                                  : DISABLED_BACKGROUND_COLOUR );
        gr.fillRect( rect.x, rect.y, rect.width, rect.height );

        // Draw arrow

        gr.setColor( isEnabled( ) ? FOREGROUND_COLOUR : DISABLED_FOREGROUND_COLOUR );
        switch ( direction )
        {
            case UP:
            {
                int x1 = (width - 1) / 2;
                int x2 = x1;
                int y = (height - arrowSize) / 2;
                for ( int i = 0; i < arrowSize; ++i )
                {
                    gr.drawLine( x1, y, x2, y );
                    --x1;
                    ++x2;
                    ++y;
                }
                break;
            }

            case DOWN:
            {
                int x1 = (width - 1) / 2;
                int x2 = x1;
                int y = height - 1 - (height - arrowSize) / 2;
                for ( int i = 0; i < arrowSize; ++i )
                {
                    gr.drawLine( x1, y, x2, y );
                    --x1;
                    ++x2;
                    --y;
                }
                break;
            }

            case LEFT:
            {
                int x = (width - arrowSize) / 2;
                int y1 = (height - 1) / 2;
                int y2 = y1;
                for ( int i = 0; i < arrowSize; ++i )
                {
                    gr.drawLine( x, y1, x, y2 );
                    ++x;
                    --y1;
                    ++y2;
                }
                break;
            }

            case RIGHT:
            {
                int x = width - 1 - (width - arrowSize) / 2;
                int y1 = (height - 1) / 2;
                int y2 = y1;
                for ( int i = 0; i < arrowSize; ++i )
                {
                    gr.drawLine( x, y1, x, y2 );
                    --x;
                    --y1;
                    ++y2;
                }
                break;
            }
        }

        // Draw border

        gr.setColor( BORDER_COLOUR );
        gr.drawRect( 0, 0, width - 1, height - 1 );

    }

    //------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Instance methods
////////////////////////////////////////////////////////////////////////

    public Direction getDirection( )
    {
        return direction;
    }

    //------------------------------------------------------------------

    public boolean isPressed( )
    {
        return pressed;
    }

    //------------------------------------------------------------------

    public void setPressed( boolean pressed )
    {
        if ( this.pressed != pressed )
        {
            this.pressed = pressed;
            repaint( );
        }
    }

    //------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Instance variables
////////////////////////////////////////////////////////////////////////

    private int         width;
    private int         height;
    private int         arrowSize;
    private Direction   direction;
    private boolean     pressed;

}

//----------------------------------------------------------------------