package com.itpwebsolutions.awt;

import java.awt.Button;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.SystemColor;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.ImageObserver;

/**
 * <p>Title: DropBox</p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: ITP Web Solutions Inc.</p>
 * @author Brian Cairns
 * @version 0.1
 */

public class ImageButton extends Button implements ImageObserver, MouseListener
{
    boolean pressed = false;    // true if mouse button has been pressed on this button and not released yet
    boolean inside = false;     // true if the mouse cursor is over the button

    String label;               // text label for this button
    Image enabled, disabled;    // images to display to the left of the text
    Image imageTemp;
    int iWidth, iHeight;        // image width and height
    int iHgap = 3;              // horizontal gap between image and text

    Rectangle rectBounds = new Rectangle();
    Dimension preferredSize;
    FontMetrics fm;

    int topOffset, leftOffset;  // offsets for image position
    int textHeight;             // ascent height of text
    int textGutter;             // difference between top of image and top of text

    /**
     * Global default insets for the button.  This was designed to emulate
     * Windows ME native buttons, suitability for use with other OS's may vary.
     */
    static Insets insets = new Insets( 5, 5, 5, 5 );

    /**
     * These control how much the text and image are offset when the button is drawn
     * in "pressed" state.  This was designed to emulate Windows ME native buttons,
     * suitability for use with other OS's may vary
     */
    static int hPressOffset = 1;
    static int vPressOffset = 1;

    /**
     * Construct a new ImageButton with the supplied image and text
     * @param text the text label
     * @param img the image to display
     */
    public ImageButton( String text, Image img )
    {
        super( text );
        label = text;
        enabled = img;
        if( img != null )
        {
            iWidth = img.getWidth( this );
            iHeight = img.getHeight( this );
            disabled = GrayFilter.createDisabledImage( img );
            super.setForeground( SystemColor.control );
        }
        else
        {
            iHgap = 0;
        }
        this.addMouseListener( this );
    }

    /**
     * Se the horizontal gap between the image and the text
     * @param h the horizontal gap in pixels
     */
    public void setHgap( int h )
    {
        iHgap = h;
    }

    /**
     * Set insets which will be applied to all image buttons.
     * This may be useful for customizing ImageButton for different operating
     * systems
     * @param ins the new insets
     */
    public static void setGlobalInsets( Insets ins )
    {
        insets = ins;
    }

    /**
     * Set the offsets for displaying a "pressed" button.  This may be useful
     * for customizing ImageButton's pressed look for different operating systems.
     * @param horiz
     * @param vert
     */
    public static void setGlobalPressOffsets( int horiz, int vert )
    {
        hPressOffset = horiz;
        vPressOffset = vert;
    }

    /**
     * paints the image button
     * @param g the graphics context
     */
    public void paint( Graphics g )
    {
        if( enabled == null )
        {
            super.paint( g );
            return;
        }

        if( preferredSize == null ) getPreferredSize();

        rectBounds = super.getBounds();

        fm = g.getFontMetrics();
        textHeight = fm.getAscent() - fm.getDescent() - fm.getLeading();
        topOffset = insets.top + ( rectBounds.height - iHeight - insets.top - insets.bottom ) / 2;
        leftOffset = insets.left + ( rectBounds.width - fm.stringWidth( label ) - iWidth - iHgap - insets.left - insets.right ) / 2;
        textGutter = ( iHeight - textHeight ) / 2;

        super.paint( g );

        if( isEnabled() )
        {
            imageTemp = enabled;
            g.setColor( SystemColor.textText );
        }
        else
        {
            imageTemp = disabled;
            g.setColor( SystemColor.textInactiveText );
        }

        if( pressed && inside )
        {
            if( imageTemp != null ) g.drawImage( imageTemp, leftOffset + hPressOffset, topOffset + vPressOffset, this );
            g.drawString( label, leftOffset + iWidth + iHgap + hPressOffset, topOffset + textGutter + textHeight + vPressOffset );
        }
        else
        {
            if( imageTemp != null ) g.drawImage( imageTemp, leftOffset, topOffset, this );
            g.drawString( label, leftOffset + iWidth + iHgap, topOffset + textGutter + textHeight );
        }
    }

    /**
     * Designed to capture the getPreferredSize() set by the OS, then delete the
     * label, and add to the preferred size based on the image size
     *
     * @return preferred dimensions of this button
     */
    public Dimension getPreferredSize()
    {
        if( enabled == null )
            return super.getPreferredSize();

        if( preferredSize == null )
        {
            preferredSize = super.getPreferredSize();

            preferredSize.width += iWidth + iHgap;
            preferredSize.height = Math.max( iHeight + insets.top + insets.bottom, preferredSize.height );
            super.setLabel( null );
        }

        return preferredSize;
    }

    public void setLabel( String text )
    {
        label = text;
        preferredSize = null;
        super.setLabel( text );
    }

    public String getLabel()
    {
        return label;
    }

    public boolean imageUpdate( Image img, int infoflags, int x, int y, int width, int height )
    {
        if( infoflags == ALLBITS )
        {
            repaint();
            return false;
        }
        return true;
    }

    public void mouseClicked(MouseEvent e) { pressed = false; }
    public void mousePressed(MouseEvent e) { pressed = true; }
    public void mouseReleased(MouseEvent e){ pressed = false; }
    public void mouseEntered(MouseEvent e) { inside = true; }
    public void mouseExited(MouseEvent e)  { inside = false; repaint(); }
}