/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2004 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.openide.explorer.propertysheet;

import org.openide.util.Utilities;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.*;

/**
 * A component which can display a description, a title and a button.
 * 
 * @author  Tim Boudreau
 */
class DescriptionComponent extends JComponent implements ActionListener, MouseListener {
    private static int fontHeight = -1;
    private JTextArea jta;
    private JLabel lbl;
    private JButton btn;
    private JScrollPane jsc;
    
    /** Creates a new instance of SplitLowerComponent */
    public DescriptionComponent() {
        init();
    }
    
    private void init() {
        setBorder (BorderFactory.createEmptyBorder (2, 2, 2, 2));
        
        jta = new JTextArea();
        jta.setLineWrap(true);
        jta.setWrapStyleWord(true);
        jta.setOpaque(false);
        jta.setBackground (getBackground());
        jta.setEditable(false);
        jta.setOpaque(false);

        //We use a JScrollPane to suppress the changes in layout that will be
        //caused by adding the raw JTextArea directly - JTextAreas can fire
        //preferred size changes from within their paint methods, leading to
        //cyclic revalidation problems
        jsc = new JScrollPane(jta);
        jsc.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
        jsc.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_NEVER);
        jsc.setBorder (BorderFactory.createEmptyBorder());
        jsc.setViewportBorder(jsc.getBorder());
        jsc.setOpaque(false);
        jsc.setBackground(getBackground());
        jsc.getViewport().setOpaque(false);


        Font f = UIManager.getFont ("Tree.font"); //NOI18N
        if (f != null) {
            jta.setFont(f);
        }

        btn = new JButton ();
        btn.addActionListener (this);
        Image help = Utilities.loadImage(
            "org/openide/resources/propertysheet/propertySheetHelp.gif"); //NOI18N

        ImageIcon helpIcon = new ImageIcon(help); //NOI18N
        btn.setIcon(helpIcon);
        btn.setPreferredSize (new Dimension (helpIcon.getIconWidth(), helpIcon.getIconHeight()));
        btn.setBorder (BorderFactory.createEmptyBorder());
        btn.setBorderPainted(false);
        btn.setFocusable(false);

        lbl = new JLabel ("Label"); //NOI18N
        lbl.setFont (lbl.getFont().deriveFont (Font.BOLD));
        
        add (jsc);
        add (lbl);
        add (btn);
        jta.addMouseListener(this);
        jsc.addMouseListener(this);
        lbl.addMouseListener(this);
        btn.addMouseListener(this);
        jsc.getViewport().addMouseListener(this);
    }
    
    public void doLayout() {
        Insets ins = getInsets();
        Dimension bttn = btn.getMinimumSize();
        Dimension lbll = lbl.getPreferredSize();
        
        int height = Math.max (bttn.height, lbll.height);
        int right = getWidth() - (ins.right + bttn.width);
        
        
        btn.setBounds (right, ins.top, 
            bttn.width, height);
        
        lbl.setBounds (ins.left, ins.top, right, height);
        
        jsc.setBounds (ins.left, height, getWidth() - (ins.left + ins.right), 
            getHeight() - height);
    }
    
    public void setDescription (String title, String txt) {
        if (title == null) {
            title = "";
        }
        if (txt == null) {
            txt = "";
        }
        lbl.setText (title);
        if (title.equals(txt)) {
            jta.setText("");
        } else {
            jta.setText (txt);
        }
    }
    
    public void setHelpEnabled (boolean val) {
        btn.setEnabled(val);
    }
    
    /**
     * Overridden to calculate a font height on the first paint
     */
    public void paint (Graphics g) {
        if (fontHeight == -1) {
            fontHeight = g.getFontMetrics(lbl.getFont()).getHeight();
        }
        super.paint(g);
    }
    
    /** Overridden to ensure the description area doesn't grow too big
     * with large amounts of text */
    public Dimension getPreferredSize() {
        Dimension d = new Dimension(super.getPreferredSize());
        if (fontHeight > 0) {
            Insets ins = getInsets();
            d.height = Math.max (50, Math.max (d.height,
                (4 * fontHeight) + ins.top + ins.bottom + 12));
        } else {
            d.height = Math.min (d.height, 64);
        }
        return d;
    }

    public Dimension getMinimumSize() {
        if (fontHeight < 0) {
            return super.getMinimumSize();
        }
        Dimension d = new Dimension(4 * fontHeight, 4 * fontHeight);
        return d;
    }

    public void actionPerformed(ActionEvent actionEvent) {
        PSheet sheet = (PSheet) SwingUtilities.getAncestorOfClass(PSheet.class, this);
        if (sheet != null) {
            sheet.helpRequested();
        }
    }

    private PSheet findSheet() {
        return (PSheet) SwingUtilities.getAncestorOfClass(PSheet.class, this);
    }

    public void mouseClicked(MouseEvent e) {
    }

    public void mouseEntered(MouseEvent e) {
    }

    public void mouseExited(MouseEvent e) {
    }

    /**
     * Forward events that might invoke the popup menu
     */
    public void mousePressed(MouseEvent e) {
        PSheet sh = findSheet();
        if (sh != null) {
            sh.mousePressed(e);
        }
    }
    
    /**
     * Forward events that might invoke the popup menu
     */
    public void mouseReleased(MouseEvent e) {
        PSheet sh = findSheet();
        if (sh != null) {
            sh.mousePressed(e);
        }
    }
    
}