/*
 *                 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 1997-2003 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.netbeans.modules.form.palette;

import java.awt.*;
import java.awt.event.MouseEvent;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.MouseInputListener;
import javax.swing.plaf.basic.BasicListUI;
import java.beans.BeanInfo;
import java.lang.ref.WeakReference;

import org.openide.nodes.Node;

/**
 * Specialized JList for palette items (content of a palette category) - having
 * special UI and renderer providing fine-tuned alignment, rollover effect,
 * showing names and different icon size. Used by CategoryPresentPanel.
 *
 * @author Tomas Pavek
 */

class CategoryList extends JList {

    private int rolloverIndex = -1;
    private boolean showNames;

    static final int BASIC_ICONSIZE = BeanInfo.ICON_COLOR_16x16;
    private int iconSize = BASIC_ICONSIZE;

    private static WeakReference rendererRef;

    /** Constructor. */
    CategoryList() {
        super();
        setOpaque(false);
        setBorder(new EmptyBorder(2, 2, 2, 1));
        setLayoutOrientation(JList.HORIZONTAL_WRAP);
        setVisibleRowCount(0);
        setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        setCellRenderer(getItemRenderer());
    }

    public void updateUI() {
        setUI(new CategoryListUI());
        invalidate();
    }
    
    // Workaround for issue 39037. Due to the following method we can
    // use getPreferredSize() in the implementation of the method
    // getPreferredHeight(). Otherwise we would have to copy the content
    // of getPreferredSize() into the layout manager of the enclosing JScrollPane.
    // We cannot change the width directly through setBounds() method
    // because it would force another repaint.
    Integer tempWidth;
    public int getWidth() {
        return (tempWidth == null) ? super.getWidth() : tempWidth.intValue();
    }

    // ---------

    boolean getShowNames() {
        return showNames;
    }

    void setShowNames(boolean show) {
        if (show != showNames) {
            showNames = show;
            firePropertyChange("cellRenderer", null, null); // NOI18N
        }
    }

    int getIconSize() {
        return iconSize;
    }

    void setIconSize(int size) {
        if (size != iconSize) {
            iconSize = size;
            firePropertyChange("cellRenderer", null, null); // NOI18N
        }
    }
    
    // workaround for bug 4832765, which can cause the
    // scroll pane to not let the user easily scroll up to the beginning
    // of the list.  An alternative would be to set the unitIncrement
    // of the JScrollBar to a fixed value. You wouldn't get the nice
    // aligned scrolling, but it should work.
    public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) {
        int row;
        if (orientation == SwingConstants.VERTICAL &&
            direction < 0 && (row = getFirstVisibleIndex()) != -1) {
            Rectangle r = getCellBounds(row, row);
            if ((r.y == visibleRect.y) && (row != 0))  {
                Point loc = r.getLocation();
                loc.y--;
                int prevIndex = locationToIndex(loc);
                Rectangle prevR = getCellBounds(prevIndex, prevIndex);
                
                if (prevR == null || prevR.y >= r.y) {
                    return 0;
                }
                return prevR.height;
            }
        }
        return super.getScrollableUnitIncrement(visibleRect, orientation, direction);
    }

    /**
     * Returns preferred height of the list for the specified width.
     *
     * @return preferred height of the list for the specified width.
     */
    public int getPreferredHeight(int width) {
        return ((CategoryListUI)getUI()).getPreferredHeight(width);
    }

    // --------
    // list item renderer

    private static ListCellRenderer getItemRenderer() {
        ListCellRenderer renderer = rendererRef == null ? null :
                                      (ListCellRenderer) rendererRef.get();
        if (renderer == null) {
            renderer = new ItemRenderer();
            rendererRef = new WeakReference(renderer);
        }
        return renderer;
    }

    static class ItemRenderer implements ListCellRenderer {

        private static JToggleButton button;
        private static Border defaultBorder;

        ItemRenderer() {
            if (button == null) {
                button = new JToggleButton();

                String laf = UIManager.getLookAndFeel().getClass().getName();
                if (laf.equals("javax.swing.plaf.metal.MetalLookAndFeel") // NOI18N
                    || laf.equals("com.sun.java.swing.plaf.windows.WindowsLookAndFeel")) // NOI18N
                { // for Metal and Windows Look&Feel use toolbar button rendering
                    button.setMargin(new Insets(1, 0, 1, 0));
                    JToolBar toolbar = new JToolBar();
                    toolbar.setRollover(true);
                    toolbar.setFloatable(false);
                    toolbar.setLayout(new BorderLayout(0, 0));
                    toolbar.setBorder(new EmptyBorder(0, 0, 0, 0));
                    toolbar.add(button);
                }
                else { // otherwise use normal button with default or empty border
                    button.setMargin(new Insets(1, 1, 1, 1));
                    defaultBorder = button.getBorder();
                }
            }
        }

        public Component getListCellRendererComponent(JList list,
                                                      Object value, 
                                                      int index,
                                                      boolean isSelected,
                                                      boolean cellHasFocus)
        {
            CategoryList categoryList = (CategoryList) list;
            boolean showNames = categoryList.getShowNames();
            int iconSize = categoryList.getIconSize();

            JComponent rendererComponent = defaultBorder == null ?
                (JComponent) button.getParent() : button;

            Node node = (Node) value;
            Icon icon = new ImageIcon(node.getIcon(iconSize));
            button.setIcon(icon);
            
            button.setText(showNames ? node.getDisplayName() : null);
            rendererComponent.setToolTipText(
                node.getShortDescription().replace('-', '.')); // NOI18N

            button.setSelected(isSelected);
            if (defaultBorder == null) { // Windows or Metal
                // let the toolbar UI render the button according to "rollover"
                button.getModel().setRollover(
                    index == categoryList.rolloverIndex && !isSelected);
            }
            else { // Mac OS X and others - set the border explicitly
                button.setBorder(defaultBorder);
            }
            button.setBorderPainted((index == categoryList.rolloverIndex) || isSelected);

            button.setHorizontalAlignment(showNames && iconSize == BASIC_ICONSIZE ?
                                   SwingConstants.LEFT : SwingConstants.CENTER);
            button.setHorizontalTextPosition(iconSize == BASIC_ICONSIZE ?
                                  SwingConstants.RIGHT : SwingConstants.CENTER);
            button.setVerticalTextPosition(iconSize == BASIC_ICONSIZE ?
                                 SwingConstants.CENTER : SwingConstants.BOTTOM);

            return rendererComponent;
        }
    }

    // ---------
    // list UI

    static class CategoryListUI extends BasicListUI {

        protected void updateLayoutState() {
            super.updateLayoutState();

            if (list.getLayoutOrientation() == JList.HORIZONTAL_WRAP) {
                Insets insets = list.getInsets();
                int listWidth = list.getWidth() - (insets.left + insets.right);
                if (listWidth >= cellWidth) {
                    int columnCount = listWidth / cellWidth;
                    cellWidth = listWidth / columnCount;
                }
            }
        }
        
        public int getPreferredHeight(int width) {
            ((CategoryList)list).tempWidth = new Integer(width);
            int result;
            try {
                result = (int)getPreferredSize(list).getHeight();
            } finally {
                ((CategoryList)list).tempWidth = null;
            }
            return result;
        }

        protected MouseInputListener createMouseInputListener() {
            return new ListMouseInputHandler();
        }

        private class ListMouseInputHandler extends MouseInputHandler {

            private int selIndex = -1;

            public void mousePressed(MouseEvent e) {
                if (getValidIndex(e.getPoint()) >= 0) {
                    selIndex = list.getSelectedIndex();
                    super.mousePressed(e);
                }
            }

            public void mouseDragged(MouseEvent e) {
                if (getValidIndex(e.getPoint()) >= 0)
                    super.mouseDragged(e);
            }

            public void mouseMoved(MouseEvent e) {
                mouseEntered(e);
            }

            public void mouseEntered(MouseEvent e) {
                if (list.isEnabled())
                    setRolloverIndex(getValidIndex(e.getPoint()));
            }

            public void mouseExited(MouseEvent e) {
                if (list.isEnabled())
                    setRolloverIndex(-1);
            }

            public void mouseReleased(MouseEvent e) {
                if (getValidIndex(e.getPoint()) >= 0) {
                    super.mouseReleased(e);
                    if (selIndex > -1 && list.getSelectedIndex() == selIndex)
                        list.removeSelectionInterval(selIndex, selIndex);
                }
            }

            private void setRolloverIndex(int index) {
                int oldIndex = ((CategoryList)list).rolloverIndex;
                if (index != oldIndex) {
                    ((CategoryList)list).rolloverIndex = index;
                    if (oldIndex > -1) {
                        Rectangle r = getCellBounds(list, oldIndex, oldIndex);
                        if (r != null)
                            list.repaint(r.x, r.y, r.width, r.height);
                    }
                    if (index > -1) {
                        Rectangle r = getCellBounds(list, index, index);
                        if (r != null)
                            list.repaint(r.x, r.y, r.width, r.height);
                    }
                }
            }
        }

        private int getValidIndex(Point p) {
            int index = locationToIndex(list, p);
            return index >= 0 && getCellBounds(list, index, index).contains(p) ?
                index : -1;
        }
    }
}