/*
    *  UnBBayes
    *  Copyright (C) 2002, 2008 Universidade de Brasilia - http://www.unb.br
    *
    *  This file is part of UnBBayes.
    *
    *  UnBBayes 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.
   *
   *  UnBBayes 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 UnBBayes.  If not, see <http://www.gnu.org/licenses/>.
   *
   */
  package unbbayes.gui.table;
  
  import java.awt.Component;
  import java.awt.Dimension;
  import java.awt.Graphics;
  import java.awt.Rectangle;
  import java.util.Enumeration;
  import java.util.Hashtable;
  import java.util.Iterator;
  import java.util.Vector;
  
  import javax.swing.JComponent;
  import javax.swing.plaf.basic.BasicTableHeaderUI;
  import javax.swing.table.TableCellRenderer;
  import javax.swing.table.TableColumn;
  import javax.swing.table.TableColumnModel;
  
  
  /**
   * This class paints groupable header cells. These can be a combination of
   * normal header cells and groupable cells.
   */
  public class GroupableTableHeaderUI extends BasicTableHeaderUI {
      
      /**
       * Contains a list of ColumnGroups that have already been painted
       * in the current paint request.
       */
      protected Vector paintedGroups = new Vector();
      
      /**
       * Paint a representation of the table header.
       * @param g the Graphics context in which to paint
       * @param c the component being painted; this argument is often ignored
       */
      public void paint(Graphics g, JComponent c) {
          Rectangle clipBounds = g.getClipBounds();
          GroupableTableColumnModel cm = (GroupableTableColumnModel)header.getColumnModel();
          if (cm == null) return;
          ((GroupableTableHeader)header).setColumnMargin();
          int column = 0;
          Dimension size = header.getSize();
          Rectangle cellRect  = new Rectangle(0, 0, size.width, size.height);
          Hashtable h = new Hashtable();
          int columnMargin = cm.getColumnMargin();
          
          Enumeration columns = cm.getColumns();
          while (columns.hasMoreElements()) {
              cellRect.height = size.height;
              cellRect.y      = 0;
              TableColumn aColumn = (TableColumn)columns.nextElement();
              Iterator colGrpIter = cm.getColumnGroups(aColumn);
              if (colGrpIter != null) {
                  int groupHeight = 0;
                  while (colGrpIter.hasNext()) {
                      ColumnGroup cGroup = (ColumnGroup)colGrpIter.next();
                      Rectangle groupRect = (Rectangle)h.get(cGroup);
                      if (groupRect == null) {
                          groupRect = new Rectangle(cellRect);
                          Dimension d = cGroup.getSize(header.getTable());
                          groupRect.width  = d.width;
                          groupRect.height = d.height;
                          h.put(cGroup, groupRect);
                      }
                      if(!paintedGroups.contains(cGroup)) {
                          paintCell(g, groupRect, cGroup);
                          paintedGroups.add(cGroup);
                      }
                      groupHeight += groupRect.height;
                      cellRect.height = size.height - groupHeight;
                      cellRect.y      = groupHeight;
                  }
              }
              cellRect.width = aColumn.getWidth();
              if (cellRect.intersects(clipBounds)) {
                  paintCell(g, cellRect, column);
              }
              cellRect.x += cellRect.width;
              column++;
         }
         paintedGroups.clear();
     }
     
     /**
      * Paints a header column cell.
      * @param g Graphics context
      * @param cellRect The rectangle to contain the cell
      * @param columnIndex The header column to be painted
      */    
     private void paintCell(Graphics g, Rectangle cellRect, int columnIndex) {
         TableColumn aColumn = header.getColumnModel().getColumn(columnIndex);
         TableCellRenderer renderer = aColumn.getHeaderRenderer();
         if(renderer == null) {
             renderer = header.getDefaultRenderer();
         }
         Component component = renderer.getTableCellRendererComponent(
         header.getTable(), aColumn.getHeaderValue(),false, false, -1, columnIndex);
         rendererPane.add(component);
         rendererPane.paintComponent(g, component, header, cellRect.x, cellRect.y,
         cellRect.width, cellRect.height, true);
     }
     
     /**
      * Paint group column cell.
      * @param g Graphics context
      * @param cellRect Rectangle that the cell with be painted in
      * @param cGroup Current column group
      */    
     private void paintCell(Graphics g, Rectangle cellRect,ColumnGroup cGroup) {
         TableCellRenderer renderer = cGroup.getHeaderRenderer();
         Component component = renderer.getTableCellRendererComponent(
         header.getTable(), cGroup.getHeaderValue(),false, false, -1, -1);
         rendererPane.add(component);
         rendererPane.paintComponent(g, component, header, cellRect.x, cellRect.y,
         cellRect.width, cellRect.height, true);
     }
     
     /**
      * Calculate and return the height of the header.
      * @return Header Height
      */    
     private int getHeaderHeight() {
         int height = 0;
         GroupableTableColumnModel columnModel = (GroupableTableColumnModel)header.getColumnModel();
         for(int column = 0; column < columnModel.getColumnCount(); column++) {
             TableColumn aColumn = columnModel.getColumn(column);
             TableCellRenderer renderer = aColumn.getHeaderRenderer();
             if(renderer == null) {
                 renderer = header.getDefaultRenderer();
             }
             Component comp = renderer.getTableCellRendererComponent(
             header.getTable(), aColumn.getHeaderValue(), false, false,-1, column);
             int cHeight = comp.getPreferredSize().height;
             Iterator iter = columnModel.getColumnGroups(aColumn);
             if (iter != null) {
                 while (iter.hasNext()) {
                     ColumnGroup cGroup = (ColumnGroup)iter.next();
                     cHeight += cGroup.getSize(header.getTable()).height;
                 }
             }
             height = Math.max(height, cHeight);
         }
         return height;
     }
     
     /**
      * Calculate and return the dimension of the header.
      * @param width Starting width to be used.
      * @return Dimension of the header
      */    
     private Dimension createHeaderSize(long width) {
         TableColumnModel columnModel = header.getColumnModel();
         width += columnModel.getColumnMargin() * columnModel.getColumnCount();
         if (width > Integer.MAX_VALUE) {
             width = Integer.MAX_VALUE;
         }
         return new Dimension((int)width, getHeaderHeight());
     }
     
     /**
      * Invokes the getPreferredSize method on each UI handled by this object.
      * @param c the component whose preferred size is being queried; this argument is ignored.
      * @return the dimension of the whole header
      */
     public Dimension getPreferredSize(JComponent c) {
         long width = 0;
         Enumeration columns = header.getColumnModel().getColumns();
         while (columns.hasMoreElements()) {
             TableColumn aColumn = (TableColumn)columns.nextElement();
             width = width + aColumn.getPreferredWidth();
         }
         return createHeaderSize(width);
     }
 }