Custom Table Model from Default Table Model

Question

I'm creating a customised table model to create a table with column header and empty rows.But it is throwing Component paint_imediatly error.If i pass in empty string to the row vector then setNumRows then no problem. If i do like this later it throws me error in my addNewRow method which was working fine before.Can anyone help?I would realy apreaciate it.Thank you.
Kavitha

Answer 1

This must be your lucky day :)
Here is my version of an EditableTableModel which displays an emptyline as the last line
import java.io.*;
import java.util.*;
import javax.swing.table.*;
import javax.swing.event.*;
* Custom TableModel, allows addition and removal of records/rows and editting of existing values.
* it also keeps track over which rows have been altered.
* column 0 is a boolean indicating wheter or not to keep this row/record
* @author Maurice Marrink
* @version 1.0
public class EditableTableModel extends AbstractTableModel implements Serializable, TableModelListener
     protected ArrayList keep,changed;          //houden bij of een rij gedel moet worden en of ie is veranderd (false = delete)
     protected ArrayList[] DATA;
     protected int emptyLineIndex;
     protected String[] kolomNamen;
     protected Object[] kolomTypen;          // bevat een object van dezelfde class als die kolom
     protected int newRowsIndex;               // houd bij vanaf welke rij niewe regels zijn toegevoegd ivm het opslaan in de db
     protected int[]primecolumns;          //houd bij welke kolommen ingevuld moeten worden voordat de volgende regel getoond wordt (default= kolom 1)
     public EditableTableModel()
          keep = new ArrayList();               //visible
          changed=new ArrayList();               // not visisble
          primecolumns=new int[0];
          DATA=new ArrayList[0];
          kolomNamen =new String[0];
          kolomTypen=new Object[0];
          emptyLineIndex=-1;
          newRowsIndex=-1;
     * the constructor, creates a new EditableTableModel
     *@param data          an array of ArrayLists each arrayList contains the values of an entire column
     *@param names          an array containg the names of the columns
     *@param type          an array containing Objects which correspond to the objects in the columns
     public EditableTableModel(ArrayList[] data, String[] names, Object[] type)
          keep = new ArrayList();               //visible
          changed=new ArrayList();               // not visisble     
          primecolumns=new int[1];
          primecolumns[0]=1;
          DATA=data;
          for(int i=0;i<getRowCount();i++)
               keep.add(new Boolean(true));
               changed.add(new Boolean(false));
          kolomNamen=names;
          kolomTypen=type;
          emptyLineIndex=getRowCount()-1;
          addNewLine();
          newRowsIndex=emptyLineIndex;               // nieuwe regels beginnen op de lege regel
          addTableModelListener(this);
     * @return the number of rows/records
     public int getRowCount()
          return DATA[0].size();
     *@return the number of columns
     public int getColumnCount()
          return DATA.length+1;
     * returns the object containing the value for this cell
     * indexes start at 0 (wheter or not to keep this row), but the actual data starts at 1
     *@param row          the row in which the cell resides
     *@param column     the column in which the cell resides
     *@return the value of the cell wrapped in the appropiate Object
     public Object getValueAt(int row, int column)
          if(column==0)
               return keep.get(row);
          else
               return DATA[column-1].get(row);
     * allows editing of an existing value
     *@param value          the new value, should be of the same Object Type as the existing one
     *@param row               the row nr of the cell
     *@param col               the column nr of the cell
     public void setValueAt(Object value, int row, int col)
          if(col==0)
               keep.set(row,value);
          else
               DATA[col-1].set(row,value);
               changed.set(row, new Boolean(true));
          fireTableCellUpdated(row, col);
     * adds a new "empty" row after all the PrimeColums of the last row have been filled with an acceptable value
     *@see setPrimeColumns
     protected void addNewLine()
          try
               for(int i=0;i<DATA.length;i++)
                    if(kolomTypen[i] instanceof Integer)
                         DATA.add(new Integer(-1));
                    else
                    if(kolomTypen[i] instanceof Boolean)
                         DATA[i].add(new Boolean(false));
                    else
                    if(kolomTypen[i] instanceof Long)
                         DATA[i].add(new Long(-1));          //displayed as "" by cellrenderer
                    else
                         DATA[i].add(kolomTypen[i].getClass().newInstance());          //nieuw object aanmaken van het type dat gespecificeerd is, Integers en Booleans moet een waarde meegegeven worden
               keep.add(new Boolean(true));
               changed.add(new Boolean(false));
               emptyLineIndex++;
          catch(Exception e)
               e.printStackTrace();
     public void tableChanged(TableModelEvent e)
          if(e.getFirstRow()==emptyLineIndex)//alleen als de emptyLine ge?dit wordt een regel toevoegen
               boolean primesfilled=true;
               for(int i=0;i<primecolumns.length;i++)
                    if(getValueAt(emptyLineIndex,primecolumns[i]).equals(null) || getValueAt(emptyLineIndex,primecolumns[i]).toString().equals("")|| getValueAt(emptyLineIndex,primecolumns[i]).toString().equals("-1"))
                         primesfilled=false;
                         break;
               if(primesfilled)     //alleen als de primaire sleutel kolommen ingevuld zijn
                    addNewLine();
     * returns the Class type of the Objects representing the column type
     *@param c     the column nr
     public Class getColumnClass(int c)
          if(c==0)
               return new Boolean(true).getClass();
          else
               return kolomTypen[c-1].getClass();
     *@param rowIndex the index of the row
     *@param columnIndex     the index of the column
     *@return true if a cell is Editable,false otherwise (all cells are Editable)
     public boolean isCellEditable(int rowIndex, int columnIndex)
          return true;
     * returns the name of the column
     *@param column     the column index
     *@return a String containing the name of the column
     public String getColumnName(int column)
          if(column==0)
               return "";
          else
               return kolomNamen[column-1];
     *@return wheter or not 1 or rows is marked for deletion
     public boolean deletionNeeded()
          Boolean B;
          for(int i=0;i<emptyLineIndex;i++)
               B=(Boolean)keep.get(i);
               if(!B.booleanValue())
                    return true;
          return false;
     * Deletes all rows which are marked for deletion
     *@return the number of rows that have been deleted
     public int deleteMarkedRows()          // zou niets uit moeten maken of je eerst deleteMarkedRows() of isSavedToDB(true) aanroept
          int aantalRows=0;
          Boolean B;
          for(int i=0;i<emptyLineIndex;i++)
               B=(Boolean)keep.get(i);
               if(!B.booleanValue())
                    if(deleteRow(i))
                         aantalRows++;
                         i--;
          return aantalRows;
     * deletes a single row
     *@param row     the row index
     *@return     true if the row was deleted, false otherwise
     protected boolean deleteRow(int row)
          boolean result=false;
          if(row==emptyLineIndex)               // emptyline kan niet gedelete worden
               return result;
          try
               for(int j=0;j<DATA.length;j++)
                    DATA[j].remove(row);
               changed.remove(row);
               keep.remove(row);
               emptyLineIndex--;
               if(row < newRowsIndex)
                    newRowsIndex--;
               result=true;
          catch(Exception e)
               e.printStackTrace();
          return result;
     * returns if the row has changed or not
     *@param row          the row index
     *@return true if 1 or more cells in this row had their value changed or if 1 or more rows were added, false otherwise
     public boolean hasChanged(int row)
          Boolean B=(Boolean)changed.get(row);
          return B.booleanValue();
     * Methode waarmee men kan bepalen of 1 van de originele waarden ook veranderd is.
     * Het geeft dus niet aan of er ook nieuwe rijen zijn toegevoegd.
     public boolean hasChanged()
          Boolean B;
          for(int i=0;i<newRowsIndex;i++)
               B=(Boolean)changed.get(i);
               if(B.booleanValue())
                    return true;
          return false;
     * if true it sets all flags indicating a change to false, else nothing
     *@param saved     boolean indicating all changes are now to be considerd to be the original values, or not
     public void isSavedToDB(boolean saved)
          if(saved)
               for(int i=0; i<changed.size();i++)
                    changed.set(i,new Boolean(false));
               newRowsIndex=emptyLineIndex;
     * @return the row nr. at which newly added entrys begin, updated after isSavedToDB(true) is called
     public int getNewRowsIndex()
          return newRowsIndex;
     * allows the specification of certain columns that need to be filled in, if not a new row will not be made vissible
     *@param columns     an array containing the column indexes which must be set to a valid value
     public void setPrimeColumns(int[] columns)
          primecolumns=columns;
     * allows retrieval of the PrimeColumns
     *@return an arrayof int containing the column indexes
     public int[] getPrimeColumns()
          return primecolumns;
Ok some of the comments are in dutch go ahead an blame me :(
if you have any questions, just ask.
i also have a TableModel which can use automatic numbering
Oh numbers (currently only Integer and Long) are initiated wth a value of -1 if you want to display them as blank cells like i wanted to you modify a cellrenderer (or use mine)
Mr Mean