Jtable retreiving data

[Fernando Hood]

I have a one column jtable with values of type byte.

I want to retreive the data at a particular column as a byte and not an object.

Any ideas?

[Rob Camick]

The API only supports Objects, but a Byte is an Object so I don't understand the problem.

If you need further help then you need to create a SSCCE (Short, Self Contained, Compilable and Executable, Example Program), that demonstrates the incorrect behaviour.

Don't forget to use the Code Formatting Tags so the posted code retains its original formatting. That is done by selecting the code and then clicking on the "Code" button above the question input area.

[Fernando Hood]

can I assign the object value returned to a byte variable.

[Rob Camick]

Did you try it?

[Fernando Hood]

incompatible types..

[Maneesh Godbole]

Fernando,
Please check your private messages for an important administrative matter.

[Rob Camick]

Did you cast the value to a Boolean?

[Fernando Hood]

Problem resolved. Just amazed that such task take so much effort to research and resolve.

I have an index comming from a micro-controller through the serial port.

Based on the value I would like to highlight the row corresponding to the index.
The user will therefore see a color jumping up and down the table depending on the incoming index values. Any ideas?

I have been able to send the data from the table to the ram of the microcontroller which subsequently stores
it into rom. I send the entire table . In the future if I change only on cell I would like to send this value out to the controller.

I am a novie at Java but realise it very important for GUI.

Regards.

[Fernando Hood]

Still trying to highlight rows in table based on a row value. Created a stand alone close that does it but cannot get it integrated
with netbeans .At the end of the loop all of the cells are painted red.Help Required.


Main Class

  

       CustomCellRenderer gainTableRenderer =new CustomCellRenderer(0,jTableGain);

      for (int i=0; i<16; i++)  {

       gainTableRenderer.setCurrentRow(i);
       gainTableRenderer.paintRow();
       jTableGain.repaint();
       
       Object obj1 = GetData(jTableGain, i, 0);
       
      String tableValueStr = obj1.toString();
      gainValue = Integer.parseInt(tableValueStr);

      System.out.println(gainValue );  

Rendering

  * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package my.InertiaDyno;

/**
 *
 * @author fernando.hood
 */
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import javax.swing.table.*;
import java.awt.*;

public class CustomCellRenderer{

  private int gainCurrentRow;
  JTable gtable;
  TableColumn tcol;
 

public void setCurrentRow(int tableRow){

    gainCurrentRow = tableRow;

}


public void paintRow(){

    tcol.setCellRenderer(new CustomTableCellRenderer());
   
}

  public CustomCellRenderer(int tableRow, JTable inputtable ){

    gainCurrentRow = tableRow;
    gtable = inputtable;
    tcol = gtable.getColumnModel().getColumn(0);
    tcol.setCellRenderer(new CustomTableCellRenderer());
  
  }


  public class CustomTableCellRenderer extends DefaultTableCellRenderer{

      public Component getTableCellRendererComponent (JTable gtable, Object obj, boolean isSelected, boolean hasFocus, int row, int column) {

      Component cell = super.getTableCellRendererComponent(gtable, obj, isSelected, hasFocus, row, column);


          if (row  == gainCurrentRow) {

              cell.setBackground(Color.lightGray);

          }

         else {

              cell.setBackground(Color.red);

        }

      
      return cell;
    }

  }
}   

[Fernando Hood]

This the code I have been trying to alter to meet my needs.

   import javax.swing.*;
import javax.swing.table.*;
import java.awt.*;

public class CustomCellRenderer{
  JTable table;
  TableColumn tcol;
  public static void main(String[] args) {
    new CustomCellRenderer();
  }

  public CustomCellRenderer(){
    JFrame frame = new JFrame("Creating a Custom Cell Reanderer!");
    JPanel panel = new JPanel();
    String data[][] = {{"Vinod","Computer","3"},
                       {"Rahul","History","2"},
                       {"Manoj","Biology","4"},
                       {"Sanjay","PSD","5"}};
    String col [] = {"Name","Course","Year"};
    DefaultTableModel model = new DefaultTableModel(data,col);
    table = new JTable(model);
    tcol = table.getColumnModel().getColumn(0);
    tcol.setCellRenderer(new CustomTableCellRenderer());
    tcol = table.getColumnModel().getColumn(1);
    tcol.setCellRenderer(new CustomTableCellRenderer());
    tcol = table.getColumnModel().getColumn(2);
    tcol.setCellRenderer(new CustomTableCellRenderer());
    JTableHeader header = table.getTableHeader();
    header.setBackground(Color.yellow);
    JScrollPane pane = new JScrollPane(table);
    panel.add(pane);
    frame.add(panel);
    frame.setSize(500,150);
    frame.setUndecorated(true);
    frame.getRootPane().setWindowDecorationStyle(JRootPane.PLAIN_DIALOG);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
  }

  public class CustomTableCellRenderer extends DefaultTableCellRenderer{
    public Component getTableCellRendererComponent (JTable table, 
Object obj, boolean isSelected, boolean hasFocus, int row, int column) {
      Component cell = super.getTableCellRendererComponent(
                         table, obj, isSelected, hasFocus, row, column);
      if (isSelected) {
        cell.setBackground(Color.green);
      } 
      else {
        if (row % 2 == 0) {
          cell.setBackground(Color.cyan);
        }
        else {
          cell.setBackground(Color.lightGray);
        }
      }
      return cell;
    }
  }
}  

[Fernando Hood]

I have put everthing in the main class.

Main

       tcol = jTableGain.getColumnModel().getColumn(0);

      for (int i=0; i<16; i++)  {

        gainCurrentRow = i;

        tcol.setCellRenderer(new CustomTableCellRenderer());
        jPanel1.repaint();
  

subclass

        public class CustomTableCellRenderer extends DefaultTableCellRenderer {

        public Component getTableCellRendererComponent(JTable table, Object obj, boolean isSelected, boolean hasFocus, int row, int column) {

            Component cell = super.getTableCellRendererComponent(table, obj, isSelected, hasFocus, row, column);


            if (row == gainCurrentRow) {

                cell.setBackground(Color.lightGray);

            } else {

                cell.setBackground(Color.red);

            }


            return cell;
        }
    }

[Fernando Hood]

Is there any one on this forum with experience to solve this issue?

[Fernando Hood]

I have written 8000 lines of asembly code and I am now stuck at a couple of lines of JAVA and no one can help.

Hmmmm!!!

[Rob Camick]

table = new JTable( ... )
{
	public Component prepareRenderer( TableCellRenderer renderer, int row, int column)
	{
		Component c = super.prepareRenderer(renderer, row, column);

		//  Alternate row color

		if (!isRowSelected(row))
			c.setBackground(row % 2 == 0 ? getBackground() : Color.LIGHT_GRAY);

		return c;
	}
};

[Fernando Hood]

Thanks but I am trying to understand what I need to do with this code.

Should I abandon the custom cell renderer subclass? Where should this method go?




JTable table = new JTable() {
This is confusing me. What is the code doing. You are creating a table and calling a method at the same time?
Netbeans already created the table .


My problem is that at the end of the scan through the table I am only seeing the last row pinted red.
as the index get incremented from 1 to 16 it is not shoing me the row corresponding to the index.It is as if it can only display the contents
after it get out of the routine and returns control to the main program.
The sample code I used is somehow able to show me each row in red as the indexd goes from 0 to 16.

  
  // This table shades every other row yellow
    JTable table = new JTable() {
        public Component prepareRenderer(TableCellRenderer renderer,
                                         int rowIndex, int vColIndex) {
            Component c = super.prepareRenderer(renderer, rowIndex, vColIndex);
            if (rowIndex % 2 == 0 && !isCellSelected(rowIndex, vColIndex)) {
                c.setBackground(Color.yellow);
            } else {
                // If not shaded, match the table's background
                c.setBackground(getBackground());
            }
            return c;
        }
    };
  

[Rob Camick]

If you don't know what the code is doing, then why did you change the code?

The code is creating a table and overriding the prepareRenderer() method, so you don't need to use any custom renderers.

If you don't know how to do this in Netbeans, then don't use Netbeans. Learn how to write your own code and don't depend on generated code.

[Fernando Hood]

Rob,

I am getting there slowly. I now understand.

However this creates the table but I want to dynamically update the table so that
as the row is changed it will turn red.