JTable cell rendering

[jite eghagha]

Hi,

My code reads data from text file, the format of each line is below: ( a small sample text file would be...just 5 lines)
00
35
25
35
00

If you would think of each line as an address [0][0]; i'm interested in repetition of addresses and wish to show this with a JTable


So far the code runs fine, it prints the number of times any address show up in the text file on the JTable.

Now i must switch to using color intensity to show repetition. (because the real text file is about 64, 64 array)

How do i shade each cell from white to red as they get more hits.

import java.awt.Color;
import java.awt.Component;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import javax.swing.table.DefaultTableCellRenderer;

public class SimpleTableDemo extends JPanel {
    private boolean DEBUG = false;
    private Object rowCol[][]  = new Object[5][5];
    private final JTable table;
/*
    class RowRenderer extends DefaultTableCellRenderer {
        public Component getTableCellRendererComponent (JTable table, Object value, boolean isSelected,
                    boolean hasFocus, int row, int column) {
                    if(row % 2 == 0)
                        setForeground(Color.RED);
                    else
                        setForeground(Color.WHITE);

                    return super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
        }
    }
  */
    public SimpleTableDemo() {

        super(new GridLayout(1,0));
        for (int x = 0; x <= 4; x++) {
            for (int y = 0; y <= 4; y++) {
                rowCol[x][y] = new Integer(0);
            }
        }
        readTextFile();
        String[] columnNames = new String[5];
        for (int x = 0; x < 5; x++) {
            columnNames[x] = Integer.toString(x);
        }

        table = new JTable(rowCol, columnNames);
        table.setRowHeight(10);
        table.setPreferredScrollableViewportSize(new Dimension(500, 70));
        table.setFillsViewportHeight(true);


        if (DEBUG) {
            table.addMouseListener(new MouseAdapter() {
                public void mouseClicked(MouseEvent e) {
                    printDebugData(table);
                }
            });
        }

        //Create the scroll pane and add the table to it.
        JScrollPane scrollPane = new JScrollPane(table);

        //Add the scroll pane to this panel.
        add(scrollPane);
    }
    public void readTextFile() {
      try{
        FileInputStream fstream = new FileInputStream("C:/Users/Jite Eghagha/Desktop/address.txt");
        DataInputStream in = new DataInputStream(fstream);
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
        String strLine;
        //Read File Line By Line
        while ((strLine = br.readLine()) != null)   {
          parseAddress(strLine);
        }
        //Close the input stream
        in.close();
        }catch (Exception e){
          //Catch exception if any
          System.err.println("Error: " + e.toString());
        }
    }
    public void parseAddress(String text){
        Character  row = text.charAt(0);
        Character  column = text.charAt(1);

        increaseOpacity(new Integer(row.toString()), new Integer(column.toString()));
    }
    public void increaseOpacity(int x, int y) {
        rowCol[x][y] = (Integer)rowCol[x][y] + new Integer(1);
        // WISH I COULD INCREASE THE COLORS INTENSITY HERE 
       rowCol[x][y] = new Color(153, 0, 153);
    }
 

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("SimpleTableDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        SimpleTableDemo newContentPane = new SimpleTableDemo();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}
    

[Paul Clapham]

Most of that code is irrelevant to your question. You're asking how to make a JLabel's colour shade from white to red depending on some parameter. White meaning zero, I suppose, and red meaning the maximum value. That's all. All of the JTable background is unhelpful.

So do you have a question about how to find the maximum value? Or just how to choose a colour value which is 0.693 of the way between white and red? Or some other question as well?

[jite eghagha]

thank you,

I am asking how to make a "cells" color get darker based on parameters. Not a JLabel, but the color of the cell itself.

[Paul Clapham]

You are using a JLabel, you know. DefaultTableCellRenderer extends JLabel. But in any case the answer to that is easy: you call the setBackground(Color) method. Make sure there is a background colour to set by also calling setOpaque(true).

[jite eghagha]

thank you.