Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.util.HashMap;
import java.util.Map;

import javax.swing.JTable;
import javax.swing.table.JTableHeader;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;

public class Main {
    public static void main(String[] argv) throws Exception {
        int rows = 10;
        int cols = 5;
        JTable table = new JTable(rows, cols);
        JTableHeader header = table.getTableHeader();

        ColumnHeaderToolTips tips = new ColumnHeaderToolTips();
        for (int c = 0; c < table.getColumnCount(); c++) {
            TableColumn col = table.getColumnModel().getColumn(c);
            tips.setToolTip(col, "Col " + c);
        }
        header.addMouseMotionListener(tips);
    }
}

class ColumnHeaderToolTips extends MouseMotionAdapter {
    TableColumn curCol;
    Map tips = new HashMap();

    public void setToolTip(TableColumn col, String tooltip) {
        if (tooltip == null) {
            tips.remove(col);
        } else {
            tips.put(col, tooltip);
        }
    }

    public void mouseMoved(MouseEvent evt) {
        JTableHeader header = (JTableHeader) evt.getSource();
        JTable table = header.getTable();
        TableColumnModel colModel = table.getColumnModel();
        int vColIndex = colModel.getColumnIndexAtX(evt.getX());
        TableColumn col = null;
        if (vColIndex >= 0) {
            col = colModel.getColumn(vColIndex);
        }
        if (col != curCol) {
            header.setToolTipText((String) tips.get(col));
            curCol = col;
        }
    }
}