Java Swing How to - Create JTable with rows of variable height

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Question

We would like to know how to create JTable with rows of variable height.

Answer

//ww  w .jav a 2s. com
//Link to the Code:
//http://www.java2s.com/Tutorial/Java/0240__Swing/CreatingaJTablewithrowsofvariableheight.htm
 
//In this Example it is suggested to use the line:
 
//table.setRowHeight(row, getPreferredSize().height + row * 10);
 
//to set the variable Row height in a Cell of a JTable.
//This works so far; however, this call triggers a new Layout of the table 
//and causes the CellRenderer to render this Cell again. So this code 
//creates a loop.
 
//I found a snippet where this is solved by testing, if the preferredSize 
//of the component + the offset is equal to the height of the row. If it 
//is equal, the new RowHeight won't be set and the call will be skipped.
//Examplecode:
 
//int offset = row * 10;
//if (getPreferredSize().height+offset != table.getRowHeight(row)) {
//            table.setRowHeight(row,  getPreferredSize().height +offset);
//}
 
//best regards
//Matthias Bonora (mat.bonora AT gmail.com)


import java.awt.Color;
import java.awt.Component;

import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableCellRenderer;

public class Main {

  public static void main(String[] argv) {

    JFrame demoFrame = new JFrame("Variable Row Height Table Demo");

    StringTableModel imageTableModel = new StringTableModel();

    JTable imageTable = new JTable(imageTableModel);
    imageTable.getColumnModel().getColumn(0).setCellRenderer(new VariableRowHeightRenderer());

    demoFrame.getContentPane().add(new JScrollPane(imageTable));

    demoFrame.pack();
    demoFrame.setVisible(true);
  }

}

class VariableRowHeightRenderer extends JLabel implements TableCellRenderer {
  public VariableRowHeightRenderer() {
    super();
    setOpaque(true);
    setHorizontalAlignment(JLabel.CENTER);
  }

  public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
      boolean hasFocus, int row, int column) {
    if (isSelected) {
      setBackground(UIManager.getColor("Table.selectionBackground"));
    }

    if (hasFocus) {
      setBorder(UIManager.getBorder("Table.focusCellHighlightBorder"));

      if (table.isCellEditable(row, column)) {
        super.setForeground(UIManager.getColor("Table.focusCellForeground"));
        super.setBackground(UIManager.getColor("Table.focusCellBackground"));
      }
    } else {
      setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
    }
    setText((String) (value));
    table.setRowHeight(row, getPreferredSize().height + row * 10);
    return this;
  }
}

class StringTableModel extends AbstractTableModel {
  public static final int IMG_COL = 0;

  public String[] m_colNames = { "Variable Dimension" };

  public Class[] m_colTypes = { String.class };

  public StringTableModel() {
    super();

  }

  public int getColumnCount() {
    return m_colNames.length;
  }

  public int getRowCount() {
    return 3;
  }

  public String getColumnName(int col) {
    return "" + col;
  }

  public Object getValueAt(int row, int col) {
    return "aa";
  }
}

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