Dennis McNulty

Rob -

(Problem resolved)

Your SSCEE had the answer to my problem. Setting the background in the table header filled in the empty space. I had thought that a JTableHeader object was merely a reorganization of data in the JTableColumnModel, and didn't have any displayable items of its own. In my large app, I am using custom table header renderers, declared as parts of TableColumns, and I had never needed to deal with table headers.

Your SCCEE also held another surprise for me. I had thought that it wasn't allowed to have a null JTableModel. About 100 lines of code in my first posting were devoted solely to building the table model.

Again, though, I'd like to know if there is some place for greenhorns like me to find existing SSCEEs. If I had known about this TableDemo2 one, I wouldn't have needed to bother anyone at CodeRanch about my problem.

Thanks - Dennis

I didn't know that Oracle demo programs didn't qualify as SSCCEs. I was hoping to avoid creating a lot of source code from scratch. Thank you for the example SSCCE. I'll give it a try in a little while. Is there any kind of repository of SSCCEs for new forum users like me?

Thanks - Dennis

I have a situation with a table that's narrower and shorter than the enclosing scroll pane's viewport, and column auto-resizing is turned off, so there's empty space below and to the right of the table. I'd like to fill the empty space with a single background color. I can fill in the bottom using scrollPane.setBackground(), and I can set most of the right side using scrollPane.getViewport().setBackground(). But I'm still left with an uncolored strip to the right of the table's column headers. I've tried using setBackground on the scroll pane's enclosing panel, and also tried using scrollPane.setColumnHeaderView() to force a new colored JPanel, but neither method has worked.

Is there any way to fill in that strip right of the table's column headers?

Below is the code I'm using, a slight variation of TableDemo.java from Oracle's Swing Example set.

Thanks in advance for any help. - Dennis


/* * TableDemo.java requires no other files. */ import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.table.AbstractTableModel; import java.awt.Color; import java.awt.Dimension; import java.awt.GridLayout; /** * TableDemo is just like SimpleTableDemo, except that it * uses a custom TableModel. */ public class TableDemo extends JPanel { private boolean DEBUG = false; public TableDemo() { super(new GridLayout(1,0)); JTable table = new JTable(new MyTableModel()); table.setPreferredScrollableViewportSize(new Dimension(500, 70)); // table.setFillsViewportHeight(true); // So area below table gets background table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF); //Create the scroll pane and add the table to it. JScrollPane scrollPane = new JScrollPane(table); Color light_blue = new Color (205, 235, 255); scrollPane.getViewport().setBackground(light_blue); // right of table scrollPane.setBackground(light_blue); // fills below table this.setBackground(light_blue); // does nothing JPanel hdr_pnl = new JPanel(); hdr_pnl.setBackground(light_blue); hdr_pnl.setOpaque(true); scrollPane.setColumnHeaderView(hdr_pnl); // does nothing //Add the scroll pane to this panel. add(scrollPane); } class MyTableModel extends AbstractTableModel { private String[] columnNames = {"First Name", "Last Name", "Sport", "# of Years", "Vegetarian"}; private Object[][] data = { {"Kathy", "Smith", "Snowboarding", new Integer(5), new Boolean(false)}, {"John", "Doe", "Rowing", new Integer(3), new Boolean(true)}, {"Sue", "Black", "Knitting", new Integer(2), new Boolean(false)}, {"Jane", "White", "Speed reading", new Integer(20), new Boolean(true)}, {"Joe", "Brown", "Pool", new Integer(10), new Boolean(true)}, {"Dennis", "Martin", "Cycling", new Integer(5), new Boolean(false)}, {"Phil", "Durt", "Jogging", new Integer(4), new Boolean(false)}, {"Arty", "Choke", "Wrestling", new Integer(7), new Boolean(false)} }; public int getColumnCount() { return columnNames.length; } public int getRowCount() { return data.length; } public String getColumnName(int col) { return columnNames[col]; } public Object getValueAt(int row, int col) { return data[row][col]; } /* * JTable uses this method to determine the default renderer/ * editor for each cell. If we didn't implement this method, * then the last column would contain text ("true"/"false"), * rather than a check box. */ public Class getColumnClass(int c) { return getValueAt(0, c).getClass(); } /* * Don't need to implement this method unless your table's * editable. */ public boolean isCellEditable(int row, int col) { //Note that the data/cell address is constant, //no matter where the cell appears onscreen. if (col < 2) { return false; } else { return true; } } /* * Don't need to implement this method unless your table's * data can change. */ public void setValueAt(Object value, int row, int col) { if (DEBUG) { System.out.println("Setting value at " + row + "," + col + " to " + value + " (an instance of " + value.getClass() + ")"); } data[row][col] = value; fireTableCellUpdated(row, col); if (DEBUG) { System.out.println("New value of data:"); printDebugData(); } } private void printDebugData() { int numRows = getRowCount(); int numCols = getColumnCount(); for (int i=0; i < numRows; i++) { System.out.print(" row " + i + ":"); for (int j=0; j < numCols; j++) { System.out.print(" " + data[i][j]); } System.out.println(); } System.out.println("--------------------------"); } } /** * 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("TableDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. TableDemo newContentPane = new TableDemo(); 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(); } }); } }