Java TableCellRenderer for a boolean checkbox field

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Krick - 03 Feb 2004 22:51 GMT

I just wanted to post some code that I recently got working
for the benefit of other programmers who may have encountered
the same problems I did getting this to work. Enjoy!

class CheckBoxTableCellRenderer
extends JCheckBox
implements TableCellRenderer {

Border noFocusBorder;
Border focusBorder;

public CheckBoxTableCellRenderer() {
super();
setOpaque(true);
setBorderPainted(true);
setHorizontalAlignment(SwingConstants.CENTER);
setVerticalAlignment(SwingConstants.CENTER);
}

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

if (isSelected) {
setForeground(table.getSelectionForeground());
setBackground(table.getSelectionBackground());
}
else {
setForeground(table.getForeground());
setBackground(table.getBackground());
}

if (hasFocus) {
if (focusBorder == null) {
focusBorder = UIManager.getBorder("Table.focusCellHighlightBorder");
}
setBorder(focusBorder);
}
else {
if (noFocusBorder == null) {
noFocusBorder = new EmptyBorder(1, 1, 1, 1);
}
setBorder(noFocusBorder);
}

setSelected(Boolean.TRUE.equals(value));
return this;
}
}

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Manish Hatwalne - 04 Feb 2004 07:23 GMT

If you return Boolean as the column class for your JTable model, this will
be done automatically by JTable.

- Manish

> I just wanted to post some code that I recently got working
> for the benefit of other programmers who may have encountered
[quoted text clipped - 46 lines]
> }
> }

Reply to this Message

Krick - 04 Feb 2004 14:55 GMT

I'm not sure what you mean. Please explain.

> If you return Boolean as the column class for your JTable model, this will
> be done automatically by JTable.
[quoted text clipped - 53 lines]
> > }
> > }

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Christian Kaufhold - 04 Feb 2004 15:51 GMT

> class CheckBoxTableCellRenderer
> extends JCheckBox
[quoted text clipped - 6 lines]
> super();
> setOpaque(true);

Do not use setOpaque for buttons.

setContentAreaFilled(true);

> setBorderPainted(true);
> setHorizontalAlignment(SwingConstants.CENTER);
[quoted text clipped - 14 lines]
> setBackground(table.getBackground());
> }

setEnabled(table.isEnabled());
setComponentOrientation(table.getComponentOrientation());

> if (hasFocus) {
> if (focusBorder == null) {
[quoted text clipped - 5 lines]
> if (noFocusBorder == null) {
> noFocusBorder = new EmptyBorder(1, 1, 1, 1);

How do you know the focusBorder has insets (1,1,1,1)?

if (focusBorder == null)
focusBorder = UIManager.getBorder("Table.focusCellHighlightBorder");

if (focusBorder != null)
{
Insets n = focusBorder.getBorderInsets(this);
noFocusBorder = new EmptyBorder(n);
}
}

Christian

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Kleopatra - 06 Feb 2004 14:53 GMT

> public Component getTableCellRendererComponent(JTable table, Object value,
> boolean isSelected,
[quoted text clipped - 5 lines]
> setBackground(table.getSelectionBackground());
> }

don't assume table != null. From the api doc:

public Component getTableCellRendererComponent(JTable table,
Object value, boolean isSelected, [...]

Parameters:
table - the JTable that is asking the renderer to draw; can be null

DefaultTableCellRenderer is similarly misbehaving - but that's no reason
not to do it correctly :-)

Greetings
Jeanette

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Krick - 06 Feb 2004 21:19 GMT

Ok, here's a revised version incorporating all the suggestions people have made...

class CheckBoxTableCellRenderer
extends JCheckBox
implements TableCellRenderer {

Border noFocusBorder;
Border focusBorder;

public CheckBoxTableCellRenderer() {
super();
//setOpaque(true);
setContentAreaFilled(true); // use this instead of setOpaque()
setBorderPainted(true);
setHorizontalAlignment(SwingConstants.CENTER);
setVerticalAlignment(SwingConstants.CENTER);
}

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

if(table == null) {
// ???
}
else {
if (isSelected) {
setForeground(table.getSelectionForeground());
setBackground(table.getSelectionBackground());
}
else {
setForeground(table.getForeground());
setBackground(table.getBackground());
}

setEnabled(table.isEnabled());
setComponentOrientation(table.getComponentOrientation());

if (hasFocus) {
if (focusBorder == null) {
focusBorder = UIManager.getBorder("Table.focusCellHighlightBorder");
}
setBorder(focusBorder);
}
else {
if (noFocusBorder == null) {
if (focusBorder == null) {
focusBorder = UIManager.getBorder("Table.focusCellHighlightBorder");
}
if (focusBorder != null) {
Insets n = focusBorder.getBorderInsets(this);
noFocusBorder = new EmptyBorder(n);
}
}
setBorder(noFocusBorder);
}

setSelected(Boolean.TRUE.equals(value));
}
return this;
}
}

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Java TableCellRenderer for a boolean checkbox field

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