Making a JTable cell editable - but *not* by double clicking

Question

I am trying to add a column to a JTable with the following behaviour (similar to Windows Explorer and similar shells):

• The cell can be clicked once to select it, as usual.
• The cell can be double-clicked to perform a separate action (launching an external program.)
• The cell value (a string) can still be edited, by single-clicking a second time (after a pause) or by pressing F2 when the cell is highlighted.

Double-clicking must not trigger editing of the cell, but I would like to leave any other default editing triggers operational if possible.

I have tried adding a MouseListener to the table, and consuming all MouseEvents, but this does not work - if I return true from isCellEditable() then my listener never receives any click events but if I return false then F2 no longer works.

Can this be achieved using only event listeners? I would prefer not to mess with the PLAF functions if I can avoid it.

Solution 1

You will have to make your own cellEditor and ovveride

public boolean isCellEditable( EventObject e )

You can distinguish between single and double click with the clickCount on the eventObject

If its a single Click and its on a selected cell you can return true otherwise return false;

retrieve row and column with

int row = ( (JTable) e.getSource() ).rowAtPoint(e.getPoint());
int column = ( (JTable) e.getSource() ).columnAtPoint(e.getPoint());

to enable F2 you can add custom inputMap en actionMap entries

similar too
table.getInputMap().put(KeyStroke.getKeyStroke("DOWN"), "doMyArrowDown");
table.getTable().getActionMap().put("doMyArrowDown", new ArrowDownAction()); 

and from your action you can then fire the cellediting yourself

table.editCellAt(row, column );

Solution 2

The DefaultCellEditor has a setClickCountToStart() method to control mouse clicks for editing. The default is 2. Changing this will have no effect on F2 functionality.

Therefore you can set editing to be a triple click.

Not sure exactly how to handle two single clicks to start editing but I guess you would use a Timer to keep track of the first click and then do the editing if the second single click is within you time interval.

Solution 3

I have solved this by wrapping the existing CellEditor with a Proxy and intercepting calls to isCellEditable, returning false for all mouse events and delegating all other calls to the original CellEditor.

This is slightly more complex than camickr's solution but works for all editors (I have 4 in all.)

Comments

[Saurabh]

No need for a timer - it just needs to be too slow to register as a double click.

[camickr]

I'd be interested in seeing the solution. Also, I don't understand how you distinguish between the initial click on the cell and the click to initiate the editing. Does your code just track the last cell that was selected and when you get two single clicks on the same cell you start editing? If so then the second click could be second or minutes later. Your initial requirement said after a "pause" which is why I suggested a Timer to control the pause interval.

[Saurabh]

This is similar to what I did with the proxy. I only override isCellEditable. The key stroke handler is included in the default editor. I do not need to re-implement that.

[Saurabh]

@carnickr, I have not implemented that part yet but yes that sounds right. There is no time limit.