Drag and Drop of cell content between 2 tables

[kohinoor2007]

Hi Guys,

Iam into implementing drag and drop of cell contents between 2 different tables,say Table1 and Table2.(Iam not dragging and dropping rows or cells,Just copying the content of one cell to another).

Have extended the java tutorial class "TableTransferHandler" and "StringTransferHandler" under

http://java.sun.com/docs/books/tutorial/uiswing/examples/dnd/index.html#ExtendedDndDemo

to satisfy my needs.

The drag is enabled for Table1 and table2 as follows.

jTable1.setDragEnabled(true);
jTable1.setTransferHandler(new TableTransferHandler());

jTable2.setDragEnabled(true);
jTable2.setTransferHandler(new TableTransferHandler());


//String Transfer Handler class.

public abstract class StringTransferHandler extends TransferHandler {
    
    protected abstract String exportString(JComponent c);
    protected abstract void importString(JComponent c, String str);
    protected abstract void cleanup(JComponent c, boolean remove);
    
    protected Transferable createTransferable(JComponent c) {
        return new StringSelection(exportString(c));
    }
    
    public int getSourceActions(JComponent c) {
        return COPY_OR_MOVE;
    }
    
    public boolean importData(JComponent c, Transferable t) {
        if (canImport(c, t.getTransferDataFlavors())) {
            try {
                String str = (String)t.getTransferData(DataFlavor.stringFlavor);
                importString(c, str);
                return true;
            } catch (UnsupportedFlavorException ufe) {
            } catch (IOException ioe) {
            }
        }

        return false;
    }
    
    protected void exportDone(JComponent c, Transferable data, int action) {
        cleanup(c, action == MOVE);
    }
    
    public boolean canImport(JComponent c, DataFlavor[] flavors) {
    	
    	 JTable table = (JTable)c;    	 
         int selColIndex = table.getSelectedColumn();
        for (int i = 0; i < flavors.length; i++) {
            if ((DataFlavor.stringFlavor.equals(flavors[i]))&& (selColIndex !=0)) {
                return true;
            }
        }        
        return false;
    }
}

//TableTransferHandler class

public class TableTransferHandler extends StringTransferHandler {
    private int[] rows = null;
    private int addIndex = -1; //Location where items were added
    private int addCount = 0;  //Number of items added.

    protected String exportString(JComponent c) {
        JTable table = (JTable)c;
        rows = table.getSelectedRows();  
        
        
        StringBuffer buff = new StringBuffer();
        int selRowIndex = table.getSelectedRow();
       int selColIndex = table.getSelectedColumn();
       String val = table.getValueAt(selRowIndex,selColIndex).toString();
       buff.append(val);       
        
        return buff.toString();
    }

    protected void importString(JComponent c, String str) {
    	
        JTable target = (JTable)c;
        DefaultTableModel model = (DefaultTableModel)target.getModel();
        //int index = target.getSelectedRow();
        int row = target.getSelectedRow();
        int column = target.getSelectedColumn();
        target.setValueAt(str, row, column);        
    }
    protected void cleanup(JComponent c, boolean remove) {
    }   
}

Now I want to put in the following functionality into my program...

[1]prevent dragging and dropping text in to the same table.That means I dont want to drag a cell content from Table1 and drop to another cell in Table1. Want to drag and drop cell content only from Table1 to Table2.

[2]Change cursor on a un-defined Target. That means how to prevent a drag from a particular column in Table1.Also how to prevent a drop to a particular column in Table2. How to change the cursor to a "NO-DRAG" cursoror "NO-DROP" cursor.

Could it be done using Drag Source Listener and drop Target Listener?.

If yes,How can these listeners attached to the table and how to do it?

If No,How Could it be done?


[3]Want to change the background colour of the cell being dragged and also the background colour of the target cell where the drop is made...

[4]Is there any out of the box way to make an undo in the target cell(where drop was made) so that the old cell value is brought back.

How can I extend my code to take care of the above said things.

Any help or suggestions is greatly appreciated.....