I want to display a new button on screen after another button (named done) is clicked.
I have to get a gridSize from text field by user. After user clicks on done button, I have to initialize JButtons array of size [gridSize][gridSize].
For now, I have initialized a new JButton as gridCell in the mouse action listener of done button. But gridCell button does not appear when I click on done button.  Where as it does appear when I initialize the gridCell button outside the scope of Mouse listener of done button. 
Here's the code that shows initialization of gridCell inside action listener of done button.
    JButton btnDone = new JButton("Done");
    btnDone.addMouseListener(new MouseAdapter() {
        @Override
        public void mouseClicked(MouseEvent arg0) {
            int gridSize = Integer.parseInt(textArea.getText());
            textArea.setText(""+gridSize);
            gridCell = new JButton[gridSize][gridSize];
            gridCell[0][0].setBounds(90, 140, 27, 23);
            frame.getContentPane().add(gridCell[0][0]);
        }
    });
    btnDone.setBounds(393, 12, 89, 23);
    frame.getContentPane().add(btnDone);
