JTree does not extend automatically, Swing embedded into SWT

Question

So I am working with Swing components embedded into SWT.

Here a simplified version of my issue, basically I have two Panel objects (panelA, panelB) with some Swing components, embedded in my Shell. I want to add an on/off option on the panelB, doing that I did except my JTree to fill out the whole Shell while panelB is off, but it didn't...

The only way I found is recreating the components but I feel like it is not the good way to do things. (For putting off the component I am using setVisible()) Any ideas to make the JTree component fill the space when panelB is off?

import javax.swing.*;
import org.eclipse.swt.SWT;
import org.eclipse.swt.awt.SWT_AWT;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;


public class testCW {

public static void main(String[] args) {

  Display display = new Display();
  Shell shell = new Shell(display);
  shell.setText("Test");
  shell.setLayout(new FillLayout());


  Composite compositeA = new Composite(shell,SWT.EMBEDDED);
  java.awt.Frame frameA = SWT_AWT.new_Frame(compositeA);
  java.awt.Panel panelA = new java.awt.Panel(new java.awt.BorderLayout());
  frameA.add(panelA);
  JScrollPane scrollPaneA = new JScrollPane(new JTree());
  panelA.add(scrollPaneA);


  Composite compositeB = new Composite(shell,SWT.EMBEDDED);
  java.awt.Frame frameB = SWT_AWT.new_Frame(compositeB);
  java.awt.Panel panelB = new java.awt.Panel(new java.awt.BorderLayout());
  frameB.add(panelB);
  JButton buttonB = new JButton("Button");
  panelB.add(buttonB);



  shell.open();
  while (!shell.isDisposed()) {
    if (!display.readAndDispatch())
    display.sleep();
    // test 1 : hide panelB or compositeB? -> run -> JTree extends well?
    // test 2 : hide panelB or compositeB? -> print panelB(compositeB)
    // -> run  -> displays well ?
    // panelB.setVisible(false);
    // compositeB.dispose();     //TEST
  }
  display.dispose();

}
}

Answer 1

Do you have to stick with FillLayout? Whenever you want to hide components in SWT it is recommended to use GridLayout. Here is an example of how to do it: http://www.java2s.com/Code/Java/SWT-JFace-Eclipse/ExcludeawidgetfromaGridLayout.htm

Answer 2

You could add a parent composite that holds the compositeA , compositeB like below :

final Composite composite = new Composite( shell, SWT.NONE);
composite.setLayout(new GridLayout( 2,false) );

Then add your composites to that parent like :

Composite compositeA = new Composite(composite, SWT.EMBEDDED);
GridData filldataA = new GridData(GridData.FILL_BOTH);
compositeA.setLayoutData(filldataA);

Note that I added GridData for the compositeA to occupy whole space initially.

Add selection listener to your SWT.PUSH button on the toolbar. Lets say - your SWT.PUSH button is swtButton. Then add a selection listener to it like below :

swtButton.addSelectionListener(new SelectionAdapter()
{
    private boolean expandTree = true;
    @Override
    public void widgetSelected(SelectionEvent e) 
    {
        Layout lo = composite.getLayout();
        GridLayout glo = (GridLayout)lo;
        if ( expandTree )
        {
            glo.makeColumnsEqualWidth = true;
            expandTree = false;
        }
        else
        {
            glo.makeColumnsEqualWidth = false;
            expandTree = true;
        }

        composite.layout();
    }
});

Basically you have a boolean in your action listener - expandTree - that toggles between button clicks, depending on true or false - make the parent composite switch between making the columns equal width true or false.

IMO you don't need compositeB