How to make TreeViewer span ScrolledComposite

Question

I have dialog with n numbers of Trees on the left side of a SashForm. Each tree is in a ScrolledComposite.

My problem is that there is so much empty space between inside the scrolled composite that isn't covered by the tree, and I don't know how to remove it.

This is the code:

import org.eclipse.draw2d.ColorConstants;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.SashForm;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.TreeItem;

public class SWTSashForm
{
 public static void main (String [] args) {
    Display display = new Display ();
    Shell shell = new Shell(display);

    shell.setLayout(new FillLayout());

    SashForm sashForm = new SashForm(shell, SWT.HORIZONTAL);


    Composite leftTablesComposite = new Composite(sashForm, SWT.NONE);
    leftTablesComposite.setLayout(new GridLayout());
    leftTablesComposite.setLayoutData(new GridData(GridData.FILL_BOTH));
    leftTablesComposite.setBackground(ColorConstants.white);


    for (int i = 0; i < 3; i++) {

        Label lbl = new Label(leftTablesComposite, SWT.NONE);
        lbl.setBackground(ColorConstants.white);
        lbl.setText("Tree " + i);

     // Configure scrolled composite
        ScrolledComposite scrolledComposite = new ScrolledComposite(leftTablesComposite, SWT.V_SCROLL | SWT.H_SCROLL | SWT.BORDER);
        scrolledComposite.setLayout(new GridLayout());
        scrolledComposite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
        scrolledComposite.setExpandVertical(true);
        scrolledComposite.setExpandHorizontal(true);
        scrolledComposite.setAlwaysShowScrollBars(true);
        scrolledComposite.setMinSize(leftTablesComposite.computeSize(SWT.DEFAULT, SWT.DEFAULT));

        // Add content to scrolled composite
        Composite scrolledContent = new Composite(scrolledComposite, SWT.NONE);
        scrolledContent.setLayout(new GridLayout());
        GridData gridData = new GridData();
        gridData.horizontalAlignment = SWT.FILL;
        gridData.grabExcessHorizontalSpace = true;
        gridData.verticalAlignment = SWT.FILL;
        gridData.grabExcessVerticalSpace = true;
        scrolledContent.setLayoutData(gridData);
        scrolledContent.setBackground(ColorConstants.white);
        scrolledComposite.setContent(scrolledContent);

        TreeViewer tree = new TreeViewer(scrolledContent);
        for(int loopIndex0 = 0; loopIndex0 < 10; loopIndex0++) {
                TreeItem treeItem0 = new TreeItem(tree.getTree(), 0);
                treeItem0.setText("Level 0 Item "+ loopIndex0);

                for(int loopIndex1 = 0; loopIndex1 < 10; loopIndex1++) {
                    TreeItem treeItem1 = new TreeItem(treeItem0, 0);
                    treeItem1.setText("Level 1 Item "+ loopIndex1);

                    for(int loopIndex2 = 0; loopIndex2 < 10; loopIndex2++) {
                        TreeItem treeItem2 = new TreeItem(treeItem1, 0);
                        treeItem2.setText("Level 2 Item "+ loopIndex2);
                    }
                }
            }

    }
    new TreeViewer(sashForm);
    shell.open();

    while (!shell.isDisposed ()) {
        if (!display.readAndDispatch ()) display.sleep ();
    }
    display.dispose ();
}

}

Answer 1

Adding this line will tell the Tree to fill the space:

tree.getTree().setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));