Question

I’m creating an application in Java and SWT and I have a problem. I want to put ExpandBar into GridLayout. Everything is ok while I don’t collapse the expand bar. When I do it, it collpases normally, but the composite isn’t re-layouted. The screen below should explain my problem:

Before collapse:

After collapse:

I tried some tricks, like for example:

bar.addExpandListener(new ExpandListener() {
    public void itemExpanded(ExpandEvent e) {
        item0.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y);
        gridData2.heightHint = composite.computeSize(SWT.DEFAULT,
                SWT.DEFAULT).y;
        comp.layout(true, true);
    }

    public void itemCollapsed(ExpandEvent e) {
        item0.setHeight(item0.getHeaderHeight());
        gridData2.heightHint = item0.getHeaderHeight();
        comp.layout(true, true);
    }
});

Altough it doesn’t work. Here is SSCCE:

package stackoverflow;

import org.eclipse.jface.window.Window;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.ExpandBar;
import org.eclipse.swt.widgets.ExpandItem;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tree;

public class MainWindowSWT extends Window {

    public MainWindowSWT() {
        super((Shell)null);

        setBlockOnOpen(true);
        open();
        Display.getCurrent().dispose();
    }

    @Override
    protected Control createContents(Composite parent) {
        final Composite comp = new Composite(getShell(), 0);

        GridLayout layout = new GridLayout(1, true);
        comp.setLayout(layout);

        Tree tree = new Tree(comp, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);
        GridData gridData = new GridData();
        gridData.verticalAlignment = GridData.FILL;
        gridData.verticalSpan = 2;
        gridData.grabExcessVerticalSpace = true;
        gridData.horizontalAlignment = GridData.FILL;
        gridData.grabExcessHorizontalSpace = true;
        tree.setLayoutData(gridData);

        final ExpandBar bar = new ExpandBar(comp, SWT.V_SCROLL);
        final Composite composite = new Composite(bar, SWT.NONE);
        GridLayout gridLayout = new GridLayout();
        gridLayout.verticalSpacing = 10;
        composite.setLayout(gridLayout);
        Button button = new Button(composite, SWT.PUSH);
        button.setText("SWT.PUSH");
        final ExpandItem item0 = new ExpandItem(bar, SWT.NONE, 0);
        item0.setText("Test");
        item0.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y);
        item0.setControl(composite);

        item0.setExpanded(true);

        final GridData gridData2 = new GridData();
        gridData2.horizontalAlignment = GridData.FILL;
        gridData2.grabExcessHorizontalSpace = true;
        bar.setLayoutData(gridData2);

        return parent;
    }
}

Ubuntu 12.04.1 amd64, SWT 3.7.2.

Thanks in advance.

// Btw: I don’t want to resize shell. I want to resize the tree above the expand bar.

Answer 1

I get it working, but I’m not satisfied with this solution…

bar.addExpandListener(new ExpandAdapter() {

    @Override
    public void itemCollapsed(ExpandEvent e) {
        new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    synchronized (this) {
                        wait(250);
                    }
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                Display.getDefault().asyncExec(new Runnable() {
                    public void run() {
                        layout();

                    }
                });
            }
        }).start();
    }

    @Override
    public void itemExpanded(ExpandEvent e) {
        new Thread(new Runnable() {

            @Override
            public void run() {
                try {
                    synchronized (this) {
                        wait(250);
                    }
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                Display.getDefault().asyncExec(new Runnable() {
                    public void run() {
                        layout();

                    }
                });
            }
        }).start();
    }
});