ResizeExpansionAdapter.java

package bndtools.editor.pages;

import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.ui.forms.events.ExpansionAdapter;
import org.eclipse.ui.forms.events.ExpansionEvent;

public class ResizeExpansionAdapter extends ExpansionAdapter {

    private final Composite layoutParent;
    private final Control control;

    public ResizeExpansionAdapter(Control control) {
        this(control.getParent(), control);
    }

    public ResizeExpansionAdapter(Composite layoutParent, Control control) {
        this.layoutParent = layoutParent;
        this.control = control;
    }

    @Override
    public void expansionStateChanged(ExpansionEvent e) {
        Object layoutData = (Boolean.TRUE.equals(e.data)) ? PageLayoutUtils.createExpanded() : PageLayoutUtils.createCollapsed();
        control.setLayoutData(layoutData);
        layoutParent.layout(true, true);
    }

}