Fixed layouting for MacOS after downloading examples.

plugins/org.yakindu.sct.examples.wizard/src/org/yakindu/sct/examples/wizard/pages/MessageArea.java

@@ -118,11 +118,10 @@ public class MessageArea extends Composite {
 	}
 
 	public void hide() {
-		state = state.HIDE;
+		state = State.HIDE;
 		setVisible(false);
 		GridData data = (GridData) getLayoutData();
 		data.exclude = true;
-		getParent().pack();
 	}
 
 	public void addSelectionListener(SelectionListener listener) {

plugins/org.yakindu.sct.examples.wizard/src/org/yakindu/sct/examples/wizard/pages/SelectExamplePage.java

@@ -95,7 +95,6 @@ public class SelectExamplePage extends WizardPage
 		GridDataFactory.fillDefaults().grab(true, false).applyTo(messageArea);
 		messageArea.addSelectionListener(this);
 		messageArea.hide();
-
 	}
 
 	@Override
@@ -151,10 +150,12 @@ public class SelectExamplePage extends WizardPage
 
 	protected void setInput(final IProgressMonitor monitor) {
 		final List<ExampleData> input = exampleService.getExamples(new NullProgressMonitor());
-
+		
 		messageArea.hide();
 		viewer.setInput(input);
 		viewer.expandAll();
+		// explicit layouting required for Unix systems
+		viewer.getControl().getParent().getParent().layout(true);
 	}
 
 	protected void createTreeViewer(Composite container) {