Preserve order for sgen model selection wizard (#796)

plugins/org.yakindu.sct.generator.genmodel.ui/src/org/yakindu/sct/generator/genmodel/ui/wizard/SGenWizardPage2.java

@@ -99,9 +99,14 @@ public class SGenWizardPage2 extends WizardPage {
 		container.setLayout(new GridLayout(1, false));
 		createGeneratorCombo(container);
 		createObjectTree(container);
-		refreshInput();
 	}
 
+	@Override
+	public void setVisible(boolean visible) {
+		super.setVisible(visible);
+		refreshInput();
+	}
+	
 	private void createObjectTree(Composite container) {
 		lblNewLabel = new Label(container, SWT.NONE);
 		lblNewLabel.setLayoutData(new GridData(SWT.LEFT, SWT.CENTER, true, false, 1, 1));

plugins/org.yakindu.sct.ui/src/org/yakindu/sct/ui/wizards/WorkspaceTreeContentProvider.java

@@ -10,7 +10,7 @@
  */
 package org.yakindu.sct.ui.wizards;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import org.eclipse.core.resources.IContainer;
@@ -85,7 +85,7 @@ public class WorkspaceTreeContentProvider implements ITreeContentProvider {
 	}
 
 	public Object[] filterForContent(Object[] inputElements) throws CoreException {
-		final Set<Object> result = new HashSet<Object>();
+		final Set<Object> result = new LinkedHashSet<Object>();
 		for (final Object obj : inputElements) {
 			((IResource) obj).accept(new IResourceVisitor() {
 				public boolean visit(IResource resource) throws CoreException {