bundles/core/org.eclipse.apogy.core.invocator.ui/src/org/eclipse/apogy/core/invocator/ui/composites/VariableComboComposite.java

/*******************************************************************************
 * Copyright (c) 2018 Agence spatiale canadienne / Canadian Space Agency 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Pierre Allard,
 *     Regent L'Archeveque,
 *     Olivier L. Larouche - initial API and implementation
 *
 * SPDX-License-Identifier: EPL-1.0
 *     
 *******************************************************************************/
package org.eclipse.apogy.core.invocator.ui.composites;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.apogy.common.emf.ApogyCommonEMFFactory;
import org.eclipse.apogy.common.emf.EIdComparator;
import org.eclipse.apogy.core.invocator.Variable;
import org.eclipse.jface.viewers.ArrayContentProvider;
import org.eclipse.jface.viewers.ComboViewer;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;

public class VariableComboComposite extends Composite {
	private final List<Variable> variableList = new ArrayList<Variable>();
	private Variable selectedVariable = null;
	private final ComboViewer comboViewer;

	public VariableComboComposite(Composite parent, int style) {
		super(parent, style);
		setLayout(new FillLayout());
		this.comboViewer = createCombo(this, SWT.READ_ONLY);
		this.comboViewer.addSelectionChangedListener(new ISelectionChangedListener() {
			@Override
			public void selectionChanged(SelectionChangedEvent event) {
				if (event.getSelection().isEmpty()) {
					newSelection(null);
				} else if (event.getSelection() instanceof IStructuredSelection) {
					IStructuredSelection iStructuredSelection = (IStructuredSelection) event.getSelection();
					if (iStructuredSelection.getFirstElement() instanceof Variable) {
						newSelection((Variable) iStructuredSelection.getFirstElement());
					} else {
						newSelection(null);
					}
				}
			}
		});
	}

	private ComboViewer createCombo(Composite parent, int style) {
		ComboViewer comboViewer = new ComboViewer(parent, SWT.DROP_DOWN | SWT.READ_ONLY);
		comboViewer.setContentProvider(ArrayContentProvider.getInstance());
		comboViewer.setLabelProvider(new LabelProvider() {
			@Override
			public String getText(Object element) {
				if (element instanceof Variable) {
					Variable variable = (Variable) element;
					return variable.getName();
				} else {
					return "";
				}
			}
		});

		// Display the combo element sorted by displayed name.
		comboViewer.setComparator(new ViewerComparator() {
			@Override
			public int compare(Viewer viewer, Object e1, Object e2) {
				Variable variable1 = (Variable) e1;
				Variable variable2 = (Variable) e2;

				int result = variable1.getName().compareTo(variable2.getName());
				if (result == 0) {
					EIdComparator<Variable> comparator = ApogyCommonEMFFactory.eINSTANCE.createEIdComparator();
					return comparator.compare(variable1, variable2);
				} else {
					return result;
				}
			}
		});

		comboViewer.setInput(this.variableList);

		return comboViewer;
	}

	public Variable getSelectedVariable() {
		return this.selectedVariable;
	}

	public void setSelectedVariable(Variable selectedVariable) {
		this.selectedVariable = selectedVariable;

		if (selectedVariable != null) {
			this.comboViewer.setSelection(new StructuredSelection(selectedVariable));
		}
	}

	public List<Variable> getVariableList() {
		return this.variableList;
	}

	public void setVariableList(List<Variable> newVariableList) {
		this.variableList.clear();
		if (newVariableList != null) {
			this.variableList.addAll(newVariableList);
		}
		this.comboViewer.setInput(this.variableList);

		// Attempts to reselect the variable.
		if (this.selectedVariable != null) {
			this.comboViewer.setSelection(new StructuredSelection(this.selectedVariable));
		}
	}

	protected void newSelection(Variable variable) {
	}
}