bundles/core/org.eclipse.apogy.core.invocator.ui/src/org/eclipse/apogy/core/invocator/ui/composites/SourceDestinationContextsComposite.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 org.eclipse.apogy.common.emf.ApogyCommonEMFPackage;
import org.eclipse.apogy.core.invocator.ApogyCoreInvocatorPackage;
import org.eclipse.apogy.core.invocator.Context;
import org.eclipse.apogy.core.invocator.ContextsList;
import org.eclipse.core.databinding.DataBindingContext;
import org.eclipse.emf.databinding.EMFObservables;
import org.eclipse.emf.databinding.EMFProperties;
import org.eclipse.jface.databinding.viewers.ViewerSupport;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Table;
import org.eclipse.ui.forms.widgets.ExpandableComposite;
import org.eclipse.ui.forms.widgets.FormToolkit;
import org.eclipse.ui.forms.widgets.Section;

public class SourceDestinationContextsComposite extends Composite {
	private DataBindingContext m_bindingContext;

	private final FormToolkit toolkit = new FormToolkit(Display.getCurrent());

	private final TableViewer sourceContextViewer;

	private final Table sourceContextTable;
	private final Table destinationContextTable;

	private ContextsList contextsList;

	private final TableViewer destinationContextViewer;

	/**
	 * Creates the parentComposite.
	 * 
	 * @param parent
	 * @param style
	 */
	public SourceDestinationContextsComposite(Composite parent, int style) {
		super(parent, style);

		addDisposeListener(new DisposeListener() {
			@Override
			public void widgetDisposed(DisposeEvent e) {
				SourceDestinationContextsComposite.this.toolkit.dispose();
				if (SourceDestinationContextsComposite.this.m_bindingContext != null) {
					SourceDestinationContextsComposite.this.m_bindingContext.dispose();
					SourceDestinationContextsComposite.this.m_bindingContext = null;
				}
			}
		});

		this.toolkit.adapt(this);
		this.toolkit.paintBordersFor(this);
		setLayout(new GridLayout(2, true));

		Section sctnSourceContext = this.toolkit.createSection(this,
				ExpandableComposite.EXPANDED | ExpandableComposite.TITLE_BAR);
		sctnSourceContext.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1));
		this.toolkit.paintBordersFor(sctnSourceContext);
		sctnSourceContext.setText("Source");
		this.sourceContextViewer = new TableViewer(sctnSourceContext, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);
		this.sourceContextViewer.setUseHashlookup(true);
		this.sourceContextTable = this.sourceContextViewer.getTable();
		this.sourceContextTable.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1));
		this.sourceContextTable.setLinesVisible(true);
		sctnSourceContext.setClient(this.sourceContextTable);

		this.sourceContextViewer.addSelectionChangedListener(new ISelectionChangedListener() {
			@Override
			public void selectionChanged(SelectionChangedEvent event) {
				sourceContextSelected();
			}
		});

		Section sctnDestinationContext = this.toolkit.createSection(this,
				ExpandableComposite.EXPANDED | ExpandableComposite.TITLE_BAR);
		sctnDestinationContext.setLayoutData(new GridData(SWT.FILL, SWT.FILL, false, false, 1, 1));
		this.toolkit.paintBordersFor(sctnDestinationContext);
		sctnDestinationContext.setText("Destination");
		this.destinationContextViewer = new TableViewer(sctnDestinationContext, SWT.BORDER);
		this.destinationContextTable = this.destinationContextViewer.getTable();
		this.destinationContextTable.setLinesVisible(true);
		this.toolkit.paintBordersFor(this.destinationContextTable);
		sctnDestinationContext.setClient(this.destinationContextTable);
		this.destinationContextViewer.addSelectionChangedListener(new ISelectionChangedListener() {
			@Override
			public void selectionChanged(SelectionChangedEvent event) {
				destinationContextSelected();
			}
		});

		// Dispose
		addDisposeListener(new DisposeListener() {
			@Override
			public void widgetDisposed(DisposeEvent e) {
				if (SourceDestinationContextsComposite.this.m_bindingContext != null)
					SourceDestinationContextsComposite.this.m_bindingContext.dispose();
			}
		});
	}

	/**
	 * Sets the {@link ContextsList} managed by the parentComposite.
	 * 
	 * @param contextsList Reference to the list of contexts.
	 */
	public void setContextsList(ContextsList contextsList) {
		setContextsList(contextsList, true);
	}

	/**
	 * Sets the {@link ContextsList} managed by the parentComposite.
	 * 
	 * @param contextsList Reference to the list of contexts.
	 * @param update       If true then data bindings are created.
	 */
	private void setContextsList(ContextsList contextsList, boolean update) {

		this.contextsList = contextsList;

		if (update) {
			if (this.m_bindingContext != null) {
				this.m_bindingContext.dispose();
				this.m_bindingContext = null;
			}

			if (this.contextsList != null) {
				this.m_bindingContext = initDataBindings();
			}
		}
	}

	/**
	 * Use this to prevent Window Pro Builder code analysis to fail with the complex
	 * data bindings code. Invokes
	 * {@link SourceDestinationContextsComposite#initDataBindingsCustom()}.
	 * 
	 * @return Reference to the data bindings context.
	 * @see SourceDestinationContextsComposite#initDataBindingsCustom()
	 */
	private DataBindingContext initDataBindings() {
		return initDataBindingsCustom();
	}

	/**
	 * Creates and returns the data bindings.
	 * 
	 * @return Reference to the data bindings context.
	 */
	private DataBindingContext initDataBindingsCustom() {
		DataBindingContext bindingContext = new DataBindingContext();

		ViewerSupport.bind(this.sourceContextViewer,
				EMFObservables.observeList(this.contextsList,
						ApogyCoreInvocatorPackage.Literals.CONTEXTS_LIST__CONTEXTS),
				EMFProperties.value(ApogyCommonEMFPackage.Literals.NAMED__NAME));

		ViewerSupport.bind(this.destinationContextViewer,
				EMFObservables.observeList(this.contextsList,
						ApogyCoreInvocatorPackage.Literals.CONTEXTS_LIST__CONTEXTS),
				EMFProperties.value(ApogyCommonEMFPackage.Literals.NAMED__NAME));

		return bindingContext;
	}

	/**
	 * This method is invoked when a new From context is selected.
	 */
	protected void sourceContextSelected() {
	}

	/**
	 * This method is invoked when a new To context is selected.
	 */
	protected void destinationContextSelected() {
	}

	/**
	 * Returns the selected From context.
	 * 
	 * @return Reference to the context.
	 */
	public Context getSelectedSourceContext() {
		Context context = null;

		if (this.sourceContextViewer.getSelection() != null
				&& this.sourceContextViewer.getSelection() instanceof IStructuredSelection) {
			IStructuredSelection selection = (IStructuredSelection) this.sourceContextViewer.getSelection();
			context = (Context) selection.getFirstElement();
		}

		return context;
	}

	/**
	 * Returns the selected To context.
	 * 
	 * @return Reference to the context.
	 */
	public Context getSelectedDestinationContext() {
		Context context = null;

		if (this.destinationContextViewer.getSelection() != null
				&& this.destinationContextViewer.getSelection() instanceof IStructuredSelection) {
			IStructuredSelection selection = (IStructuredSelection) this.destinationContextViewer.getSelection();
			context = (Context) selection.getFirstElement();
		}
		return context;
	}
}