rtm/org.eclipse.statet.rtm.base.ui/src/org/eclipse/statet/ecommons/emf/ui/forms/EObjectListProperty.java

/*=============================================================================#
 # Copyright (c) 2012, 2019 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ecommons.emf.ui.forms;

import java.util.Collection;
import java.util.Iterator;

import org.eclipse.core.databinding.observable.IObserving;
import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.emf.common.notify.AdapterFactory;
import org.eclipse.emf.common.notify.Notification;
import org.eclipse.emf.databinding.edit.EMFEditProperties;
import org.eclipse.emf.databinding.edit.IEMFEditListProperty;
import org.eclipse.emf.ecore.EClass;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.emf.edit.command.CommandParameter;
import org.eclipse.emf.edit.domain.EditingDomain;
import org.eclipse.emf.edit.provider.IViewerNotification;
import org.eclipse.emf.edit.ui.dnd.EditingDomainViewerDropAdapter;
import org.eclipse.emf.edit.ui.dnd.LocalTransfer;
import org.eclipse.emf.edit.ui.dnd.ViewerDragAdapter;
import org.eclipse.emf.edit.ui.provider.AdapterFactoryContentProvider;
import org.eclipse.emf.edit.ui.provider.AdapterFactoryLabelProvider;
import org.eclipse.jface.action.IContributionItem;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.databinding.viewers.ObservableListContentProvider;
import org.eclipse.jface.databinding.viewers.typed.ViewerProperties;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Menu;

import org.eclipse.statet.ecommons.emf.core.databinding.IEMFEditContext;
import org.eclipse.statet.ecommons.ui.components.ButtonGroup;
import org.eclipse.statet.ecommons.ui.content.ElementSourceSelectionProvider;
import org.eclipse.statet.ecommons.ui.util.MenuUtils;
import org.eclipse.statet.ecommons.ui.viewers.ViewerUtils;
import org.eclipse.statet.ecommons.ui.viewers.ViewerUtils.TableComposite;


public class EObjectListProperty<TProperty extends EObject> extends EFProperty {
	
	
	private class LabelProvider extends AdapterFactoryLabelProvider {
		
		protected Viewer viewer;
		protected AdapterFactoryContentProvider.ViewerRefresh viewerRefresh;
		
		public LabelProvider(final AdapterFactory adapterFactory, final Viewer viewer) {
			super(adapterFactory);
			
			this.viewer= viewer;
		}
		
		@Override
		public void notifyChanged(final Notification notification) {
			if (this.viewer != null && this.viewer.getControl() != null && !this.viewer.getControl().isDisposed()
					&& notification instanceof IViewerNotification) {
				final IViewerNotification viewerNotification= (IViewerNotification) notification;
				if (viewerNotification.isLabelUpdate()) {
					if (this.viewerRefresh == null) {
						this.viewerRefresh= new AdapterFactoryContentProvider.ViewerRefresh(this.viewer);
					}
					if (this.viewerRefresh.addNotification(viewerNotification)) {
						this.viewer.getControl().getDisplay().asyncExec(this.viewerRefresh);
					}
				}
			}
			super.notifyChanged(notification);
		}
		
	}
	
	private class AddHandler extends ButtonGroup.AddHandler {
		
		
		private MenuManager menuManager;
		
		
		public AddHandler() {
		}
		
		
		@Override
		public boolean run(final IStructuredSelection selection) {
			if (this.menuManager == null) {
				this.menuManager= new MenuManager();
			}
			else {
				this.menuManager.removeAll();
			}
			fillMenu(this.menuManager);
			
			final Menu menu= this.menuManager.createContextMenu(getControl());
			MenuUtils.setPullDownPosition(menu, getControl());
			menu.setVisible(true);
			return false;
		}
		
		protected void fillMenu(final MenuManager menuManager) {
			final EditingDomain editingDomain= getEditingDomain();
			final EObject base= (EObject) getBaseObservable().getValue();
			if (base == null) {
				return;
			}
			final Collection<?> descriptors= editingDomain.getNewChildDescriptors(base, null);
			for (final Object descriptor : descriptors) {
				if (!(descriptor instanceof CommandParameter)) {
					continue;
				}
				final CommandParameter parameter= (CommandParameter) descriptor;
				if (parameter.getEStructuralFeature() != getEFeature()) {
					continue;
				}
				final IContributionItem item= new EditCommandContributionItem(parameter,
						editingDomain, getBaseObservable() ) {
					@Override
					protected void executed(final Collection<?> result) {
						final Iterator<?> iter= result.iterator();
						if (iter.hasNext()) {
							final TProperty value= (TProperty) iter.next();
							if (EObjectListProperty.this.modelObservable.contains(value)) {
								EObjectListProperty.this.singleSelectionObservable.setValue(value);
							}
						}
					}
				};
				menuManager.add(item);
			}
		}
		
		@Override
		public void widgetDisposed(final DisposeEvent e) {
			if (this.menuManager != null) {
				this.menuManager.dispose();
			}
		}
		
	}
	
	
	private TableComposite widget;
	private ButtonGroup<TProperty> buttonGroup;
	
	private IObservableList<TProperty> modelObservable;
	
	private ElementSourceSelectionProvider selectionProvider;
	private IObservableValue<TProperty> singleSelectionObservable;
	
	
	public EObjectListProperty(final String label, final String tooltip,
			final EClass eClass, final EStructuralFeature eFeature) {
		super(label, tooltip, eClass, eFeature);
	}
	
	
	@Override
	public void create(final Composite parent, final IEFFormPage page) {
		this.widget= page.getToolkit().createPropSingleColumnTable(parent, 10, 25);
		
		this.widget.viewer.setContentProvider(new ObservableListContentProvider());
		this.widget.viewer.setLabelProvider(new LabelProvider(
				page.getEditor().getAdapterFactory(), this.widget.viewer ));
		
		this.buttonGroup= new ButtonGroup<>(parent);
		this.buttonGroup.setLayoutData(new GridData(SWT.FILL, SWT.FILL, false, false));
		
		customizeButtonGroup(this.buttonGroup);
	}
	
	protected void customizeButtonGroup(final ButtonGroup<TProperty> buttonGroup) {
		buttonGroup.addAddButton(new AddHandler());
		buttonGroup.addDeleteButton(null);
		buttonGroup.addSeparator();
		buttonGroup.addUpButton(null);
		buttonGroup.addDownButton(null);
	}
	
	@Override
	public Control getControl() {
		return this.widget;
	}
	
	public TableViewer getViewer() {
		return this.widget.viewer;
	}
	
	@Override
	public void bind(final IEMFEditContext context) {
		super.bind(context);
		
		final IEMFEditListProperty emfProperty= EMFEditProperties.list(getEditingDomain(),
				getEFeature() );
		this.modelObservable= emfProperty.observeDetail(getBaseObservable());
		((IObserving) this.modelObservable).getObserved();
		
		this.widget.viewer.setInput(this.modelObservable);
		this.buttonGroup.connectTo(this.widget.viewer, this.modelObservable, null);
		
		register(this.widget.table, IEFPropertyExpressions.EOBJECT_LIST_ID);
		this.selectionProvider= new ElementSourceSelectionProvider(this.widget.viewer, this);
		ViewerUtils.setSelectionProvider(this.widget.table, this.selectionProvider);
		
		{	final int operations= (DND.DROP_DEFAULT | DND.DROP_COPY | DND.DROP_MOVE);
			final Transfer[] transfers= new Transfer[] { LocalTransfer.getInstance() };
			this.widget.viewer.addDragSupport(operations, transfers, new ViewerDragAdapter(this.widget.viewer));
			this.widget.viewer.addDropSupport(operations, transfers, new EditingDomainViewerDropAdapter(
					getEditingDomain(), this.widget.viewer ));
		}
		
		this.singleSelectionObservable=
				ViewerProperties.singlePostSelection((Class<TProperty>)this.modelObservable.getElementType())
						.observe(this.widget.viewer);
		
		this.buttonGroup.updateState();
	}
	
	@Override
	public IObservableList<TProperty> getPropertyObservable() {
		return this.modelObservable;
	}
	
	public IObservableValue<TProperty> getSingleSelectionObservable() {
		return this.singleSelectionObservable;
	}
	
	public ISelectionProvider getSelectionProvider() {
		return this.selectionProvider;
	}
	
}