examples/org.eclipse.jface.examples.databinding/src/org/eclipse/jface/examples/databinding/snippets/Snippet020TreeViewerWithSetFactory.java

/*******************************************************************************
 * Copyright (c) 2005, 2018 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Matthew Hall - bugs 260329, 260337
 *     Simon Scholz <simon.scholz@vogella.com> - Bug 442278, 434283
 *******************************************************************************/
package org.eclipse.jface.examples.databinding.snippets;

import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.util.HashSet;
import java.util.Set;

import org.eclipse.core.databinding.DataBindingContext;
import org.eclipse.core.databinding.beans.typed.BeanProperties;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.value.ComputedValue;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.core.databinding.observable.value.WritableValue;
import org.eclipse.jface.databinding.swt.DisplayRealm;
import org.eclipse.jface.databinding.swt.typed.WidgetProperties;
import org.eclipse.jface.databinding.viewers.ViewerSupport;
import org.eclipse.jface.databinding.viewers.typed.ViewerProperties;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.ViewerComparator;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;

public class Snippet020TreeViewerWithSetFactory {

	private Button pasteButton;
	private Button copyButton;
	private Button addChildBeanButton;
	private Button removeBeanButton;
	private TreeViewer beanViewer;
	private Tree tree;
	private Text beanText;
	private DataBindingContext m_bindingContext;

	private Bean input = createBean("input");
	private IObservableValue<Bean> clipboard;
	static int counter = 0;

	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		Display display = Display.getDefault();

		Realm.runWithDefault(DisplayRealm.getRealm(display), () -> {
			Shell shell = new Snippet020TreeViewerWithSetFactory().createShell();

			while (!shell.isDisposed()) {
				if (!display.readAndDispatch()) {
					display.sleep();
				}
			}
		});

		display.dispose();
	}

	/**
	 * Create contents of the window.
	 */
	protected Shell createShell() {
		Shell shell = new Shell();
		final GridLayout gridLayout_1 = new GridLayout();
		gridLayout_1.numColumns = 2;
		shell.setLayout(gridLayout_1);
		shell.setSize(535, 397);
		shell.setText("SWT Application");

		final Composite group = new Composite(shell, SWT.NONE);
		final RowLayout rowLayout = new RowLayout();
		rowLayout.marginTop = 0;
		rowLayout.marginRight = 0;
		rowLayout.marginLeft = 0;
		rowLayout.marginBottom = 0;
		rowLayout.pack = false;
		group.setLayout(rowLayout);
		group.setLayoutData(new GridData(SWT.FILL, SWT.FILL, false, false, 2, 1));

		final Button addRootButton = new Button(group, SWT.NONE);
		addRootButton.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(final SelectionEvent e) {
				Set<Bean> set = input.getSet();
				Bean root = createBean("root");
				set.add(root);
				input.setSet(set);

				beanViewer.setSelection(new StructuredSelection(root));
				beanText.selectAll();
				beanText.setFocus();
			}
		});
		addRootButton.setText("Add Root");

		addChildBeanButton = new Button(group, SWT.NONE);
		addChildBeanButton.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(final SelectionEvent e) {
				Bean parent = getSelectedBean();
				Set<Bean> set = new HashSet<>(parent.getSet());
				Bean child = createBean("child" + (counter++));
				set.add(child);
				parent.setSet(set);

				// TODO: Remove?
				// beanViewer.setSelection(new StructuredSelection(parent));
				// beanText.selectAll();
				// beanText.setFocus();
			}
		});
		addChildBeanButton.setText("Add Child");

		removeBeanButton = new Button(group, SWT.NONE);
		removeBeanButton.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(final SelectionEvent e) {
				TreeItem selectedItem = beanViewer.getTree().getSelection()[0];
				Bean bean = (Bean) selectedItem.getData();
				TreeItem parentItem = selectedItem.getParentItem();
				Bean parent;
				if (parentItem == null) {
					parent = input;
				} else {
					parent = (Bean) parentItem.getData();
				}

				Set<Bean> set = new HashSet<>(parent.getSet());
				set.remove(bean);
				parent.setSet(set);
			}
		});
		removeBeanButton.setText("Remove");

		copyButton = new Button(group, SWT.NONE);
		copyButton.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(final SelectionEvent e) {
				clipboard.setValue(getSelectedBean());
			}
		});
		copyButton.setText("Copy");

		pasteButton = new Button(group, SWT.NONE);
		pasteButton.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(final SelectionEvent e) {
				Bean copy = clipboard.getValue();
				if (copy == null) {
					return;
				}
				Bean parent = getSelectedBean();
				if (parent == null) {
					parent = input;
				}

				Set<Bean> set = new HashSet<>(parent.getSet());
				set.add(copy);
				parent.setSet(set);

				beanViewer.setSelection(new StructuredSelection(copy));
				beanText.selectAll();
				beanText.setFocus();
			}
		});
		pasteButton.setText("Paste");

		final Button refreshButton = new Button(group, SWT.NONE);
		refreshButton.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(final SelectionEvent e) {
				beanViewer.refresh();
			}
		});
		refreshButton.setText("Refresh");

		beanViewer = new TreeViewer(shell, SWT.FULL_SELECTION | SWT.BORDER);
		beanViewer.setUseHashlookup(true);
		beanViewer.setComparator(new ViewerComparator());
		tree = beanViewer.getTree();
		tree.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 2, 1));

		final Label itemNameLabel = new Label(shell, SWT.NONE);
		itemNameLabel.setText("Item Name");

		beanText = new Text(shell, SWT.BORDER);
		final GridData gd_beanValue = new GridData(SWT.FILL, SWT.CENTER, true, false);
		beanText.setLayoutData(gd_beanValue);
		m_bindingContext = initDataBindings();
		//
		initExtraBindings(m_bindingContext);

		shell.open();

		return shell;
	}

	private static Bean createBean(String name) {
		return new Bean(name);
	}

	protected DataBindingContext initDataBindings() {
		IObservableValue<Bean> treeViewerSelectionObserveSelection = ViewerProperties.singleSelection(Bean.class)
				.observe(beanViewer);
		IObservableValue<String> textTextObserveWidget = WidgetProperties.text(SWT.Modify).observe(beanText);
		IObservableValue<String> treeViewerValueObserveDetailValue = BeanProperties
				.value(Bean.class, "text", String.class).observeDetail(treeViewerSelectionObserveSelection);

		DataBindingContext bindingContext = new DataBindingContext();

		bindingContext.bindValue(textTextObserveWidget, treeViewerValueObserveDetailValue);

		return bindingContext;
	}

	private Bean getSelectedBean() {
		IStructuredSelection selection = beanViewer.getStructuredSelection();
		if (selection.isEmpty()) {
			return null;
		}
		return (Bean) selection.getFirstElement();
	}

	private void initExtraBindings(DataBindingContext bindingContext) {
		final IObservableValue<Bean> beanViewerSelection = ViewerProperties.singleSelection(Bean.class)
				.observe(beanViewer);
		IObservableValue<Boolean> beanSelected = ComputedValue.create(() -> beanViewerSelection.getValue() != null);
		bindingContext.bindValue(WidgetProperties.enabled().observe(addChildBeanButton), beanSelected);
		bindingContext.bindValue(WidgetProperties.enabled().observe(removeBeanButton), beanSelected);

		clipboard = new WritableValue<>();
		bindingContext.bindValue(WidgetProperties.enabled().observe(copyButton), beanSelected);
		bindingContext.bindValue(WidgetProperties.enabled().observe(pasteButton),
				ComputedValue.create(() -> clipboard.getValue() != null));

		ViewerSupport.bind(beanViewer, input, BeanProperties.set("set", Bean.class),
				BeanProperties.value(Bean.class, "text"));
	}

	static class Bean {
		/* package */PropertyChangeSupport changeSupport = new PropertyChangeSupport(this);
		private String text;
		private Set<Bean> set;

		public Bean(String text) {
			this.text = text;
			set = new HashSet<>();
		}

		public void addPropertyChangeListener(PropertyChangeListener listener) {
			changeSupport.addPropertyChangeListener(listener);
		}

		public void removePropertyChangeListener(PropertyChangeListener listener) {
			changeSupport.removePropertyChangeListener(listener);
		}

		public String getText() {
			return text;
		}

		public void setText(String value) {
			changeSupport.firePropertyChange("text", this.text, this.text = value);
		}

		public Set<Bean> getSet() {
			if (set == null) {
				return null;
			}
			return new HashSet<>(set);
		}

		public void setSet(Set<Bean> set) {
			if (set != null) {
				set = new HashSet<>(set);
			}
			changeSupport.firePropertyChange("set", this.set, this.set = set);
		}

		public boolean hasListeners(String propertyName) {
			return changeSupport.hasListeners(propertyName);
		}
	}
}