org.eclipse.jface.examples.databinding.snippets.Snippet022ComputedListCombo.java Source code

Introduction

Here is the source code for org.eclipse.jface.examples.databinding.snippets.Snippet022ComputedListCombo.java

Source

/*******************************************************************************
 * Copyright (c) 2008, 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
 *     Simon Scholz <simon.scholz@vogella.com> - Bug 434283
 ******************************************************************************/

package org.eclipse.jface.examples.databinding.snippets;

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

import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.list.ComputedList;
import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.core.databinding.observable.list.WritableList;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.jface.databinding.swt.DisplayRealm;
import org.eclipse.jface.databinding.swt.typed.WidgetProperties;
import org.eclipse.jface.databinding.viewers.ObservableListContentProvider;
import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.jface.layout.GridLayoutFactory;
import org.eclipse.jface.viewers.ComboViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Shell;

/**
 * @since 3.2
 *
 */
public class Snippet022ComputedListCombo {
    private static WritableList<Thing> model;

    public static void main(String[] args) {
        Display display = new Display();
        final Shell shell = new Shell(display);
        shell.setLayout(new GridLayout(1, false));

        Realm.runWithDefault(DisplayRealm.getRealm(display), () -> {
            Snippet022ComputedListCombo snippet = new Snippet022ComputedListCombo();
            snippet.createModel();
            snippet.createControls(shell);
        });

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

    /**
     *
     */
    protected void createModel() {
        model = new WritableList<>();
        model.add(new Thing("Alice", true, false));
        model.add(new Thing("Beth", true, false));
        model.add(new Thing("Cathy", true, false));
        model.add(new Thing("Arthur", false, true));
        model.add(new Thing("Bob", false, true));
        model.add(new Thing("Curtis", false, true));
        model.add(new Thing("Snail", true, true));
        model.add(new Thing("Nail", false, false));
    }

    /**
     * @param shell
     */
    protected void createControls(Shell shell) {
        Composite composite = new Composite(shell, SWT.NONE);
        Group group = new Group(composite, SWT.NONE);
        group.setText("Filter");
        Button male = new Button(group, SWT.CHECK);
        male.setText("Male");
        Button female = new Button(group, SWT.CHECK);
        female.setText("Female");
        final IObservableValue<Boolean> femaleObservable = WidgetProperties.buttonSelection().observe(female);
        final IObservableValue<Boolean> maleObservable = WidgetProperties.buttonSelection().observe(male);
        Combo combo = new Combo(composite, SWT.DROP_DOWN | SWT.READ_ONLY);
        GridDataFactory.defaultsFor(combo).align(SWT.BEGINNING, SWT.BEGINNING).applyTo(combo);
        ComboViewer viewer = new ComboViewer(combo);
        viewer.setContentProvider(new ObservableListContentProvider<>());
        // We should really have an out-of-the box filtered list...
        IObservableList<Thing> filteredList = new ComputedList<Thing>() {
            @Override
            protected List<Thing> calculate() {
                List<Thing> result = new ArrayList<>();
                for (Thing thing : model) {
                    if (femaleObservable.getValue() && !thing.female)
                        continue;
                    if (maleObservable.getValue() && !thing.male)
                        continue;
                    result.add(thing);
                }
                return result;
            }
        };
        viewer.setInput(filteredList);
        GridLayoutFactory.swtDefaults().applyTo(group);
        GridLayoutFactory.swtDefaults().applyTo(composite);
    }

    static class Thing {
        String name;
        boolean male;
        boolean female;

        public Thing(String name, boolean female, boolean male) {
            this.name = name;
            this.female = female;
            this.male = male;
        }

        @Override
        public String toString() {
            return name;
        }
    }
}