/*******************************************************************************
 * Copyright (c) 2009 Matthew Hall and others.
 * 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:
 *     Matthew Hall - initial API and implementation (bug 268472)
 ******************************************************************************/

module org.eclipse.jface.examples.databinding.snippets.Snippet033CrossValidationControlDecoration;

import java.lang.all;

import java.util.Date;

import org.eclipse.core.databinding.observable.Observables;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.core.databinding.validation.MultiValidator;
import org.eclipse.core.databinding.validation.ValidationStatus;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.jface.databinding.swt.WidgetProperties;
import org.eclipse.jface.internal.databinding.provisional.fieldassist.ControlDecorationSupport;
import org.eclipse.jface.internal.databinding.provisional.fieldassist.ControlDecorationUpdater;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.DateTime;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;

/**
 * @since 3.2
 * 
 */
public class Snippet033CrossValidationControlDecoration {
    protected Shell shell;
    private DateTime startDate;
    private DateTime endDate;

    /**
     * Launch the application
     * 
     * @param args
     */
    public static void main(String[] args) {
        try {
            Snippet033CrossValidationControlDecoration window = new Snippet033CrossValidationControlDecoration();
            window.open();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * Open the window
     */
    public void open() {
        final Display display = Display.getDefault();
        Realm.runWithDefault(SWTObservables.getRealm(display), new Runnable() {
            public void run() {
                createContents();
                shell.pack();
                shell.open();
                while (!shell.isDisposed()) {
                    if (!display.readAndDispatch())
                        display.sleep();
                }
            }
        });
    }

    protected void createContents() {
        shell = new Shell();
        GridLayout layout = new GridLayout();
        layout.numColumns = 4;
        shell.setLayout(layout);
        shell.setText("Snippet033CrossValidationControlDecoration.java");

        final Label label = new Label(shell, SWT.NONE);
        label.setLayoutData(new GridData());
        label.setText("Start date");
        startDate = new DateTime(shell, SWT.CALENDAR);
        final GridData gd_startDate = new GridData();
        gd_startDate.horizontalIndent = 10;
        startDate.setLayoutData(gd_startDate);

        final Label startDateLabel = new Label(shell, SWT.NONE);
        startDateLabel.setLayoutData(new GridData());
        startDateLabel.setText("End date");
        endDate = new DateTime(shell, SWT.CALENDAR);
        final GridData gd_endDate = new GridData();
        gd_endDate.horizontalIndent = 10;
        endDate.setLayoutData(gd_endDate);

        bindUI();
    }

    private void bindUI() {
        IObservableValue startDateObservable = WidgetProperties.selection()
                .observe(startDate);
        IObservableValue endDateObservable = WidgetProperties.selection()
                .observe(endDate);

        ControlDecorationSupport.create(new DateRangeValidator(
                startDateObservable, endDateObservable,
                "Start date must be on or before end date"), SWT.LEFT
                | SWT.CENTER);

        // Customize the decoration's description text and image
        ControlDecorationUpdater decorationUpdater = new ControlDecorationUpdater() {
            protected String getDescriptionText(IStatus status) {
                return "ERROR: " + super.getDescriptionText(status);
            }

            protected Image getImage(IStatus status) {
                return status.isOK() ? null : Display.getCurrent()
                        .getSystemImage(SWT.ICON_ERROR);
            }
        };
        ControlDecorationSupport.create(new DateRangeValidator(Observables
                .constantObservableValue(new Date()), startDateObservable,
                "Choose a starting date later than today"), SWT.LEFT | SWT.TOP,
                (Composite) null, decorationUpdater);
    }

    private static class DateRangeValidator extends MultiValidator {
        private final IObservableValue start;
        private final IObservableValue end;
        private final String errorMessage;

        public DateRangeValidator(IObservableValue start, IObservableValue end,
                String errorMessage) {
            this.start = start;
            this.end = end;
            this.errorMessage = errorMessage;
        }

        protected IStatus validate() {
            Date startDate = (Date) start.getValue();
            Date endDate = (Date) end.getValue();
            if (startDate.compareTo(endDate) > 0)
                return ValidationStatus.error(errorMessage);
            return ValidationStatus.ok();
        }
    }
}
void main( String[] args ){
    Snippet033CrossValidationControlDecoration.main(args);
}