org.eclipse.papyrus.widgets.editors.ReferenceCombo.java Source code

Introduction

Here is the source code for org.eclipse.papyrus.widgets.editors.ReferenceCombo.java

Source

/*****************************************************************************
 * Copyright (c) 2010 CEA LIST.
 *    
 * 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:
 *  Camille Letavernier (CEA LIST) camille.letavernier@cea.fr - Initial API and implementation
 *****************************************************************************/
package org.eclipse.papyrus.widgets.editors;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.databinding.viewers.ViewerProperties;
import org.eclipse.jface.viewers.ComboViewer;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.papyrus.widgets.Activator;
import org.eclipse.papyrus.widgets.providers.EncapsulatedContentProvider;
import org.eclipse.papyrus.widgets.providers.IStaticContentProvider;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CCombo;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;

/**
 * An editor representing a single reference as a Combo Box
 * This Editor needs a ContentProvider and a LabelProvider,
 * describing the objects that can be referred by this property
 * 
 * @author Camille Letavernier
 * 
 */
public class ReferenceCombo extends AbstractValueEditor implements SelectionListener {

    /**
     * The viewer displaying the available values from the model
     */
    private ComboViewer viewer;

    /**
     * The combo used to select the reference
     */
    private CCombo combo;

    private boolean unsettable;

    protected Button unset;

    /**
     * 
     * Constructor.
     * 
     * @param parent
     *        The Composite in which this editor is diplayed
     * @param style
     *        The style for this editor's combo
     */
    public ReferenceCombo(Composite parent, int style) {
        this(parent, style, null);
    }

    /**
     * 
     * Constructor.
     * 
     * @param parent
     *        The Composite in which this editor is diplayed
     * @param style
     *        The style for this editor's combo
     * @param label
     *        The label for this editor
     */
    public ReferenceCombo(Composite parent, int style, String label) {
        super(parent, label);

        ((GridLayout) getLayout()).numColumns = 3;

        combo = factory.createCCombo(this, style | SWT.BORDER);
        combo.setBackground(new Color(combo.getDisplay(), 255, 255, 255));
        combo.setLayoutData(getDefaultLayoutData());
        combo.setEditable(false);

        viewer = new ComboViewer(combo);

        unset = new Button(this, SWT.PUSH);
        unset.setImage(Activator.getDefault().getImage("/icons/Delete_12x12.gif")); //$NON-NLS-1$
        unset.setToolTipText("Unset the current value");
        unset.addSelectionListener(this);

        setCommitOnFocusLost(combo);
    }

    /**
     * Sets the Content and Label providers for this editor
     * 
     * @param contentProvider
     * 
     * @param labelProvider
     */
    public void setProviders(IStaticContentProvider contentProvider, ILabelProvider labelProvider) {
        Assert.isNotNull(contentProvider, "The content provider should not be null"); //$NON-NLS-1$
        setContentProvider(contentProvider);

        if (labelProvider != null) {
            setLabelProvider(labelProvider);
        }
    }

    /**
     * Sets the content provider for this combo. The Content provider should
     * specify the objects that can be referred by this property
     * 
     * @param provider
     */
    public void setContentProvider(IStaticContentProvider provider) {
        viewer.setContentProvider(new EncapsulatedContentProvider(provider));
        viewer.setInput(""); //$NON-NLS-1$
        setWidgetObservable(ViewerProperties.singleSelection().observe(viewer), true);
    }

    /**
     * The Label provider associated to the available objects that
     * can be referred by this property
     * 
     * @param provider
     */
    public void setLabelProvider(ILabelProvider provider) {
        viewer.setLabelProvider(provider);
    }

    /**
     * Retrieves the ComboViewer associated to this Editor
     * 
     * @return
     *         The ComboViewer associated to this editor
     */
    public ComboViewer getViewer() {
        return viewer;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Object getEditableType() {
        return Object.class;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public Object getValue() {
        IStructuredSelection selection = (IStructuredSelection) viewer.getSelection();
        if (selection.isEmpty()) {
            return null;
        }
        return selection.getFirstElement();
    }

    @Override
    public void setReadOnly(boolean readOnly) {
        combo.setEnabled(!readOnly);
        updateControls();
    }

    @Override
    public boolean isReadOnly() {
        return !combo.isEnabled();
    }

    @Override
    public void setToolTipText(String text) {
        combo.setToolTipText(text);
        super.setLabelToolTipText(text);
    }

    public void setUnsettable(boolean unsettable) {
        this.unsettable = unsettable;
    }

    protected void updateControls() {
        unset.setEnabled(unsettable && !isReadOnly());
    }

    protected void unsetAction() {
        viewer.setSelection(StructuredSelection.EMPTY);
        //      if (modelProperty != null){
        //         modelProperty.setValue(null);
        //      }
    }

    public void widgetSelected(SelectionEvent e) {
        if (e.widget == unset) {
            unsetAction();
        }
    }

    public void widgetDefaultSelected(SelectionEvent e) {
        //Nothing
    }
}