org.activiti.designer.eclipse.property.PropertiesLabelProvider.java Source code

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Here is the source code for org.activiti.designer.eclipse.property.PropertiesLabelProvider.java

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/*******************************************************************************
 * <copyright>
 *
 * Copyright (c) 2005, 2010 SAP AG.
 * 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:
 *    SAP AG - initial API, implementation and documentation
 *
 * </copyright>
 *
 *******************************************************************************/
package org.activiti.designer.eclipse.property;

import java.util.Iterator;

import org.eclipse.core.runtime.Assert;
import org.eclipse.emf.ecore.EModelElement;
import org.eclipse.emf.ecore.ENamedElement;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.gef.EditPart;
import org.eclipse.graphiti.mm.pictograms.PictogramElement;
import org.eclipse.graphiti.services.Graphiti;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.swt.graphics.Image;
import org.eclipse.ui.views.properties.tabbed.ITypeMapper;

/**
 * Label provider for the title bar for the tabbed property sheet page.
 */
public class PropertiesLabelProvider extends LabelProvider {

    private ITypeMapper typeMapper;

    /**
     * constructor.
     */
    public PropertiesLabelProvider() {
        super();
        typeMapper = new TypeMapper();
    }

    /**
     * @see org.eclipse.jface.viewers.ILabelProvider#getImage(java.lang.Object)
     */
    @Override
    public Image getImage(Object objects) {

        if (objects == null || objects.equals(StructuredSelection.EMPTY)) {
            return null;
        }
        final boolean multiple[] = { false };
        Object object = getObject(objects, multiple);
        if (object == null) {
            return null;
        } else {
            if (!(object instanceof EditPart)) {
                return null;
            }
        }
        return null;
    }

    /**
     * @see org.eclipse.jface.viewers.ILabelProvider#getText(java.lang.Object)
     */
    @Override
    public String getText(Object objects) {
        if (objects == null || objects.equals(StructuredSelection.EMPTY)) {
            return "No items selected";//$NON-NLS-1$
        }
        final boolean multiple[] = { false };
        Object object = getObject(objects, multiple);
        if (object == null || ((IStructuredSelection) objects).size() > 1) {
            return ((IStructuredSelection) objects).size() + " items selected";//$NON-NLS-1$
        } else {
            if (object instanceof EditPart) {
                object = ((EditPart) object).getModel();
            }
            if (object instanceof EObject) {
                EObject robj = (EObject) object;
                if (robj instanceof PictogramElement) {
                    PictogramElement pe = (PictogramElement) robj;
                    EObject businessObject = Graphiti.getLinkService()
                            .getBusinessObjectForLinkedPictogramElement(pe);
                    if (businessObject == null) {
                        businessObject = robj;
                    }

                    // return the name of the MetamodelClass
                    EObject refMetaObject = businessObject.eClass();
                    if (refMetaObject instanceof ENamedElement) {
                        return ((ENamedElement) refMetaObject).getName();
                    }
                    return ""; // no luck //$NON-NLS-1$
                } else {
                    return "" + ((EModelElement) robj.eClass()).getClass().getName(); //$NON-NLS-1$
                }
            } else {
                return object.toString();
            }
        }
    }

    /**
     * Determine if a multiple object selection has been passed to the label
     * provider. If the objects is a IStructuredSelection, see if all the
     * objects in the selection are the same and if so, we want to provide
     * labels for the common selected element.
     * 
     * @param objects
     *            a single object or a IStructuredSelection.
     * @param multiple
     *            first element in the array is true if there is multiple
     *            unequal selected elements in a IStructuredSelection.
     * @return the object to get labels for.
     */
    private Object getObject(Object objects, boolean multiple[]) {
        Assert.isNotNull(objects);
        Object object = null;
        if (objects instanceof IStructuredSelection) {
            IStructuredSelection selection = (IStructuredSelection) objects;
            object = selection.getFirstElement();
            if (selection.size() == 1) {
                // one element selected
                multiple[0] = false;
                return object;
            }
            // multiple elements selected
            multiple[0] = true;
            Class<?> firstClass = typeMapper.mapType(object);
            // determine if all the objects in the selection are the same type
            if (selection.size() > 1) {
                for (Iterator<?> i = selection.iterator(); i.hasNext();) {
                    Object next = i.next();
                    Class<?> nextClass = typeMapper.mapType(next);
                    if (!nextClass.equals(firstClass)) {
                        // two elements not equal == multiple selected unequal
                        multiple[0] = false;
                        object = null;
                        break;
                    }
                }
            }
        } else {
            multiple[0] = false;
            object = objects;
        }
        return object;
    }

}