org.polymap.core.project.ProjectPluginSession.java Source code

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Here is the source code for org.polymap.core.project.ProjectPluginSession.java

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/* 
 * polymap.org
 * Copyright 2009-2013, Polymap GmbH. All rights reserved.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 */
package org.polymap.core.project;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.eclipse.swt.widgets.Display;

import org.eclipse.rwt.SessionSingletonBase;

import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;

import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.ISelectionListener;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PlatformUI;

import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.ListenerList;

import org.polymap.core.project.ui.PartListenerAdapter;
import org.polymap.core.runtime.Polymap;

/**
 * The session dependent part of the {@link MapEditorPlugin} API and
 * implementation.
 * 
 * @author <a href="http://www.polymap.de">Falko Braeutigam</a> 
 * @since 3.0
 */
public class ProjectPluginSession extends SessionSingletonBase {

    private static Log log = LogFactory.getLog(ProjectPluginSession.class);

    // static factory *************************************

    /**
     * Gets or creates the Platform instance for the application session of the
     * current thread.
     */
    public static ProjectPluginSession instance() {
        return (ProjectPluginSession) getInstance(ProjectPluginSession.class);
    }

    // instance *******************************************

    /** The map that is currently selected in the UI, or null. */
    private IMap selectedMap;

    private ListenerList mapSelectionListeners = new ListenerList(ListenerList.IDENTITY);

    protected ProjectPluginSession() {
        Display display = Polymap.getSessionDisplay();
        if (display != null) {
            display.asyncExec(new Runnable() {
                public void run() {
                    IWorkbench workbench = PlatformUI.getWorkbench();
                    if (workbench == null) {
                        return;
                    }
                    IWorkbenchWindow window = workbench.getActiveWorkbenchWindow();
                    if (window == null) {
                        return;
                    }
                    IWorkbenchPage page = window.getActivePage();
                    if (page == null) {
                        return;
                    }

                    // selection listener
                    page.addSelectionListener(new ISelectionListener() {
                        public void selectionChanged(IWorkbenchPart part, ISelection sel) {
                            log.debug("selection: " + sel);
                            if (sel instanceof IStructuredSelection) {
                                //
                                Object elm = ((IStructuredSelection) sel).getFirstElement();
                                if (elm != null && elm instanceof IMap) {
                                    selectedMap = (IMap) elm;
                                }
                                fireEvent(part);
                            }
                        }
                    });

                    // part listener
                    page.addPartListener(new PartListenerAdapter() {
                        public void partActivated(IWorkbenchPart part) {
                            if (part instanceof IEditorPart) {
                                IEditorInput input = ((IEditorPart) part).getEditorInput();
                                if (input instanceof IAdaptable) {
                                    selectedMap = (IMap) ((IAdaptable) input).getAdapter(IMap.class);
                                    fireEvent(part);
                                }
                            }
                        }

                        public void partOpened(IWorkbenchPart part) {
                            partActivated(part);
                        }
                    });
                }
            });
        }
    }

    protected void fireEvent(IWorkbenchPart part) {
        // fire event
        PropertyChangeEvent ev = new PropertyChangeEvent(part, "selectedMap", null, selectedMap);
        for (Object listener : mapSelectionListeners.getListeners()) {
            ((PropertyChangeListener) listener).propertyChange(ev);
        }
    }

    public IMap getSelectedMap() {
        return selectedMap;
    }

    public void addMapSelectionListener(PropertyChangeListener listener) {
        mapSelectionListeners.add(listener);
    }

    public void removeMapSelectionListener(PropertyChangeListener listener) {
        mapSelectionListeners.remove(listener);
    }

}