src/core/qgsmaplayerregistry.h

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/***************************************************************************
                          qgsmaplayerregistry.h
           Singleton class for keeping track of loaded layers
                             -------------------
    begin                : Sun June 04 2004
    copyright            : (C) 2004 by Tim Sutton
    email                : tim@linfiniti.com
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
/* $Id$ */

#ifndef QGSMAPLAYERREGISTRY_H
#define QGSMAPLAYERREGISTRY_H

#include <QMap>
#include <QObject>

class QString;
class QStringList;

class QgsMapLayer;

class CORE_EXPORT QgsMapLayerRegistry : public QObject
{
    Q_OBJECT

  public:

    static QgsMapLayerRegistry * instance();
    int count();

    ~QgsMapLayerRegistry();

    QgsMapLayer * mapLayer( QString theLayerId );

    QMap<QString, QgsMapLayer*> & mapLayers();

    QgsMapLayer *addMapLayer( QgsMapLayer * theMapLayer, bool theEmitSignal = true );

    void removeMapLayer( QString theLayerId, bool theEmitSignal = true );

    void removeAllMapLayers();

    /* Clears all layer caches, resetting them to zero and
     * freeing up any memory they may have been using. Layer
     * caches are used to speed up rendering in certain situations
     * see ticket #1974 for more details.
     * @note this method was added in QGIS 1.4
     */
    void clearAllLayerCaches();

    void reloadAllLayers();

  signals:

    void layerWillBeRemoved( QString theLayerId );

    void layerWasAdded( QgsMapLayer * theMapLayer );

    void removedAll();

  protected:

    QgsMapLayerRegistry( QObject * parent = 0 );

  private:

    static QgsMapLayerRegistry* mInstance;

    QMap<QString, QgsMapLayer*> mMapLayers;

    void connectNotify( const char * signal );


}; // class QgsMapLayerRegistry

#endif //QgsMapLayerRegistry_H