qgsdataitemproviderregistry.cpp

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/***************************************************************************
  qgsdataitemproviderregistry.cpp
  --------------------------------------
  Date                 : March 2015
  Copyright            : (C) 2015 by Martin Dobias
  Email                : wonder dot sk at gmail dot 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.                                   *
 *                                                                         *
 ***************************************************************************/

#include "qgsdataitemproviderregistry.h"

#include "qgsdataitem.h"
#include "qgsdataitemprovider.h"
#include "qgsdataprovider.h"
#include "qgslogger.h"
#include "qgsproviderregistry.h"

typedef QList<QgsDataItemProvider*> dataItemProviders_t();


class QgsDataItemProviderFromPlugin : public QgsDataItemProvider
{
  public:
    QgsDataItemProviderFromPlugin( const QString& name, dataCapabilities_t* capabilitiesFunc, dataItem_t* dataItemFunc )
        : mName( name )
        , mCapabilitiesFunc( capabilitiesFunc )
        , mDataItemFunc( dataItemFunc )
    {
    }

    virtual QString name() override { return mName; }

    virtual int capabilities() override { return mCapabilitiesFunc(); }

    virtual QgsDataItem* createDataItem( const QString& path, QgsDataItem* parentItem ) override { return mDataItemFunc( path, parentItem ); }

  protected:
    QString mName;
    dataCapabilities_t* mCapabilitiesFunc;
    dataItem_t* mDataItemFunc;
};


QgsDataItemProviderRegistry::QgsDataItemProviderRegistry()
{
  QStringList providersList = QgsProviderRegistry::instance()->providerList();

  Q_FOREACH ( const QString& key, providersList )
  {
    QLibrary *library = QgsProviderRegistry::instance()->providerLibrary( key );
    if ( !library )
      continue;

    // new / better way of returning data items from providers

    dataItemProviders_t* dataItemProvidersFn = reinterpret_cast< dataItemProviders_t * >( cast_to_fptr( library->resolve( "dataItemProviders" ) ) );
    if ( dataItemProvidersFn )
    {
      // the function is a factory - we keep ownership of the returned providers
      mProviders << dataItemProvidersFn();
    }

    // legacy support - using dataItem() and dataCapabilities() methods

    dataCapabilities_t * dataCapabilities = reinterpret_cast< dataCapabilities_t * >( cast_to_fptr( library->resolve( "dataCapabilities" ) ) );
    if ( !dataCapabilities )
    {
      QgsDebugMsg( library->fileName() + " does not have dataCapabilities" );
      continue;
    }

    dataItem_t *dataItem = reinterpret_cast< dataItem_t * >( cast_to_fptr( library->resolve( "dataItem" ) ) );
    if ( !dataItem )
    {
      QgsDebugMsg( library->fileName() + " does not have dataItem" );
      continue;
    }

    mProviders.append( new QgsDataItemProviderFromPlugin( library->fileName(), dataCapabilities, dataItem ) );
  }
}

QgsDataItemProviderRegistry* QgsDataItemProviderRegistry::instance()
{
  static QgsDataItemProviderRegistry sInstance;
  return &sInstance;
}

QgsDataItemProviderRegistry::~QgsDataItemProviderRegistry()
{
  qDeleteAll( mProviders );
}

void QgsDataItemProviderRegistry::addProvider( QgsDataItemProvider* provider )
{
  mProviders.append( provider );
}

void QgsDataItemProviderRegistry::removeProvider( QgsDataItemProvider* provider )
{
  int index = mProviders.indexOf( provider );
  if ( index >= 0 )
    delete mProviders.takeAt( index );
}