qgsprovidersublayertask.cpp

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/***************************************************************************
                             qgsprovidersublayertask.cpp
                             ----------------------
    begin                : June 2021
    copyright            : (C) 2021 by Nyall Dawson
    email                : nyall dot dawson 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 "qgsprovidersublayertask.h"
#include "qgsfeedback.h"
#include "qgsprovidermetadata.h"
#include "qgsproviderregistry.h"
#include "qgsprovidersublayerdetails.h"
#include "qgsreadwritelocker.h"
 
QgsProviderSublayerTask::QgsProviderSublayerTask( const QString &uri, bool includeSystemTables )
  : QgsTask( tr( "Retrieving layers" ), QgsTask::CanCancel | QgsTask::CancelWithoutPrompt | QgsTask::Silent )
  , mUri( uri )
  , mIncludeSystemTables( includeSystemTables )
{
}
 
QgsProviderSublayerTask::QgsProviderSublayerTask( const QString &uri, const QString &providerKey, bool includeSystemTables )
  : QgsTask( tr( "Retrieving layers" ), QgsTask::CanCancel | QgsTask::CancelWithoutPrompt | QgsTask::Silent )
  , mUri( uri )
  , mProviderKey( providerKey )
  , mIncludeSystemTables( includeSystemTables )
{
}
 
QList<QgsProviderSublayerDetails> QgsProviderSublayerTask::results() const
{
  const QgsReadWriteLocker locker( mLock, QgsReadWriteLocker::Read );
  return mResults;
}
 
QgsProviderSublayerTask::~QgsProviderSublayerTask() = default;
 
bool QgsProviderSublayerTask::run()
{
  mFeedback = std::make_unique< QgsFeedback >();
 
  Qgis::SublayerQueryFlags flags = Qgis::SublayerQueryFlag::ResolveGeometryType | Qgis::SublayerQueryFlag::CountFeatures;
  if ( mIncludeSystemTables )
    flags |= Qgis::SublayerQueryFlag::IncludeSystemTables;
 
  QList<QgsProviderSublayerDetails> res;
  if ( mProviderKey.isEmpty() )
    res = QgsProviderRegistry::instance()->querySublayers( mUri, flags, mFeedback.get() );
  else
  {
    QgsProviderMetadata *provider = QgsProviderRegistry::instance()->providerMetadata( mProviderKey );
    if ( provider )
      res = provider->querySublayers( mUri, flags, mFeedback.get() );
  }
 
  const QgsReadWriteLocker locker( mLock, QgsReadWriteLocker::Write );
  mResults = res;
 
  return true;
}
 
void QgsProviderSublayerTask::cancel()
{
  if ( mFeedback )
    mFeedback->cancel();
 
  QgsTask::cancel();
}