qgstemporalutils.cpp

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/***************************************************************************
  qgstemporalutils.cpp
  -----------------------
  Date                 : March 2020
  Copyright            : (C) 2020 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 "qgstemporalutils.h"
#include "qgsproject.h"
#include "qgsmaplayertemporalproperties.h"
#include "qgsrasterlayer.h"
#include "qgsmeshlayer.h"
#include "qgsvectorlayer.h"
#include "qgsvectorlayertemporalproperties.h"
#include "qgsrasterlayertemporalproperties.h"
#include "qgsmeshlayertemporalproperties.h"
#include "qgstemporalnavigationobject.h"
#include "qgsmapdecoration.h"
#include "qgsmapsettings.h"
#include "qgsmaprenderercustompainterjob.h"
#include "qgsexpressioncontextutils.h"
 
QgsDateTimeRange QgsTemporalUtils::calculateTemporalRangeForProject( QgsProject *project )
{
  const QMap<QString, QgsMapLayer *> &mapLayers = project->mapLayers();
  QgsMapLayer *currentLayer = nullptr;
 
  QDateTime minDate;
  QDateTime maxDate;
 
  for ( QMap<QString, QgsMapLayer *>::const_iterator it = mapLayers.constBegin(); it != mapLayers.constEnd(); ++it )
  {
    currentLayer = it.value();
 
    if ( !currentLayer->temporalProperties() || !currentLayer->temporalProperties()->isActive() )
      continue;
    QgsDateTimeRange layerRange = currentLayer->temporalProperties()->calculateTemporalExtent( currentLayer );
 
    if ( layerRange.begin().isValid() && ( !minDate.isValid() ||  layerRange.begin() < minDate ) )
      minDate = layerRange.begin();
    if ( layerRange.end().isValid() && ( !maxDate.isValid() ||  layerRange.end() > maxDate ) )
      maxDate = layerRange.end();
  }
 
  return QgsDateTimeRange( minDate, maxDate );
}
 
bool QgsTemporalUtils::exportAnimation( const QgsMapSettings &mapSettings, const QgsTemporalUtils::AnimationExportSettings &settings, QString &error, QgsFeedback *feedback )
{
  if ( settings.fileNameTemplate.isEmpty() )
  {
    error = QObject::tr( "Filename template is empty" );
    return false;
  }
  int numberOfDigits = settings.fileNameTemplate.count( QLatin1Char( '#' ) );
  if ( numberOfDigits < 0 )
  {
    error = QObject::tr( "Wrong filename template format (must contain #)" );
    return false;
  }
  const QString token( numberOfDigits, QLatin1Char( '#' ) );
  if ( !settings.fileNameTemplate.contains( token ) )
  {
    error = QObject::tr( "Filename template must contain all # placeholders in one continuous group." );
    return false;
  }
  if ( !QDir().mkpath( settings.outputDirectory ) )
  {
    error = QObject::tr( "Output directory creation failure." );
    return false;
  }
 
  QgsTemporalNavigationObject navigator;
  navigator.setTemporalExtents( settings.animationRange );
  navigator.setFrameDuration( settings.frameDuration );
  QgsMapSettings ms = mapSettings;
  const QgsExpressionContext context = ms.expressionContext();
 
  const long long totalFrames = navigator.totalFrameCount();
  long long currentFrame = 0;
 
  while ( currentFrame < totalFrames )
  {
    if ( feedback )
    {
      if ( feedback->isCanceled() )
      {
        error = QObject::tr( "Export canceled" );
        return false;
      }
      feedback->setProgress( currentFrame / static_cast<double>( totalFrames ) * 100 );
    }
    ++currentFrame;
 
    navigator.setCurrentFrameNumber( currentFrame );
 
    ms.setIsTemporal( true );
    ms.setTemporalRange( navigator.dateTimeRangeForFrameNumber( currentFrame ) );
 
    QgsExpressionContext frameContext = context;
    frameContext.appendScope( navigator.createExpressionContextScope() );
    frameContext.appendScope( QgsExpressionContextUtils::mapSettingsScope( ms ) );
    ms.setExpressionContext( frameContext );
 
    QString fileName( settings.fileNameTemplate );
    const QString frameNoPaddedLeft( QStringLiteral( "%1" ).arg( currentFrame, numberOfDigits, 10, QChar( '0' ) ) ); // e.g. 0001
    fileName.replace( token, frameNoPaddedLeft );
    const QString path = QDir( settings.outputDirectory ).filePath( fileName );
 
    QImage img = QImage( ms.outputSize(), ms.outputImageFormat() );
    img.setDotsPerMeterX( 1000 * ms.outputDpi() / 25.4 );
    img.setDotsPerMeterY( 1000 * ms.outputDpi() / 25.4 );
    img.fill( ms.backgroundColor().rgb() );
 
    QPainter p( &img );
    QgsMapRendererCustomPainterJob job( ms, &p );
    job.start();
    job.waitForFinished();
 
    QgsRenderContext context = QgsRenderContext::fromMapSettings( ms );
    context.setPainter( &p );
 
    const auto constMDecorations = settings.decorations;
    for ( QgsMapDecoration *decoration : constMDecorations )
    {
      decoration->render( ms, context );
    }
 
    p.end();
 
    img.save( path );
  }
 
  return true;
}