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[Atlas] Add feature sorting and filtering
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Hugo Mercier committed Feb 6, 2013
1 parent a05fc28 commit b477179af7ac67b6cdb6b8c7674d1f0c1135bc73
Showing with 105 additions and 6 deletions.
  1. +76 −6 src/core/composer/qgsatlascomposition.cpp
  2. +29 −0 src/core/composer/qgsatlascomposition.h
@@ -30,7 +30,8 @@ QgsAtlasComposition::QgsAtlasComposition( QgsComposition* composition ) :
mEnabled( false ),
mComposerMap( 0 ),
mHideCoverage( false ), mFixedScale( false ), mMargin( 0.10 ), mFilenamePattern( "'output_'||$feature" ),
mCoverageLayer( 0 ), mSingleFile( false )
mCoverageLayer( 0 ), mSingleFile( false ),
mSortFeatures( false ), mSortAscending( true ), mFeatureFilter( "" )
{

// declare special columns with a default value
@@ -52,6 +53,33 @@ void QgsAtlasComposition::setCoverageLayer( QgsVectorLayer* layer )
QgsExpression::setSpecialColumn( "$numfeatures", QVariant(( int )mFeatureIds.size() ) );
}

//
// Private class only used for the sorting of features
class FieldSorter
{
public:
FieldSorter( QgsAtlasComposition::SorterKeys& keys, bool ascending = true ) : mKeys( keys ), mAscending( ascending ) {}

bool operator()( const QgsFeatureId& id1, const QgsFeatureId& id2 )
{
bool result;
if ( mKeys[ id1 ].type() == QVariant::Int ) {
result = mKeys[ id1 ].toInt() < mKeys[ id2 ].toInt();
}
else if ( mKeys[ id1 ].type() == QVariant::Double ) {
result = mKeys[ id1 ].toDouble() < mKeys[ id2 ].toDouble();
}
else if ( mKeys[ id1 ].type() == QVariant::String ) {
result = (QString::localeAwareCompare(mKeys[ id1 ].toString(), mKeys[ id2 ].toString()) < 0);
}

return mAscending ? result : !result;
}
private:
QgsAtlasComposition::SorterKeys& mKeys;
bool mAscending;
};

void QgsAtlasComposition::beginRender()
{
if ( !mComposerMap || !mCoverageLayer )
@@ -84,13 +112,45 @@ void QgsAtlasComposition::beginRender()
// select all features with all attributes
QgsFeatureIterator fit = mCoverageLayer->getFeatures();

std::auto_ptr<QgsExpression> filterExpression;
if ( mFeatureFilter.size() > 0 ) {
filterExpression = std::auto_ptr<QgsExpression>(new QgsExpression( mFeatureFilter ));
if ( filterExpression->hasParserError() )
{
throw std::runtime_error( "Feature filter parser error: " + filterExpression->parserErrorString().toStdString() );
}
}

// We cannot use nextFeature() directly since the feature pointer is rewinded by the rendering process
// We thus store the feature ids for future extraction
QgsFeature feat;
mFeatureIds.clear();
mFeatureKeys.clear();
while ( fit.nextFeature( feat ) )
{
mFeatureIds.push_back( feat.id() );
if ( mFeatureFilter.size() > 0 ) {
QVariant result = filterExpression->evaluate( &feat, mCoverageLayer->pendingFields() );
if ( filterExpression->hasEvalError() )
{
throw std::runtime_error( "Feature filter eval error: " + filterExpression->evalErrorString().toStdString() );
}

// skip this feature if the filter evaluation if false
if ( !result.toBool() ) {
continue;
}
}
mFeatureIds.push_back( feat.id() );

if ( mSortFeatures ) {
mFeatureKeys.insert( std::make_pair( feat.id(), feat.attributes()[ mSortKeyAttributeIdx ] ) );
}
}

// sort features, if asked for
if ( mSortFeatures ) {
FieldSorter sorter( mFeatureKeys, mSortAscending );
std::sort( mFeatureIds.begin(), mFeatureIds.end(), sorter );
}

mOrigExtent = mComposerMap->extent();
@@ -159,10 +219,6 @@ void QgsAtlasComposition::prepareForFeature( size_t featureI )
{
QgsExpression::setSpecialColumn( "$feature", QVariant(( int )featureI + 1 ) );
QVariant filenameRes = mFilenameExpr->evaluate( &mCurrentFeature );
if ( mFilenameExpr->hasEvalError() )
{
throw std::runtime_error( "Filename eval error: " + mFilenameExpr->evalErrorString().toStdString() );
}

mCurrentFilename = filenameRes.toString();
}
@@ -284,6 +340,13 @@ void QgsAtlasComposition::writeXML( QDomElement& elem, QDomDocument& doc ) const
atlasElem.setAttribute( "margin", QString::number( mMargin ) );
atlasElem.setAttribute( "filenamePattern", mFilenamePattern );

atlasElem.setAttribute( "sortFeatures", mSortFeatures ? "true" : "false" );
if ( mSortFeatures ) {
atlasElem.setAttribute( "sortKey", QString::number(mSortKeyAttributeIdx) );
atlasElem.setAttribute( "sortAscending", mSortAscending ? "true" : "false" );
}
atlasElem.setAttribute( "featureFilter", mFeatureFilter );

elem.appendChild( atlasElem );
}

@@ -324,5 +387,12 @@ void QgsAtlasComposition::readXML( const QDomElement& atlasElem, const QDomDocum
mSingleFile = atlasElem.attribute( "singleFile", "false" ) == "true" ? true : false;
mFilenamePattern = atlasElem.attribute( "filenamePattern", "" );

mSortFeatures = atlasElem.attribute( "sortFeatures", "false" ) == "true" ? true : false;
if ( mSortFeatures ) {
mSortKeyAttributeIdx = atlasElem.attribute( "sortKey", "0" ).toInt();
mSortAscending = atlasElem.attribute( "sortAscending", "true" ) == "true" ? true : false;
}
mFeatureFilter = atlasElem.attribute( "featureFilter", "" );

emit parameterChanged();
}
@@ -66,6 +66,18 @@ class CORE_EXPORT QgsAtlasComposition : public QObject
bool singleFile() const { return mSingleFile; }
void setSingleFile( bool single ) { mSingleFile = single; }

bool sortFeatures() const { return mSortFeatures; }
void setSortFeatures( bool doSort ) { mSortFeatures = doSort; }

bool sortAscending() const { return mSortAscending; }
void setSortAscending( bool ascending ) { mSortAscending = ascending; }

QString featureFilter() const { return mFeatureFilter; }
void setFeatureFilter( const QString& expression ) { mFeatureFilter = expression; }

size_t sortKeyAttributeIndex() const { return mSortKeyAttributeIdx; }
void setSortKeyAttributeIndex( size_t idx ) { mSortKeyAttributeIdx = idx; }

/** Begins the rendering. */
void beginRender();
/** Ends the rendering. Restores original extent */
@@ -103,7 +115,24 @@ class CORE_EXPORT QgsAtlasComposition : public QObject

QgsCoordinateTransform mTransform;
QString mCurrentFilename;
// feature ordering
bool mSortFeatures;
// sort direction
bool mSortAscending;
public:
typedef std::map< QgsFeatureId, QVariant > SorterKeys;
private:
// value of field that is used for ordering of features
SorterKeys mFeatureKeys;
// key (attribute index) used for ordering
size_t mSortKeyAttributeIdx;

// feature expression filter (or empty)
QString mFeatureFilter;

// id of each iterated feature (after filtering and sorting)
std::vector<QgsFeatureId> mFeatureIds;

QgsFeature mCurrentFeature;
QgsRectangle mOrigExtent;
bool mRestoreLayer;

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