/
qgsgraduatedsymbolrendererv2.cpp
1476 lines (1261 loc) · 41.6 KB
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qgsgraduatedsymbolrendererv2.cpp
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/***************************************************************************
qgsgraduatedsymbolrendererv2.cpp
---------------------
begin : November 2009
copyright : (C) 2009 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 "qgsgraduatedsymbolrendererv2.h"
#include "qgssymbolv2.h"
#include "qgssymbollayerv2utils.h"
#include "qgsvectorcolorrampv2.h"
#include "qgspointdisplacementrenderer.h"
#include "qgsinvertedpolygonrenderer.h"
#include "qgsfeature.h"
#include "qgsvectorlayer.h"
#include "qgslogger.h"
#include "qgsvectordataprovider.h"
#include "qgsexpression.h"
#include <QDomDocument>
#include <QDomElement>
#include <QSettings> // for legend
#include <limits> // for jenks classification
#include <cmath> // for pretty classification
#include <ctime>
QgsRendererRangeV2::QgsRendererRangeV2()
: mLowerValue( 0 ), mUpperValue( 0 ), mSymbol( 0 ), mLabel()
{
}
QgsRendererRangeV2::QgsRendererRangeV2( double lowerValue, double upperValue, QgsSymbolV2* symbol, QString label, bool render )
: mLowerValue( lowerValue )
, mUpperValue( upperValue )
, mSymbol( symbol )
, mLabel( label )
, mRender( render )
{
}
QgsRendererRangeV2::QgsRendererRangeV2( const QgsRendererRangeV2& range )
: mLowerValue( range.mLowerValue )
, mUpperValue( range.mUpperValue )
, mSymbol( range.mSymbol.data() ? range.mSymbol->clone() : NULL )
, mLabel( range.mLabel )
, mRender( range.mRender )
{
}
// cpy and swap idiom, note that the cpy is done with 'pass by value'
QgsRendererRangeV2& QgsRendererRangeV2::operator=( QgsRendererRangeV2 range )
{
swap( range );
return *this;
}
void QgsRendererRangeV2::swap( QgsRendererRangeV2 & other )
{
qSwap( mLowerValue, other.mLowerValue );
qSwap( mUpperValue, other.mUpperValue );
qSwap( mSymbol, other.mSymbol );
std::swap( mLabel, other.mLabel );
}
double QgsRendererRangeV2::lowerValue() const
{
return mLowerValue;
}
double QgsRendererRangeV2::upperValue() const
{
return mUpperValue;
}
QgsSymbolV2* QgsRendererRangeV2::symbol() const
{
return mSymbol.data();
}
QString QgsRendererRangeV2::label() const
{
return mLabel;
}
void QgsRendererRangeV2::setSymbol( QgsSymbolV2* s )
{
if ( mSymbol.data() != s ) mSymbol.reset( s );
}
void QgsRendererRangeV2::setLabel( QString label )
{
mLabel = label;
}
void QgsRendererRangeV2::setUpperValue( double upperValue )
{
mUpperValue = upperValue;
}
void QgsRendererRangeV2::setLowerValue( double lowerValue )
{
mLowerValue = lowerValue;
}
bool QgsRendererRangeV2::renderState() const
{
return mRender;
}
void QgsRendererRangeV2::setRenderState( bool render )
{
mRender = render;
}
QString QgsRendererRangeV2::dump() const
{
return QString( "%1 - %2::%3::%4\n" ).arg( mLowerValue ).arg( mUpperValue ).arg( mLabel ).arg( mSymbol->dump() );
}
void QgsRendererRangeV2::toSld( QDomDocument &doc, QDomElement &element, QgsStringMap props ) const
{
if ( !mSymbol.data() || props.value( "attribute", "" ).isEmpty() )
return;
QString attrName = props[ "attribute" ];
QDomElement ruleElem = doc.createElement( "se:Rule" );
element.appendChild( ruleElem );
QDomElement nameElem = doc.createElement( "se:Name" );
nameElem.appendChild( doc.createTextNode( mLabel ) );
ruleElem.appendChild( nameElem );
QDomElement descrElem = doc.createElement( "se:Description" );
QDomElement titleElem = doc.createElement( "se:Title" );
QString descrStr = QString( "range: %1 - %2" ).arg( mLowerValue ).arg( mUpperValue );
titleElem.appendChild( doc.createTextNode( !mLabel.isEmpty() ? mLabel : descrStr ) );
descrElem.appendChild( titleElem );
ruleElem.appendChild( descrElem );
// create the ogc:Filter for the range
QString filterFunc = QString( "%1 > %2 AND %1 <= %3" )
.arg( attrName.replace( "\"", "\"\"" ) )
.arg( mLowerValue ).arg( mUpperValue );
QgsSymbolLayerV2Utils::createFunctionElement( doc, ruleElem, filterFunc );
mSymbol->toSld( doc, ruleElem, props );
}
///////////
QgsGraduatedSymbolRendererV2::QgsGraduatedSymbolRendererV2( QString attrName, QgsRangeList ranges )
: QgsFeatureRendererV2( "graduatedSymbol" ),
mAttrName( attrName ),
mRanges( ranges ),
mMode( Custom ),
mInvertedColorRamp( false ),
mUnits(""),
mDecimalPlaces(4),
mScaleMethod( DEFAULT_SCALE_METHOD )
{
// TODO: check ranges for sanity (NULL symbols, invalid ranges)
}
QgsGraduatedSymbolRendererV2::~QgsGraduatedSymbolRendererV2()
{
mRanges.clear(); // should delete all the symbols
}
QgsSymbolV2* QgsGraduatedSymbolRendererV2::symbolForValue( double value )
{
for ( QgsRangeList::iterator it = mRanges.begin(); it != mRanges.end(); ++it )
{
if ( it->lowerValue() <= value && it->upperValue() >= value )
{
if ( it->renderState() || mCounting )
return it->symbol();
else
return NULL;
}
}
// the value is out of the range: return NULL instead of symbol
return NULL;
}
QgsSymbolV2* QgsGraduatedSymbolRendererV2::symbolForFeature( QgsFeature& feature )
{
const QgsAttributes& attrs = feature.attributes();
QVariant value;
if ( mAttrNum < 0 || mAttrNum >= attrs.count() )
{
value = mExpression->evaluate( &feature );
}
else
{
value = attrs[mAttrNum];
}
// Null values should not be categorized
if ( value.isNull() )
return NULL;
// find the right category
QgsSymbolV2* symbol = symbolForValue( value.toDouble() );
if ( symbol == NULL )
return NULL;
if ( !mRotation.data() && !mSizeScale.data() )
return symbol; // no data-defined rotation/scaling - just return the symbol
// find out rotation, size scale
const double rotation = mRotation.data() ? mRotation->evaluate( feature ).toDouble() : 0;
const double sizeScale = mSizeScale.data() ? mSizeScale->evaluate( feature ).toDouble() : 1.;
// take a temporary symbol (or create it if doesn't exist)
QgsSymbolV2* tempSymbol = mTempSymbols[symbol];
// modify the temporary symbol and return it
if ( tempSymbol->type() == QgsSymbolV2::Marker )
{
QgsMarkerSymbolV2* markerSymbol = static_cast<QgsMarkerSymbolV2*>( tempSymbol );
if ( mRotation.data() ) markerSymbol->setAngle( rotation );
markerSymbol->setSize( sizeScale * static_cast<QgsMarkerSymbolV2*>( symbol )->size() );
markerSymbol->setScaleMethod( mScaleMethod );
}
else if ( tempSymbol->type() == QgsSymbolV2::Line )
{
QgsLineSymbolV2* lineSymbol = static_cast<QgsLineSymbolV2*>( tempSymbol );
lineSymbol->setWidth( sizeScale * static_cast<QgsLineSymbolV2*>( symbol )->width() );
}
return tempSymbol;
}
void QgsGraduatedSymbolRendererV2::startRender( QgsRenderContext& context, const QgsFields& fields )
{
mCounting = context.rendererScale() == 0.0;
// find out classification attribute index from name
mAttrNum = fields.fieldNameIndex( mAttrName );
if ( mAttrNum == -1 )
{
mExpression.reset( new QgsExpression( mAttrName ) );
mExpression->prepare( fields );
}
QgsRangeList::iterator it = mRanges.begin();
for ( ; it != mRanges.end(); ++it )
{
it->symbol()->startRender( context, &fields );
if ( mRotation.data() || mSizeScale.data() )
{
QgsSymbolV2* tempSymbol = it->symbol()->clone();
tempSymbol->setRenderHints(( mRotation.data() ? QgsSymbolV2::DataDefinedRotation : 0 ) |
( mSizeScale.data() ? QgsSymbolV2::DataDefinedSizeScale : 0 ) );
tempSymbol->startRender( context, &fields );
mTempSymbols[ it->symbol()] = tempSymbol;
}
}
}
void QgsGraduatedSymbolRendererV2::stopRender( QgsRenderContext& context )
{
QgsRangeList::iterator it = mRanges.begin();
for ( ; it != mRanges.end(); ++it )
it->symbol()->stopRender( context );
// cleanup mTempSymbols
QHash<QgsSymbolV2*, QgsSymbolV2*>::iterator it2 = mTempSymbols.begin();
for ( ; it2 != mTempSymbols.end(); ++it2 )
{
it2.value()->stopRender( context );
delete it2.value();
}
mTempSymbols.clear();
}
QList<QString> QgsGraduatedSymbolRendererV2::usedAttributes()
{
QSet<QString> attributes;
// mAttrName can contain either attribute name or an expression.
// Sometimes it is not possible to distinguish between those two,
// e.g. "a - b" can be both a valid attribute name or expression.
// Since we do not have access to fields here, try both options.
attributes << mAttrName;
QgsExpression testExpr( mAttrName );
if ( !testExpr.hasParserError() )
attributes.unite( testExpr.referencedColumns().toSet() );
if ( mRotation.data() ) attributes.unite( mRotation->referencedColumns().toSet() );
if ( mSizeScale.data() ) attributes.unite( mSizeScale->referencedColumns().toSet() );
QgsRangeList::const_iterator range_it = mRanges.constBegin();
for ( ; range_it != mRanges.constEnd(); ++range_it )
{
QgsSymbolV2* symbol = range_it->symbol();
if ( symbol )
{
attributes.unite( symbol->usedAttributes() );
}
}
return attributes.toList();
}
bool QgsGraduatedSymbolRendererV2::updateRangeSymbol( int rangeIndex, QgsSymbolV2* symbol )
{
if ( rangeIndex < 0 || rangeIndex >= mRanges.size() )
return false;
mRanges[rangeIndex].setSymbol( symbol );
return true;
}
bool QgsGraduatedSymbolRendererV2::updateRangeLabel( int rangeIndex, QString label )
{
if ( rangeIndex < 0 || rangeIndex >= mRanges.size() )
return false;
mRanges[rangeIndex].setLabel( label );
return true;
}
bool QgsGraduatedSymbolRendererV2::updateRangeUpperValue( int rangeIndex, double value )
{
if ( rangeIndex < 0 || rangeIndex >= mRanges.size() )
return false;
QgsRendererRangeV2 &range=mRanges[rangeIndex];
bool isDefaultLabel= range.label() == defaultRangeLabel(range);
range.setUpperValue( value );
if( isDefaultLabel ) range.setLabel(defaultRangeLabel(range));
return true;
}
bool QgsGraduatedSymbolRendererV2::updateRangeLowerValue( int rangeIndex, double value )
{
if ( rangeIndex < 0 || rangeIndex >= mRanges.size() )
return false;
QgsRendererRangeV2 &range=mRanges[rangeIndex];
bool isDefaultLabel= range.label() == defaultRangeLabel(range);
range.setLowerValue( value );
if( isDefaultLabel ) range.setLabel(defaultRangeLabel(range));
return true;
}
bool QgsGraduatedSymbolRendererV2::updateRangeRenderState( int rangeIndex, bool value )
{
if ( rangeIndex < 0 || rangeIndex >= mRanges.size() )
return false;
mRanges[rangeIndex].setRenderState( value );
return true;
}
QString QgsGraduatedSymbolRendererV2::defaultRangeLabel(const QgsRendererRangeV2 & range )
{
return QString::number( range.lowerValue(), 'f', mDecimalPlaces )
+ " - " + QString::number( range.upperValue(), 'f', mDecimalPlaces ) + mUnits;
}
QString QgsGraduatedSymbolRendererV2::dump() const
{
QString s = QString( "GRADUATED: attr %1\n" ).arg( mAttrName );
for ( int i = 0; i < mRanges.count(); i++ )
s += mRanges[i].dump();
return s;
}
QgsFeatureRendererV2* QgsGraduatedSymbolRendererV2::clone() const
{
QgsGraduatedSymbolRendererV2* r = new QgsGraduatedSymbolRendererV2( mAttrName, mRanges );
r->setMode( mMode );
if ( mSourceSymbol.data() )
r->setSourceSymbol( mSourceSymbol->clone() );
if ( mSourceColorRamp.data() )
{
r->setSourceColorRamp( mSourceColorRamp->clone() );
r->setInvertedColorRamp( mInvertedColorRamp );
}
r->setUsingSymbolLevels( usingSymbolLevels() );
r->setRotationField( rotationField() );
r->setSizeScaleField( sizeScaleField() );
r->setScaleMethod( scaleMethod() );
r->setUnits( units(), false );
r->setDecimalPlaces( decimalPlaces(), false );
return r;
}
void QgsGraduatedSymbolRendererV2::toSld( QDomDocument& doc, QDomElement &element ) const
{
QgsStringMap props;
props[ "attribute" ] = mAttrName;
if ( mRotation.data() )
props[ "angle" ] = mRotation->expression();
if ( mSizeScale.data() )
props[ "scale" ] = mSizeScale->expression();
// create a Rule for each range
for ( QgsRangeList::const_iterator it = mRanges.constBegin(); it != mRanges.constEnd(); ++it )
{
QgsStringMap catProps( props );
it->toSld( doc, element, catProps );
}
}
QgsSymbolV2List QgsGraduatedSymbolRendererV2::symbols()
{
QgsSymbolV2List lst;
for ( int i = 0; i < mRanges.count(); i++ )
lst.append( mRanges[i].symbol() );
return lst;
}
static QList<double> _calcEqualIntervalBreaks( double minimum, double maximum, int classes )
{
// Equal interval algorithm
//
// Returns breaks based on dividing the range ('minimum' to 'maximum')
// into 'classes' parts.
double step = ( maximum - minimum ) / classes;
QList<double> breaks;
double value = minimum;
for ( int i = 0; i < classes; i++ )
{
value += step;
breaks.append( value );
}
// floating point arithmetics is not precise:
// set the last break to be exactly maximum so we do not miss it
breaks[classes-1] = maximum;
return breaks;
}
static QList<double> _calcQuantileBreaks( QList<double> values, int classes )
{
// q-th quantile of a data set:
// value where q fraction of data is below and (1-q) fraction is above this value
// Xq = (1 - r) * X_NI1 + r * X_NI2
// NI1 = (int) (q * (n+1))
// NI2 = NI1 + 1
// r = q * (n+1) - (int) (q * (n+1))
// (indices of X: 1...n)
// sort the values first
qSort( values );
QList<double> breaks;
// If there are no values to process: bail out
if ( !values.count() )
return breaks;
int n = values.count();
double Xq = n > 0 ? values[0] : 0.0;
for ( int i = 1; i < classes; i++ )
{
if ( n > 1 )
{
double q = i / ( double ) classes;
double a = q * ( n - 1 );
int aa = ( int )( a );
double r = a - aa;
Xq = ( 1 - r ) * values[aa] + r * values[aa+1];
}
breaks.append( Xq );
}
breaks.append( values[ n-1 ] );
return breaks;
}
static QList<double> _calcPrettyBreaks( double minimum, double maximum, int classes )
{
// C++ implementation of R's pretty algorithm
// Based on code for determining optimal tick placement for statistical graphics
// from the R statistical programming language.
// Code ported from R implementation from 'labeling' R package
//
// Computes a sequence of about 'classes' equally spaced round values
// which cover the range of values from 'minimum' to 'maximum'.
// The values are chosen so that they are 1, 2 or 5 times a power of 10.
QList<double> breaks;
if ( classes < 1 )
{
breaks.append( maximum );
return breaks;
}
int minimumCount = ( int ) classes / 3;
double shrink = 0.75;
double highBias = 1.5;
double adjustBias = 0.5 + 1.5 * highBias;
int divisions = classes;
double h = highBias;
double cell;
int U;
bool small = false;
double dx = maximum - minimum;
if ( dx == 0 && maximum == 0 )
{
cell = 1.0;
small = true;
U = 1;
}
else
{
cell = qMax( qAbs( minimum ), qAbs( maximum ) );
if ( adjustBias >= 1.5 * h + 0.5 )
{
U = 1 + ( 1.0 / ( 1 + h ) );
}
else
{
U = 1 + ( 1.5 / ( 1 + adjustBias ) );
}
small = dx < ( cell * U * qMax( 1, divisions ) * 1e-07 * 3.0 );
}
if ( small )
{
if ( cell > 10 )
{
cell = 9 + cell / 10;
cell = cell * shrink;
}
if ( minimumCount > 1 )
{
cell = cell / minimumCount;
}
}
else
{
cell = dx;
if ( divisions > 1 )
{
cell = cell / divisions;
}
}
if ( cell < 20 * 1e-07 )
{
cell = 20 * 1e-07;
}
double base = pow( 10.0, floor( log10( cell ) ) );
double unit = base;
if (( 2 * base ) - cell < h *( cell - unit ) )
{
unit = 2.0 * base;
if (( 5 * base ) - cell < adjustBias *( cell - unit ) )
{
unit = 5.0 * base;
if (( 10.0 * base ) - cell < h *( cell - unit ) )
{
unit = 10.0 * base;
}
}
}
// Maybe used to correct for the epsilon here??
int start = floor( minimum / unit + 1e-07 );
int end = ceil( maximum / unit - 1e-07 );
// Extend the range out beyond the data. Does this ever happen??
while ( start * unit > minimum + ( 1e-07 * unit ) )
{
start = start - 1;
}
while ( end * unit < maximum - ( 1e-07 * unit ) )
{
end = end + 1;
}
QgsDebugMsg( QString( "pretty classes: %1" ).arg( end ) );
// If we don't have quite enough labels, extend the range out
// to make more (these labels are beyond the data :( )
int k = floor( 0.5 + end - start );
if ( k < minimumCount )
{
k = minimumCount - k;
if ( start >= 0 )
{
end = end + k / 2;
start = start - k / 2 + k % 2;
}
else
{
start = start - k / 2;
end = end + k / 2 + k % 2;
}
}
double minimumBreak = start * unit;
//double maximumBreak = end * unit;
int count = end - start;
for ( int i = 1; i < count + 1; i++ )
{
breaks.append( minimumBreak + i * unit );
}
if ( breaks.isEmpty() )
return breaks;
if ( breaks.first() < minimum )
{
breaks[0] = minimum;
}
if ( breaks.last() > maximum )
{
breaks[breaks.count()-1] = maximum;
}
return breaks;
} // _calcPrettyBreaks
static QList<double> _calcStdDevBreaks( QList<double> values, int classes, QList<double> &labels )
{
// C++ implementation of the standard deviation class interval algorithm
// as implemented in the 'classInt' package available for the R statistical
// prgramming language.
// Returns breaks based on '_calcPrettyBreaks' of the centred and scaled
// values of 'values', and may have a number of classes different from 'classes'.
// If there are no values to process: bail out
if ( !values.count() )
return QList<double>();
double mean = 0.0;
double stdDev = 0.0;
int n = values.count();
double minimum = values[0];
double maximum = values[0];
for ( int i = 0; i < n; i++ )
{
mean += values[i];
minimum = qMin( values[i], minimum ); // could use precomputed max and min
maximum = qMax( values[i], maximum ); // but have to go through entire list anyway
}
mean = mean / ( double ) n;
double sd = 0.0;
for ( int i = 0; i < n; i++ )
{
sd = values[i] - mean;
stdDev += sd * sd;
}
stdDev = sqrt( stdDev / n );
QList<double> breaks = _calcPrettyBreaks(( minimum - mean ) / stdDev, ( maximum - mean ) / stdDev, classes );
for ( int i = 0; i < breaks.count(); i++ )
{
labels.append( breaks[i] );
breaks[i] = ( breaks[i] * stdDev ) + mean;
}
return breaks;
} // _calcStdDevBreaks
static QList<double> _calcJenksBreaks( QList<double> values, int classes,
double minimum, double maximum,
int maximumSize = 1000 )
{
// Jenks Optimal (Natural Breaks) algorithm
// Based on the Jenks algorithm from the 'classInt' package available for
// the R statistical prgramming language, and from Python code from here:
// http://danieljlewis.org/2010/06/07/jenks-natural-breaks-algorithm-in-python/
// and is based on a JAVA and Fortran code available here:
// https://stat.ethz.ch/pipermail/r-sig-geo/2006-March/000811.html
// Returns class breaks such that classes are internally homogeneous while
// assuring heterogeneity among classes.
if ( !values.count() )
return QList<double>();
if ( classes <= 1 )
{
return QList<double>() << maximum;
}
if ( classes >= values.size() )
{
return values;
}
QVector<double> sample;
// if we have lots of values, we need to take a random sample
if ( values.size() > maximumSize )
{
// for now, sample at least maximumSize values or a 10% sample, whichever
// is larger. This will produce a more representative sample for very large
// layers, but could end up being computationally intensive...
qsrand( time( 0 ) );
sample.resize( qMax( maximumSize, values.size() / 10 ) );
QgsDebugMsg( QString( "natural breaks (jenks) sample size: %1" ).arg( sample.size() ) );
QgsDebugMsg( QString( "values:%1" ).arg( values.size() ) );
sample[ 0 ] = minimum;
sample[ 1 ] = maximum;;
for ( int i = 2; i < sample.size(); i++ )
{
// pick a random integer from 0 to n
double r = qrand();
int j = floor( r / RAND_MAX * ( values.size() - 1 ) );
sample[ i ] = values[ j ];
}
}
else
{
sample = values.toVector();
}
int n = sample.size();
// sort the sample values
qSort( sample );
QVector< QVector<int> > matrixOne( n + 1 );
QVector< QVector<double> > matrixTwo( n + 1 );
for ( int i = 0; i <= n; i++ )
{
matrixOne[i].resize( classes + 1 );
matrixTwo[i].resize( classes + 1 );
}
for ( int i = 1; i <= classes; i++ )
{
matrixOne[0][i] = 1;
matrixOne[1][i] = 1;
matrixTwo[0][i] = 0.0;
for ( int j = 2; j <= n; j++ )
{
matrixTwo[j][i] = std::numeric_limits<double>::max();
}
}
for ( int l = 2; l <= n; l++ )
{
double s1 = 0.0;
double s2 = 0.0;
int w = 0;
double v = 0.0;
for ( int m = 1; m <= l; m++ )
{
int i3 = l - m + 1;
double val = sample[ i3 - 1 ];
s2 += val * val;
s1 += val;
w++;
v = s2 - ( s1 * s1 ) / ( double ) w;
int i4 = i3 - 1;
if ( i4 != 0 )
{
for ( int j = 2; j <= classes; j++ )
{
if ( matrixTwo[l][j] >= v + matrixTwo[i4][j - 1] )
{
matrixOne[l][j] = i4;
matrixTwo[l][j] = v + matrixTwo[i4][j - 1];
}
}
}
}
matrixOne[l][1] = 1;
matrixTwo[l][1] = v;
}
QVector<double> breaks( classes );
breaks[classes-1] = sample[n-1];
for ( int j = classes, k = n; j >= 2; j-- )
{
int id = matrixOne[k][j] - 1;
breaks[j - 2] = sample[id];
k = matrixOne[k][j] - 1;
}
return breaks.toList();
} //_calcJenksBreaks
QgsGraduatedSymbolRendererV2* QgsGraduatedSymbolRendererV2::createRenderer(
QgsVectorLayer* vlayer,
QString attrName,
int classes,
Mode mode,
QgsSymbolV2* symbol,
QgsVectorColorRampV2* ramp,
bool inverted,
QString units,
int decimalPlaces )
{
QgsRangeList ranges;
QgsGraduatedSymbolRendererV2* r = new QgsGraduatedSymbolRendererV2( attrName, ranges );
r->setSourceSymbol( symbol->clone() );
r->setSourceColorRamp( ramp->clone() );
r->setInvertedColorRamp( inverted );
r->setMode( mode );
r->setUnits( units );
r->updateClasses(vlayer,mode,classes);
r->setDecimalPlaces( decimalPlaces );
return r;
}
QList<double> QgsGraduatedSymbolRendererV2::getDataValues( QgsVectorLayer *vlayer )
{
QList<double> values;
QScopedPointer<QgsExpression> expression;
int attrNum = vlayer->fieldNameIndex( mAttrName );
if ( attrNum == -1 )
{
// try to use expression
expression.reset( new QgsExpression( mAttrName ) );
if ( expression->hasParserError() || !expression->prepare( vlayer->pendingFields() ) )
return values; // should have a means to report errors
}
QgsFeature f;
QStringList lst;
if ( expression.isNull() )
lst.append( mAttrName );
else
lst = expression->referencedColumns();
QgsFeatureIterator fit = vlayer->getFeatures( QgsFeatureRequest().setFlags( QgsFeatureRequest::NoGeometry ).setSubsetOfAttributes( lst, vlayer->pendingFields() ) );
// create list of non-null attribute values
while ( fit.nextFeature( f ) )
{
QVariant v = expression.isNull() ? f.attribute( attrNum ) : expression->evaluate( f );
if ( !v.isNull() )
values.append( v.toDouble() );
}
return values;
}
void QgsGraduatedSymbolRendererV2::updateClasses( QgsVectorLayer *vlayer, Mode mode, int nclasses )
{
// Custom classes are not recalculated
setMode(mode);
if( mode == Custom ) return;
if ( nclasses < 1 ) nclasses=1;
QList<double> values;
bool valuesLoaded=false;
double minimum;
double maximum;
int attrNum = vlayer->fieldNameIndex( mAttrName );
if ( attrNum == -1 )
{
values=getDataValues( vlayer );
qSort( values );
minimum = values.first();
maximum = values.last();
valuesLoaded=true;
}
else
{
minimum = vlayer->minimumValue( attrNum ).toDouble();
maximum = vlayer->maximumValue( attrNum ).toDouble();
}
QgsDebugMsg( QString( "min %1 // max %2" ).arg( minimum ).arg( maximum ) );
QList<double> breaks;
QList<double> labels;
if ( mode == EqualInterval )
{
breaks = _calcEqualIntervalBreaks( minimum, maximum, nclasses );
}
else if ( mode == Pretty )
{
breaks = _calcPrettyBreaks( minimum, maximum, nclasses );
}
else if ( mode == Quantile || mode == Jenks || mode == StdDev )
{
// get values from layer
if( ! valuesLoaded )
{
values=getDataValues( vlayer );
}
// calculate the breaks
if ( mode == Quantile )
{
breaks = _calcQuantileBreaks( values, nclasses );
}
else if ( mode == Jenks )
{
breaks = _calcJenksBreaks( values, nclasses, minimum, maximum );
}
else if ( mode == StdDev )
{
breaks = _calcStdDevBreaks( values, nclasses, labels );
}
}
else
{
Q_ASSERT( false );
}
double lower, upper = minimum;
QString label;
deleteAllClasses();
// "breaks" list contains all values at class breaks plus maximum as last break
int i = 0;
for ( QList<double>::iterator it = breaks.begin(); it != breaks.end(); ++it, ++i )
{
lower = upper; // upper border from last interval
upper = *it;
// Symbol based on range
QgsSymbolV2* newSymbol = mSourceSymbol->clone();
QgsRendererRangeV2 range = QgsRendererRangeV2( lower, upper, newSymbol, "" );
// Label - either StdDev label or default label for a range
if ( mode == StdDev )
{
if ( i == 0 )
{
label = "< " + QString::number( labels[i], 'f', 2 ) + " Std Dev";
}
else if ( i == labels.count() - 1 )
{
label = ">= " + QString::number( labels[i-1], 'f', 2 ) + " Std Dev";
}
else
{
label = QString::number( labels[i-1], 'f', 2 ) + " Std Dev" + " - " + QString::number( labels[i], 'f', 2 ) + " Std Dev";
}
}
else
{
label=defaultRangeLabel(range);
}
range.setLabel(label);
addClass( range );
}
updateColorRamp(0,mInvertedColorRamp);
}
QgsFeatureRendererV2* QgsGraduatedSymbolRendererV2::create( QDomElement& element )
{
QDomElement symbolsElem = element.firstChildElement( "symbols" );
if ( symbolsElem.isNull() )
return NULL;
QDomElement rangesElem = element.firstChildElement( "ranges" );
if ( rangesElem.isNull() )
return NULL;
QgsSymbolV2Map symbolMap = QgsSymbolLayerV2Utils::loadSymbols( symbolsElem );
QgsRangeList ranges;
QDomElement rangeElem = rangesElem.firstChildElement();
while ( !rangeElem.isNull() )
{