qgsrulebasedrendererwidget.cpp

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/***************************************************************************
    qgsrulebasedrendererwidget.cpp - Settings widget for rule-based renderer
    ---------------------
    begin                : May 2010
    copyright            : (C) 2010 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 "qgsrulebasedrendererwidget.h"
 
#include "qgsrulebasedrenderer.h"
#include "qgsfeatureiterator.h"
#include "qgssymbollayerutils.h"
#include "qgssymbol.h"
#include "qgsvectorlayer.h"
#include "qgsapplication.h"
#include "qgsexpression.h"
#include "qgssymbolselectordialog.h"
#include "qgslogger.h"
#include "qgsreadwritecontext.h"
#include "qstring.h"
#include "qgssinglesymbolrenderer.h"
#include "qgspanelwidget.h"
#include "qgsmapcanvas.h"
#include "qgssettings.h"
#include "qgsguiutils.h"
 
#include <QKeyEvent>
#include <QMenu>
#include <QProgressDialog>
#include <QTreeWidgetItem>
#include <QVBoxLayout>
#include <QMessageBox>
#include <QClipboard>
 
#ifdef ENABLE_MODELTEST
#include "modeltest.h"
#endif
 
 
QgsRendererWidget *QgsRuleBasedRendererWidget::create( QgsVectorLayer *layer, QgsStyle *style, QgsFeatureRenderer *renderer )
{
  return new QgsRuleBasedRendererWidget( layer, style, renderer );
}
 
QgsRuleBasedRendererWidget::QgsRuleBasedRendererWidget( QgsVectorLayer *layer, QgsStyle *style, QgsFeatureRenderer *renderer )
  : QgsRendererWidget( layer, style )
  , mContextMenu( new QMenu( this ) )
{
  mRenderer = nullptr;
  // try to recognize the previous renderer
  // (null renderer means "no previous renderer")
 
 
  if ( renderer )
  {
    mRenderer.reset( QgsRuleBasedRenderer::convertFromRenderer( renderer, layer ) );
  }
  if ( !mRenderer )
  {
    // some default options
    QgsSymbol *symbol = QgsSymbol::defaultSymbol( mLayer->geometryType() );
 
    mRenderer = std::make_unique< QgsRuleBasedRenderer >( symbol );
  }
 
  setupUi( this );
  this->layout()->setContentsMargins( 0, 0, 0, 0 );
 
  mModel = new QgsRuleBasedRendererModel( mRenderer.get(), viewRules );
#ifdef ENABLE_MODELTEST
  new ModelTest( mModel, this ); // for model validity checking
#endif
  viewRules->setModel( mModel );
 
  mDeleteAction = new QAction( tr( "Remove Rule" ), this );
  mDeleteAction->setShortcut( QKeySequence( QKeySequence::Delete ) );
 
  viewRules->addAction( mCopyAction );
  viewRules->addAction( mPasteAction );
  viewRules->addAction( mDeleteAction );
 
  mRefineMenu = new QMenu( tr( "Refine Current Rule" ), btnRefineRule );
  mRefineMenu->addAction( tr( "Add Scales to Rule" ), this, SLOT( refineRuleScales() ) );
  mRefineMenu->addAction( tr( "Add Categories to Rule" ), this, SLOT( refineRuleCategories() ) );
  mRefineMenu->addAction( tr( "Add Ranges to Rule" ), this, SLOT( refineRuleRanges() ) );
  btnRefineRule->setMenu( mRefineMenu );
 
  btnAddRule->setIcon( QIcon( QgsApplication::iconPath( "symbologyAdd.svg" ) ) );
  btnEditRule->setIcon( QIcon( QgsApplication::iconPath( "symbologyEdit.svg" ) ) );
  btnRemoveRule->setIcon( QIcon( QgsApplication::iconPath( "symbologyRemove.svg" ) ) );
 
  connect( viewRules, &QAbstractItemView::doubleClicked, this, static_cast < void ( QgsRuleBasedRendererWidget::* )( const QModelIndex &index ) > ( &QgsRuleBasedRendererWidget::editRule ) );
 
  // support for context menu (now handled generically)
  connect( viewRules, &QWidget::customContextMenuRequested,  this, &QgsRuleBasedRendererWidget::showContextMenu );
 
  connect( viewRules->selectionModel(), &QItemSelectionModel::currentChanged, this, &QgsRuleBasedRendererWidget::currentRuleChanged );
  connect( viewRules->selectionModel(), &QItemSelectionModel::selectionChanged, this, &QgsRuleBasedRendererWidget::selectedRulesChanged );
 
  connect( btnAddRule, &QAbstractButton::clicked, this, &QgsRuleBasedRendererWidget::addRule );
  connect( btnEditRule, &QAbstractButton::clicked, this, static_cast < void ( QgsRuleBasedRendererWidget::* )() > ( &QgsRuleBasedRendererWidget::editRule ) );
  connect( btnRemoveRule, &QAbstractButton::clicked, this, &QgsRuleBasedRendererWidget::removeRule );
  connect( mDeleteAction, &QAction::triggered, this, &QgsRuleBasedRendererWidget::removeRule );
  connect( btnCountFeatures, &QAbstractButton::clicked, this, &QgsRuleBasedRendererWidget::countFeatures );
 
  connect( btnRenderingOrder, &QAbstractButton::clicked, this, &QgsRuleBasedRendererWidget::setRenderingOrder );
 
  connect( mModel, &QAbstractItemModel::dataChanged, this, &QgsPanelWidget::widgetChanged );
  connect( mModel, &QAbstractItemModel::rowsInserted, this, &QgsPanelWidget::widgetChanged );
  connect( mModel, &QAbstractItemModel::rowsRemoved, this, &QgsPanelWidget::widgetChanged );
 
  currentRuleChanged();
  selectedRulesChanged();
 
  // store/restore header section widths
  connect( viewRules->header(), &QHeaderView::sectionResized, this, &QgsRuleBasedRendererWidget::saveSectionWidth );
 
  restoreSectionWidths();
 
  connect( mContextMenu, &QMenu::aboutToShow, this, [ = ]
  {
    std::unique_ptr< QgsSymbol > tempSymbol( QgsSymbolLayerUtils::symbolFromMimeData( QApplication::clipboard()->mimeData() ) );
    mPasteSymbolAction->setEnabled( static_cast< bool >( tempSymbol ) );
  } );
}
 
QgsRuleBasedRendererWidget::~QgsRuleBasedRendererWidget()
{
  qDeleteAll( mCopyBuffer );
}
 
QgsFeatureRenderer *QgsRuleBasedRendererWidget::renderer()
{
  return mRenderer.get();
}
 
void QgsRuleBasedRendererWidget::setDockMode( bool dockMode )
{
  if ( dockMode )
  {
    // when in dock mode, these shortcuts conflict with the main window shortcuts and cannot be used
    if ( mDeleteAction )
      mDeleteAction->setShortcut( QKeySequence() );
  }
  QgsRendererWidget::setDockMode( dockMode );
}
 
void QgsRuleBasedRendererWidget::addRule()
{
  QgsSymbol *s = QgsSymbol::defaultSymbol( mLayer->geometryType() );
  QgsRuleBasedRenderer::Rule *newrule = new QgsRuleBasedRenderer::Rule( s );
 
  QgsRuleBasedRenderer::Rule *current = currentRule();
  if ( current )
  {
    // add after this rule
    QModelIndex currentIndex = viewRules->selectionModel()->currentIndex();
    mModel->insertRule( currentIndex.parent(), currentIndex.row() + 1, newrule );
    QModelIndex newindex = mModel->index( currentIndex.row() + 1, 0, currentIndex.parent() );
    viewRules->selectionModel()->setCurrentIndex( newindex, QItemSelectionModel::ClearAndSelect );
  }
  else
  {
    // append to root rule
    int rows = mModel->rowCount();
    mModel->insertRule( QModelIndex(), rows, newrule );
    QModelIndex newindex = mModel->index( rows, 0 );
    viewRules->selectionModel()->setCurrentIndex( newindex, QItemSelectionModel::ClearAndSelect );
  }
  editRule();
}
 
QgsRuleBasedRenderer::Rule *QgsRuleBasedRendererWidget::currentRule()
{
  QItemSelectionModel *sel = viewRules->selectionModel();
  QModelIndex idx = sel->currentIndex();
  if ( !idx.isValid() )
    return nullptr;
  return mModel->ruleForIndex( idx );
}
 
void QgsRuleBasedRendererWidget::editRule()
{
  editRule( viewRules->selectionModel()->currentIndex() );
}
 
void QgsRuleBasedRendererWidget::editRule( const QModelIndex &index )
{
  if ( !index.isValid() )
    return;
 
  QgsRuleBasedRenderer::Rule *rule = mModel->ruleForIndex( index );
  QgsPanelWidget *panel = QgsPanelWidget::findParentPanel( this );
 
  if ( panel && panel->dockMode() )
  {
    QgsRendererRulePropsWidget *widget = new QgsRendererRulePropsWidget( rule, mLayer, mStyle, this, mContext );//panel?
    widget->setPanelTitle( tr( "Edit Rule" ) );
    connect( widget, &QgsPanelWidget::panelAccepted, this, &QgsRuleBasedRendererWidget::ruleWidgetPanelAccepted );
    connect( widget, &QgsPanelWidget::widgetChanged, this, &QgsRuleBasedRendererWidget::liveUpdateRuleFromPanel );
    openPanel( widget );
    return;
  }
 
  QgsRendererRulePropsDialog dlg( rule, mLayer, mStyle, this, mContext );
  if ( dlg.exec() )
  {
    mModel->updateRule( index.parent(), index.row() );
    mModel->clearFeatureCounts();
    emit widgetChanged();
  }
}
 
void QgsRuleBasedRendererWidget::removeRule()
{
  QItemSelection sel = viewRules->selectionModel()->selection();
  QgsDebugMsg( QStringLiteral( "REMOVE RULES!!! ranges: %1" ).arg( sel.count() ) );
  const auto constSel = sel;
  for ( const QItemSelectionRange &range : constSel )
  {
    QgsDebugMsg( QStringLiteral( "RANGE: r %1 - %2" ).arg( range.top() ).arg( range.bottom() ) );
    if ( range.isValid() )
      mModel->removeRows( range.top(), range.bottom() - range.top() + 1, range.parent() );
  }
  // make sure that the selection is gone
  viewRules->selectionModel()->clear();
  mModel->clearFeatureCounts();
}
 
void QgsRuleBasedRendererWidget::currentRuleChanged( const QModelIndex &current, const QModelIndex &previous )
{
  Q_UNUSED( previous )
  btnEditRule->setEnabled( current.isValid() );
}
 
 
#include "qgscategorizedsymbolrenderer.h"
#include "qgscategorizedsymbolrendererwidget.h"
#include "qgsgraduatedsymbolrenderer.h"
#include "qgsgraduatedsymbolrendererwidget.h"
#include "qgsexpressionbuilderdialog.h"
#include <QDialogButtonBox>
#include <QInputDialog>
#include <QClipboard>
 
void QgsRuleBasedRendererWidget::refineRule( int type )
{
  QModelIndexList indexlist = viewRules->selectionModel()->selectedRows();
 
  if ( indexlist.isEmpty() )
    return;
 
 
  if ( type == 0 ) // categories
    refineRuleCategoriesGui();
  else if ( type == 1 ) // ranges
    refineRuleRangesGui();
  else // scales
    refineRuleScalesGui( indexlist );
 
  // TODO: set initial rule's symbol to NULL (?)
 
  // show the newly added rules
  const auto constIndexlist = indexlist;
  for ( const QModelIndex &index : constIndexlist )
    viewRules->expand( index );
}
 
void QgsRuleBasedRendererWidget::refineRuleCategories()
{
  refineRule( 0 );
}
 
void QgsRuleBasedRendererWidget::refineRuleRanges()
{
  refineRule( 1 );
}
 
void QgsRuleBasedRendererWidget::refineRuleScales()
{
  refineRule( 2 );
}
 
void QgsRuleBasedRendererWidget::refineRuleCategoriesGui()
{
  QgsCategorizedSymbolRendererWidget *w = new QgsCategorizedSymbolRendererWidget( mLayer, mStyle, nullptr );
  w->setPanelTitle( tr( "Add Categories to Rules" ) );
  connect( w, &QgsPanelWidget::panelAccepted, this, &QgsRuleBasedRendererWidget::refineRuleCategoriesAccepted );
  w->setContext( mContext );
  openPanel( w );
}
 
void QgsRuleBasedRendererWidget::refineRuleRangesGui()
{
  QgsGraduatedSymbolRendererWidget *w = new QgsGraduatedSymbolRendererWidget( mLayer, mStyle, nullptr );
  w->setPanelTitle( tr( "Add Ranges to Rules" ) );
  connect( w, &QgsPanelWidget::panelAccepted, this, &QgsRuleBasedRendererWidget::refineRuleRangesAccepted );
  w->setContext( mContext );
  openPanel( w );
}
 
void QgsRuleBasedRendererWidget::refineRuleScalesGui( const QModelIndexList &indexList )
{
  for ( const QModelIndex &index : indexList )
  {
    QgsRuleBasedRenderer::Rule *initialRule = mModel->ruleForIndex( index );
 
    // If any of the rules don't have a symbol let the user know and exit.
    if ( !initialRule->symbol() )
    {
      QMessageBox::warning( this, tr( "Scale Refinement" ), tr( "Parent rule %1 must have a symbol for this operation." ).arg( initialRule->label() ) );
      return;
    }
  }
 
  QString txt = QInputDialog::getText( this,
                                       tr( "Scale Refinement" ),
                                       tr( "Please enter scale denominators at which will split the rule, separate them by commas (e.g. 1000,5000):" ) );
  if ( txt.isEmpty() )
    return;
 
  QList<int> scales;
  bool ok;
  const auto constSplit = txt.split( ',' );
  for ( const QString &item : constSplit )
  {
    int scale = item.toInt( &ok );
    if ( ok )
      scales.append( scale );
    else
      QMessageBox::information( this, tr( "Scale Refinement" ), tr( "\"%1\" is not valid scale denominator, ignoring it." ).arg( item ) );
  }
 
  for ( const QModelIndex &index : indexList )
  {
    QgsRuleBasedRenderer::Rule *initialRule = mModel->ruleForIndex( index );
    mModel->willAddRules( index, scales.count() + 1 );
    QgsRuleBasedRenderer::refineRuleScales( initialRule, scales );
  }
  mModel->finishedAddingRules();
}
 
void QgsRuleBasedRendererWidget::setSymbolLevels( const QList<QgsLegendSymbolItem> &levels, bool )
{
  if ( !mRenderer )
    return;
 
  for ( const QgsLegendSymbolItem &legendSymbol : std::as_const( levels ) )
  {
    QgsSymbol *sym = legendSymbol.symbol();
    for ( int layer = 0; layer < sym->symbolLayerCount(); layer++ )
    {
      mRenderer->setLegendSymbolItem( legendSymbol.ruleKey(), sym->clone() );
    }
  }
 
  emit widgetChanged();
}
 
QList<QgsSymbol *> QgsRuleBasedRendererWidget::selectedSymbols()
{
  QList<QgsSymbol *> symbolList;
 
  if ( !mRenderer )
  {
    return symbolList;
  }
 
  QItemSelection sel = viewRules->selectionModel()->selection();
  const auto constSel = sel;
  for ( const QItemSelectionRange &range : constSel )
  {
    QModelIndex parent = range.parent();
    QgsRuleBasedRenderer::Rule *parentRule = mModel->ruleForIndex( parent );
    const QgsRuleBasedRenderer::RuleList &children = parentRule->children();
    for ( int row = range.top(); row <= range.bottom(); row++ )
    {
      symbolList.append( children.at( row )->symbol() );
    }
  }
 
  return symbolList;
}
 
QgsRuleBasedRenderer::RuleList QgsRuleBasedRendererWidget::selectedRules()
{
  QgsRuleBasedRenderer::RuleList rl;
  QItemSelection sel = viewRules->selectionModel()->selection();
  const auto constSel = sel;
  for ( const QItemSelectionRange &range : constSel )
  {
    QModelIndex parent = range.parent();
    QgsRuleBasedRenderer::Rule *parentRule = mModel->ruleForIndex( parent );
    const QgsRuleBasedRenderer::RuleList &children = parentRule->children();
    for ( int row = range.top(); row <= range.bottom(); row++ )
    {
      rl.append( children.at( row )->clone() );
    }
  }
  return rl;
}
 
void QgsRuleBasedRendererWidget::refreshSymbolView()
{
  // TODO: model/view
  /*
  if ( treeRules )
  {
    treeRules->populateRules();
  }
  */
  emit widgetChanged();
}
 
void QgsRuleBasedRendererWidget::keyPressEvent( QKeyEvent *event )
{
  if ( !event )
  {
    return;
  }
 
  if ( event->key() == Qt::Key_C && event->modifiers() == Qt::ControlModifier )
  {
    qDeleteAll( mCopyBuffer );
    mCopyBuffer.clear();
    mCopyBuffer = selectedRules();
  }
  else if ( event->key() == Qt::Key_V && event->modifiers() == Qt::ControlModifier )
  {
    QgsRuleBasedRenderer::RuleList::const_iterator rIt = mCopyBuffer.constBegin();
    for ( ; rIt != mCopyBuffer.constEnd(); ++rIt )
    {
      int rows = mModel->rowCount();
      mModel->insertRule( QModelIndex(), rows, ( *rIt )->clone() );
    }
  }
}
 
#include "qgssymbollevelsdialog.h"
 
void QgsRuleBasedRendererWidget::setRenderingOrder()
{
  QgsPanelWidget *panel = QgsPanelWidget::findParentPanel( this );
  if ( panel && panel->dockMode() )
  {
    QgsSymbolLevelsWidget *widget = new QgsSymbolLevelsWidget( mRenderer.get(), true, panel );
    widget->setForceOrderingEnabled( true );
    widget->setPanelTitle( tr( "Symbol Levels" ) );
    connect( widget, &QgsPanelWidget::widgetChanged, this, [ = ]()
    {
      setSymbolLevels( widget->symbolLevels(), widget->usingLevels() );
    } );
    panel->openPanel( widget );
  }
  else
  {
    QgsSymbolLevelsDialog dlg( mRenderer.get(), true, panel );
    dlg.setForceOrderingEnabled( true );
    if ( dlg.exec() )
    {
      setSymbolLevels( dlg.symbolLevels(), dlg.usingLevels() );
    }
  }
}
 
void QgsRuleBasedRendererWidget::saveSectionWidth( int section, int oldSize, int newSize )
{
  Q_UNUSED( oldSize )
  // skip last section, as it stretches
  if ( section == 5 )
    return;
  QgsSettings settings;
  QString path = "/Windows/RuleBasedTree/sectionWidth/" + QString::number( section );
  settings.setValue( path, newSize );
}
 
void QgsRuleBasedRendererWidget::restoreSectionWidths()
{
  QgsSettings settings;
  QString path = QStringLiteral( "/Windows/RuleBasedTree/sectionWidth/" );
  QHeaderView *head = viewRules->header();
  head->resizeSection( 0, settings.value( path + QString::number( 0 ), 150 ).toInt() );
  head->resizeSection( 1, settings.value( path + QString::number( 1 ), 150 ).toInt() );
  head->resizeSection( 2, settings.value( path + QString::number( 2 ), 80 ).toInt() );
  head->resizeSection( 3, settings.value( path + QString::number( 3 ), 80 ).toInt() );
  head->resizeSection( 4, settings.value( path + QString::number( 4 ), 50 ).toInt() );
  head->resizeSection( 5, settings.value( path + QString::number( 5 ), 50 ).toInt() );
}
 
void QgsRuleBasedRendererWidget::copy()
{
  QModelIndexList indexlist = viewRules->selectionModel()->selectedRows();
  QgsDebugMsgLevel( QString::number( indexlist.count() ), 2 );
 
  if ( indexlist.isEmpty() )
    return;
 
  QMimeData *mime = mModel->mimeData( indexlist );
  QApplication::clipboard()->setMimeData( mime );
}
 
void QgsRuleBasedRendererWidget::paste()
{
  const QMimeData *mime = QApplication::clipboard()->mimeData();
  QModelIndexList indexlist = viewRules->selectionModel()->selectedRows();
  QModelIndex index;
  if ( indexlist.isEmpty() )
    index = mModel->index( mModel->rowCount(), 0 );
  else
    index = indexlist.first();
  mModel->dropMimeData( mime, Qt::CopyAction, index.row(), index.column(), index.parent() );
}
 
void QgsRuleBasedRendererWidget::pasteSymbolToSelection()
{
  std::unique_ptr< QgsSymbol > tempSymbol( QgsSymbolLayerUtils::symbolFromMimeData( QApplication::clipboard()->mimeData() ) );
  if ( !tempSymbol )
    return;
 
  const QModelIndexList indexList = viewRules->selectionModel()->selectedRows();
  for ( const QModelIndex &index : indexList )
  {
    if ( QgsRuleBasedRenderer::Rule *rule = mModel->ruleForIndex( index ) )
    {
      if ( !rule->symbol() || rule->symbol()->type() != tempSymbol->type() )
        continue;
 
      mModel->setSymbol( index, tempSymbol->clone() );
    }
  }
  emit widgetChanged();
}
 
void QgsRuleBasedRendererWidget::refineRuleCategoriesAccepted( QgsPanelWidget *panel )
{
  QgsCategorizedSymbolRendererWidget *w = qobject_cast<QgsCategorizedSymbolRendererWidget *>( panel );
 
  // create new rules
  QgsCategorizedSymbolRenderer *r = static_cast<QgsCategorizedSymbolRenderer *>( w->renderer() );
  QModelIndexList indexList = viewRules->selectionModel()->selectedRows();
  const auto constIndexList = indexList;
  for ( const QModelIndex &index : constIndexList )
  {
    QgsRuleBasedRenderer::Rule *initialRule = mModel->ruleForIndex( index );
    mModel->willAddRules( index, r->categories().count() );
    QgsRuleBasedRenderer::refineRuleCategories( initialRule, r );
  }
  mModel->finishedAddingRules();
}
 
void QgsRuleBasedRendererWidget::refineRuleRangesAccepted( QgsPanelWidget *panel )
{
  QgsGraduatedSymbolRendererWidget *w = qobject_cast<QgsGraduatedSymbolRendererWidget *>( panel );
  // create new rules
  QgsGraduatedSymbolRenderer *r = static_cast<QgsGraduatedSymbolRenderer *>( w->renderer() );
  QModelIndexList indexList = viewRules->selectionModel()->selectedRows();
  const auto constIndexList = indexList;
  for ( const QModelIndex &index : constIndexList )
  {
    QgsRuleBasedRenderer::Rule *initialRule = mModel->ruleForIndex( index );
    mModel->willAddRules( index, r->ranges().count() );
    QgsRuleBasedRenderer::refineRuleRanges( initialRule, r );
  }
  mModel->finishedAddingRules();
}
 
void QgsRuleBasedRendererWidget::ruleWidgetPanelAccepted( QgsPanelWidget *panel )
{
  QgsRendererRulePropsWidget *widget = qobject_cast<QgsRendererRulePropsWidget *>( panel );
  if ( !widget )
    return;
 
  widget->apply();
 
  // model should know about the change and emit dataChanged signal for the view
  QModelIndex index = viewRules->selectionModel()->currentIndex();
  mModel->updateRule( index.parent(), index.row() );
  mModel->clearFeatureCounts();
}
 
void QgsRuleBasedRendererWidget::liveUpdateRuleFromPanel()
{
  ruleWidgetPanelAccepted( qobject_cast<QgsPanelWidget *>( sender() ) );
}
 
void QgsRuleBasedRendererWidget::showContextMenu( QPoint )
{
  mContextMenu->clear();
  mContextMenu->addAction( mCopyAction );
  mContextMenu->addAction( mPasteAction );
 
  const QList< QAction * > actions = contextMenu->actions();
  for ( QAction *act : actions )
  {
    mContextMenu->addAction( act );
  }
 
  mContextMenu->addMenu( mRefineMenu );
 
  mContextMenu->exec( QCursor::pos() );
}
 
 
void QgsRuleBasedRendererWidget::countFeatures()
{
  if ( !mLayer || !mRenderer || !mRenderer->rootRule() )
  {
    return;
  }
  QHash<QgsRuleBasedRenderer::Rule *, QgsRuleBasedRendererCount> countMap;
 
  QgsRuleBasedRenderer::RuleList ruleList = mRenderer->rootRule()->descendants();
  // insert all so that we have counts 0
  const auto constRuleList = ruleList;
  for ( QgsRuleBasedRenderer::Rule *rule : constRuleList )
  {
    countMap[rule].count = 0;
    countMap[rule].duplicateCount = 0;
  }
 
  QgsRenderContext renderContext;
  renderContext.setRendererScale( 0 ); // ignore scale
 
  QgsExpressionContext context( mContext.globalProjectAtlasMapLayerScopes( mLayer ) );
 
  // additional scopes
  const auto constAdditionalExpressionContextScopes = mContext.additionalExpressionContextScopes();
  for ( const QgsExpressionContextScope &scope : constAdditionalExpressionContextScopes )
  {
    context.appendScope( new QgsExpressionContextScope( scope ) );
  }
 
  renderContext.setExpressionContext( context );
 
  mRenderer->startRender( renderContext, mLayer->fields() );
  // QgsRuleBasedRenderer::filter must be called after startRender
  QgsFeatureRequest req = QgsFeatureRequest().setFilterExpression( mRenderer->filter( mLayer->fields() ) );
  req.setExpressionContext( context );
  req.setSubsetOfAttributes( mRenderer->usedAttributes( renderContext ), mLayer->fields() );
  QgsFeatureIterator fit = mLayer->getFeatures( req );
 
  long long nFeatures = mLayer->featureCount();
  QProgressDialog p( tr( "Calculating feature count." ), tr( "Abort" ), 0, 100 );
  p.setWindowModality( Qt::WindowModal );
  long long featuresCounted = 0;
 
  QgsFeature f;
  while ( fit.nextFeature( f ) )
  {
    renderContext.expressionContext().setFeature( f );
    QgsRuleBasedRenderer::RuleList featureRuleList = mRenderer->rootRule()->rulesForFeature( f, &renderContext );
 
    const auto constFeatureRuleList = featureRuleList;
    for ( QgsRuleBasedRenderer::Rule *rule : constFeatureRuleList )
    {
      countMap[rule].count++;
      if ( featureRuleList.size() > 1 )
      {
        countMap[rule].duplicateCount++;
      }
      const auto constFeatureRuleList = featureRuleList;
      for ( QgsRuleBasedRenderer::Rule *duplicateRule : constFeatureRuleList )
      {
        if ( duplicateRule == rule ) continue;
        countMap[rule].duplicateCountMap[duplicateRule] += 1;
      }
    }
    ++featuresCounted;
    if ( featuresCounted % 50 == 0 )
    {
      if ( featuresCounted > nFeatures ) //sometimes the feature count is not correct
      {
        p.setMaximum( 0 );
      }
      p.setValue( static_cast< double >( featuresCounted ) / nFeatures * 100.0 );
      if ( p.wasCanceled() )
      {
        return;
      }
    }
  }
  p.setValue( nFeatures );
 
  mRenderer->stopRender( renderContext );
 
#ifdef QGISDEBUG
  const auto constKeys = countMap.keys();
  for ( QgsRuleBasedRenderer::Rule *rule : constKeys )
  {
    QgsDebugMsg( QStringLiteral( "rule: %1 count %2" ).arg( rule->label() ).arg( countMap[rule].count ) );
  }
#endif
 
  mModel->setFeatureCounts( countMap );
}
 
void QgsRuleBasedRendererWidget::selectedRulesChanged()
{
  bool enabled = !viewRules->selectionModel()->selectedIndexes().isEmpty();
  btnRefineRule->setEnabled( enabled );
  btnRemoveRule->setEnabled( enabled );
}
 
 
QgsRendererRulePropsWidget::QgsRendererRulePropsWidget( QgsRuleBasedRenderer::Rule *rule, QgsVectorLayer *layer, QgsStyle *style, QWidget *parent, const QgsSymbolWidgetContext &context )
  : QgsPanelWidget( parent )
  , mRule( rule )
  , mLayer( layer )
  , mContext( context )
{
  setupUi( this );
  layout()->setContentsMargins( 0, 0, 0, 0 );
 
  mElseRadio->setChecked( mRule->isElse() );
  mFilterRadio->setChecked( !mRule->isElse() );
  editFilter->setText( mRule->filterExpression() );
  editFilter->setToolTip( mRule->filterExpression() );
  editLabel->setText( mRule->label() );
  editDescription->setText( mRule->description() );
  editDescription->setToolTip( mRule->description() );
 
  if ( mRule->dependsOnScale() )
  {
    groupScale->setChecked( true );
    mScaleRangeWidget->setScaleRange( std::max( rule->minimumScale(), 0.0 ),
                                      std::max( rule->maximumScale(), 0.0 ) );
  }
  mScaleRangeWidget->setMapCanvas( mContext.mapCanvas() );
 
  if ( mRule->symbol() )
  {
    groupSymbol->setChecked( true );
    mSymbol = mRule->symbol()->clone(); // use a clone!
  }
  else
  {
    groupSymbol->setChecked( false );
    mSymbol = QgsSymbol::defaultSymbol( mLayer->geometryType() );
  }
 
  mSymbolSelector = new QgsSymbolSelectorWidget( mSymbol, style, mLayer, this );
  mSymbolSelector->setContext( mContext );
  connect( mSymbolSelector, &QgsPanelWidget::widgetChanged, this, &QgsPanelWidget::widgetChanged );
  connect( mSymbolSelector, &QgsPanelWidget::showPanel, this, &QgsPanelWidget::openPanel );
 
  QVBoxLayout *l = new QVBoxLayout;
  l->addWidget( mSymbolSelector );
  groupSymbol->setLayout( l );
 
  connect( btnExpressionBuilder, &QAbstractButton::clicked, this, &QgsRendererRulePropsWidget::buildExpression );
  connect( btnTestFilter, &QAbstractButton::clicked, this, &QgsRendererRulePropsWidget::testFilter );
  connect( editFilter, &QLineEdit::textChanged, this, &QgsPanelWidget::widgetChanged );
  connect( editLabel, &QLineEdit::editingFinished, this, &QgsPanelWidget::widgetChanged );
  connect( editDescription, &QLineEdit::editingFinished, this, &QgsPanelWidget::widgetChanged );
  connect( groupSymbol, &QGroupBox::toggled, this, &QgsPanelWidget::widgetChanged );
  connect( groupScale, &QGroupBox::toggled, this, &QgsPanelWidget::widgetChanged );
  connect( mScaleRangeWidget, &QgsScaleRangeWidget::rangeChanged, this, &QgsPanelWidget::widgetChanged );
  connect( mFilterRadio, &QRadioButton::toggled, this, [ = ]( bool toggled ) { filterFrame->setEnabled( toggled ) ; } );
  connect( mElseRadio, &QRadioButton::toggled, this, [ = ]( bool toggled ) { if ( toggled ) editFilter->setText( QStringLiteral( "ELSE" ) );} );
}
 
#include "qgsvscrollarea.h"
 
QgsRendererRulePropsDialog::QgsRendererRulePropsDialog( QgsRuleBasedRenderer::Rule *rule, QgsVectorLayer *layer, QgsStyle *style, QWidget *parent, const QgsSymbolWidgetContext &context )
  : QDialog( parent )
{
 
#ifdef Q_OS_MAC
  setWindowModality( Qt::WindowModal );
#endif
 
  QVBoxLayout *layout = new QVBoxLayout( this );
  QgsVScrollArea *scrollArea = new QgsVScrollArea( this );
  scrollArea->setFrameShape( QFrame::NoFrame );
  layout->addWidget( scrollArea );
 
  buttonBox = new QDialogButtonBox( QDialogButtonBox::Cancel | QDialogButtonBox::Help | QDialogButtonBox::Ok );
  mPropsWidget = new QgsRendererRulePropsWidget( rule, layer, style, this, context );
 
  scrollArea->setWidget( mPropsWidget );
  layout->addWidget( buttonBox );
  this->setWindowTitle( "Edit Rule" );
  QgsGui::instance()->enableAutoGeometryRestore( this );
 
  connect( buttonBox, &QDialogButtonBox::accepted, this, &QgsRendererRulePropsDialog::accept );
  connect( buttonBox, &QDialogButtonBox::rejected, this, &QDialog::reject );
  connect( buttonBox, &QDialogButtonBox::helpRequested, this, &QgsRendererRulePropsDialog::showHelp );
}
 
void QgsRendererRulePropsDialog::testFilter()
{
  mPropsWidget->testFilter();
}
 
void QgsRendererRulePropsDialog::buildExpression()
{
  mPropsWidget->buildExpression();
}
 
void QgsRendererRulePropsDialog::accept()
{
  mPropsWidget->apply();
  QDialog::accept();
}
 
void QgsRendererRulePropsDialog::showHelp()
{
  QgsHelp::openHelp( QStringLiteral( "working_with_vector/vector_properties.html#rule-based-rendering" ) );
}
 
 
void QgsRendererRulePropsWidget::buildExpression()
{
  QgsExpressionContext context( mContext.globalProjectAtlasMapLayerScopes( mLayer ) );
 
  // additional scopes
  const auto constAdditionalExpressionContextScopes = mContext.additionalExpressionContextScopes();
  for ( const QgsExpressionContextScope &scope : constAdditionalExpressionContextScopes )
  {
    context.appendScope( new QgsExpressionContextScope( scope ) );
  }
 
  QgsExpressionBuilderDialog dlg( mLayer, editFilter->text(), this, QStringLiteral( "generic" ), context );
 
  if ( dlg.exec() )
    editFilter->setText( dlg.expressionText() );
}
 
void QgsRendererRulePropsWidget::testFilter()
{
  if ( !mFilterRadio->isChecked() )
    return;
 
  QgsExpression filter( editFilter->text() );
  if ( filter.hasParserError() )
  {
    QMessageBox::critical( this, tr( "Test Filter" ),  tr( "Filter expression parsing error:\n" ) + filter.parserErrorString() );
    return;
  }
 
  QgsExpressionContext context( mContext.globalProjectAtlasMapLayerScopes( mLayer ) );
 
  // additional scopes
  const auto constAdditionalExpressionContextScopes = mContext.additionalExpressionContextScopes();
  for ( const QgsExpressionContextScope &scope : constAdditionalExpressionContextScopes )
  {
    context.appendScope( new QgsExpressionContextScope( scope ) );
  }
 
  if ( !filter.prepare( &context ) )
  {
    QMessageBox::critical( this, tr( "Test Filter" ), filter.evalErrorString() );
    return;
  }
 
  QApplication::setOverrideCursor( Qt::WaitCursor );
 
  QgsFeatureRequest req = QgsFeatureRequest().setNoAttributes()
                          .setFlags( QgsFeatureRequest::NoGeometry )
                          .setFilterExpression( editFilter->text() )
                          .setExpressionContext( context );
 
  QgsFeatureIterator fit = mLayer->getFeatures( req );
 
  int count = 0;
  QgsFeature f;
  while ( fit.nextFeature( f ) )
  {
    count++;
  }
 
  QApplication::restoreOverrideCursor();
 
  QMessageBox::information( this, tr( "Test Filter" ), tr( "Filter returned %n feature(s)", "number of filtered features", count ) );
}
 
void QgsRendererRulePropsWidget::apply()
{
  QString filter = mElseRadio->isChecked() ? QStringLiteral( "ELSE" ) : editFilter->text();
  mRule->setFilterExpression( filter );
  mRule->setLabel( editLabel->text() );
  mRule->setDescription( editDescription->text() );
  // caution: rule uses scale denom, scale widget uses true scales
  mRule->setMinimumScale( groupScale->isChecked() ? mScaleRangeWidget->minimumScale() : 0 );
  mRule->setMaximumScale( groupScale->isChecked() ? mScaleRangeWidget->maximumScale() : 0 );
  mRule->setSymbol( groupSymbol->isChecked() ? mSymbol->clone() : nullptr );
}
 
void QgsRendererRulePropsWidget::setDockMode( bool dockMode )
{
  QgsPanelWidget::setDockMode( dockMode );
  mSymbolSelector->setDockMode( dockMode );
}
 
 
/*
  setDragEnabled(true);
  viewport()->setAcceptDrops(true);
  setDropIndicatorShown(true);
  setDragDropMode(QAbstractItemView::InternalMove);
*/
 
 
QgsRuleBasedRendererModel::QgsRuleBasedRendererModel( QgsRuleBasedRenderer *renderer, QObject *parent )
  : QAbstractItemModel( parent )
  , mR( renderer )
{
}
 
Qt::ItemFlags QgsRuleBasedRendererModel::flags( const QModelIndex &index ) const
{
  if ( !index.isValid() )
    return Qt::ItemIsDropEnabled;
 
  // allow drop only at first column
  Qt::ItemFlag drop = ( index.column() == 0 ? Qt::ItemIsDropEnabled : Qt::NoItemFlags );
 
  Qt::ItemFlag checkable = ( index.column() == 0 ? Qt::ItemIsUserCheckable : Qt::NoItemFlags );
 
  return Qt::ItemIsEnabled | Qt::ItemIsSelectable |
         Qt::ItemIsEditable | checkable |
         Qt::ItemIsDragEnabled | drop;
}
 
QVariant QgsRuleBasedRendererModel::data( const QModelIndex &index, int role ) const
{
  if ( !index.isValid() )
    return QVariant();
 
  QgsRuleBasedRenderer::Rule *rule = ruleForIndex( index );
 
  if ( role == Qt::DisplayRole || role == Qt::ToolTipRole )
  {
    switch ( index.column() )
    {
      case 0:
        return rule->label();
      case 1:
        if ( rule->isElse() )
        {
          return "ELSE";
        }
        else
        {
          return rule->filterExpression().isEmpty() ? tr( "(no filter)" ) : rule->filterExpression();
        }
      case 2:
        return rule->dependsOnScale() ? QgsScaleComboBox::toString( rule->minimumScale() ) : QVariant();
      case 3:
        return rule->dependsOnScale() ? QgsScaleComboBox::toString( rule->maximumScale() ) : QVariant();
      case 4:
        if ( mFeatureCountMap.count( rule ) == 1 )
        {
          return QVariant( mFeatureCountMap[rule].count );
        }
        return QVariant();
      case 5:
        if ( mFeatureCountMap.count( rule ) == 1 )
        {
          if ( role == Qt::DisplayRole )
          {
            return QVariant( mFeatureCountMap[rule].duplicateCount );
          }
          else // tooltip - detailed info about duplicates
          {
            if ( mFeatureCountMap[rule].duplicateCount > 0 )
            {
              QString tip = QStringLiteral( "<p style='margin:0px;'><ul>" );
              const auto duplicateMap = mFeatureCountMap[rule].duplicateCountMap;
              for ( auto it = duplicateMap.constBegin(); it != duplicateMap.constEnd(); ++it )
              {
                QString label = it.key()->label().replace( '&', QLatin1String( "&amp;" ) ).replace( '>', QLatin1String( "&gt;" ) ).replace( '<', QLatin1String( "&lt;" ) );
                tip += tr( "<li><nobr>%1 features also in rule %2</nobr></li>" ).arg( it.value() ).arg( label );
              }
              tip += QLatin1String( "</ul>" );
              return tip;
            }
            else
            {
              return 0;
            }
          }
        }
        return QVariant();
      default:
        return QVariant();
    }
  }
  else if ( role == Qt::DecorationRole && index.column() == 0 && rule->symbol() )
  {
    const int iconSize = QgsGuiUtils::scaleIconSize( 16 );
    return QgsSymbolLayerUtils::symbolPreviewIcon( rule->symbol(), QSize( iconSize, iconSize ) );
  }
  else if ( role == Qt::TextAlignmentRole )
  {
    return ( index.column() == 2 || index.column() == 3 ) ? Qt::AlignRight : Qt::AlignLeft;
  }
  else if ( role == Qt::FontRole && index.column() == 1 )
  {
    if ( rule->isElse() )
    {
      QFont italicFont;
      italicFont.setItalic( true );
      return italicFont;
    }
    return QVariant();
  }
  else if ( role == Qt::EditRole )
  {
    switch ( index.column() )
    {
      case 0:
        return rule->label();
      case 1:
        return rule->filterExpression();
      case 2:
        return rule->minimumScale();
      case 3:
        return rule->maximumScale();
      default:
        return QVariant();
    }
  }
  else if ( role == Qt::CheckStateRole )
  {
    if ( index.column() != 0 )
      return QVariant();
    return rule->active() ? Qt::Checked : Qt::Unchecked;
  }
  else
    return QVariant();
}
 
QVariant QgsRuleBasedRendererModel::headerData( int section, Qt::Orientation orientation, int role ) const
{
  if ( orientation == Qt::Horizontal && role == Qt::DisplayRole && section >= 0 && section < 7 )
  {
    QStringList lst;
    lst << tr( "Label" ) << tr( "Rule" ) << tr( "Min. Scale" ) << tr( "Max. Scale" ) << tr( "Count" ) << tr( "Duplicate Count" );
    return lst[section];
  }
  else if ( orientation == Qt::Horizontal && role == Qt::ToolTipRole )
  {
    if ( section == 4 ) // Count
    {
      return tr( "Number of features in this rule." );
    }
    else if ( section == 5 )  // Duplicate count
    {
      return tr( "Number of features in this rule which are also present in other rule(s)." );
    }
  }
 
  return QVariant();
}
 
int QgsRuleBasedRendererModel::rowCount( const QModelIndex &parent ) const
{
  if ( parent.column() > 0 )
    return 0;
 
  QgsRuleBasedRenderer::Rule *parentRule = ruleForIndex( parent );
 
  return parentRule->children().count();
}
 
int QgsRuleBasedRendererModel::columnCount( const QModelIndex & ) const
{
  return 6;
}
 
QModelIndex QgsRuleBasedRendererModel::index( int row, int column, const QModelIndex &parent ) const
{
  if ( hasIndex( row, column, parent ) )
  {
    QgsRuleBasedRenderer::Rule *parentRule = ruleForIndex( parent );
    QgsRuleBasedRenderer::Rule *childRule = parentRule->children()[row];
    return createIndex( row, column, childRule );
  }
  return QModelIndex();
}
 
QModelIndex QgsRuleBasedRendererModel::parent( const QModelIndex &index ) const
{
  if ( !index.isValid() )
    return QModelIndex();
 
  QgsRuleBasedRenderer::Rule *childRule = ruleForIndex( index );
  QgsRuleBasedRenderer::Rule *parentRule = childRule->parent();
 
  if ( parentRule == mR->rootRule() )
    return QModelIndex();
 
  // this is right: we need to know row number of our parent (in our grandparent)
  int row = parentRule->parent()->children().indexOf( parentRule );
 
  return createIndex( row, 0, parentRule );
}
 
bool QgsRuleBasedRendererModel::setData( const QModelIndex &index, const QVariant &value, int role )
{
  if ( !index.isValid() )
    return false;
 
  QgsRuleBasedRenderer::Rule *rule = ruleForIndex( index );
 
  if ( role == Qt::CheckStateRole )
  {
    rule->setActive( value.toInt() == Qt::Checked );
    emit dataChanged( index, index );
    return true;
  }
 
  if ( role != Qt::EditRole )
    return false;
 
  switch ( index.column() )
  {
    case 0: // label
      rule->setLabel( value.toString() );
      break;
    case 1: // filter
      rule->setFilterExpression( value.toString() );
      break;
    case 2: // scale min
      rule->setMinimumScale( value.toDouble() );
      break;
    case 3: // scale max
      rule->setMaximumScale( value.toDouble() );
      break;
    default:
      return false;
  }
 
  emit dataChanged( index, index );
  return true;
}
 
Qt::DropActions QgsRuleBasedRendererModel::supportedDropActions() const
{
  return Qt::MoveAction; // | Qt::CopyAction
}
 
QStringList QgsRuleBasedRendererModel::mimeTypes() const
{
  QStringList types;
  types << QStringLiteral( "application/vnd.text.list" );
  return types;
}
 
QMimeData *QgsRuleBasedRendererModel::mimeData( const QModelIndexList &indexes ) const
{
  QMimeData *mimeData = new QMimeData();
  QByteArray encodedData;
 
  QDataStream stream( &encodedData, QIODevice::WriteOnly );
 
  const auto constIndexes = indexes;
  for ( const QModelIndex &index : constIndexes )
  {
    // each item consists of several columns - let's add it with just first one
    if ( !index.isValid() || index.column() != 0 )
      continue;
 
    // we use a clone of the existing rule because it has a new unique rule key
    // non-unique rule keys would confuse other components using them (e.g. legend)
    QgsRuleBasedRenderer::Rule *rule = ruleForIndex( index )->clone();
    QDomDocument doc;
    QgsSymbolMap symbols;
 
    QDomElement rootElem = doc.createElement( QStringLiteral( "rule_mime" ) );
    rootElem.setAttribute( QStringLiteral( "type" ), QStringLiteral( "renderer" ) ); // for determining whether rules are from renderer or labeling
    QDomElement rulesElem = rule->save( doc, symbols );
    rootElem.appendChild( rulesElem );
    QDomElement symbolsElem = QgsSymbolLayerUtils::saveSymbols( symbols, QStringLiteral( "symbols" ), doc, QgsReadWriteContext() );
    rootElem.appendChild( symbolsElem );
    doc.appendChild( rootElem );
 
    delete rule;
 
    stream << doc.toString( -1 );
  }
 
  mimeData->setData( QStringLiteral( "application/vnd.text.list" ), encodedData );
  return mimeData;
}
 
 
// manipulate DOM before dropping it so that rules are more useful
void _labeling2rendererRules( QDomElement &ruleElem )
{
  // labeling rules recognize only "description"
  if ( ruleElem.hasAttribute( QStringLiteral( "description" ) ) )
    ruleElem.setAttribute( QStringLiteral( "label" ), ruleElem.attribute( QStringLiteral( "description" ) ) );
 
  // run recursively
  QDomElement childRuleElem = ruleElem.firstChildElement( QStringLiteral( "rule" ) );
  while ( !childRuleElem.isNull() )
  {
    _labeling2rendererRules( childRuleElem );
    childRuleElem = childRuleElem.nextSiblingElement( QStringLiteral( "rule" ) );
  }
}
 
 
bool QgsRuleBasedRendererModel::dropMimeData( const QMimeData *data,
    Qt::DropAction action, int row, int column, const QModelIndex &parent )
{
  Q_UNUSED( column )
 
  if ( action == Qt::IgnoreAction )
    return true;
 
  if ( !data->hasFormat( QStringLiteral( "application/vnd.text.list" ) ) )
    return false;
 
  if ( parent.column() > 0 )
    return false;
 
  QByteArray encodedData = data->data( QStringLiteral( "application/vnd.text.list" ) );
  QDataStream stream( &encodedData, QIODevice::ReadOnly );
  int rows = 0;
 
  if ( row == -1 )
  {
    // the item was dropped at a parent - we may decide where to put the items - let's append them
    row = rowCount( parent );
  }
 
  while ( !stream.atEnd() )
  {
    QString text;
    stream >> text;
 
    QDomDocument doc;
    if ( !doc.setContent( text ) )
      continue;
    QDomElement rootElem = doc.documentElement();
    if ( rootElem.tagName() != QLatin1String( "rule_mime" ) )
      continue;
    if ( rootElem.attribute( QStringLiteral( "type" ) ) == QLatin1String( "labeling" ) )
      rootElem.appendChild( doc.createElement( QStringLiteral( "symbols" ) ) );
    QDomElement symbolsElem = rootElem.firstChildElement( QStringLiteral( "symbols" ) );
    if ( symbolsElem.isNull() )
      continue;
    QgsSymbolMap symbolMap = QgsSymbolLayerUtils::loadSymbols( symbolsElem, QgsReadWriteContext() );
    QDomElement ruleElem = rootElem.firstChildElement( QStringLiteral( "rule" ) );
    if ( rootElem.attribute( QStringLiteral( "type" ) ) == QLatin1String( "labeling" ) )
      _labeling2rendererRules( ruleElem );
    QgsRuleBasedRenderer::Rule *rule = QgsRuleBasedRenderer::Rule::create( ruleElem, symbolMap );
 
    insertRule( parent, row + rows, rule );
 
    ++rows;
  }
  return true;
}
 
QgsRuleBasedRenderer::Rule *QgsRuleBasedRendererModel::ruleForIndex( const QModelIndex &index ) const
{
  if ( index.isValid() )
    return static_cast<QgsRuleBasedRenderer::Rule *>( index.internalPointer() );
  return mR->rootRule();
}
 
bool QgsRuleBasedRendererModel::removeRows( int row, int count, const QModelIndex &parent )
{
  QgsRuleBasedRenderer::Rule *parentRule = ruleForIndex( parent );
 
  if ( row < 0 || row >= parentRule->children().count() )
    return false;
 
  QgsDebugMsg( QStringLiteral( "Called: row %1 count %2 parent ~~%3~~" ).arg( row ).arg( count ).arg( parentRule->dump() ) );
 
  beginRemoveRows( parent, row, row + count - 1 );
 
  for ( int i = 0; i < count; i++ )
  {
    if ( row < parentRule->children().count() )
    {
      //QgsRuleBasedRenderer::Rule* r = parentRule->children()[row];
      parentRule->removeChildAt( row );
      //parentRule->takeChildAt( row );
    }
    else
    {
      QgsDebugMsg( QStringLiteral( "trying to remove invalid index - this should not happen!" ) );
    }
  }
 
  endRemoveRows();
 
  return true;
}
 
 
void QgsRuleBasedRendererModel::insertRule( const QModelIndex &parent, int before, QgsRuleBasedRenderer::Rule *newrule )
{
  beginInsertRows( parent, before, before );
 
  QgsDebugMsg( QStringLiteral( "insert before %1 rule: %2" ).arg( before ).arg( newrule->dump() ) );
 
  QgsRuleBasedRenderer::Rule *parentRule = ruleForIndex( parent );
  parentRule->insertChild( before, newrule );
 
  endInsertRows();
}
 
void QgsRuleBasedRendererModel::updateRule( const QModelIndex &parent, int row )
{
  emit dataChanged( index( row, 0, parent ),
                    index( row, columnCount( parent ), parent ) );
}
 
void QgsRuleBasedRendererModel::updateRule( const QModelIndex &idx )
{
  emit dataChanged( index( 0, 0, idx ),
                    index( rowCount( idx ) - 1, columnCount( idx ) - 1, idx ) );
 
  for ( int i = 0; i < rowCount( idx ); i++ )
  {
    updateRule( index( i, 0, idx ) );
  }
}
 
 
void QgsRuleBasedRendererModel::removeRule( const QModelIndex &index )
{
  if ( !index.isValid() )
    return;
 
  beginRemoveRows( index.parent(), index.row(), index.row() );
 
  QgsRuleBasedRenderer::Rule *rule = ruleForIndex( index );
  rule->parent()->removeChild( rule );
 
  endRemoveRows();
}
 
void QgsRuleBasedRendererModel::setSymbol( const QModelIndex &index, QgsSymbol *symbol )
{
  QgsRuleBasedRenderer::Rule *rule = ruleForIndex( index );
  rule->setSymbol( symbol );
  emit dataChanged( index, index );
}
 
void QgsRuleBasedRendererModel::willAddRules( const QModelIndex &parent, int count )
{
  int row = rowCount( parent ); // only consider appending
  beginInsertRows( parent, row, row + count - 1 );
}
 
void QgsRuleBasedRendererModel::finishedAddingRules()
{
  endInsertRows();
}
 
void QgsRuleBasedRendererModel::setFeatureCounts( const QHash<QgsRuleBasedRenderer::Rule *, QgsRuleBasedRendererCount> &countMap )
{
  mFeatureCountMap = countMap;
  updateRule( QModelIndex() );
}
 
void QgsRuleBasedRendererModel::clearFeatureCounts()
{
  mFeatureCountMap.clear();
  updateRule( QModelIndex() );
}