src/core/composer/qgscomposition.cpp

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/***************************************************************************
                              qgscomposition.cpp
                             -------------------
    begin                : January 2005
    copyright            : (C) 2005 by Radim Blazek
    email                : blazek@itc.it
 ***************************************************************************/
/***************************************************************************
 *                                                                         *
 *   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 <stdexcept>

#include "qgscomposition.h"
#include "qgscomposerarrow.h"
#include "qgscomposerframe.h"
#include "qgscomposerhtml.h"
#include "qgscomposerlabel.h"
#include "qgscomposerlegend.h"
#include "qgscomposermap.h"
#include "qgscomposeritemgroup.h"
#include "qgscomposerpicture.h"
#include "qgscomposerscalebar.h"
#include "qgscomposershape.h"
#include "qgscomposerlabel.h"
#include "qgscomposerattributetable.h"
#include "qgsaddremovemultiframecommand.h"
#include "qgscomposermultiframecommand.h"
#include "qgslogger.h"
#include "qgspaintenginehack.h"
#include "qgspaperitem.h"
#include "qgsgeometry.h"
#include "qgsvectorlayer.h"
#include "qgsvectordataprovider.h"
#include "qgsexpression.h"
#include <QDomDocument>
#include <QDomElement>
#include <QGraphicsRectItem>
#include <QPainter>
#include <QPrinter>
#include <QSettings>
#include <QDir>


QgsComposition::QgsComposition( QgsMapRenderer* mapRenderer )
    : QGraphicsScene( 0 ),
    mMapRenderer( mapRenderer ),
    mPlotStyle( QgsComposition::Preview ),
    mPageWidth( 297 ),
    mPageHeight( 210 ),
    mSpaceBetweenPages( 10 ),
    mPrintAsRaster( false ),
    mUseAdvancedEffects( true ),
    mSelectionTolerance( 0.0 ),
    mSnapToGrid( false ),
    mSnapGridResolution( 10.0 ),
    mSnapGridOffsetX( 0.0 ),
    mSnapGridOffsetY( 0.0 ),
    mAlignmentSnap( true ),
    mAlignmentSnapTolerance( 2 ),
    mActiveItemCommand( 0 ),
    mActiveMultiFrameCommand( 0 ),
    mAtlasComposition( this )
{
  setBackgroundBrush( Qt::gray );
  addPaperItem();

  mPrintResolution = 300; //hardcoded default
  loadSettings();
}

QgsComposition::QgsComposition()
    : QGraphicsScene( 0 ),
    mMapRenderer( 0 ),
    mPlotStyle( QgsComposition::Preview ),
    mPageWidth( 297 ),
    mPageHeight( 210 ),
    mSpaceBetweenPages( 10 ),
    mPrintAsRaster( false ),
    mUseAdvancedEffects( true ),
    mSelectionTolerance( 0.0 ),
    mSnapToGrid( false ),
    mSnapGridResolution( 10.0 ),
    mSnapGridOffsetX( 0.0 ),
    mSnapGridOffsetY( 0.0 ),
    mAlignmentSnap( true ),
    mAlignmentSnapTolerance( 2 ),
    mActiveItemCommand( 0 ),
    mActiveMultiFrameCommand( 0 ),
    mAtlasComposition( this )
{
  loadSettings();

}

QgsComposition::~QgsComposition()
{
  removePaperItems();
  deleteAndRemoveMultiFrames();

  // make sure that all composer items are removed before
  // this class is deconstructed - to avoid segfaults
  // when composer items access in destructor composition that isn't valid anymore
  clear();
  delete mActiveItemCommand;
  delete mActiveMultiFrameCommand;
}

void QgsComposition::setPaperSize( double width, double height )
{
  mPageWidth = width;
  mPageHeight = height;
  double currentY = 0;
  for ( int i = 0; i < mPages.size(); ++i )
  {
    mPages.at( i )->setSceneRect( QRectF( 0, currentY, width, height ) );
    currentY += ( height + mSpaceBetweenPages );
  }
}

double QgsComposition::paperHeight() const
{
  return mPageHeight;
}

double QgsComposition::paperWidth() const
{
  return mPageWidth;
}

void QgsComposition::setNumPages( int pages )
{
  int currentPages = numPages();
  int diff = pages - currentPages;
  if ( diff >= 0 )
  {
    for ( int i = 0; i < diff; ++i )
    {
      addPaperItem();
    }
  }
  else
  {
    diff = -diff;
    for ( int i = 0; i < diff; ++i )
    {
      delete mPages.last();
      mPages.removeLast();
    }
  }

  // update the corresponding variable
  QgsExpression::setSpecialColumn( "$numpages", QVariant(( int )numPages() ) );

  emit nPagesChanged();
}

int QgsComposition::numPages() const
{
  return mPages.size();
}

QgsComposerItem* QgsComposition::composerItemAt( const QPointF & position )
{
  QList<QGraphicsItem*> itemList;
  if ( mSelectionTolerance <= 0.0 )
  {
    itemList = items( position );
  }
  else
  {
    itemList = items( QRectF( position.x() - mSelectionTolerance, position.y() - mSelectionTolerance, 2 * mSelectionTolerance, 2 * mSelectionTolerance ),
                      Qt::IntersectsItemShape, Qt::DescendingOrder );
  }
  QList<QGraphicsItem *>::iterator itemIt = itemList.begin();

  for ( ; itemIt != itemList.end(); ++itemIt )
  {
    QgsComposerItem* composerItem = dynamic_cast<QgsComposerItem *>( *itemIt );
    QgsPaperItem* paperItem = dynamic_cast<QgsPaperItem*>( *itemIt );
    if ( composerItem && !paperItem )
    {
      return composerItem;
    }
  }
  return 0;
}

int QgsComposition::pageNumberAt( const QPointF& position ) const
{
  return position.y() / ( paperHeight() + spaceBetweenPages() );
}

int QgsComposition::itemPageNumber( const QgsComposerItem* item ) const
{
  return pageNumberAt( QPointF( item->transform().dx(), item->transform().dy() ) );
}

QList<QgsComposerItem*> QgsComposition::selectedComposerItems()
{
  QList<QgsComposerItem*> composerItemList;

  QList<QGraphicsItem *> graphicsItemList = selectedItems();
  QList<QGraphicsItem *>::iterator itemIter = graphicsItemList.begin();

  for ( ; itemIter != graphicsItemList.end(); ++itemIter )
  {
    QgsComposerItem* composerItem = dynamic_cast<QgsComposerItem *>( *itemIter );
    if ( composerItem )
    {
      composerItemList.push_back( composerItem );
    }
  }

  return composerItemList;
}

QList<const QgsComposerMap*> QgsComposition::composerMapItems() const
{
  QList<const QgsComposerMap*> resultList;

  QList<QGraphicsItem *> itemList = items();
  QList<QGraphicsItem *>::iterator itemIt = itemList.begin();
  for ( ; itemIt != itemList.end(); ++itemIt )
  {
    const QgsComposerMap* composerMap = dynamic_cast<const QgsComposerMap *>( *itemIt );
    if ( composerMap )
    {
      resultList.push_back( composerMap );
    }
  }

  return resultList;
}

const QgsComposerMap* QgsComposition::getComposerMapById( int id ) const
{
  QList<QGraphicsItem *> itemList = items();
  QList<QGraphicsItem *>::iterator itemIt = itemList.begin();
  for ( ; itemIt != itemList.end(); ++itemIt )
  {
    const QgsComposerMap* composerMap = dynamic_cast<const QgsComposerMap *>( *itemIt );
    if ( composerMap )
    {
      if ( composerMap->id() == id )
      {
        return composerMap;
      }
    }
  }
  return 0;
}

const QgsComposerHtml* QgsComposition::getComposerHtmlByItem( QgsComposerItem *item ) const
{
  // an html item will be a composer frame and if it is we can try to get
  // its multiframe parent and then try to cast that to a composer html
  const QgsComposerFrame* composerFrame =
    dynamic_cast<const QgsComposerFrame *>( item );
  if ( composerFrame )
  {
    const QgsComposerMultiFrame * mypMultiFrame = composerFrame->multiFrame();
    const QgsComposerHtml* composerHtml =
      dynamic_cast<const QgsComposerHtml *>( mypMultiFrame );
    if ( composerHtml )
    {
      return composerHtml;
    }
  }
  return 0;
}

const QgsComposerItem* QgsComposition::getComposerItemById( QString theId ) const
{
  QList<QGraphicsItem *> itemList = items();
  QList<QGraphicsItem *>::iterator itemIt = itemList.begin();
  for ( ; itemIt != itemList.end(); ++itemIt )
  {
    const QgsComposerItem* mypItem = dynamic_cast<const QgsComposerItem *>( *itemIt );
    if ( mypItem )
    {
      if ( mypItem->id() == theId )
      {
        return mypItem;
      }
    }
  }
  return 0;
}
/*
const QgsComposerItem* QgsComposition::getComposerItemByUuid( QString theUuid, bool inAllComposers ) const
{
  //This does not work since it seems impossible to get the QgisApp::instance() from here... Is there a workaround ?
  QSet<QgsComposer*> composers = QSet<QgsComposer*>();

  if( inAllComposers )
  {
    composers = QgisApp::instance()->printComposers();
  }
  else
  {
    composers.insert( this )
  }

  QSet<QgsComposer*>::const_iterator it = composers.constBegin();
  for ( ; it != composers.constEnd(); ++it )
  {
    QList<QGraphicsItem *> itemList = ( *it )->items();
    QList<QGraphicsItem *>::iterator itemIt = itemList.begin();
    for ( ; itemIt != itemList.end(); ++itemIt )
    {
      const QgsComposerItem* mypItem = dynamic_cast<const QgsComposerItem *>( *itemIt );
      if ( mypItem )
      {
        if ( mypItem->uuid() == theUuid )
        {
          return mypItem;
        }
      }
    }
  }

  return 0;
}
*/

const QgsComposerItem* QgsComposition::getComposerItemByUuid( QString theUuid ) const
{
  QList<QGraphicsItem *> itemList = items();
  QList<QGraphicsItem *>::iterator itemIt = itemList.begin();
  for ( ; itemIt != itemList.end(); ++itemIt )
  {
    const QgsComposerItem* mypItem = dynamic_cast<const QgsComposerItem *>( *itemIt );
    if ( mypItem )
    {
      if ( mypItem->uuid() == theUuid )
      {
        return mypItem;
      }
    }
  }

  return 0;
}


void QgsComposition::setUseAdvancedEffects( bool effectsEnabled )
{
  mUseAdvancedEffects = effectsEnabled;

  //toggle effects for all composer items
  QList<QGraphicsItem*> itemList = items();
  QList<QGraphicsItem*>::const_iterator itemIt = itemList.constBegin();
  for ( ; itemIt != itemList.constEnd(); ++itemIt )
  {
    QgsComposerItem* composerItem = dynamic_cast<QgsComposerItem*>( *itemIt );
    if ( composerItem )
    {
      composerItem->setEffectsEnabled( effectsEnabled );
    }
  }
}

int QgsComposition::pixelFontSize( double pointSize ) const
{
  //in QgsComposition, one unit = one mm
  double sizeMillimeters = pointSize * 0.3527;
  return qRound( sizeMillimeters ); //round to nearest mm
}

double QgsComposition::pointFontSize( int pixelSize ) const
{
  double sizePoint = pixelSize / 0.3527;
  return sizePoint;
}

bool QgsComposition::writeXML( QDomElement& composerElem, QDomDocument& doc )
{
  if ( composerElem.isNull() )
  {
    return false;
  }

  QDomElement compositionElem = doc.createElement( "Composition" );
  compositionElem.setAttribute( "paperWidth", QString::number( mPageWidth ) );
  compositionElem.setAttribute( "paperHeight", QString::number( mPageHeight ) );
  compositionElem.setAttribute( "numPages", mPages.size() );

  //snapping
  if ( mSnapToGrid )
  {
    compositionElem.setAttribute( "snapping", "1" );
  }
  else
  {
    compositionElem.setAttribute( "snapping", "0" );
  }
  compositionElem.setAttribute( "snapGridResolution", QString::number( mSnapGridResolution ) );
  compositionElem.setAttribute( "snapGridOffsetX", QString::number( mSnapGridOffsetX ) );
  compositionElem.setAttribute( "snapGridOffsetY", QString::number( mSnapGridOffsetY ) );

  //custom snap lines
  QList< QGraphicsLineItem* >::const_iterator snapLineIt = mSnapLines.constBegin();
  for ( ; snapLineIt != mSnapLines.constEnd(); ++snapLineIt )
  {
    QDomElement snapLineElem = doc.createElement( "SnapLine" );
    QLineF line = ( *snapLineIt )->line();
    snapLineElem.setAttribute( "x1", QString::number( line.x1() ) );
    snapLineElem.setAttribute( "y1", QString::number( line.y1() ) );
    snapLineElem.setAttribute( "x2", QString::number( line.x2() ) );
    snapLineElem.setAttribute( "y2", QString::number( line.y2() ) );
    compositionElem.appendChild( snapLineElem );
  }

  compositionElem.setAttribute( "printResolution", mPrintResolution );
  compositionElem.setAttribute( "printAsRaster", mPrintAsRaster );

  compositionElem.setAttribute( "alignmentSnap", mAlignmentSnap ? 1 : 0 );
  compositionElem.setAttribute( "alignmentSnapTolerance", mAlignmentSnapTolerance );

  //save items except paper items and frame items (they are saved with the corresponding multiframe)
  QList<QGraphicsItem*> itemList = items();
  QList<QGraphicsItem*>::const_iterator itemIt = itemList.constBegin();
  for ( ; itemIt != itemList.constEnd(); ++itemIt )
  {
    const QgsComposerItem* composerItem = dynamic_cast<const QgsComposerItem*>( *itemIt );
    if ( composerItem )
    {
      if ( composerItem->type() != QgsComposerItem::ComposerPaper &&  composerItem->type() != QgsComposerItem::ComposerFrame )
      {
        composerItem->writeXML( compositionElem, doc );
      }
    }
  }

  //save multiframes
  QSet<QgsComposerMultiFrame*>::const_iterator multiFrameIt = mMultiFrames.constBegin();
  for ( ; multiFrameIt != mMultiFrames.constEnd(); ++multiFrameIt )
  {
    ( *multiFrameIt )->writeXML( compositionElem, doc );
  }
  composerElem.appendChild( compositionElem );

  return true;
}

bool QgsComposition::readXML( const QDomElement& compositionElem, const QDomDocument& doc )
{
  Q_UNUSED( doc );
  if ( compositionElem.isNull() )
  {
    return false;
  }

  //create pages
  bool widthConversionOk, heightConversionOk;
  mPageWidth = compositionElem.attribute( "paperWidth" ).toDouble( &widthConversionOk );
  mPageHeight = compositionElem.attribute( "paperHeight" ).toDouble( &heightConversionOk );
  emit paperSizeChanged();
  int numPages = compositionElem.attribute( "numPages", "1" ).toInt();

  if ( widthConversionOk && heightConversionOk )
  {
    removePaperItems();
    for ( int i = 0; i < numPages; ++i )
    {
      addPaperItem();
    }
  }

  //snapping
  if ( compositionElem.attribute( "snapping" ) == "0" )
  {
    mSnapToGrid = false;
  }
  else
  {
    mSnapToGrid = true;
  }
  mSnapGridResolution = compositionElem.attribute( "snapGridResolution" ).toDouble();
  mSnapGridOffsetX = compositionElem.attribute( "snapGridOffsetX" ).toDouble();
  mSnapGridOffsetY = compositionElem.attribute( "snapGridOffsetY" ).toDouble();

  //custom snap lines
  QDomNodeList snapLineNodes = compositionElem.elementsByTagName( "SnapLine" );
  for ( int i = 0; i < snapLineNodes.size(); ++i )
  {
    QDomElement snapLineElem = snapLineNodes.at( i ).toElement();
    QGraphicsLineItem* snapItem = addSnapLine();
    double x1 = snapLineElem.attribute( "x1" ).toDouble();
    double y1 = snapLineElem.attribute( "y1" ).toDouble();
    double x2 = snapLineElem.attribute( "x2" ).toDouble();
    double y2 = snapLineElem.attribute( "y2" ).toDouble();
    snapItem->setLine( x1, y1, x2, y2 );
  }

  mAlignmentSnap = compositionElem.attribute( "alignmentSnap", "1" ).toInt() == 0 ? false : true;
  mAlignmentSnapTolerance = compositionElem.attribute( "alignmentSnapTolerance", "2.0" ).toDouble();

  mPrintAsRaster = compositionElem.attribute( "printAsRaster" ).toInt();
  mPrintResolution = compositionElem.attribute( "printResolution", "300" ).toInt();

  updatePaperItems();
  return true;
}

bool QgsComposition::loadFromTemplate( const QDomDocument& doc, QMap<QString, QString>* substitutionMap, bool addUndoCommands )
{
  deleteAndRemoveMultiFrames();

  //delete all items and emit itemRemoved signal
  QList<QGraphicsItem *> itemList = items();
  QList<QGraphicsItem *>::iterator itemIter = itemList.begin();
  for ( ; itemIter != itemList.end(); ++itemIter )
  {
    QgsComposerItem* cItem = dynamic_cast<QgsComposerItem*>( *itemIter );
    if ( cItem )
    {
      removeItem( cItem );
      emit itemRemoved( cItem );
      delete cItem;
    }
  }
  mItemZList.clear();

  mPages.clear();
  mUndoStack.clear();

  QDomDocument importDoc;
  if ( substitutionMap )
  {
    QString xmlString = doc.toString();
    QMap<QString, QString>::const_iterator sIt = substitutionMap->constBegin();
    for ( ; sIt != substitutionMap->constEnd(); ++sIt )
    {
      xmlString = xmlString.replace( "[" + sIt.key() + "]", encodeStringForXML( sIt.value() ) );
    }

    QString errorMsg;
    int errorLine, errorColumn;
    if ( !importDoc.setContent( xmlString, &errorMsg, &errorLine, &errorColumn ) )
    {
      return false;
    }
  }
  else
  {
    importDoc = doc;
  }

  //read general settings
  QDomElement compositionElem = importDoc.documentElement().firstChildElement( "Composition" );
  if ( compositionElem.isNull() )
  {
    return false;
  }

  bool ok = readXML( compositionElem, importDoc );
  if ( !ok )
  {
    return false;
  }

  // remove all uuid attributes since we don't want duplicates UUIDS
  QDomNodeList composerItemsNodes = importDoc.elementsByTagName( "ComposerItem" );
  for ( int i = 0; i < composerItemsNodes.count(); ++i )
  {
    QDomNode composerItemNode = composerItemsNodes.at( i );
    if ( composerItemNode.isElement() )
    {
      composerItemNode.toElement().removeAttribute( "uuid" );
    }
  }

  //addItemsFromXML
  addItemsFromXML( importDoc.documentElement(), importDoc, 0, addUndoCommands, 0 );

  // read atlas parameters
  QDomElement atlasElem = importDoc.documentElement().firstChildElement( "Atlas" );
  atlasComposition().readXML( atlasElem, importDoc );
  return true;
}

void QgsComposition::addItemsFromXML( const QDomElement& elem, const QDomDocument& doc, QMap< QgsComposerMap*, int >* mapsToRestore,
                                      bool addUndoCommands, QPointF* pos, bool pasteInPlace )
{
  QPointF* pasteInPlacePt = 0;
  if ( pasteInPlace )
  {
    pasteInPlacePt = new QPointF( 0, pageNumberAt( *pos ) * ( mPageHeight + mSpaceBetweenPages ) );
  }
  QDomNodeList composerLabelList = elem.elementsByTagName( "ComposerLabel" );
  for ( int i = 0; i < composerLabelList.size(); ++i )
  {
    QDomElement currentComposerLabelElem = composerLabelList.at( i ).toElement();
    QgsComposerLabel* newLabel = new QgsComposerLabel( this );
    newLabel->readXML( currentComposerLabelElem, doc );
    if ( pos )
    {
      if ( pasteInPlacePt )
      {
        newLabel->setItemPosition( newLabel->transform().dx(), fmod( newLabel->transform().dy(), ( paperHeight() + spaceBetweenPages() ) ) );
        newLabel->move( pasteInPlacePt->x(), pasteInPlacePt->y() );
      }
      else
      {
        newLabel->setItemPosition( pos->x(), pos->y() );
      }
    }
    addComposerLabel( newLabel );
    if ( addUndoCommands )
    {
      pushAddRemoveCommand( newLabel, tr( "Label added" ) );
    }
  }
  // map
  QDomNodeList composerMapList = elem.elementsByTagName( "ComposerMap" );
  for ( int i = 0; i < composerMapList.size(); ++i )
  {
    QDomElement currentComposerMapElem = composerMapList.at( i ).toElement();
    QgsComposerMap* newMap = new QgsComposerMap( this );
    newMap->readXML( currentComposerMapElem, doc );
    newMap->assignFreeId();

    if ( mapsToRestore )
    {
      mapsToRestore->insert( newMap, ( int )( newMap->previewMode() ) );
      newMap->setPreviewMode( QgsComposerMap::Rectangle );
    }
    addComposerMap( newMap, false );

    if ( pos )
    {
      if ( pasteInPlace )
      {
        newMap->setItemPosition( newMap->transform().dx(), fmod( newMap->transform().dy(), ( paperHeight() + spaceBetweenPages() ) ) );
        newMap->move( pasteInPlacePt->x(), pasteInPlacePt->y() );
      }
      else
      {
        newMap->setItemPosition( pos->x(), pos->y() );
      }
    }

    if ( addUndoCommands )
    {
      pushAddRemoveCommand( newMap, tr( "Map added" ) );
    }
  }
  // arrow
  QDomNodeList composerArrowList = elem.elementsByTagName( "ComposerArrow" );
  for ( int i = 0; i < composerArrowList.size(); ++i )
  {
    QDomElement currentComposerArrowElem = composerArrowList.at( i ).toElement();
    QgsComposerArrow* newArrow = new QgsComposerArrow( this );
    newArrow->readXML( currentComposerArrowElem, doc );
    if ( pos )
    {
      if ( pasteInPlace )
      {
        newArrow->setItemPosition( newArrow->transform().dx(), fmod( newArrow->transform().dy(), ( paperHeight() + spaceBetweenPages() ) ) );
        newArrow->move( pasteInPlacePt->x(), pasteInPlacePt->y() );
      }
      else
      {
        newArrow->setItemPosition( pos->x(), pos->y() );
      }
    }
    addComposerArrow( newArrow );
    if ( addUndoCommands )
    {
      pushAddRemoveCommand( newArrow, tr( "Arrow added" ) );
    }
  }
  // scalebar
  QDomNodeList composerScaleBarList = elem.elementsByTagName( "ComposerScaleBar" );
  for ( int i = 0; i < composerScaleBarList.size(); ++i )
  {
    QDomElement currentComposerScaleBarElem = composerScaleBarList.at( i ).toElement();
    QgsComposerScaleBar* newScaleBar = new QgsComposerScaleBar( this );
    newScaleBar->readXML( currentComposerScaleBarElem, doc );
    if ( pos )
    {
      if ( pasteInPlace )
      {
        newScaleBar->setItemPosition( newScaleBar->transform().dx(), fmod( newScaleBar->transform().dy(), ( paperHeight() + spaceBetweenPages() ) ) );
        newScaleBar->move( pasteInPlacePt->x(), pasteInPlacePt->y() );
      }
      else
      {
        newScaleBar->setItemPosition( pos->x(), pos->y() );
      }
    }
    addComposerScaleBar( newScaleBar );
    if ( addUndoCommands )
    {
      pushAddRemoveCommand( newScaleBar, tr( "Scale bar added" ) );
    }
  }
  // shape
  QDomNodeList composerShapeList = elem.elementsByTagName( "ComposerShape" );
  for ( int i = 0; i < composerShapeList.size(); ++i )
  {
    QDomElement currentComposerShapeElem = composerShapeList.at( i ).toElement();
    QgsComposerShape* newShape = new QgsComposerShape( this );
    newShape->readXML( currentComposerShapeElem, doc );
    if ( pos )
    {
      if ( pasteInPlace )
      {
        newShape->setItemPosition( newShape->transform().dx(), fmod( newShape->transform().dy(), ( paperHeight() + spaceBetweenPages() ) ) );
        newShape->move( pasteInPlacePt->x(), pasteInPlacePt->y() );
      }
      else
      {
        newShape->setItemPosition( pos->x(), pos->y() );
      }
    }
    addComposerShape( newShape );
    if ( addUndoCommands )
    {
      pushAddRemoveCommand( newShape, tr( "Shape added" ) );
    }
  }
  // picture
  QDomNodeList composerPictureList = elem.elementsByTagName( "ComposerPicture" );
  for ( int i = 0; i < composerPictureList.size(); ++i )
  {
    QDomElement currentComposerPictureElem = composerPictureList.at( i ).toElement();
    QgsComposerPicture* newPicture = new QgsComposerPicture( this );
    newPicture->readXML( currentComposerPictureElem, doc );
    if ( pos )
    {
      if ( pasteInPlace )
      {
        newPicture->setItemPosition( newPicture->transform().dx(), fmod( newPicture->transform().dy(), ( paperHeight() + spaceBetweenPages() ) ) );
        newPicture->move( pasteInPlacePt->x(), pasteInPlacePt->y() );
      }
      else
      {
        newPicture->setItemPosition( pos->x(), pos->y() );
      }
    }
    addComposerPicture( newPicture );
    if ( addUndoCommands )
    {
      pushAddRemoveCommand( newPicture, tr( "Picture added" ) );
    }
  }
  // legend
  QDomNodeList composerLegendList = elem.elementsByTagName( "ComposerLegend" );
  for ( int i = 0; i < composerLegendList.size(); ++i )
  {
    QDomElement currentComposerLegendElem = composerLegendList.at( i ).toElement();
    QgsComposerLegend* newLegend = new QgsComposerLegend( this );
    newLegend->readXML( currentComposerLegendElem, doc );
    if ( pos )
    {
      if ( pasteInPlace )
      {
        newLegend->setItemPosition( newLegend->transform().dx(), fmod( newLegend->transform().dy(), ( paperHeight() + spaceBetweenPages() ) ) );
        newLegend->move( pasteInPlacePt->x(), pasteInPlacePt->y() );
      }
      else
      {
        newLegend->setItemPosition( pos->x(), pos->y() );
      }
    }
    addComposerLegend( newLegend );
    if ( addUndoCommands )
    {
      pushAddRemoveCommand( newLegend, tr( "Legend added" ) );
    }
  }
  // table
  QDomNodeList composerTableList = elem.elementsByTagName( "ComposerAttributeTable" );
  for ( int i = 0; i < composerTableList.size(); ++i )
  {
    QDomElement currentComposerTableElem = composerTableList.at( i ).toElement();
    QgsComposerAttributeTable* newTable = new QgsComposerAttributeTable( this );
    newTable->readXML( currentComposerTableElem, doc );
    if ( pos )
    {
      if ( pasteInPlace )
      {
        newTable->setItemPosition( newTable->transform().dx(), fmod( newTable->transform().dy(), ( paperHeight() + spaceBetweenPages() ) ) );
        newTable->move( pasteInPlacePt->x(), pasteInPlacePt->y() );
      }
      else
      {
        newTable->setItemPosition( pos->x(), pos->y() );
      }
    }
    addComposerTable( newTable );
    if ( addUndoCommands )
    {
      pushAddRemoveCommand( newTable, tr( "Table added" ) );
    }
  }
  //html
  QDomNodeList composerHtmlList = elem.elementsByTagName( "ComposerHtml" );
  for ( int i = 0; i < composerHtmlList.size(); ++i )
  {
    QDomElement currentHtmlElem = composerHtmlList.at( i ).toElement();
    QgsComposerHtml* newHtml = new QgsComposerHtml( this, false );
    newHtml->readXML( currentHtmlElem, doc );
    newHtml->setCreateUndoCommands( true );
    this->addMultiFrame( newHtml );
  }
}

void QgsComposition::addItemToZList( QgsComposerItem* item )
{
  if ( !item )
  {
    return;
  }
  mItemZList.push_back( item );
  QgsDebugMsg( QString::number( mItemZList.size() ) );
  item->setZValue( mItemZList.size() );
}

void QgsComposition::removeItemFromZList( QgsComposerItem* item )
{
  if ( !item )
  {
    return;
  }
  mItemZList.removeAll( item );
}

void QgsComposition::raiseSelectedItems()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  QList<QgsComposerItem*>::iterator it = selectedItems.begin();
  for ( ; it != selectedItems.end(); ++it )
  {
    raiseItem( *it );
  }

  //update all positions
  updateZValues();
  update();
}

void QgsComposition::raiseItem( QgsComposerItem* item )
{
  //search item
  QMutableLinkedListIterator<QgsComposerItem*> it( mItemZList );
  if ( it.findNext( item ) )
  {
    if ( it.hasNext() )
    {
      it.remove();
      it.next();
      it.insert( item );
    }
  }
}

void QgsComposition::lowerSelectedItems()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  QList<QgsComposerItem*>::iterator it = selectedItems.begin();
  for ( ; it != selectedItems.end(); ++it )
  {
    lowerItem( *it );
  }

  //update all positions
  updateZValues();
  update();
}

void QgsComposition::lowerItem( QgsComposerItem* item )
{
  //search item
  QMutableLinkedListIterator<QgsComposerItem*> it( mItemZList );
  if ( it.findNext( item ) )
  {
    it.previous();
    if ( it.hasPrevious() )
    {
      it.remove();
      it.previous();
      it.insert( item );
    }
  }
}

void QgsComposition::moveSelectedItemsToTop()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  QList<QgsComposerItem*>::iterator it = selectedItems.begin();

  for ( ; it != selectedItems.end(); ++it )
  {
    moveItemToTop( *it );
  }

  //update all positions
  updateZValues();
  update();
}

void QgsComposition::moveItemToTop( QgsComposerItem* item )
{
  //search item
  QMutableLinkedListIterator<QgsComposerItem*> it( mItemZList );
  if ( it.findNext( item ) )
  {
    it.remove();
  }
  mItemZList.push_back( item );
}

void QgsComposition::moveSelectedItemsToBottom()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  QList<QgsComposerItem*>::iterator it = selectedItems.begin();
  for ( ; it != selectedItems.end(); ++it )
  {
    moveItemToBottom( *it );
  }

  //update all positions
  updateZValues();
  update();
}

void QgsComposition::moveItemToBottom( QgsComposerItem* item )
{
  //search item
  QMutableLinkedListIterator<QgsComposerItem*> it( mItemZList );
  if ( it.findNext( item ) )
  {
    it.remove();
  }
  mItemZList.push_front( item );
}

void QgsComposition::alignSelectedItemsLeft()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  if ( selectedItems.size() < 2 )
  {
    return;
  }

  QRectF selectedItemBBox;
  if ( boundingRectOfSelectedItems( selectedItemBBox ) != 0 )
  {
    return;
  }

  double minXCoordinate = selectedItemBBox.left();

  //align items left to minimum x coordinate
  QUndoCommand* parentCommand = new QUndoCommand( tr( "Aligned items left" ) );
  QList<QgsComposerItem*>::iterator align_it = selectedItems.begin();
  for ( ; align_it != selectedItems.end(); ++align_it )
  {
    QgsComposerItemCommand* subcommand = new QgsComposerItemCommand( *align_it, "", parentCommand );
    subcommand->savePreviousState();
    QTransform itemTransform = ( *align_it )->transform();
    itemTransform.translate( minXCoordinate - itemTransform.dx(), 0 );
    ( *align_it )->setTransform( itemTransform );
    subcommand->saveAfterState();
  }
  mUndoStack.push( parentCommand );
}

void QgsComposition::alignSelectedItemsHCenter()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  if ( selectedItems.size() < 2 )
  {
    return;
  }

  QRectF selectedItemBBox;
  if ( boundingRectOfSelectedItems( selectedItemBBox ) != 0 )
  {
    return;
  }

  double averageXCoord = ( selectedItemBBox.left() + selectedItemBBox.right() ) / 2.0;

  //place items
  QUndoCommand* parentCommand = new QUndoCommand( tr( "Aligned items hcenter" ) );
  QList<QgsComposerItem*>::iterator align_it = selectedItems.begin();
  for ( ; align_it != selectedItems.end(); ++align_it )
  {
    QgsComposerItemCommand* subcommand = new QgsComposerItemCommand( *align_it, "", parentCommand );
    subcommand->savePreviousState();
    QTransform itemTransform = ( *align_it )->transform();
    itemTransform.translate( averageXCoord - itemTransform.dx() - ( *align_it )->rect().width() / 2.0, 0 );
    ( *align_it )->setTransform( itemTransform );
    subcommand->saveAfterState();
  }
  mUndoStack.push( parentCommand );
}

void QgsComposition::alignSelectedItemsRight()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  if ( selectedItems.size() < 2 )
  {
    return;
  }

  QRectF selectedItemBBox;
  if ( boundingRectOfSelectedItems( selectedItemBBox ) != 0 )
  {
    return;
  }

  double maxXCoordinate = selectedItemBBox.right();

  //align items right to maximum x coordinate
  QUndoCommand* parentCommand = new QUndoCommand( tr( "Aligned items right" ) );
  QList<QgsComposerItem*>::iterator align_it = selectedItems.begin();
  for ( ; align_it != selectedItems.end(); ++align_it )
  {
    QgsComposerItemCommand* subcommand = new QgsComposerItemCommand( *align_it, "", parentCommand );
    subcommand->savePreviousState();
    QTransform itemTransform = ( *align_it )->transform();
    itemTransform.translate( maxXCoordinate - itemTransform.dx() - ( *align_it )->rect().width(), 0 );
    ( *align_it )->setTransform( itemTransform );
    subcommand->saveAfterState();
  }
  mUndoStack.push( parentCommand );
}

void QgsComposition::alignSelectedItemsTop()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  if ( selectedItems.size() < 2 )
  {
    return;
  }

  QRectF selectedItemBBox;
  if ( boundingRectOfSelectedItems( selectedItemBBox ) != 0 )
  {
    return;
  }

  double minYCoordinate = selectedItemBBox.top();

  QUndoCommand* parentCommand = new QUndoCommand( tr( "Aligned items top" ) );
  QList<QgsComposerItem*>::iterator align_it = selectedItems.begin();
  for ( ; align_it != selectedItems.end(); ++align_it )
  {
    QgsComposerItemCommand* subcommand = new QgsComposerItemCommand( *align_it, "", parentCommand );
    subcommand->savePreviousState();
    QTransform itemTransform = ( *align_it )->transform();
    itemTransform.translate( 0, minYCoordinate - itemTransform.dy() );
    ( *align_it )->setTransform( itemTransform );
    subcommand->saveAfterState();
  }
  mUndoStack.push( parentCommand );
}

void QgsComposition::alignSelectedItemsVCenter()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  if ( selectedItems.size() < 2 )
  {
    return;
  }

  QRectF selectedItemBBox;
  if ( boundingRectOfSelectedItems( selectedItemBBox ) != 0 )
  {
    return;
  }

  double averageYCoord = ( selectedItemBBox.top() + selectedItemBBox.bottom() ) / 2.0;
  QUndoCommand* parentCommand = new QUndoCommand( tr( "Aligned items vcenter" ) );
  QList<QgsComposerItem*>::iterator align_it = selectedItems.begin();
  for ( ; align_it != selectedItems.end(); ++align_it )
  {
    QgsComposerItemCommand* subcommand = new QgsComposerItemCommand( *align_it, "", parentCommand );
    subcommand->savePreviousState();
    QTransform itemTransform = ( *align_it )->transform();
    itemTransform.translate( 0, averageYCoord - itemTransform.dy() - ( *align_it )->rect().height() / 2 );
    ( *align_it )->setTransform( itemTransform );
    subcommand->saveAfterState();
  }
  mUndoStack.push( parentCommand );
}

void QgsComposition::alignSelectedItemsBottom()
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  if ( selectedItems.size() < 2 )
  {
    return;
  }

  QRectF selectedItemBBox;
  if ( boundingRectOfSelectedItems( selectedItemBBox ) != 0 )
  {
    return;
  }

  double maxYCoord = selectedItemBBox.bottom();
  QUndoCommand* parentCommand = new QUndoCommand( tr( "Aligned items bottom" ) );
  QList<QgsComposerItem*>::iterator align_it = selectedItems.begin();
  for ( ; align_it != selectedItems.end(); ++align_it )
  {
    QgsComposerItemCommand* subcommand = new QgsComposerItemCommand( *align_it, "", parentCommand );
    subcommand->savePreviousState();
    QTransform itemTransform = ( *align_it )->transform();
    itemTransform.translate( 0, maxYCoord - itemTransform.dy() - ( *align_it )->rect().height() );
    ( *align_it )->setTransform( itemTransform );
    subcommand->saveAfterState();
  }
  mUndoStack.push( parentCommand );
}

void QgsComposition::updateZValues()
{
  int counter = 1;
  QLinkedList<QgsComposerItem*>::iterator it = mItemZList.begin();
  QgsComposerItem* currentItem = 0;

  QUndoCommand* parentCommand = new QUndoCommand( tr( "Item z-order changed" ) );
  for ( ; it != mItemZList.end(); ++it )
  {
    currentItem = *it;
    if ( currentItem )
    {
      QgsComposerItemCommand* subcommand = new QgsComposerItemCommand( *it, "", parentCommand );
      subcommand->savePreviousState();
      currentItem->setZValue( counter );
      subcommand->saveAfterState();
    }
    ++counter;
  }
  mUndoStack.push( parentCommand );
}

void QgsComposition::sortZList()
{
  if ( mItemZList.size() < 2 )
  {
    return;
  }

  QLinkedList<QgsComposerItem*>::const_iterator lIt = mItemZList.constBegin();
  QLinkedList<QgsComposerItem*> sortedList;

  for ( ; lIt != mItemZList.constEnd(); ++lIt )
  {
    QLinkedList<QgsComposerItem*>::iterator insertIt = sortedList.begin();
    for ( ; insertIt != sortedList.end(); ++insertIt )
    {
      if (( *lIt )->zValue() < ( *insertIt )->zValue() )
      {
        break;
      }
    }
    sortedList.insert( insertIt, ( *lIt ) );
  }

  mItemZList = sortedList;
}

QPointF QgsComposition::snapPointToGrid( const QPointF& scenePoint ) const
{
  if ( !mSnapToGrid || mSnapGridResolution <= 0 )
  {
    return scenePoint;
  }

  //y offset to current page
  int pageNr = ( int )( scenePoint.y() / ( mPageHeight + mSpaceBetweenPages ) );
  double yOffset = pageNr * ( mPageHeight + mSpaceBetweenPages );
  double yPage = scenePoint.y() - yOffset; //y-coordinate relative to current page

  //snap x coordinate
  int xRatio = ( int )(( scenePoint.x() - mSnapGridOffsetX ) / mSnapGridResolution + 0.5 );
  int yRatio = ( int )(( yPage - mSnapGridOffsetY ) / mSnapGridResolution + 0.5 );

  return QPointF( xRatio * mSnapGridResolution + mSnapGridOffsetX, yRatio * mSnapGridResolution + mSnapGridOffsetY + yOffset );
}

QPointF QgsComposition::alignItem( const QgsComposerItem* item, double& alignX, double& alignY, double dx, double dy )
{
  if ( !item )
  {
    return QPointF();
  }

  double left = item->transform().dx() + dx;
  double right = left + item->rect().width();
  double midH = ( left + right ) / 2.0;
  double top = item->transform().dy() + dy;
  double bottom = top + item->rect().height();
  double midV = ( top + bottom ) / 2.0;

  QMap<double, const QgsComposerItem* > xAlignCoordinates;
  QMap<double, const QgsComposerItem* > yAlignCoordinates;
  collectAlignCoordinates( xAlignCoordinates, yAlignCoordinates, item );

  //find nearest matches x
  double xItemLeft = left; //new left coordinate of the item
  double xAlignCoord = 0;
  double smallestDiffX = DBL_MAX;

  checkNearestItem( left, xAlignCoordinates, smallestDiffX, 0, xItemLeft, xAlignCoord );
  checkNearestItem( midH, xAlignCoordinates, smallestDiffX, ( left - right ) / 2.0, xItemLeft, xAlignCoord );
  checkNearestItem( right, xAlignCoordinates, smallestDiffX, left - right, xItemLeft, xAlignCoord );

  //find nearest matches y
  double yItemTop = top; //new top coordinate of the item
  double yAlignCoord = 0;
  double smallestDiffY = DBL_MAX;

  checkNearestItem( top, yAlignCoordinates, smallestDiffY, 0, yItemTop, yAlignCoord );
  checkNearestItem( midV, yAlignCoordinates, smallestDiffY, ( top - bottom ) / 2.0, yItemTop, yAlignCoord );
  checkNearestItem( bottom, yAlignCoordinates, smallestDiffY, top - bottom, yItemTop, yAlignCoord );

  double xCoord = ( smallestDiffX < 5 ) ? xItemLeft : item->transform().dx() + dx;
  alignX = ( smallestDiffX < 5 ) ? xAlignCoord : -1;
  double yCoord = ( smallestDiffY < 5 ) ? yItemTop : item->transform().dy() + dy;
  alignY = ( smallestDiffY < 5 ) ? yAlignCoord : -1;
  return QPointF( xCoord, yCoord );
}

QPointF QgsComposition::alignPos( const QPointF& pos, const QgsComposerItem* excludeItem, double& alignX, double& alignY )
{
  QMap<double, const QgsComposerItem* > xAlignCoordinates;
  QMap<double, const QgsComposerItem* > yAlignCoordinates;
  collectAlignCoordinates( xAlignCoordinates, yAlignCoordinates, excludeItem );

  double nearestX = pos.x();
  double nearestY = pos.y();
  if ( !nearestItem( xAlignCoordinates, pos.x(), nearestX )
       || !nearestItem( yAlignCoordinates, pos.y(), nearestY ) )
  {
    alignX = -1;
    alignY = -1;
    return pos;
  }

  QPointF result( pos.x(), pos.y() );
  if ( abs( nearestX - pos.x() ) < mAlignmentSnapTolerance )
  {
    result.setX( nearestX );
    alignX = nearestX;
  }
  else
  {
    alignX = -1;
  }

  if ( abs( nearestY - pos.y() ) < mAlignmentSnapTolerance )
  {
    result.setY( nearestY );
    alignY = nearestY;
  }
  else
  {
    alignY = -1;
  }
  return result;
}

QGraphicsLineItem* QgsComposition::addSnapLine()
{
  QGraphicsLineItem* item = new QGraphicsLineItem();
  QPen linePen( Qt::SolidLine );
  linePen.setColor( Qt::red );
  // use a pen width of 0, since this activates a cosmetic pen
  // which doesn't scale with the composer and keeps a constant size
  linePen.setWidthF( 0 );
  item->setPen( linePen );
  item->setZValue( 100 );
  addItem( item );
  mSnapLines.push_back( item );
  return item;
}

void QgsComposition::removeSnapLine( QGraphicsLineItem* line )
{
  removeItem( line );
  mSnapLines.removeAll( line );
  delete line;
}

void QgsComposition::setSnapLinesVisible( bool visible )
{
  QList< QGraphicsLineItem* >::iterator it = mSnapLines.begin();
  for ( ; it != mSnapLines.end(); ++it )
  {
    if ( visible )
    {
      ( *it )->show();
    }
    else
    {
      ( *it )->hide();
    }
  }
}

QGraphicsLineItem* QgsComposition::nearestSnapLine( bool horizontal, double x, double y, double tolerance,
    QList< QPair< QgsComposerItem*, QgsComposerItem::ItemPositionMode> >& snappedItems )
{
  double minSqrDist = DBL_MAX;
  QGraphicsLineItem* item = 0;
  double currentXCoord = 0;
  double currentYCoord = 0;
  double currentSqrDist = 0;
  double sqrTolerance = tolerance * tolerance;

  snappedItems.clear();

  QList< QGraphicsLineItem* >::const_iterator it = mSnapLines.constBegin();
  for ( ; it != mSnapLines.constEnd(); ++it )
  {
    bool itemHorizontal = qgsDoubleNear(( *it )->line().y2() - ( *it )->line().y1(), 0 );
    if ( horizontal && itemHorizontal )
    {
      currentYCoord = ( *it )->line().y1();
      currentSqrDist = ( y - currentYCoord ) * ( y - currentYCoord );
    }
    else if ( !itemHorizontal )
    {
      currentXCoord = ( *it )->line().x1();
      currentSqrDist = ( x - currentXCoord ) * ( x - currentXCoord );
    }

    if ( currentSqrDist < minSqrDist && currentSqrDist < sqrTolerance )
    {
      item = *it;
      minSqrDist = currentSqrDist;
    }
  }

  double itemTolerance = 0.0000001;
  if ( item )
  {
    //go through all the items to find items snapped to this snap line
    QList<QGraphicsItem *> itemList = items();
    QList<QGraphicsItem *>::iterator itemIt = itemList.begin();
    for ( ; itemIt != itemList.end(); ++itemIt )
    {
      QgsComposerItem* currentItem = dynamic_cast<QgsComposerItem*>( *itemIt );
      if ( !currentItem || currentItem->type() == QgsComposerItem::ComposerPaper )
      {
        continue;
      }

      if ( horizontal )
      {
        if ( qgsDoubleNear( currentYCoord, currentItem->transform().dy() + currentItem->rect().top(), itemTolerance ) )
        {
          snappedItems.append( qMakePair( currentItem, QgsComposerItem::UpperMiddle ) );
        }
        else if ( qgsDoubleNear( currentYCoord, currentItem->transform().dy() + currentItem->rect().center().y(), itemTolerance ) )
        {
          snappedItems.append( qMakePair( currentItem, QgsComposerItem::Middle ) );
        }
        else if ( qgsDoubleNear( currentYCoord, currentItem->transform().dy() + currentItem->rect().bottom(), itemTolerance ) )
        {
          snappedItems.append( qMakePair( currentItem, QgsComposerItem::LowerMiddle ) );
        }
      }
      else
      {
        if ( qgsDoubleNear( currentXCoord, currentItem->transform().dx(), itemTolerance ) )
        {
          snappedItems.append( qMakePair( currentItem, QgsComposerItem::MiddleLeft ) );
        }
        else if ( qgsDoubleNear( currentXCoord, currentItem->transform().dx() + currentItem->rect().center().x(), itemTolerance ) )
        {
          snappedItems.append( qMakePair( currentItem, QgsComposerItem::Middle ) );
        }
        else if ( qgsDoubleNear( currentXCoord,  currentItem->transform().dx() + currentItem->rect().width(), itemTolerance ) )
        {
          snappedItems.append( qMakePair( currentItem, QgsComposerItem::MiddleRight ) );
        }
      }
    }
  }

  return item;
}

int QgsComposition::boundingRectOfSelectedItems( QRectF& bRect )
{
  QList<QgsComposerItem*> selectedItems = selectedComposerItems();
  if ( selectedItems.size() < 1 )
  {
    return 1;
  }

  //set the box to the first item
  QgsComposerItem* currentItem = selectedItems.at( 0 );
  double minX = currentItem->transform().dx();
  double minY = currentItem->transform().dy();
  double maxX = minX + currentItem->rect().width();
  double maxY = minY + currentItem->rect().height();

  double currentMinX, currentMinY, currentMaxX, currentMaxY;

  for ( int i = 1; i < selectedItems.size(); ++i )
  {
    currentItem = selectedItems.at( i );
    currentMinX = currentItem->transform().dx();
    currentMinY = currentItem->transform().dy();
    currentMaxX = currentMinX + currentItem->rect().width();
    currentMaxY = currentMinY + currentItem->rect().height();

    if ( currentMinX < minX )
      minX = currentMinX;
    if ( currentMaxX > maxX )
      maxX = currentMaxX;
    if ( currentMinY < minY )
      minY = currentMinY;
    if ( currentMaxY > maxY )
      maxY = currentMaxY;
  }

  bRect.setTopLeft( QPointF( minX, minY ) );
  bRect.setBottomRight( QPointF( maxX, maxY ) );
  return 0;
}

void QgsComposition::setSnapToGridEnabled( bool b )
{
  mSnapToGrid = b;
  updatePaperItems();
  saveSettings();
}

void QgsComposition::setSnapGridResolution( double r )
{
  mSnapGridResolution = r;
  updatePaperItems();
  saveSettings();
}

void QgsComposition::setSnapGridOffsetX( double offset )
{
  mSnapGridOffsetX = offset;
  updatePaperItems();
  saveSettings();
}

void QgsComposition::setSnapGridOffsetY( double offset )
{
  mSnapGridOffsetY = offset;
  updatePaperItems();
  saveSettings();
}

void QgsComposition::setGridPen( const QPen& p )
{
  mGridPen = p;
  updatePaperItems();
  saveSettings();
}

void QgsComposition::setGridStyle( GridStyle s )
{
  mGridStyle = s;
  updatePaperItems();
  saveSettings();
}

void QgsComposition::setSelectionTolerance( double tol )
{
  mSelectionTolerance = tol;
  saveSettings();
}

void QgsComposition::loadSettings()
{
  //read grid style, grid color and pen width from settings
  QSettings s;

  QString gridStyleString;
  int red, green, blue;
  double penWidth;

  gridStyleString = s.value( "/qgis/composerGridStyle", "Dots" ).toString();
  penWidth = s.value( "/qgis/composerGridWidth", 0.5 ).toDouble();
  red = s.value( "/qgis/composerGridRed", 0 ).toInt();
  green = s.value( "/qgis/composerGridGreen", 0 ).toInt();
  blue = s.value( "/qgis/composerGridBlue", 0 ).toInt();

  mGridPen.setColor( QColor( red, green, blue ) );
  mGridPen.setWidthF( penWidth );

  if ( gridStyleString == "Dots" )
  {
    mGridStyle = Dots;
  }
  else if ( gridStyleString == "Crosses" )
  {
    mGridStyle = Crosses;
  }
  else
  {
    mGridStyle = Solid;
  }

  mSelectionTolerance = s.value( "/qgis/composerSelectionTolerance", 0.0 ).toDouble();
}

void QgsComposition::saveSettings()
{
  //store grid appearance settings
  QSettings s;
  s.setValue( "/qgis/composerGridWidth", mGridPen.widthF() );
  s.setValue( "/qgis/composerGridRed", mGridPen.color().red() );
  s.setValue( "/qgis/composerGridGreen", mGridPen.color().green() );
  s.setValue( "/qgis/composerGridBlue", mGridPen.color().blue() );

  if ( mGridStyle == Solid )
  {
    s.setValue( "/qgis/composerGridStyle", "Solid" );
  }
  else if ( mGridStyle == Dots )
  {
    s.setValue( "/qgis/composerGridStyle", "Dots" );
  }
  else if ( mGridStyle == Crosses )
  {
    s.setValue( "/qgis/composerGridStyle", "Crosses" );
  }

  //store also selection tolerance
  s.setValue( "/qgis/composerSelectionTolerance", mSelectionTolerance );
}

void QgsComposition::beginCommand( QgsComposerItem* item, const QString& commandText, QgsComposerMergeCommand::Context c )
{
  delete mActiveItemCommand;
  if ( !item )
  {
    mActiveItemCommand = 0;
    return;
  }

  if ( c == QgsComposerMergeCommand::Unknown )
  {
    mActiveItemCommand = new QgsComposerItemCommand( item, commandText );
  }
  else
  {
    mActiveItemCommand = new QgsComposerMergeCommand( c, item, commandText );
  }
  mActiveItemCommand->savePreviousState();
}

void QgsComposition::endCommand()
{
  if ( mActiveItemCommand )
  {
    mActiveItemCommand->saveAfterState();
    if ( mActiveItemCommand->containsChange() ) //protect against empty commands
    {
      mUndoStack.push( mActiveItemCommand );
    }
    else
    {
      delete mActiveItemCommand;
    }
    mActiveItemCommand = 0;
  }
}

void QgsComposition::cancelCommand()
{
  delete mActiveItemCommand;
  mActiveItemCommand = 0;
}

void QgsComposition::beginMultiFrameCommand( QgsComposerMultiFrame* multiFrame, const QString& text )
{
  delete mActiveMultiFrameCommand;
  mActiveMultiFrameCommand = new QgsComposerMultiFrameCommand( multiFrame, text );
  mActiveMultiFrameCommand->savePreviousState();
}

void QgsComposition::endMultiFrameCommand()
{
  if ( mActiveMultiFrameCommand )
  {
    mActiveMultiFrameCommand->saveAfterState();
    if ( mActiveMultiFrameCommand->containsChange() )
    {
      mUndoStack.push( mActiveMultiFrameCommand );
    }
    else
    {
      delete mActiveMultiFrameCommand;
    }
    mActiveMultiFrameCommand = 0;
  }
}

void QgsComposition::addMultiFrame( QgsComposerMultiFrame* multiFrame )
{
  mMultiFrames.insert( multiFrame );
}

void QgsComposition::removeMultiFrame( QgsComposerMultiFrame* multiFrame )
{
  mMultiFrames.remove( multiFrame );
}

void QgsComposition::addComposerArrow( QgsComposerArrow* arrow )
{
  addItem( arrow );
  emit composerArrowAdded( arrow );
  clearSelection();
  arrow->setSelected( true );
  emit selectedItemChanged( arrow );
}

void QgsComposition::addComposerLabel( QgsComposerLabel* label )
{
  addItem( label );
  emit composerLabelAdded( label );
  clearSelection();
  label->setSelected( true );
  emit selectedItemChanged( label );
}

void QgsComposition::addComposerMap( QgsComposerMap* map, bool setDefaultPreviewStyle )
{
  addItem( map );
  if ( setDefaultPreviewStyle )
  {
    //set default preview mode to cache. Must be done here between adding composer map to scene and emiting signal
    map->setPreviewMode( QgsComposerMap::Cache );
  }

  if ( map->previewMode() != QgsComposerMap::Rectangle )
  {
    map->cache();
  }

  emit composerMapAdded( map );
  clearSelection();
  map->setSelected( true );
  emit selectedItemChanged( map );
}

void QgsComposition::addComposerScaleBar( QgsComposerScaleBar* scaleBar )
{
  addItem( scaleBar );
  emit composerScaleBarAdded( scaleBar );
  clearSelection();
  scaleBar->setSelected( true );
  emit selectedItemChanged( scaleBar );
}

void QgsComposition::addComposerLegend( QgsComposerLegend* legend )
{
  //take first available map
  QList<const QgsComposerMap*> mapItemList = composerMapItems();
  if ( mapItemList.size() > 0 )
  {
    legend->setComposerMap( mapItemList.at( 0 ) );
  }
  addItem( legend );
  emit composerLegendAdded( legend );
  clearSelection();
  legend->setSelected( true );
  emit selectedItemChanged( legend );
}

void QgsComposition::addComposerPicture( QgsComposerPicture* picture )
{
  addItem( picture );
  emit composerPictureAdded( picture );
  clearSelection();
  picture->setSelected( true );
  emit selectedItemChanged( picture );
}

void QgsComposition::addComposerShape( QgsComposerShape* shape )
{
  addItem( shape );
  emit composerShapeAdded( shape );
  clearSelection();
  shape->setSelected( true );
  emit selectedItemChanged( shape );
}

void QgsComposition::addComposerTable( QgsComposerAttributeTable* table )
{
  addItem( table );
  emit composerTableAdded( table );
  clearSelection();
  table->setSelected( true );
  emit selectedItemChanged( table );
}

void QgsComposition::addComposerHtmlFrame( QgsComposerHtml* html, QgsComposerFrame* frame )
{
  addItem( frame );
  emit composerHtmlFrameAdded( html, frame );
  clearSelection();
  frame->setSelected( true );
  emit selectedItemChanged( frame );
}

void QgsComposition::removeComposerItem( QgsComposerItem* item, bool createCommand )
{
  QgsComposerMap* map = dynamic_cast<QgsComposerMap *>( item );

  if ( !map || !map->isDrawing() ) //don't delete a composer map while it draws
  {
    removeItem( item );
    QgsComposerItemGroup* itemGroup = dynamic_cast<QgsComposerItemGroup*>( item );
    if ( itemGroup )
    {
      //add add/remove item command for every item in the group
      QUndoCommand* parentCommand = new QUndoCommand( tr( "Remove item group" ) );

      QSet<QgsComposerItem*> groupedItems = itemGroup->items();
      QSet<QgsComposerItem*>::iterator it = groupedItems.begin();
      for ( ; it != groupedItems.end(); ++it )
      {
        QgsAddRemoveItemCommand* subcommand = new QgsAddRemoveItemCommand( QgsAddRemoveItemCommand::Removed, *it, this, "", parentCommand );
        connectAddRemoveCommandSignals( subcommand );
        emit itemRemoved( *it );
      }

      undoStack()->push( parentCommand );
      delete itemGroup;
      emit itemRemoved( itemGroup );
    }
    else
    {
      bool frameItem = ( item->type() == QgsComposerItem::ComposerFrame );
      QgsComposerMultiFrame* multiFrame = 0;
      if ( createCommand )
      {
        if ( frameItem ) //multiframe tracks item changes
        {
          multiFrame = static_cast<QgsComposerFrame*>( item )->multiFrame();
          item->beginItemCommand( tr( "Frame deleted" ) );
          emit itemRemoved( item );
          item->endItemCommand();
        }
        else
        {
          emit itemRemoved( item );
          pushAddRemoveCommand( item, tr( "Item deleted" ), QgsAddRemoveItemCommand::Removed );
        }
      }
      else
      {
        emit itemRemoved( item );
      }

      //check if there are frames left. If not, remove the multi frame
      if ( frameItem && multiFrame )
      {
        if ( multiFrame->frameCount() < 1 )
        {
          removeMultiFrame( multiFrame );
          if ( createCommand )
          {
            QgsAddRemoveMultiFrameCommand* command = new QgsAddRemoveMultiFrameCommand( QgsAddRemoveMultiFrameCommand::Removed,
                multiFrame, this, tr( "Multiframe removed" ) );
            undoStack()->push( command );
          }
          else
          {
            delete multiFrame;
          }
        }
      }
    }
  }
}

void QgsComposition::pushAddRemoveCommand( QgsComposerItem* item, const QString& text, QgsAddRemoveItemCommand::State state )
{
  QgsAddRemoveItemCommand* c = new QgsAddRemoveItemCommand( state, item, this, text );
  connectAddRemoveCommandSignals( c );
  undoStack()->push( c );
}

void QgsComposition::connectAddRemoveCommandSignals( QgsAddRemoveItemCommand* c )
{
  if ( !c )
  {
    return;
  }

  QObject::connect( c, SIGNAL( itemRemoved( QgsComposerItem* ) ), this, SIGNAL( itemRemoved( QgsComposerItem* ) ) );
  QObject::connect( c, SIGNAL( itemAdded( QgsComposerItem* ) ), this, SLOT( sendItemAddedSignal( QgsComposerItem* ) ) );
}

void QgsComposition::sendItemAddedSignal( QgsComposerItem* item )
{
  //cast and send proper signal
  item->setSelected( true );
  QgsComposerArrow* arrow = dynamic_cast<QgsComposerArrow*>( item );
  if ( arrow )
  {
    emit composerArrowAdded( arrow );
    emit selectedItemChanged( arrow );
    return;
  }
  QgsComposerLabel* label = dynamic_cast<QgsComposerLabel*>( item );
  if ( label )
  {
    emit composerLabelAdded( label );
    emit selectedItemChanged( label );
    return;
  }
  QgsComposerMap* map = dynamic_cast<QgsComposerMap*>( item );
  if ( map )
  {
    emit composerMapAdded( map );
    emit selectedItemChanged( map );
    return;
  }
  QgsComposerScaleBar* scalebar = dynamic_cast<QgsComposerScaleBar*>( item );
  if ( scalebar )
  {
    emit composerScaleBarAdded( scalebar );
    emit selectedItemChanged( scalebar );
    return;
  }
  QgsComposerLegend* legend = dynamic_cast<QgsComposerLegend*>( item );
  if ( legend )
  {
    emit composerLegendAdded( legend );
    emit selectedItemChanged( legend );
    return;
  }
  QgsComposerPicture* picture = dynamic_cast<QgsComposerPicture*>( item );
  if ( picture )
  {
    emit composerPictureAdded( picture );
    emit selectedItemChanged( picture );
    return;
  }
  QgsComposerShape* shape = dynamic_cast<QgsComposerShape*>( item );
  if ( shape )
  {
    emit composerShapeAdded( shape );
    emit selectedItemChanged( shape );
    return;
  }
  QgsComposerAttributeTable* table = dynamic_cast<QgsComposerAttributeTable*>( item );
  if ( table )
  {
    emit composerTableAdded( table );
    emit selectedItemChanged( table );
    return;
  }
  QgsComposerFrame* frame = dynamic_cast<QgsComposerFrame*>( item );
  if ( frame )
  {
    //emit composerFrameAdded( multiframe, frame, );
    QgsComposerMultiFrame* mf = frame->multiFrame();
    QgsComposerHtml* html = dynamic_cast<QgsComposerHtml*>( mf );
    if ( html )
    {
      emit composerHtmlFrameAdded( html, frame );
    }
    emit selectedItemChanged( frame );
    return;
  }
}

void QgsComposition::updatePaperItems()
{
  QList< QgsPaperItem* >::iterator paperIt = mPages.begin();
  for ( ; paperIt != mPages.end(); ++paperIt )
  {
    ( *paperIt )->update();
  }
}

void QgsComposition::addPaperItem()
{
  double paperHeight = this->paperHeight();
  double paperWidth = this->paperWidth();
  double currentY = paperHeight * mPages.size() + mPages.size() * mSpaceBetweenPages; //add 10mm visible space between pages
  QgsPaperItem* paperItem = new QgsPaperItem( 0, currentY, paperWidth, paperHeight, this ); //default size A4
  paperItem->setBrush( Qt::white );
  addItem( paperItem );
  paperItem->setZValue( 0 );
  mPages.push_back( paperItem );

  QgsExpression::setSpecialColumn( "$numpages", QVariant(( int )mPages.size() ) );
}

void QgsComposition::removePaperItems()
{
  for ( int i = 0; i < mPages.size(); ++i )
  {
    delete mPages.at( i );
  }
  mPages.clear();
  QgsExpression::setSpecialColumn( "$numpages", QVariant(( int )0 ) );
}

void QgsComposition::deleteAndRemoveMultiFrames()
{
  QSet<QgsComposerMultiFrame*>::iterator multiFrameIt = mMultiFrames.begin();
  for ( ; multiFrameIt != mMultiFrames.end(); ++multiFrameIt )
  {
    delete *multiFrameIt;
  }
  mMultiFrames.clear();
}

void QgsComposition::beginPrintAsPDF( QPrinter& printer, const QString& file )
{
  printer.setOutputFormat( QPrinter::PdfFormat );
  printer.setOutputFileName( file );
  printer.setPaperSize( QSizeF( paperWidth(), paperHeight() ), QPrinter::Millimeter );

  QgsPaintEngineHack::fixEngineFlags( printer.paintEngine() );
}

void QgsComposition::exportAsPDF( const QString& file )
{
  QPrinter printer;
  beginPrintAsPDF( printer, file );
  print( printer );
}

void QgsComposition::doPrint( QPrinter& printer, QPainter& p )
{
//QgsComposition starts page numbering at 0
  int fromPage = ( printer.fromPage() < 1 ) ? 0 : printer.fromPage() - 1 ;
  int toPage = ( printer.toPage() < 1 ) ? numPages() - 1 : printer.toPage() - 1;

  if ( mPrintAsRaster )
  {
    for ( int i = fromPage; i <= toPage; ++i )
    {
      if ( i > fromPage )
      {
        printer.newPage();
      }

      QImage image = printPageAsRaster( i );
      if ( !image.isNull() )
      {
        QRectF targetArea( 0, 0, image.width(), image.height() );
        p.drawImage( targetArea, image, targetArea );
      }
    }
  }

  if ( !mPrintAsRaster )
  {
    for ( int i = fromPage; i <= toPage; ++i )
    {
      if ( i > fromPage )
      {
        printer.newPage();
      }
      renderPage( &p, i );
    }
  }
}

void QgsComposition::beginPrint( QPrinter &printer )
{
  //set resolution based on composer setting
  printer.setFullPage( true );
  printer.setColorMode( QPrinter::Color );

  //set user-defined resolution
  printer.setResolution( printResolution() );
}

void QgsComposition::print( QPrinter &printer )
{
  beginPrint( printer );
  QPainter p( &printer );
  doPrint( printer, p );
}

QImage QgsComposition::printPageAsRaster( int page )
{
  //print out via QImage, code copied from on_mActionExportAsImage_activated
  int width = ( int )( printResolution() * paperWidth() / 25.4 );
  int height = ( int )( printResolution() * paperHeight() / 25.4 );
  QImage image( QSize( width, height ), QImage::Format_ARGB32 );
  if ( !image.isNull() )
  {
    image.setDotsPerMeterX( printResolution() / 25.4 * 1000 );
    image.setDotsPerMeterY( printResolution() / 25.4 * 1000 );
    image.fill( 0 );
    QPainter imagePainter( &image );
    renderPage( &imagePainter, page );
  }
  return image;
}

void QgsComposition::renderPage( QPainter* p, int page )
{
  if ( mPages.size() <= page )
  {
    return;
  }

  QgsPaperItem* paperItem = mPages[page];
  if ( !paperItem )
  {
    return;
  }

  QPaintDevice* paintDevice = p->device();
  if ( !paintDevice )
  {
    return;
  }

  QRectF paperRect = QRectF( paperItem->transform().dx(), paperItem->transform().dy(), paperItem->rect().width(), paperItem->rect().height() );

  QgsComposition::PlotStyle savedPlotStyle = mPlotStyle;
  mPlotStyle = QgsComposition::Print;

  setSnapLinesVisible( false );
  render( p, QRectF( 0, 0, paintDevice->width(), paintDevice->height() ), paperRect );
  setSnapLinesVisible( true );

  mPlotStyle = savedPlotStyle;
}

QString QgsComposition::encodeStringForXML( const QString& str )
{
  QString modifiedStr( str );
  modifiedStr.replace( "&", "&amp;" );
  modifiedStr.replace( "\"", "&quot;" );
  modifiedStr.replace( "'", "&apos;" );
  modifiedStr.replace( "<", "&lt;" );
  modifiedStr.replace( ">", "&gt;" );
  return modifiedStr;
}

void QgsComposition::collectAlignCoordinates( QMap< double, const QgsComposerItem* >& alignCoordsX, QMap< double, const QgsComposerItem* >& alignCoordsY,
    const QgsComposerItem* excludeItem )
{
  alignCoordsX.clear();
  alignCoordsY.clear();

  QList<QGraphicsItem *> itemList = items();
  QList<QGraphicsItem *>::iterator itemIt = itemList.begin();
  for ( ; itemIt != itemList.end(); ++itemIt )
  {
    const QgsComposerItem* currentItem = dynamic_cast<const QgsComposerItem *>( *itemIt );
    if ( excludeItem )
    {
      if ( !currentItem || currentItem == excludeItem )
      {
        continue;
      }
      alignCoordsX.insert( currentItem->transform().dx(), currentItem );
      alignCoordsX.insert( currentItem->transform().dx() + currentItem->rect().width(), currentItem );
      alignCoordsX.insert( currentItem->transform().dx() + currentItem->rect().center().x(), currentItem );
      alignCoordsY.insert( currentItem->transform().dy() + currentItem->rect().top(), currentItem );
      alignCoordsY.insert( currentItem->transform().dy() + currentItem->rect().center().y(), currentItem );
      alignCoordsY.insert( currentItem->transform().dy() + currentItem->rect().bottom(), currentItem );
    }
  }

  //arbitrary snap lines
  QList< QGraphicsLineItem* >::const_iterator sIt = mSnapLines.constBegin();
  for ( ; sIt != mSnapLines.constEnd(); ++sIt )
  {
    double x = ( *sIt )->line().x1();
    double y = ( *sIt )->line().y1();
    if ( qgsDoubleNear( y, 0.0 ) )
    {
      alignCoordsX.insert( x, 0 );
    }
    else
    {
      alignCoordsY.insert( y, 0 );
    }
  }
}

void QgsComposition::checkNearestItem( double checkCoord, const QMap< double, const QgsComposerItem* >& alignCoords, double& smallestDiff,
                                       double itemCoordOffset, double& itemCoord, double& alignCoord ) const
{
  double currentCoord = 0;
  if ( !nearestItem( alignCoords, checkCoord, currentCoord ) )
  {
    return;
  }

  double currentDiff = abs( checkCoord - currentCoord );
  if ( currentDiff < mAlignmentSnapTolerance )
  {
    itemCoord = currentCoord + itemCoordOffset;
    alignCoord = currentCoord;
    smallestDiff = currentDiff;
  }
}

bool QgsComposition::nearestItem( const QMap< double, const QgsComposerItem* >& coords, double value, double& nearestValue )
{
  if ( coords.size() < 1 )
  {
    return false;
  }

  QMap< double, const QgsComposerItem* >::const_iterator it = coords.lowerBound( value );
  if ( it == coords.constBegin() ) //value smaller than first map value
  {
    nearestValue = it.key();
    return true;
  }
  else if ( it == coords.constEnd() ) //value larger than last map value
  {
    --it;
    nearestValue = it.key();
    return true;
  }
  else
  {
    //get smaller value and larger value and return the closer one
    double upperVal = it.key();
    --it;
    double lowerVal = it.key();

    double lowerDiff = value - lowerVal;
    double upperDiff = upperVal - value;
    if ( lowerDiff < upperDiff )
    {
      nearestValue = lowerVal;
      return true;
    }
    else
    {
      nearestValue = upperVal;
      return true;
    }
  }
}