qgslayertreegroup.cpp

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/***************************************************************************
  qgslayertreegroup.cpp
  --------------------------------------
  Date                 : May 2014
  Copyright            : (C) 2014 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 "qgslayertreegroup.h"

#include "qgslayertree.h"
#include "qgslayertreeutils.h"
#include "qgsmaplayer.h"

#include <QDomElement>
#include <QStringList>


QgsLayerTreeGroup::QgsLayerTreeGroup( const QString &name, bool checked )
  : QgsLayerTreeNode( NodeGroup, checked )
  , mName( name )
{
  connect( this, &QgsLayerTreeNode::visibilityChanged, this, &QgsLayerTreeGroup::nodeVisibilityChanged );
}

QgsLayerTreeGroup::QgsLayerTreeGroup( const QgsLayerTreeGroup &other )
  : QgsLayerTreeNode( other )
  , mName( other.mName )
  , mChangingChildVisibility( other.mChangingChildVisibility )
  , mMutuallyExclusive( other.mMutuallyExclusive )
  , mMutuallyExclusiveChildIndex( other.mMutuallyExclusiveChildIndex )
{
  connect( this, &QgsLayerTreeNode::visibilityChanged, this, &QgsLayerTreeGroup::nodeVisibilityChanged );
}

QString QgsLayerTreeGroup::name() const
{
  return mName;
}

void QgsLayerTreeGroup::setName( const QString &n )
{
  if ( mName == n )
    return;

  mName = n;
  emit nameChanged( this, n );
}


QgsLayerTreeGroup *QgsLayerTreeGroup::insertGroup( int index, const QString &name )
{
  QgsLayerTreeGroup *grp = new QgsLayerTreeGroup( name );
  insertChildNode( index, grp );
  return grp;
}

QgsLayerTreeGroup *QgsLayerTreeGroup::addGroup( const QString &name )
{
  QgsLayerTreeGroup *grp = new QgsLayerTreeGroup( name );
  addChildNode( grp );
  return grp;
}

QgsLayerTreeLayer *QgsLayerTreeGroup::insertLayer( int index, QgsMapLayer *layer )
{
  if ( !layer )
    return nullptr;

  QgsLayerTreeLayer *ll = new QgsLayerTreeLayer( layer );
  insertChildNode( index, ll );
  return ll;
}

QgsLayerTreeLayer *QgsLayerTreeGroup::addLayer( QgsMapLayer *layer )
{
  if ( !layer )
    return nullptr;

  QgsLayerTreeLayer *ll = new QgsLayerTreeLayer( layer );
  addChildNode( ll );
  return ll;
}

void QgsLayerTreeGroup::insertChildNode( int index, QgsLayerTreeNode *node )
{
  QList<QgsLayerTreeNode *> nodes;
  nodes << node;
  insertChildNodes( index, nodes );
}

void QgsLayerTreeGroup::insertChildNodes( int index, const QList<QgsLayerTreeNode *> &nodes )
{
  QgsLayerTreeNode *meChild = nullptr;
  if ( mMutuallyExclusive && mMutuallyExclusiveChildIndex >= 0 && mMutuallyExclusiveChildIndex < mChildren.count() )
    meChild = mChildren.at( mMutuallyExclusiveChildIndex );

  // low-level insert
  insertChildrenPrivate( index, nodes );

  if ( mMutuallyExclusive )
  {
    if ( meChild )
    {
      // the child could have change its index - or the new children may have been also set as visible
      mMutuallyExclusiveChildIndex = mChildren.indexOf( meChild );
    }
    else if ( mChecked )
    {
      // we have not picked a child index yet, but we should pick one now
      // ... so pick the first one from the newly added
      if ( index == -1 )
        index = mChildren.count() - nodes.count(); // get real insertion index
      mMutuallyExclusiveChildIndex = index;
    }
    updateChildVisibilityMutuallyExclusive();
  }
}

void QgsLayerTreeGroup::addChildNode( QgsLayerTreeNode *node )
{
  insertChildNode( -1, node );
}

void QgsLayerTreeGroup::removeChildNode( QgsLayerTreeNode *node )
{
  int i = mChildren.indexOf( node );
  if ( i >= 0 )
    removeChildren( i, 1 );
}

void QgsLayerTreeGroup::removeLayer( QgsMapLayer *layer )
{
  for ( QgsLayerTreeNode *child : qgis::as_const( mChildren ) )
  {
    if ( QgsLayerTree::isLayer( child ) )
    {
      QgsLayerTreeLayer *childLayer = QgsLayerTree::toLayer( child );
      if ( childLayer->layer() == layer )
      {
        removeChildren( mChildren.indexOf( child ), 1 );
        break;
      }
    }
  }
}

void QgsLayerTreeGroup::removeChildren( int from, int count )
{
  QgsLayerTreeNode *meChild = nullptr;
  if ( mMutuallyExclusive && mMutuallyExclusiveChildIndex >= 0 && mMutuallyExclusiveChildIndex < mChildren.count() )
    meChild = mChildren.at( mMutuallyExclusiveChildIndex );

  removeChildrenPrivate( from, count );

  if ( meChild )
  {
    // the child could have change its index - or may have been removed completely
    mMutuallyExclusiveChildIndex = mChildren.indexOf( meChild );
    // we need to uncheck this group
    //if ( mMutuallyExclusiveChildIndex == -1 )
    //  setItemVisibilityChecked( false );
  }
}

void QgsLayerTreeGroup::removeChildrenGroupWithoutLayers()
{
  // clean the layer tree by removing empty group
  const auto childNodes = children();
  for ( QgsLayerTreeNode *treeNode : childNodes )
  {
    if ( treeNode->nodeType() == QgsLayerTreeNode::NodeGroup )
    {
      QgsLayerTreeGroup *treeGroup = qobject_cast<QgsLayerTreeGroup *>( treeNode );
      if ( treeGroup->findLayerIds().isEmpty() )
        removeChildNode( treeNode );
      else
        treeGroup->removeChildrenGroupWithoutLayers();
    }
  }
}

void QgsLayerTreeGroup::removeAllChildren()
{
  removeChildren( 0, mChildren.count() );
}

QgsLayerTreeLayer *QgsLayerTreeGroup::findLayer( QgsMapLayer *layer ) const
{
  if ( !layer )
    return nullptr;

  return findLayer( layer->id() );
}

QgsLayerTreeLayer *QgsLayerTreeGroup::findLayer( const QString &layerId ) const
{
  for ( QgsLayerTreeNode *child : qgis::as_const( mChildren ) )
  {
    if ( QgsLayerTree::isLayer( child ) )
    {
      QgsLayerTreeLayer *childLayer = QgsLayerTree::toLayer( child );
      if ( childLayer->layerId() == layerId )
        return childLayer;
    }
    else if ( QgsLayerTree::isGroup( child ) )
    {
      QgsLayerTreeLayer *res = QgsLayerTree::toGroup( child )->findLayer( layerId );
      if ( res )
        return res;
    }
  }
  return nullptr;
}

QList<QgsLayerTreeLayer *> QgsLayerTreeGroup::findLayers() const
{
  QList<QgsLayerTreeLayer *> list;
  for ( QgsLayerTreeNode *child : qgis::as_const( mChildren ) )
  {
    if ( QgsLayerTree::isLayer( child ) )
      list << QgsLayerTree::toLayer( child );
    else if ( QgsLayerTree::isGroup( child ) )
      list << QgsLayerTree::toGroup( child )->findLayers();
  }
  return list;
}

QgsLayerTreeGroup *QgsLayerTreeGroup::findGroup( const QString &name )
{
  for ( QgsLayerTreeNode *child : qgis::as_const( mChildren ) )
  {
    if ( QgsLayerTree::isGroup( child ) )
    {
      QgsLayerTreeGroup *childGroup = QgsLayerTree::toGroup( child );
      if ( childGroup->name() == name )
        return childGroup;
      else
      {
        QgsLayerTreeGroup *grp = childGroup->findGroup( name );
        if ( grp )
          return grp;
      }
    }
  }
  return nullptr;
}

QList<QgsLayerTreeGroup *> QgsLayerTreeGroup::findGroups() const
{
  QList<QgsLayerTreeGroup *> list;

  for ( QgsLayerTreeNode *child : mChildren )
  {
    if ( QgsLayerTree::isGroup( child ) )
      list << QgsLayerTree::toGroup( child );
  }
  return list;
}

QgsLayerTreeGroup *QgsLayerTreeGroup::readXml( QDomElement &element, const QgsReadWriteContext &context )
{
  if ( element.tagName() != QLatin1String( "layer-tree-group" ) )
    return nullptr;

  QString name =  context.projectTranslator()->translate( QStringLiteral( "project:layergroups" ), element.attribute( QStringLiteral( "name" ) ) );
  bool isExpanded = ( element.attribute( QStringLiteral( "expanded" ), QStringLiteral( "1" ) ) == QLatin1String( "1" ) );
  bool checked = QgsLayerTreeUtils::checkStateFromXml( element.attribute( QStringLiteral( "checked" ) ) ) != Qt::Unchecked;
  bool isMutuallyExclusive = element.attribute( QStringLiteral( "mutually-exclusive" ), QStringLiteral( "0" ) ) == QLatin1String( "1" );
  int mutuallyExclusiveChildIndex = element.attribute( QStringLiteral( "mutually-exclusive-child" ), QStringLiteral( "-1" ) ).toInt();

  QgsLayerTreeGroup *groupNode = new QgsLayerTreeGroup( name, checked );
  groupNode->setExpanded( isExpanded );

  groupNode->readCommonXml( element );

  groupNode->readChildrenFromXml( element, context );

  groupNode->setIsMutuallyExclusive( isMutuallyExclusive, mutuallyExclusiveChildIndex );

  return groupNode;
}

QgsLayerTreeGroup *QgsLayerTreeGroup::readXml( QDomElement &element, const QgsProject *project, const QgsReadWriteContext &context )
{
  QgsLayerTreeGroup *node = readXml( element, context );
  if ( node )
    node->resolveReferences( project );
  return node;
}

void QgsLayerTreeGroup::writeXml( QDomElement &parentElement, const QgsReadWriteContext &context )
{
  QDomDocument doc = parentElement.ownerDocument();
  QDomElement elem = doc.createElement( QStringLiteral( "layer-tree-group" ) );
  elem.setAttribute( QStringLiteral( "name" ), mName );
  elem.setAttribute( QStringLiteral( "expanded" ), mExpanded ? "1" : "0" );
  elem.setAttribute( QStringLiteral( "checked" ), mChecked ? QStringLiteral( "Qt::Checked" ) : QStringLiteral( "Qt::Unchecked" ) );
  if ( mMutuallyExclusive )
  {
    elem.setAttribute( QStringLiteral( "mutually-exclusive" ), QStringLiteral( "1" ) );
    elem.setAttribute( QStringLiteral( "mutually-exclusive-child" ), mMutuallyExclusiveChildIndex );
  }

  writeCommonXml( elem );

  for ( QgsLayerTreeNode *node : qgis::as_const( mChildren ) )
    node->writeXml( elem, context );

  parentElement.appendChild( elem );
}

void QgsLayerTreeGroup::readChildrenFromXml( QDomElement &element, const QgsReadWriteContext &context )
{
  QList<QgsLayerTreeNode *> nodes;
  QDomElement childElem = element.firstChildElement();
  while ( !childElem.isNull() )
  {
    QgsLayerTreeNode *newNode = QgsLayerTreeNode::readXml( childElem, context );
    if ( newNode )
      nodes << newNode;

    childElem = childElem.nextSiblingElement();
  }

  insertChildNodes( -1, nodes );
}

QString QgsLayerTreeGroup::dump() const
{
  QString header = QStringLiteral( "GROUP: %1 checked=%2 expanded=%3\n" ).arg( name() ).arg( mChecked ).arg( mExpanded );
  QStringList childrenDump;
  for ( QgsLayerTreeNode *node : qgis::as_const( mChildren ) )
    childrenDump << node->dump().split( '\n' );
  for ( int i = 0; i < childrenDump.count(); ++i )
    childrenDump[i].prepend( "  " );
  return header + childrenDump.join( QStringLiteral( "\n" ) );
}

QgsLayerTreeGroup *QgsLayerTreeGroup::clone() const
{
  return new QgsLayerTreeGroup( *this );
}

void QgsLayerTreeGroup::resolveReferences( const QgsProject *project, bool looseMatching )
{
  for ( QgsLayerTreeNode *node : qgis::as_const( mChildren ) )
    node->resolveReferences( project, looseMatching );
}

static bool _nodeIsChecked( QgsLayerTreeNode *node )
{
  return node->itemVisibilityChecked();
}


bool QgsLayerTreeGroup::isMutuallyExclusive() const
{
  return mMutuallyExclusive;
}

void QgsLayerTreeGroup::setIsMutuallyExclusive( bool enabled, int initialChildIndex )
{
  mMutuallyExclusive = enabled;
  mMutuallyExclusiveChildIndex = initialChildIndex;

  if ( !enabled )
  {
    return;
  }

  if ( mMutuallyExclusiveChildIndex < 0 || mMutuallyExclusiveChildIndex >= mChildren.count() )
  {
    // try to use first checked index
    int index = 0;
    for ( QgsLayerTreeNode *child : qgis::as_const( mChildren ) )
    {
      if ( _nodeIsChecked( child ) )
      {
        mMutuallyExclusiveChildIndex = index;
        break;
      }
      index++;
    }
  }

  updateChildVisibilityMutuallyExclusive();
}

QStringList QgsLayerTreeGroup::findLayerIds() const
{
  QStringList lst;
  for ( QgsLayerTreeNode *child : qgis::as_const( mChildren ) )
  {
    if ( QgsLayerTree::isGroup( child ) )
      lst << QgsLayerTree::toGroup( child )->findLayerIds();
    else if ( QgsLayerTree::isLayer( child ) )
      lst << QgsLayerTree::toLayer( child )->layerId();
  }
  return lst;
}

void QgsLayerTreeGroup::nodeVisibilityChanged( QgsLayerTreeNode *node )
{
  int childIndex = mChildren.indexOf( node );
  if ( childIndex == -1 )
    return; // not a direct child - ignore

  if ( mMutuallyExclusive )
  {
    if ( _nodeIsChecked( node ) )
      mMutuallyExclusiveChildIndex = childIndex;
    else if ( mMutuallyExclusiveChildIndex == childIndex )
      mMutuallyExclusiveChildIndex = -1;

    // we need to make sure there is only one child node checked
    updateChildVisibilityMutuallyExclusive();
  }
}

void QgsLayerTreeGroup::updateChildVisibilityMutuallyExclusive()
{
  if ( mChildren.isEmpty() )
    return;

  mChangingChildVisibility = true; // guard against running again setVisible() triggered from children

  int index = 0;
  for ( QgsLayerTreeNode *child : qgis::as_const( mChildren ) )
  {
    child->setItemVisibilityChecked( index == mMutuallyExclusiveChildIndex );
    ++index;
  }

  mChangingChildVisibility = false;
}

void QgsLayerTreeGroup::setItemVisibilityCheckedRecursive( bool checked )
{
  QgsLayerTreeNode::setItemVisibilityChecked( checked );

  mChangingChildVisibility = true; // guard against running again setVisible() triggered from children

  int index = 0;
  for ( QgsLayerTreeNode *child : qgis::as_const( mChildren ) )
  {
    child->setItemVisibilityCheckedRecursive( checked && ( mMutuallyExclusiveChildIndex < 0 || index == mMutuallyExclusiveChildIndex ) );
    ++index;
  }

  mChangingChildVisibility = false;
}