QGIS API Documentation  3.21.0-Master (5b68dc587e)
qgslayertreeregistrybridge.cpp
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1 /***************************************************************************
2  qgslayertreeregistrybridge.cpp
3  --------------------------------------
4  Date : May 2014
5  Copyright : (C) 2014 by Martin Dobias
6  Email : wonder dot sk at gmail dot com
7  ***************************************************************************
8  * *
9  * This program is free software; you can redistribute it and/or modify *
10  * it under the terms of the GNU General Public License as published by *
11  * the Free Software Foundation; either version 2 of the License, or *
12  * (at your option) any later version. *
13  * *
14  ***************************************************************************/
15 
17 
18 #include "qgslayertree.h"
19 
20 #include "qgsproject.h"
21 #include "qgslogger.h"
22 
24  : QObject( parent )
25  , mRoot( root )
26  , mProject( project )
27  , mRegistryRemovingLayers( false )
28  , mEnabled( true )
29  , mNewLayersVisible( true )
30  , mInsertionPoint( root, 0 )
31 {
33  connect( mProject, qOverload<const QStringList &>( &QgsProject::layersWillBeRemoved ), this, &QgsLayerTreeRegistryBridge::layersWillBeRemoved );
34 
37 }
38 
40 {
41  mInsertionPoint.group = parentGroup;
42  mInsertionPoint.position = index;
43 }
44 
46 {
47  mInsertionPoint = insertionPoint;
48 }
49 
50 void QgsLayerTreeRegistryBridge::layersAdded( const QList<QgsMapLayer *> &layers )
51 {
52  if ( !mEnabled )
53  return;
54 
55  QList<QgsLayerTreeNode *> nodes;
56  for ( QgsMapLayer *layer : layers )
57  {
58  QgsLayerTreeLayer *nodeLayer = new QgsLayerTreeLayer( layer );
60 
61  nodes << nodeLayer;
62 
63  // check whether the layer is marked as embedded
64  const QString projectFile = mProject->layerIsEmbedded( nodeLayer->layerId() );
65  if ( !projectFile.isEmpty() )
66  {
67  nodeLayer->setCustomProperty( QStringLiteral( "embedded" ), 1 );
68  nodeLayer->setCustomProperty( QStringLiteral( "embedded_project" ), projectFile );
69  }
70  }
71 
72  // add new layers to the right place
74 
75  // tell other components that layers have been added - this signal is used in QGIS to auto-select the first layer
76  emit addedLayersToLayerTree( layers );
77 }
78 
79 void QgsLayerTreeRegistryBridge::layersWillBeRemoved( const QStringList &layerIds )
80 {
81  QgsDebugMsgLevel( QStringLiteral( "%1 layers will be removed, enabled:%2" ).arg( layerIds.count() ).arg( mEnabled ), 4 );
82 
83  if ( !mEnabled )
84  return;
85 
86  // when we start removing child nodes, the bridge would try to remove those layers from
87  // the registry _again_ in groupRemovedChildren() - this prevents it
89 
90  const auto constLayerIds = layerIds;
91  for ( const QString &layerId : constLayerIds )
92  {
93  QgsLayerTreeLayer *nodeLayer = mRoot->findLayer( layerId );
94  if ( nodeLayer )
95  qobject_cast<QgsLayerTreeGroup *>( nodeLayer->parent() )->removeChildNode( nodeLayer );
96  }
97 
99 }
100 
101 
102 static void _collectLayerIdsInGroup( QgsLayerTreeGroup *group, int indexFrom, int indexTo, QStringList &lst )
103 {
104  for ( int i = indexFrom; i <= indexTo; ++i )
105  {
106  QgsLayerTreeNode *child = group->children().at( i );
107  if ( QgsLayerTree::isLayer( child ) )
108  {
109  lst << QgsLayerTree::toLayer( child )->layerId();
110  }
111  else if ( QgsLayerTree::isGroup( child ) )
112  {
113  _collectLayerIdsInGroup( QgsLayerTree::toGroup( child ), 0, child->children().count() - 1, lst );
114  }
115  }
116 }
117 
119 {
121  return; // do not try to remove those layers again
122 
123  Q_ASSERT( mLayerIdsForRemoval.isEmpty() );
124 
125  Q_ASSERT( QgsLayerTree::isGroup( node ) );
126  QgsLayerTreeGroup *group = QgsLayerTree::toGroup( node );
127 
128  _collectLayerIdsInGroup( group, indexFrom, indexTo, mLayerIdsForRemoval );
129 }
130 
132 {
134  return; // do not try to remove those layers again
135 
136  // remove only those that really do not exist in the tree
137  // (ignores layers that were dragged'n'dropped: 1. drop new 2. remove old)
138  QStringList toRemove;
139  const auto constMLayerIdsForRemoval = mLayerIdsForRemoval;
140  for ( const QString &layerId : constMLayerIdsForRemoval )
141  if ( !mRoot->findLayer( layerId ) )
142  toRemove << layerId;
143  mLayerIdsForRemoval.clear();
144 
145  QgsDebugMsgLevel( QStringLiteral( "%1 layers will be removed" ).arg( toRemove.count() ), 4 );
146 
147  // delay the removal of layers from the registry. There may be other slots connected to map layer registry's signals
148  // that might disrupt the execution flow - e.g. a processEvents() call may force update of layer tree view with
149  // semi-broken tree model
150  QMetaObject::invokeMethod( this, "removeLayersFromRegistry", Qt::QueuedConnection, Q_ARG( QStringList, toRemove ) );
151 }
152 
153 void QgsLayerTreeRegistryBridge::removeLayersFromRegistry( const QStringList &layerIds )
154 {
155  mProject->removeMapLayers( layerIds );
156 }
Layer tree group node serves as a container for layers and further groups.
void insertChildNodes(int index, const QList< QgsLayerTreeNode * > &nodes)
Insert existing nodes at specified position.
QgsLayerTreeLayer * findLayer(QgsMapLayer *layer) const
Find layer node representing the map layer.
Layer tree node points to a map layer.
QString layerId() const
Returns the ID for the map layer associated with this node.
This class is a base class for nodes in a layer tree.
void removedChildren(QgsLayerTreeNode *node, int indexFrom, int indexTo)
Emitted when one or more nodes has been removed from a node within the tree.
void setCustomProperty(const QString &key, const QVariant &value)
Sets a custom property for the node. Properties are stored in a map and saved in project file.
void willRemoveChildren(QgsLayerTreeNode *node, int indexFrom, int indexTo)
Emitted when one or more nodes will be removed from a node within the tree.
QgsLayerTreeNode * parent()
Gets pointer to the parent. If parent is nullptr, the node is a root node.
QList< QgsLayerTreeNode * > children()
Gets list of children of the node. Children are owned by the parent.
void setItemVisibilityChecked(bool checked)
Check or uncheck a node (independently of its ancestors or children)
void removeLayersFromRegistry(const QStringList &layerIds)
void layersWillBeRemoved(const QStringList &layerIds)
void layersAdded(const QList< QgsMapLayer * > &layers)
void addedLayersToLayerTree(const QList< QgsMapLayer * > &layers)
Tell others we have just added layers to the tree (used in QGIS to auto-select first newly added laye...
void groupWillRemoveChildren(QgsLayerTreeNode *node, int indexFrom, int indexTo)
QgsLayerTreeRegistryBridge(QgsLayerTreeGroup *root, QgsProject *project, QObject *parent=nullptr)
Create the instance that synchronizes given project with a layer tree root.
Q_DECL_DEPRECATED void setLayerInsertionPoint(QgsLayerTreeGroup *parentGroup, int index)
Set where the new layers should be inserted - can be used to follow current selection.
static bool isLayer(const QgsLayerTreeNode *node)
Check whether the node is a valid layer node.
Definition: qgslayertree.h:53
static QgsLayerTreeLayer * toLayer(QgsLayerTreeNode *node)
Cast node to a layer.
Definition: qgslayertree.h:75
static bool isGroup(QgsLayerTreeNode *node)
Check whether the node is a valid group node.
Definition: qgslayertree.h:43
static QgsLayerTreeGroup * toGroup(QgsLayerTreeNode *node)
Cast node to a group.
Definition: qgslayertree.h:64
Base class for all map layer types.
Definition: qgsmaplayer.h:73
Encapsulates a QGIS project, including sets of map layers and their styles, layouts,...
Definition: qgsproject.h:101
void layersWillBeRemoved(const QStringList &layerIds)
Emitted when one or more layers are about to be removed from the registry.
void removeMapLayers(const QStringList &layerIds)
Remove a set of layers from the registry by layer ID.
void legendLayersAdded(const QList< QgsMapLayer * > &layers)
Emitted, when a layer was added to the registry and the legend.
QString layerIsEmbedded(const QString &id) const
Returns the source project file path if the layer with matching id is embedded from other project fil...
#define QgsDebugMsgLevel(str, level)
Definition: qgslogger.h:39
A structure to define the insertion point to the layer tree.