QGIS API Documentation 3.39.0-Master (bca3cdb6021)
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qgslayertreelayer.cpp
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1/***************************************************************************
2 qgslayertreelayer.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
16#include "qgslayertreelayer.h"
17
18#include "qgslayertreeutils.h"
19#include "qgsmaplayer.h"
20#include "qgsproject.h"
21#include "qgsproviderregistry.h"
22#include "qgssymbollayerutils.h"
23
25 : QgsLayerTreeNode( NodeLayer, true )
26 , mRef( layer )
27 , mLayerName( layer->name() )
28{
30}
31
32QgsLayerTreeLayer::QgsLayerTreeLayer( const QString &layerId, const QString &name, const QString &source, const QString &provider )
33 : QgsLayerTreeNode( NodeLayer, true )
34 , mRef( layerId, name, source, provider )
35 , mLayerName( name.isEmpty() ? QStringLiteral( "(?)" ) : name )
36{
37}
38
40 : QgsLayerTreeNode( other )
41 , mRef( other.mRef )
42 , mLayerName( other.mLayerName )
43 , mPatchShape( other.mPatchShape )
44 , mPatchSize( other.mPatchSize )
45 , mSplitBehavior( other.mSplitBehavior )
46{
48}
49
50void QgsLayerTreeLayer::resolveReferences( const QgsProject *project, bool looseMatching )
51{
52 if ( mRef )
53 return; // already assigned
54
55 if ( !looseMatching )
56 {
57 mRef.resolve( project );
58 }
59 else
60 {
61 mRef.resolveWeakly( project );
62 }
63
64 if ( !mRef )
65 return;
66
68 emit layerLoaded();
69}
70
72{
73 if ( !mRef )
74 return;
75
76 connect( mRef.layer, &QgsMapLayer::nameChanged, this, &QgsLayerTreeLayer::layerNameChanged );
77 connect( mRef.layer, &QgsMapLayer::willBeDeleted, this, &QgsLayerTreeLayer::layerWillBeDeleted );
78}
79
80
82{
83 return ( mRef && mUseLayerName ) ? mRef->name() : mLayerName;
84}
85
86void QgsLayerTreeLayer::setName( const QString &n )
87{
88 if ( mRef && mUseLayerName )
89 {
90 if ( mRef->name() == n )
91 return;
92 mRef->setName( n );
93 // no need to emit signal: we will be notified from layer's nameChanged() signal
94 }
95 else
96 {
97 if ( mLayerName == n )
98 return;
99 mLayerName = n;
100 emit nameChanged( this, n );
101 }
102}
103
105{
106 if ( element.tagName() != QLatin1String( "layer-tree-layer" ) )
107 return nullptr;
108
109 const QString layerID = element.attribute( QStringLiteral( "id" ) );
110 const QString layerName = element.attribute( QStringLiteral( "name" ) );
111
112 const QString providerKey = element.attribute( QStringLiteral( "providerKey" ) );
113 const QString sourceRaw = element.attribute( QStringLiteral( "source" ) );
114 const QString source = providerKey.isEmpty() ? sourceRaw : QgsProviderRegistry::instance()->relativeToAbsoluteUri( providerKey, sourceRaw, context );
115
116 const Qt::CheckState checked = QgsLayerTreeUtils::checkStateFromXml( element.attribute( QStringLiteral( "checked" ) ) );
117 const bool isExpanded = ( element.attribute( QStringLiteral( "expanded" ), QStringLiteral( "1" ) ) == QLatin1String( "1" ) );
118 const QString labelExpression = element.attribute( QStringLiteral( "legend_exp" ) );
119
120 // needs to have the layer reference resolved later
121 QgsLayerTreeLayer *nodeLayer = new QgsLayerTreeLayer( layerID, layerName, source, providerKey );
122
123 nodeLayer->readCommonXml( element );
124
125 nodeLayer->setItemVisibilityChecked( checked != Qt::Unchecked );
126 nodeLayer->setExpanded( isExpanded );
128
129 const QDomElement patchElem = element.firstChildElement( QStringLiteral( "patch" ) );
130 if ( !patchElem.isNull() )
131 {
133 patch.readXml( patchElem, context );
134 nodeLayer->setPatchShape( patch );
135 }
136
137 nodeLayer->setPatchSize( QgsSymbolLayerUtils::decodeSize( element.attribute( QStringLiteral( "patch_size" ) ) ) );
138
139 nodeLayer->setLegendSplitBehavior( static_cast< LegendNodesSplitBehavior >( element.attribute( QStringLiteral( "legend_split_behavior" ), QStringLiteral( "0" ) ).toInt() ) );
140
141 return nodeLayer;
142}
143
144QgsLayerTreeLayer *QgsLayerTreeLayer::readXml( QDomElement &element, const QgsProject *project, const QgsReadWriteContext &context )
145{
146 QgsLayerTreeLayer *node = readXml( element, context );
147 if ( node )
148 node->resolveReferences( project );
149 return node;
150}
151
152void QgsLayerTreeLayer::writeXml( QDomElement &parentElement, const QgsReadWriteContext &context )
153{
154 QDomDocument doc = parentElement.ownerDocument();
155 QDomElement elem = doc.createElement( QStringLiteral( "layer-tree-layer" ) );
156 elem.setAttribute( QStringLiteral( "id" ), layerId() );
157 elem.setAttribute( QStringLiteral( "name" ), name() );
158
159 if ( mRef )
160 {
161 const QString providerKey = mRef->dataProvider() ? mRef->dataProvider()->name() : QString();
162 const QString source = providerKey.isEmpty() ? mRef->publicSource() : QgsProviderRegistry::instance()->absoluteToRelativeUri( providerKey, mRef->publicSource(), context );
163 elem.setAttribute( QStringLiteral( "source" ), source );
164 elem.setAttribute( QStringLiteral( "providerKey" ), providerKey );
165 }
166
167 elem.setAttribute( QStringLiteral( "checked" ), mChecked ? QStringLiteral( "Qt::Checked" ) : QStringLiteral( "Qt::Unchecked" ) );
168 elem.setAttribute( QStringLiteral( "expanded" ), mExpanded ? "1" : "0" );
169 elem.setAttribute( QStringLiteral( "legend_exp" ), mLabelExpression );
170
171 if ( !mPatchShape.isNull() )
172 {
173 QDomElement patchElem = doc.createElement( QStringLiteral( "patch" ) );
174 mPatchShape.writeXml( patchElem, doc, context );
175 elem.appendChild( patchElem );
176 }
177 elem.setAttribute( QStringLiteral( "patch_size" ), QgsSymbolLayerUtils::encodeSize( mPatchSize ) );
178
179 elem.setAttribute( QStringLiteral( "legend_split_behavior" ), mSplitBehavior );
180
181 writeCommonXml( elem );
182
183 parentElement.appendChild( elem );
184}
185
187{
188 return QStringLiteral( "LAYER: %1 checked=%2 expanded=%3 id=%4\n" ).arg( name() ).arg( mChecked ).arg( mExpanded ).arg( layerId() );
189}
190
192{
193 return new QgsLayerTreeLayer( *this );
194}
195
196void QgsLayerTreeLayer::layerWillBeDeleted()
197{
198 Q_ASSERT( mRef );
199
200 emit layerWillBeUnloaded();
201
202 mLayerName = mRef->name();
203 // in theory we do not even need to do this - the weak ref should clear itself
204 mRef.layer.clear();
205 // layerId stays in the reference
206
207}
208
210{
211 mUseLayerName = use;
212}
213
215{
216 return mUseLayerName;
217}
218
219void QgsLayerTreeLayer::layerNameChanged()
220{
221 Q_ASSERT( mRef );
222 emit nameChanged( this, mRef->name() );
223}
224
225void QgsLayerTreeLayer::setLabelExpression( const QString &expression )
226{
227 mLabelExpression = expression;
228}
229
231{
232 return mPatchShape;
233}
234
236{
237 mPatchShape = shape;
238}
239
virtual QString name() const =0
Returns a provider name.
Layer tree node points to a map layer.
QString dump() const override
Returns string with layer tree structure. For debug purposes only.
void resolveReferences(const QgsProject *project, bool looseMatching=false) override
Resolves reference to layer from stored layer ID (if it has not been resolved already)
void writeXml(QDomElement &parentElement, const QgsReadWriteContext &context) override
Write layer tree to XML.
QString layerId() const
Returns the ID for the map layer associated with this node.
QString mLabelExpression
Expression to evaluate in the legend.
void setPatchSize(QSizeF size)
Sets the user (overridden) size for the legend node.
QgsMapLayerRef mRef
Weak reference to the layer (or just it's ID if the reference is not resolved yet)
void layerWillBeUnloaded()
Emitted when a previously available layer got unloaded (from layer registry).
void setName(const QString &n) override
Sets the layer's name.
QString labelExpression() const
Returns the expression member of the LayerTreeNode.
LegendNodesSplitBehavior
Legend node column split behavior.
void setUseLayerName(bool use=true)
Uses the layer's name if use is true, or the name manually set if false.
QgsLegendPatchShape patchShape() const
Returns the symbol patch shape to use when rendering the legend node symbol.
void setLabelExpression(const QString &expression)
set the expression to evaluate
QgsLayerTreeLayer(QgsMapLayer *layer)
bool useLayerName() const
Returns whether the layer's name is used, or the name manually set.
void setPatchShape(const QgsLegendPatchShape &shape)
Sets the symbol patch shape to use when rendering the legend node symbol.
QString name() const override
Returns the layer's name.
void layerLoaded()
Emitted when a previously unavailable layer got loaded.
static QgsLayerTreeLayer * readXml(QDomElement &element, const QgsReadWriteContext &context)
Read layer node from XML.
void setLegendSplitBehavior(LegendNodesSplitBehavior behavior)
Sets the column split behavior for the node.
QString mLayerName
Layer name - only used if layer does not exist or if mUseLayerName is false.
QgsLayerTreeLayer * clone() const override
Create a copy of the node. Returns new instance.
This class is a base class for nodes in a layer tree.
void readCommonXml(QDomElement &element)
Read common XML elements.
void nameChanged(QgsLayerTreeNode *node, QString name)
Emitted when the name of the node is changed.
void setExpanded(bool expanded)
Sets whether the node should be shown as expanded or collapsed in GUI.
void writeCommonXml(QDomElement &element)
Write common XML elements.
bool mExpanded
whether the node should be shown in GUI as expanded
bool isExpanded() const
Returns whether the node should be shown as expanded or collapsed in GUI.
void setItemVisibilityChecked(bool checked)
Check or uncheck a node (independently of its ancestors or children)
static Qt::CheckState checkStateFromXml(const QString &txt)
Convert QString to Qt::CheckState.
Represents a patch shape for use in map legends.
void readXml(const QDomElement &element, const QgsReadWriteContext &context)
Read settings from a DOM element.
bool isNull() const
Returns true if the patch shape is a null QgsLegendPatchShape, which indicates that the default legen...
void writeXml(QDomElement &element, QDomDocument &doc, const QgsReadWriteContext &context) const
Write settings into a DOM element.
Base class for all map layer types.
Definition qgsmaplayer.h:76
QString name
Definition qgsmaplayer.h:80
QString publicSource(bool hidePassword=false) const
Gets a version of the internal layer definition that has sensitive bits removed (for example,...
void willBeDeleted()
Emitted in the destructor when the layer is about to be deleted, but it is still in a perfectly valid...
void setName(const QString &name)
Set the display name of the layer.
void nameChanged()
Emitted when the name has been changed.
virtual Q_INVOKABLE QgsDataProvider * dataProvider()
Returns the layer's data provider, it may be nullptr.
Encapsulates a QGIS project, including sets of map layers and their styles, layouts,...
Definition qgsproject.h:107
QString absoluteToRelativeUri(const QString &providerKey, const QString &uri, const QgsReadWriteContext &context) const
Converts absolute path(s) to relative path(s) in the given provider-specific URI.
static QgsProviderRegistry * instance(const QString &pluginPath=QString())
Means of accessing canonical single instance.
QString relativeToAbsoluteUri(const QString &providerKey, const QString &uri, const QgsReadWriteContext &context) const
Converts relative path(s) to absolute path(s) in the given provider-specific URI.
The class is used as a container of context for various read/write operations on other objects.
static QString encodeSize(QSizeF size)
Encodes a QSizeF to a string.
static QSizeF decodeSize(const QString &string)
Decodes a QSizeF from a string.
TYPE * resolveWeakly(const QgsProject *project, MatchType matchType=MatchType::All)
Resolves the map layer by attempting to find a matching layer in a project using a weak match.
QPointer< TYPE > layer
Weak pointer to map layer.
TYPE * resolve(const QgsProject *project)
Resolves the map layer by attempting to find a layer with matching ID within a project.