QGIS API Documentation  2.15.0-Master (13f053b)
qgscomposerobject.cpp
Go to the documentation of this file.
1 /***************************************************************************
2  qgscomposerobject.cpp
3  -------------------
4  begin : July 2014
5  copyright : (C) 2014 by Nyall Dawson,Radim Blazek
6  email : nyall dot dawson at gmail dot com
7  ***************************************************************************/
8 
9 /***************************************************************************
10  * *
11  * This program is free software; you can redistribute it and/or modify *
12  * it under the terms of the GNU General Public License as published by *
13  * the Free Software Foundation; either version 2 of the License, or *
14  * (at your option) any later version. *
15  * *
16  ***************************************************************************/
17 
18 #include <QPainter>
19 
20 #include "qgscomposition.h"
21 #include "qgscomposerutils.h"
22 #include "qgscomposerobject.h"
23 #include "qgsdatadefined.h"
24 
26  : QObject( nullptr )
27  , mComposition( composition )
28 {
29 
30  // data defined strings
31  mDataDefinedNames.insert( QgsComposerObject::TestProperty, QString( "dataDefinedTestProperty" ) );
32 
33  if ( mComposition )
34  {
35  //connect to atlas toggling on/off and coverage layer and feature changes
36  //to update data defined values
37  connect( &mComposition->atlasComposition(), SIGNAL( toggled( bool ) ), this, SLOT( refreshDataDefinedProperty() ) );
38  connect( &mComposition->atlasComposition(), SIGNAL( coverageLayerChanged( QgsVectorLayer* ) ), this, SLOT( refreshDataDefinedProperty() ) );
39  connect( &mComposition->atlasComposition(), SIGNAL( featureChanged( QgsFeature* ) ), this, SLOT( refreshDataDefinedProperty() ) );
40  //also, refreshing composition triggers a recalculation of data defined properties
41  connect( mComposition, SIGNAL( refreshItemsTriggered() ), this, SLOT( refreshDataDefinedProperty() ) );
42 
43  //toggling atlas or changing coverage layer requires data defined expressions to be reprepared
44  connect( &mComposition->atlasComposition(), SIGNAL( toggled( bool ) ), this, SLOT( prepareDataDefinedExpressions() ) );
45  connect( &mComposition->atlasComposition(), SIGNAL( coverageLayerChanged( QgsVectorLayer* ) ), this, SLOT( prepareDataDefinedExpressions() ) );
46  }
47 
48 }
49 
51 {
52  qDeleteAll( mDataDefinedProperties );
53 }
54 
56 {
57  if ( elem.isNull() )
58  {
59  return false;
60  }
61 
62  //data defined properties
63  QgsComposerUtils::writeDataDefinedPropertyMap( elem, doc, &mDataDefinedNames, &mDataDefinedProperties );
64 
65  //custom properties
66  mCustomProperties.writeXml( elem, doc );
67 
68  return true;
69 }
70 
71 bool QgsComposerObject::readXML( const QDomElement &itemElem, const QDomDocument &doc )
72 {
73  Q_UNUSED( doc );
74  if ( itemElem.isNull() )
75  {
76  return false;
77  }
78 
79  //data defined properties
80  QgsComposerUtils::readDataDefinedPropertyMap( itemElem, &mDataDefinedNames, &mDataDefinedProperties );
81 
82  //custom properties
83  mCustomProperties.readXml( itemElem );
84 
85  return true;
86 }
87 
89 {
90  if ( property == QgsComposerObject::AllProperties || property == QgsComposerObject::NoProperty )
91  {
92  //bad property requested, don't return anything
93  return nullptr;
94  }
95 
96  //find corresponding QgsDataDefined and return it
98  if ( it != mDataDefinedProperties.constEnd() )
99  {
100  return it.value();
101  }
102 
103  //could not find matching QgsDataDefined
104  return nullptr;
105 }
106 
107 void QgsComposerObject::setDataDefinedProperty( const QgsComposerObject::DataDefinedProperty property, const bool active, const bool useExpression, const QString &expression, const QString &field )
108 {
109  if ( property == QgsComposerObject::AllProperties || property == QgsComposerObject::NoProperty )
110  {
111  //bad property requested
112  return;
113  }
114 
115  bool defaultVals = ( !active && !useExpression && expression.isEmpty() && field.isEmpty() );
116 
117  if ( mDataDefinedProperties.contains( property ) )
118  {
120  if ( it != mDataDefinedProperties.constEnd() )
121  {
122  QgsDataDefined* dd = it.value();
123  dd->setActive( active );
124  dd->setExpressionString( expression );
125  dd->setField( field );
126  dd->setUseExpression( useExpression );
127  }
128  }
129  else if ( !defaultVals )
130  {
131  QgsDataDefined* dd = new QgsDataDefined( active, useExpression, expression, field );
132  mDataDefinedProperties.insert( property, dd );
133  }
134 }
135 
137 {
138  //nothing to do in base class for now
139 }
140 
142 {
143  Q_UNUSED( property );
144  Q_UNUSED( context );
145 
146  //nothing to do in base class for now
147 }
148 
150 {
151  if ( !mComposition )
152  {
153  return false;
154  }
155  return mComposition->dataDefinedEvaluate( property, expressionValue, context, &mDataDefinedProperties );
156 }
157 
158 void QgsComposerObject::prepareDataDefinedExpressions() const
159 {
161 
162  //prepare all QgsDataDefineds
164  if ( it != mDataDefinedProperties.constEnd() )
165  {
166  it.value()->prepareExpression( *context.data() );
167  }
168 }
169 
170 void QgsComposerObject::setCustomProperty( const QString& key, const QVariant& value )
171 {
172  mCustomProperties.setValue( key, value );
173 }
174 
175 QVariant QgsComposerObject::customProperty( const QString& key, const QVariant& defaultValue ) const
176 {
177  return mCustomProperties.value( key, defaultValue );
178 }
179 
181 {
182  mCustomProperties.remove( key );
183 }
184 
186 {
187  return mCustomProperties.keys();
188 }
189 
191 {
192  QgsExpressionContext* context = nullptr;
193  if ( mComposition )
194  {
196  }
197  else
198  {
199  context = new QgsExpressionContext();
202  }
203  return context;
204 }
void setActive(bool active)
virtual bool writeXML(QDomElement &elem, QDomDocument &doc) const
Stores item state in DOM element.
A container class for data source field mapping or expression.
bool contains(const Key &key) const
void readXml(const QDomNode &parentNode, const QString &keyStartsWith=QString())
Read store contents from XML.
QgsObjectCustomProperties mCustomProperties
Custom properties for object.
const_iterator constBegin() const
static void readDataDefinedPropertyMap(const QDomElement &itemElem, QMap< QgsComposerObject::DataDefinedProperty, QString > *dataDefinedNames, QMap< QgsComposerObject::DataDefinedProperty, QgsDataDefined * > *dataDefinedProperties)
Reads all data defined properties from xml.
QMap< QgsComposerObject::DataDefinedProperty, QString > mDataDefinedNames
Map of data defined properties for the item to string name to use when exporting item to xml...
virtual void refreshDataDefinedProperty(const DataDefinedProperty property=AllProperties, const QgsExpressionContext *context=nullptr)
Refreshes a data defined property for the item by reevaluating the property&#39;s value and redrawing the...
const_iterator constFind(const Key &key) const
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:187
static void writeDataDefinedPropertyMap(QDomElement &itemElem, QDomDocument &doc, const QMap< QgsComposerObject::DataDefinedProperty, QString > *dataDefinedNames, const QMap< QgsComposerObject::DataDefinedProperty, QgsDataDefined * > *dataDefinedProperties)
Writes data defined properties to xml.
QVariant customProperty(const QString &key, const QVariant &defaultValue=QVariant()) const
Read a custom property from the object.
void remove(const QString &key)
Remove a key (entry) from the store.
DataDefinedProperty
Data defined properties for different item types.
QgsComposerObject(QgsComposition *composition)
Constructor.
QgsDataDefined * dataDefinedProperty(const DataDefinedProperty property) const
Returns a reference to the data defined settings for one of the item&#39;s data defined properties...
QVariant value(const QString &key, const QVariant &defaultValue=QVariant()) const
Return value for the given key. If the key is not stored, default value will be used.
void setUseExpression(bool use)
Controls if the field or the expression part is active.
virtual QgsExpressionContext * createExpressionContext() const
Creates an expression context relating to the objects&#39; current state.
void setValue(const QString &key, const QVariant &value)
Add an entry to the store. If the entry with the keys exists already, it will be overwritten.
static QgsExpressionContextScope * globalScope()
Creates a new scope which contains variables and functions relating to the global QGIS context...
QVariant property(const char *name) const
void setField(const QString &field)
Set the field name which this QgsDataDefined represents.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
QStringList keys() const
Return list of stored keys.
bool isEmpty() const
const_iterator constEnd() const
void removeCustomProperty(const QString &key)
Remove a custom property from the object.
const T & value() const
virtual void repaint()
Triggers a redraw for the item.
Graphics scene for map printing.
T * data() const
QgsExpressionContext * createExpressionContext() const
Creates an expression context relating to the compositions&#39;s current state.
bool dataDefinedEvaluate(const QgsComposerObject::DataDefinedProperty property, QVariant &expressionValue, const QgsExpressionContext &context=QgsExpressionContext()) const
Evaluate a data defined property and return the calculated value.
bool isNull() const
QgsComposition * mComposition
void writeXml(QDomNode &parentNode, QDomDocument &doc) const
Write store contents to XML.
virtual bool readXML(const QDomElement &itemElem, const QDomDocument &doc)
Sets item state from DOM element.
void setCustomProperty(const QString &key, const QVariant &value)
Set a custom property for the object.
void appendScope(QgsExpressionContextScope *scope)
Appends a scope to the end of the context.
void setDataDefinedProperty(const DataDefinedProperty property, const bool active, const bool useExpression, const QString &expression, const QString &field)
Sets parameters for a data defined property for the item.
QStringList customProperties() const
Return list of keys stored in custom properties for the object.
QgsAtlasComposition & atlasComposition()
iterator insert(const Key &key, const T &value)
static QgsExpressionContextScope * projectScope()
Creates a new scope which contains variables and functions relating to the current QGIS project...
bool connect(const QObject *sender, const char *signal, const QObject *receiver, const char *method, Qt::ConnectionType type)
Represents a vector layer which manages a vector based data sets.
void setExpressionString(const QString &expr)
Sets the expression for this QgsDataDefined.
const T value(const Key &key) const