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qgslabel.h
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1 /***************************************************************************
2  qgslabel.h - render vector labels
3  -------------------
4  begin : August 2004
5  copyright : (C) 2004 by Radim Blazek
6  email : blazek@itc.it
7  ***************************************************************************/
8 /***************************************************************************
9  * *
10  * This program is free software; you can redistribute it and/or modify *
11  * it under the terms of the GNU General Public License as published by *
12  * the Free Software Foundation; either version 2 of the License, or *
13  * (at your option) any later version. *
14  * *
15  ***************************************************************************/
16 #ifndef QGSLABEL_H
17 #define QGSLABEL_H
18 
19 #include <vector>
20 
21 #include <QColor>
22 #include <QList>
23 #include <QMap>
24 
25 #include "qgspoint.h"
26 
27 class QDomNode;
28 class QDomDocument;
29 class QDomElement;
30 class QString;
31 class QPainter;
32 class QPaintDevice;
33 
34 class QgsFeature;
35 class QgsField;
37 
38 #include "qgsfield.h"
39 #include "qgsrectangle.h"
40 #include "qgsrendercontext.h"
41 
42 typedef QList<int> QgsAttributeList;
43 
44 class QgsFields;
45 
51 class CORE_EXPORT QgsLabel
52 {
53  public:
54  QgsLabel( const QgsFields & fields );
55 
56  ~QgsLabel();
57 
58  /* Fields */
60  {
61  Text = 0,
83  StrikeOut, // added in 1.5
84  LabelFieldCount
85  };
86 
87  struct labelpoint
88  {
90  double angle;
91  };
92 
100  void renderLabel( QgsRenderContext &renderContext, QgsFeature &feature, bool selected, QgsLabelAttributes *classAttributes = 0 );
101 
105  void readXML( const QDomNode& node );
106 
108  void writeXML( QDomNode & label_node, QDomDocument & document ) const;
109 
111  void addRequiredFields( QgsAttributeList& fields ) const;
112 
114  void setFields( const QgsFields & fields );
115 
117  QgsFields & fields();
118 
123  QgsLabelAttributes *labelAttributes();
124 
126  void setLabelField( int attr, int fieldIndex );
127 
129  QString labelField( int attr ) const;
130 
136  QString fieldValue( int attr, QgsFeature& feature );
137 
139  void setMinScale( float theMinScale );
140  float minScale() const;
141 
143  void setMaxScale( float theMaxScale );
144  float maxScale() const;
145 
147  void setScaleBasedVisibility( bool theVisibilityFlag );
148  bool scaleBasedVisibility() const;
149 
150  private:
154  void renderLabel( QgsRenderContext &renderContext, QgsPoint point,
155  QString text, QFont font, QPen pen,
156  int dx, int dy,
157  double xoffset, double yoffset,
158  double ang,
159  int width, int height, int alignment );
160 
161  bool readLabelField( QDomElement &el, int attr, QString prefix );
162 
164  void labelPoint( std::vector<labelpoint>&, QgsFeature &feature );
165 
167  const unsigned char* labelPoint( labelpoint& point, const unsigned char* wkb, size_t wkblen );
168 
171 
174 
177 
179  std::vector<QString> mLabelField;
180 
182  std::vector<int> mLabelFieldIdx;
183 
185  float mMinScale;
187  float mMaxScale;
190 };
191 
192 #endif
QgsLabelAttributes * mLabelAttributes
Default layer attributes.
Definition: qgslabel.h:173
QColor mSelectionColor
Color to draw selected features.
Definition: qgslabel.h:170
Container of fields for a vector layer.
Definition: qgsfield.h:161
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:113
bool mScaleBasedVisibility
A flag that tells us whether to use the above vars to restrict the label's visibility.
Definition: qgslabel.h:189
QgsFields mFields
Available layer fields.
Definition: qgslabel.h:176
QList< int > QgsAttributeList
Definition: qgslabel.h:36
float mMaxScale
Maximum scale at which this label should be displayed.
Definition: qgslabel.h:187
QList< int > QgsAttributeList
Encapsulate a field in an attribute table or data source.
Definition: qgsfield.h:31
A class to represent a point geometry.
Definition: qgspoint.h:63
A class to render labels.
Definition: qgslabel.h:51
Contains information about the context of a rendering operation.
std::vector< int > mLabelFieldIdx
Label field indexes.
Definition: qgslabel.h:182
LabelField
Definition: qgslabel.h:59
std::vector< QString > mLabelField
Label fields.
Definition: qgslabel.h:179
A class to store attributes needed for label rendering.
float mMinScale
Minimum scale at which this label should be displayed.
Definition: qgslabel.h:185