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QgsLabel Class Reference

A class to render labels. More...

#include <qgslabel.h>

Collaboration diagram for QgsLabel:
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Classes

struct  labelpoint
 

Public Types

enum  LabelField {
  Text = 0, Family, Size, SizeType,
  Bold, Italic, Underline, Color,
  XCoordinate, YCoordinate, XOffset, YOffset,
  Angle, Alignment, BufferEnabled, BufferSize,
  BufferColor, BufferBrush, BorderWidth, BorderColor,
  BorderStyle, MultilineEnabled, StrikeOut, LabelFieldCount
}
 

Public Member Functions

 QgsLabel (const QgsFields &fields)
 
 ~QgsLabel ()
 
void renderLabel (QgsRenderContext &renderContext, QgsFeature &feature, bool selected, QgsLabelAttributes *classAttributes=0)
 render label More...
 
void readXML (const QDomNode &node)
 Reads the renderer configuration from an XML file. More...
 
void writeXML (QDomNode &label_node, QDomDocument &document) const
 Writes the contents of the renderer to a configuration file. More...
 
void addRequiredFields (QgsAttributeList &fields) const
 add vector of required fields to existing list of fields More...
 
void setFields (const QgsFields &fields)
 Set available fields. More...
 
QgsFieldsfields ()
 Available vector fields. More...
 
QgsLabelAttributeslabelAttributes ()
 Pointer to default attributes. More...
 
void setLabelField (int attr, int fieldIndex)
 Set label field. More...
 
QString labelField (int attr) const
 label field More...
 
QString fieldValue (int attr, QgsFeature &feature)
 Get field value if : 1) field name is not empty 2) field exists 3) value is defined otherwise returns empty string. More...
 
void setMinScale (float theMinScale)
 Accessor and mutator for the minimum scale member. More...
 
float minScale () const
 
void setMaxScale (float theMaxScale)
 Accessor and mutator for the maximum scale member. More...
 
float maxScale () const
 
void setScaleBasedVisibility (bool theVisibilityFlag)
 Accessor and mutator for the scale based visilibility flag. More...
 
bool scaleBasedVisibility () const
 

Private Member Functions

void renderLabel (QgsRenderContext &renderContext, QgsPoint point, QString text, QFont font, QPen pen, int dx, int dy, double xoffset, double yoffset, double ang, int width, int height, int alignment)
 Does the actual rendering of a label at the given point. More...
 
bool readLabelField (QDomElement &el, int attr, QString prefix)
 
void labelPoint (std::vector< labelpoint > &, QgsFeature &feature)
 Get label point for simple feature in map units. More...
 
const unsigned char * labelPoint (labelpoint &point, const unsigned char *wkb, size_t wkblen)
 Get label point for the given feature in wkb format. More...
 

Private Attributes

QColor mSelectionColor
 Color to draw selected features. More...
 
QgsLabelAttributesmLabelAttributes
 Default layer attributes. More...
 
QgsFields mFields
 Available layer fields. More...
 
std::vector< QString > mLabelField
 Label fields. More...
 
std::vector< int > mLabelFieldIdx
 Label field indexes. More...
 
float mMinScale
 Minimum scale at which this label should be displayed. More...
 
float mMaxScale
 Maximum scale at which this label should be displayed. More...
 
bool mScaleBasedVisibility
 A flag that tells us whether to use the above vars to restrict the label's visibility. More...
 

Detailed Description

A class to render labels.

Label rendering properties can be either specified directly or in most cases determined dynamically based on the value of an attribute.

Definition at line 51 of file qgslabel.h.

Constructor & Destructor Documentation

QgsLabel::QgsLabel ( const QgsFields fields)

Definition at line 47 of file qgslabel.cpp.

References fields(), LabelFieldCount, mFields, mLabelAttributes, and mLabelFieldIdx.

QgsLabel::~QgsLabel ( )

Definition at line 61 of file qgslabel.cpp.

References mLabelAttributes.

Member Function Documentation

void QgsLabel::addRequiredFields ( QgsAttributeList fields) const

add vector of required fields to existing list of fields

Definition at line 459 of file qgslabel.cpp.

References LabelFieldCount, and mLabelFieldIdx.

Referenced by QgsVectorLayer::drawLabels().

QgsFields & QgsLabel::fields ( void  )

Available vector fields.

Definition at line 486 of file qgslabel.cpp.

References mFields.

Referenced by QgsLabel(), and setFields().

QString QgsLabel::fieldValue ( int  attr,
QgsFeature feature 
)

Get field value if : 1) field name is not empty 2) field exists 3) value is defined otherwise returns empty string.

Definition at line 66 of file qgslabel.cpp.

References QgsFeature::attribute(), and mLabelFieldIdx.

Referenced by renderLabel().

QgsLabelAttributes * QgsLabel::labelAttributes ( void  )

Pointer to default attributes.

Note
this replaces the to-be-deprecated layerAttributes method.
introduced in QGIS 1.4

Definition at line 510 of file qgslabel.cpp.

References mLabelAttributes.

QString QgsLabel::labelField ( int  attr) const

label field

Definition at line 499 of file qgslabel.cpp.

References QgsFields::count(), LabelFieldCount, mFields, and mLabelFieldIdx.

Referenced by QgsVectorLayer::writeSymbology(), and writeXML().

void QgsLabel::labelPoint ( std::vector< labelpoint > &  points,
QgsFeature feature 
)
private
const unsigned char * QgsLabel::labelPoint ( labelpoint point,
const unsigned char *  wkb,
size_t  wkblen 
)
private
float QgsLabel::maxScale ( ) const

Definition at line 1397 of file qgslabel.cpp.

References mMaxScale.

Referenced by QgsVectorLayer::drawLabels(), and QgsVectorLayer::writeSymbology().

float QgsLabel::minScale ( ) const

Definition at line 1387 of file qgslabel.cpp.

References mMinScale.

Referenced by QgsVectorLayer::drawLabels(), and QgsVectorLayer::writeSymbology().

bool QgsLabel::readLabelField ( QDomElement &  el,
int  attr,
QString  prefix = "field" 
)
private

Definition at line 694 of file qgslabel.cpp.

References QgsFields::count(), mFields, and mLabelFieldIdx.

Referenced by readXML().

void QgsLabel::readXML ( const QDomNode &  node)
void QgsLabel::renderLabel ( QgsRenderContext renderContext,
QgsFeature feature,
bool  selected,
QgsLabelAttributes classAttributes = 0 
)
void QgsLabel::renderLabel ( QgsRenderContext renderContext,
QgsPoint  point,
QString  text,
QFont  font,
QPen  pen,
int  dx,
int  dy,
double  xoffset,
double  yoffset,
double  ang,
int  width,
int  height,
int  alignment 
)
private
bool QgsLabel::scaleBasedVisibility ( ) const

Definition at line 1377 of file qgslabel.cpp.

References mScaleBasedVisibility.

Referenced by QgsVectorLayer::drawLabels(), and QgsVectorLayer::writeSymbology().

void QgsLabel::setFields ( const QgsFields fields)

Set available fields.

Definition at line 481 of file qgslabel.cpp.

References fields(), and mFields.

void QgsLabel::setLabelField ( int  attr,
int  fieldIndex 
)

Set label field.

Definition at line 491 of file qgslabel.cpp.

References LabelFieldCount, and mLabelFieldIdx.

void QgsLabel::setMaxScale ( float  theMaxScale)

Accessor and mutator for the maximum scale member.

Definition at line 1392 of file qgslabel.cpp.

References mMaxScale.

Referenced by QgsVectorLayer::readSymbology().

void QgsLabel::setMinScale ( float  theMinScale)

Accessor and mutator for the minimum scale member.

Definition at line 1382 of file qgslabel.cpp.

References mMinScale.

Referenced by QgsVectorLayer::readSymbology().

void QgsLabel::setScaleBasedVisibility ( bool  theVisibilityFlag)

Accessor and mutator for the scale based visilibility flag.

Definition at line 1372 of file qgslabel.cpp.

References mScaleBasedVisibility.

Referenced by QgsVectorLayer::readSymbology().

void QgsLabel::writeXML ( QDomNode &  label_node,
QDomDocument &  document 
) const

Writes the contents of the renderer to a configuration file.

Definition at line 1022 of file qgslabel.cpp.

References Alignment, QgsLabelAttributes::alignment(), QgsLabelAttributes::alignmentIsSet(), QgsLabelAttributes::alignmentName(), Angle, MathUtils::angle(), QgsLabelAttributes::angle(), QgsLabelAttributes::angleIsAuto(), QgsLabelAttributes::angleIsSet(), Bold, QgsLabelAttributes::bold(), QgsLabelAttributes::boldIsSet(), BufferColor, QgsLabelAttributes::bufferColor(), QgsLabelAttributes::bufferColorIsSet(), BufferEnabled, QgsLabelAttributes::bufferEnabled(), BufferSize, QgsLabelAttributes::bufferSize(), QgsLabelAttributes::bufferSizeIsSet(), QgsLabelAttributes::bufferSizeType(), Color, QgsLabelAttributes::color(), QgsLabelAttributes::colorIsSet(), Family, QgsLabelAttributes::family(), QgsLabelAttributes::familyIsSet(), Italic, QgsLabelAttributes::italic(), QgsLabelAttributes::italicIsSet(), labelField(), mLabelAttributes, mLabelFieldIdx, MultilineEnabled, QgsLabelAttributes::multilineEnabled(), QgsLabelAttributes::offsetIsSet(), QgsLabelAttributes::offsetType(), QgsLabelAttributes::selectedOnly(), Size, size, QgsLabelAttributes::size(), QgsLabelAttributes::sizeIsSet(), SizeType, QgsLabelAttributes::sizeType(), StrikeOut, QgsLabelAttributes::strikeOut(), QgsLabelAttributes::strikeOutIsSet(), Text, QgsLabelAttributes::text(), QgsLabelAttributes::textIsSet(), Underline, QgsLabelAttributes::underline(), QgsLabelAttributes::underlineIsSet(), QgsLabelAttributes::unitsName(), XCoordinate, XOffset, QgsLabelAttributes::xOffset(), YCoordinate, YOffset, and QgsLabelAttributes::yOffset().

Referenced by QgsVectorLayer::writeSymbology().

Member Data Documentation

QgsFields QgsLabel::mFields
private

Available layer fields.

Definition at line 176 of file qgslabel.h.

Referenced by fields(), labelField(), QgsLabel(), readLabelField(), and setFields().

QgsLabelAttributes* QgsLabel::mLabelAttributes
private

Default layer attributes.

Definition at line 173 of file qgslabel.h.

Referenced by labelAttributes(), QgsLabel(), readXML(), renderLabel(), writeXML(), and ~QgsLabel().

std::vector<QString> QgsLabel::mLabelField
private

Label fields.

Definition at line 179 of file qgslabel.h.

std::vector<int> QgsLabel::mLabelFieldIdx
private

Label field indexes.

Definition at line 182 of file qgslabel.h.

Referenced by addRequiredFields(), fieldValue(), labelField(), QgsLabel(), readLabelField(), setLabelField(), and writeXML().

float QgsLabel::mMaxScale
private

Maximum scale at which this label should be displayed.

Definition at line 187 of file qgslabel.h.

Referenced by maxScale(), and setMaxScale().

float QgsLabel::mMinScale
private

Minimum scale at which this label should be displayed.

Definition at line 185 of file qgslabel.h.

Referenced by minScale(), and setMinScale().

bool QgsLabel::mScaleBasedVisibility
private

A flag that tells us whether to use the above vars to restrict the label's visibility.

Definition at line 189 of file qgslabel.h.

Referenced by scaleBasedVisibility(), and setScaleBasedVisibility().

QColor QgsLabel::mSelectionColor
private

Color to draw selected features.

Definition at line 170 of file qgslabel.h.


The documentation for this class was generated from the following files: