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QgsMapRenderer Class Reference

A non GUI class for rendering a map layer set onto a QPainter. More...

#include <qgsmaprenderer.h>

Collaboration diagram for QgsMapRenderer:
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[legend]

List of all members.

Public Types

enum  OutputUnits { Millimeters, Pixels }
 Output units for pen width and point marker width/height. More...

Public Slots

void onDrawingProgress (int current, int total)
 called by signal from layer current being drawn

Signals

void drawingProgress (int current, int total)
void hasCrsTransformEnabled (bool flag)
void destinationSrsChanged ()
void updateMap ()
void mapUnitsChanged ()
void drawError (QgsMapLayer *)
 emitted when layer's draw() returned false

Public Member Functions

 QgsMapRenderer ()
 constructor
 ~QgsMapRenderer ()
 destructor
void render (QPainter *painter)
 starts rendering
bool setExtent (const QgsRectangle &extent)
 sets extent and checks whether suitable (returns false if not)
QgsRectangle extent () const
 returns current extent
const QgsMapToPixelcoordinateTransform ()
double scale () const
void setScale (double scale)
 Sets scale for scale based visibility.
double mapUnitsPerPixel () const
int width () const
int height () const
void updateScale ()
 Recalculate the map scale.
Q_DECL_DEPRECATED QgsDistanceAreadistanceArea ()
 Return the measuring object.
QGis::UnitType mapUnits () const
void setMapUnits (QGis::UnitType u)
void enableOverviewMode (bool isOverview=true)
 sets whether map image will be for overview
void setOutputSize (QSize size, int dpi)
void setOutputSize (QSizeF size, double dpi)
double outputDpi ()
 accessor for output dpi
QSize outputSize ()
 accessor for output size
QSizeF outputSizeF ()
QgsRectangle layerExtentToOutputExtent (QgsMapLayer *theLayer, QgsRectangle extent)
 transform extent in layer's CRS to extent in output CRS
QgsPoint layerToMapCoordinates (QgsMapLayer *theLayer, QgsPoint point)
 transform coordinates from layer's CRS to output CRS
QgsPoint mapToLayerCoordinates (QgsMapLayer *theLayer, QgsPoint point)
 transform coordinates from output CRS to layer's CRS
QgsRectangle mapToLayerCoordinates (QgsMapLayer *theLayer, QgsRectangle rect)
 transform rect's coordinates from output CRS to layer's CRS
void setProjectionsEnabled (bool enabled)
 sets whether to use projections for this layer set
bool hasCrsTransformEnabled ()
 returns true if projections are enabled for this layer set
Q_DECL_DEPRECATED void setDestinationSrs (const QgsCoordinateReferenceSystem &srs)
 sets destination coordinate reference system
Q_DECL_DEPRECATED const
QgsCoordinateReferenceSystem
destinationSrs ()
 returns CRS of destination coordinate reference system
void setDestinationCrs (const QgsCoordinateReferenceSystem &crs)
 sets destination coordinate reference system
const
QgsCoordinateReferenceSystem
destinationCrs ()
 returns CRS of destination coordinate reference system
void setOutputUnits (OutputUnits u)
OutputUnits outputUnits () const
QgsRectangle fullExtent ()
 returns current extent of layer set
QStringList & layerSet ()
 returns current layer set
void setLayerSet (const QStringList &layers)
 change current layer set
void updateFullExtent ()
 updates extent of the layer set
bool readXML (QDomNode &theNode)
 read settings
bool writeXML (QDomNode &theNode, QDomDocument &theDoc)
 write settings
QgsRenderContextrendererContext ()
 Accessor for render context.
QgsLabelingEngineInterfacelabelingEngine ()
 Labeling engine (NULL if there's no custom engine)
void setLabelingEngine (QgsLabelingEngineInterface *iface)
 Set labeling engine.

Protected Member Functions

void adjustExtentToSize ()
 adjust extent to fit the pixmap size
bool splitLayersExtent (QgsMapLayer *layer, QgsRectangle &extent, QgsRectangle &r2)
 Convenience function to project an extent into the layer source CRS, but also split it into two extents if it crosses the +/- 180 degree line.
QgsOverlayObjectPositionManageroverlayManagerFromSettings ()
 Creates an overlay object position manager subclass according to the current settings.

Protected Attributes

double mMapUnitsPerPixel
 map units per pixel
double mScale
 Map scale at its current zool level.
QgsScaleCalculatormScaleCalculator
 scale calculator
QgsRectangle mExtent
 current extent to be drawn
QgsRectangle mLastExtent
 Last extent to we drew so we know if we can used layer render caching or not.
bool mOverview
 indicates whether it's map image for overview
QSizeF mSize
bool mProjectionsEnabled
 detemines whether on the fly projection support is enabled
QgsCoordinateReferenceSystemmDestCRS
 destination spatial reference system of the projection
QStringList mLayerSet
 stores array of layers to be rendered (identified by string)
QgsRectangle mFullExtent
 full extent of the layer set
QgsDistanceAreamDistArea
 tool for measuring
QgsRenderContext mRenderContext
 Encapsulates context of rendering.
OutputUnits mOutputUnits
 Output units.
QgsLabelingEngineInterfacemLabelingEngine
 Labeling engine (NULL by default)

Static Protected Attributes

static bool mDrawing = false
 indicates drawing in progress

Detailed Description

A non GUI class for rendering a map layer set onto a QPainter.

Definition at line 100 of file qgsmaprenderer.h.


Member Enumeration Documentation

Output units for pen width and point marker width/height.

Enumerator:
Millimeters 
Pixels 

Definition at line 107 of file qgsmaprenderer.h.


Constructor & Destructor Documentation

QgsMapRenderer::QgsMapRenderer ( )
QgsMapRenderer::~QgsMapRenderer ( )

destructor

Definition at line 64 of file qgsmaprenderer.cpp.

References mDestCRS, mDistArea, mLabelingEngine, and mScaleCalculator.


Member Function Documentation

void QgsMapRenderer::adjustExtentToSize ( )
protected
const QgsMapToPixel* QgsMapRenderer::coordinateTransform ( )
inline
const QgsCoordinateReferenceSystem & QgsMapRenderer::destinationCrs ( )
Q_DECL_DEPRECATED const QgsCoordinateReferenceSystem& QgsMapRenderer::destinationSrs ( )
inline

returns CRS of destination coordinate reference system

Note:
deprecated by qgis 1.7
See also:
destinationCrs

Definition at line 189 of file qgsmaprenderer.h.

void QgsMapRenderer::destinationSrsChanged ( )
signal

Referenced by setDestinationCrs().

Q_DECL_DEPRECATED QgsDistanceArea* QgsMapRenderer::distanceArea ( )
inline

Return the measuring object.

Deprecated:

Definition at line 145 of file qgsmaprenderer.h.

void QgsMapRenderer::drawError ( QgsMapLayer )
signal

emitted when layer's draw() returned false

Referenced by render().

void QgsMapRenderer::drawingProgress ( int  current,
int  total 
)
signal

Referenced by render().

void QgsMapRenderer::enableOverviewMode ( bool  isOverview = true)
inline

sets whether map image will be for overview

Definition at line 150 of file qgsmaprenderer.h.

Referenced by QgsMapOverviewCanvas::QgsMapOverviewCanvas().

QgsRectangle QgsMapRenderer::extent ( ) const
QgsRectangle QgsMapRenderer::fullExtent ( )

returns current extent of layer set

Definition at line 890 of file qgsmaprenderer.cpp.

References mFullExtent, and updateFullExtent().

Referenced by QgsMapCanvas::fullExtent().

bool QgsMapRenderer::hasCrsTransformEnabled ( )
void QgsMapRenderer::hasCrsTransformEnabled ( bool  flag)
signal
int QgsMapRenderer::height ( ) const
inline

Definition at line 138 of file qgsmaprenderer.h.

QgsLabelingEngineInterface* QgsMapRenderer::labelingEngine ( )
inline

Labeling engine (NULL if there's no custom engine)

Note:
Added in QGIS v1.4

Definition at line 224 of file qgsmaprenderer.h.

Referenced by QgsComposerMap::draw().

QgsRectangle QgsMapRenderer::layerExtentToOutputExtent ( QgsMapLayer theLayer,
QgsRectangle  extent 
)

transform extent in layer's CRS to extent in output CRS

Definition at line 742 of file qgsmaprenderer.cpp.

References QgsMapLayer::crs(), extent(), hasCrsTransformEnabled(), mDestCRS, QgsDebugMsg, and QgsException::what().

Referenced by updateFullExtent(), and QgsMapCanvas::zoomToSelected().

QStringList & QgsMapRenderer::layerSet ( )
QgsPoint QgsMapRenderer::layerToMapCoordinates ( QgsMapLayer theLayer,
QgsPoint  point 
)
QgsPoint QgsMapRenderer::mapToLayerCoordinates ( QgsMapLayer theLayer,
QgsPoint  point 
)
QgsRectangle QgsMapRenderer::mapToLayerCoordinates ( QgsMapLayer theLayer,
QgsRectangle  rect 
)

transform rect's coordinates from output CRS to layer's CRS

Definition at line 809 of file qgsmaprenderer.cpp.

References QgsMapLayer::crs(), hasCrsTransformEnabled(), mDestCRS, QgsDebugMsg, QgsCoordinateTransform::ReverseTransform, and QgsException::what().

QGis::UnitType QgsMapRenderer::mapUnits ( ) const
void QgsMapRenderer::mapUnitsChanged ( )
signal

Referenced by setMapUnits().

double QgsMapRenderer::mapUnitsPerPixel ( ) const
inline
void QgsMapRenderer::onDrawingProgress ( int  current,
int  total 
)
slot

called by signal from layer current being drawn

Definition at line 636 of file qgsmaprenderer.cpp.

References updateMap().

Referenced by render().

double QgsMapRenderer::outputDpi ( )

accessor for output dpi

Definition at line 139 of file qgsmaprenderer.cpp.

References QgsScaleCalculator::dpi(), and mScaleCalculator.

Referenced by QgsQuickPrint::printMap(), and QgsMapCanvasItem::setRenderContextVariables().

QSize QgsMapRenderer::outputSize ( )

accessor for output size

Definition at line 144 of file qgsmaprenderer.cpp.

References mSize.

Referenced by QgsQuickPrint::printMap().

QSizeF QgsMapRenderer::outputSizeF ( )

Definition at line 149 of file qgsmaprenderer.cpp.

References mSize.

OutputUnits QgsMapRenderer::outputUnits ( ) const
inline

Definition at line 199 of file qgsmaprenderer.h.

Referenced by QgsMapCanvasItem::setRenderContextVariables().

QgsOverlayObjectPositionManager * QgsMapRenderer::overlayManagerFromSettings ( )
protected

Creates an overlay object position manager subclass according to the current settings.

Note:
this method was added in version 1.1

Definition at line 907 of file qgsmaprenderer.cpp.

References QgsPALObjectPositionManager::setPlacementAlgorithm().

Referenced by render().

bool QgsMapRenderer::readXML ( QDomNode &  theNode)
void QgsMapRenderer::render ( QPainter *  painter)

starts rendering

Definition at line 216 of file qgsmaprenderer.cpp.

References QgsOverlayObjectPositionManager::addLayer(), QgsMapLayer::cacheImage(), QgsMapLayerRegistry::clearAllLayerCaches(), QgsMapLayer::crs(), QgsScaleCalculator::dpi(), QgsMapLayer::draw(), drawError(), drawingProgress(), QgsLabelingEngineInterface::drawLabeling(), QgsMapLayer::drawLabels(), QgsLabelingEngineInterface::exit(), QgsMapLayer::extent(), QgsOverlayObjectPositionManager::findObjectPositions(), hasCrsTransformEnabled(), QgsMapLayer::hasScaleBasedVisibility(), QgsLabelingEngineInterface::init(), QgsMapLayerRegistry::instance(), QgsVectorLayer::isEditable(), QgsRectangle::isEmpty(), QgsRectangle::isFinite(), QgsRenderContext::labelingEngine(), QgsMapLayerRegistry::mapLayer(), QgsRenderContext::mapToPixel(), QgsScaleCalculator::mapUnits(), QgsMapToPixel::mapUnitsPerPixel(), QgsMapLayer::maximumScale(), mDestCRS, mDrawing, mExtent, Millimeters, QgsMapLayer::minimumScale(), mLabelingEngine, mLastExtent, mLayerSet, mOutputUnits, mOverview, mRenderContext, mScale, mScaleCalculator, mSize, QgsMapLayer::name(), onDrawingProgress(), overlayManagerFromSettings(), QgsRenderContext::painter(), QgsDebugMsg, QgsMapLayer::RasterLayer, QgsRenderContext::rasterScaleFactor(), QgsOverlayObjectPositionManager::removeLayers(), QgsRenderContext::rendererScale(), QgsRenderContext::renderingStopped(), QgsRenderContext::scaleFactor(), QgsMapLayer::setCacheImage(), QgsRenderContext::setCoordinateTransform(), QgsRenderContext::setDrawEditingInformation(), QgsRenderContext::setExtent(), QgsRenderContext::setLabelingEngine(), QgsRenderContext::setMapToPixel(), QgsMapToPixel::setMapUnitsPerPixel(), QgsRenderContext::setPainter(), QgsRenderContext::setRasterScaleFactor(), QgsRenderContext::setRendererScale(), QgsRenderContext::setRenderingStopped(), QgsRenderContext::setScaleFactor(), QgsMapToPixel::setYMaximum(), splitLayersExtent(), QgsRectangle::toString(), QgsMapLayer::type(), QgsMapLayer::VectorLayer, QgsVectorLayer::vectorOverlays(), and QgsLabelingEngineInterface::willUseLayer().

Referenced by QgsComposerMap::draw(), QgsQuickPrint::printMap(), QgsMapOverviewCanvas::refresh(), QgsMapCanvasMap::render(), and QgsMapCanvas::saveAsImage().

QgsRenderContext* QgsMapRenderer::rendererContext ( )
inline

Accessor for render context.

Definition at line 220 of file qgsmaprenderer.h.

Referenced by QgsComposerMap::draw(), QgsMapCanvas::paintEvent(), and QgsMapCanvas::setRenderFlag().

double QgsMapRenderer::scale ( ) const
inline
void QgsMapRenderer::setDestinationCrs ( const QgsCoordinateReferenceSystem crs)
Q_DECL_DEPRECATED void QgsMapRenderer::setDestinationSrs ( const QgsCoordinateReferenceSystem srs)
inline

sets destination coordinate reference system

Note:
deprecated by qgis 1.7
See also:
setDestinationCrs

Definition at line 183 of file qgsmaprenderer.h.

bool QgsMapRenderer::setExtent ( const QgsRectangle extent)
void QgsMapRenderer::setLabelingEngine ( QgsLabelingEngineInterface iface)

Set labeling engine.

Previous engine (if any) is deleted. Takes ownership of the engine. Added in QGIS v1.4

Definition at line 1084 of file qgsmaprenderer.cpp.

References mLabelingEngine.

Referenced by QgsComposerMap::draw().

void QgsMapRenderer::setLayerSet ( const QStringList &  layers)

change current layer set

Definition at line 896 of file qgsmaprenderer.cpp.

References mLayerSet, and updateFullExtent().

Referenced by QgsComposerMap::draw(), QgsMapOverviewCanvas::setLayerSet(), and QgsMapCanvas::setLayerSet().

void QgsMapRenderer::setMapUnits ( QGis::UnitType  u)
void QgsMapRenderer::setOutputSize ( QSize  size,
int  dpi 
)
void QgsMapRenderer::setOutputSize ( QSizeF  size,
double  dpi 
)
void QgsMapRenderer::setOutputUnits ( OutputUnits  u)
inline

Definition at line 197 of file qgsmaprenderer.h.

void QgsMapRenderer::setProjectionsEnabled ( bool  enabled)
void QgsMapRenderer::setScale ( double  scale)
inline

Sets scale for scale based visibility.

Normally, the scale is calculated automatically. This function is only used to force a preview scale (e.g. for print composer)

Definition at line 134 of file qgsmaprenderer.h.

Referenced by QgsComposerMap::draw().

bool QgsMapRenderer::splitLayersExtent ( QgsMapLayer layer,
QgsRectangle extent,
QgsRectangle r2 
)
protected

Convenience function to project an extent into the layer source CRS, but also split it into two extents if it crosses the +/- 180 degree line.

Modifies the given extent to be in the source CRS coordinates, and if it was split, returns true, and also sets the contents of the r2 parameter

Definition at line 685 of file qgsmaprenderer.cpp.

References QgsMapLayer::crs(), extent(), hasCrsTransformEnabled(), mDestCRS, QgsDebugMsg, QgsCoordinateTransform::ReverseTransform, QgsRectangle::setXMaximum(), QgsRectangle::setXMinimum(), QgsPoint::x(), QgsRectangle::xMaximum(), QgsRectangle::xMinimum(), QgsRectangle::yMaximum(), and QgsRectangle::yMinimum().

Referenced by render().

void QgsMapRenderer::updateFullExtent ( )
void QgsMapRenderer::updateMap ( )
signal

Referenced by onDrawingProgress().

void QgsMapRenderer::updateScale ( )

Recalculate the map scale.

Definition at line 78 of file qgsmaprenderer.cpp.

References QgsScaleCalculator::calculate(), mExtent, mScale, mScaleCalculator, and mSize.

Referenced by adjustExtentToSize(), and setMapUnits().

int QgsMapRenderer::width ( ) const
inline

Definition at line 137 of file qgsmaprenderer.h.

bool QgsMapRenderer::writeXML ( QDomNode &  theNode,
QDomDocument &  theDoc 
)

Member Data Documentation

QgsCoordinateReferenceSystem* QgsMapRenderer::mDestCRS
protected
QgsDistanceArea* QgsMapRenderer::mDistArea
protected

tool for measuring

Definition at line 310 of file qgsmaprenderer.h.

Referenced by QgsMapRenderer(), setDestinationCrs(), setProjectionsEnabled(), and ~QgsMapRenderer().

bool QgsMapRenderer::mDrawing = false
staticprotected

indicates drawing in progress

Definition at line 271 of file qgsmaprenderer.h.

Referenced by QgsMapRenderer(), and render().

QgsRectangle QgsMapRenderer::mExtent
protected

current extent to be drawn

Definition at line 283 of file qgsmaprenderer.h.

Referenced by adjustExtentToSize(), extent(), render(), setExtent(), and updateScale().

QgsRectangle QgsMapRenderer::mFullExtent
protected

full extent of the layer set

Definition at line 307 of file qgsmaprenderer.h.

Referenced by fullExtent(), and updateFullExtent().

QgsLabelingEngineInterface* QgsMapRenderer::mLabelingEngine
protected

Labeling engine (NULL by default)

Definition at line 319 of file qgsmaprenderer.h.

Referenced by QgsMapRenderer(), render(), setLabelingEngine(), and ~QgsMapRenderer().

QgsRectangle QgsMapRenderer::mLastExtent
protected

Last extent to we drew so we know if we can used layer render caching or not.

Note there are no accessors for this as it is intended to internal use only.

Note:
added in QGIS 1.4

Definition at line 290 of file qgsmaprenderer.h.

Referenced by render(), and setExtent().

QStringList QgsMapRenderer::mLayerSet
protected

stores array of layers to be rendered (identified by string)

Definition at line 304 of file qgsmaprenderer.h.

Referenced by layerSet(), render(), setLayerSet(), and updateFullExtent().

double QgsMapRenderer::mMapUnitsPerPixel
protected

map units per pixel

Definition at line 274 of file qgsmaprenderer.h.

Referenced by adjustExtentToSize().

OutputUnits QgsMapRenderer::mOutputUnits
protected

Output units.

Definition at line 316 of file qgsmaprenderer.h.

Referenced by QgsMapRenderer(), and render().

bool QgsMapRenderer::mOverview
protected

indicates whether it's map image for overview

Definition at line 293 of file qgsmaprenderer.h.

Referenced by QgsMapRenderer(), and render().

bool QgsMapRenderer::mProjectionsEnabled
protected

detemines whether on the fly projection support is enabled

Definition at line 298 of file qgsmaprenderer.h.

Referenced by hasCrsTransformEnabled(), QgsMapRenderer(), and setProjectionsEnabled().

QgsRenderContext QgsMapRenderer::mRenderContext
protected

Encapsulates context of rendering.

Definition at line 313 of file qgsmaprenderer.h.

Referenced by adjustExtentToSize(), and render().

double QgsMapRenderer::mScale
protected

Map scale at its current zool level.

Definition at line 277 of file qgsmaprenderer.h.

Referenced by adjustExtentToSize(), render(), and updateScale().

QgsScaleCalculator* QgsMapRenderer::mScaleCalculator
protected

scale calculator

Definition at line 280 of file qgsmaprenderer.h.

Referenced by mapUnits(), outputDpi(), QgsMapRenderer(), render(), setMapUnits(), setOutputSize(), updateScale(), and ~QgsMapRenderer().

QSizeF QgsMapRenderer::mSize
protected

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