QGIS API Documentation
3.16.0-Hannover (43b64b13f3)
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Abstract base class for all rendered symbols. More...
#include <qgssymbol.h>
Public Types | |
enum | PreviewFlag { FlagIncludeCrosshairsForMarkerSymbols = 1 << 0 } |
Flags for controlling how symbol preview images are generated. More... | |
enum | RenderHint { DynamicRotation = 2 } |
Flags controlling behavior of symbols during rendering. More... | |
enum | ScaleMethod { ScaleArea, ScaleDiameter } |
Scale method. More... | |
enum | SymbolType { Marker, Line, Fill, Hybrid } |
Type of the symbol. More... | |
Public Member Functions | |
virtual | ~QgsSymbol () |
bool | appendSymbolLayer (QgsSymbolLayer *layer) |
Appends a symbol layer at the end of the current symbol layer list. More... | |
QImage | asImage (QSize size, QgsRenderContext *customContext=nullptr) |
Returns an image of the symbol at the specified size. More... | |
QImage | bigSymbolPreviewImage (QgsExpressionContext *expressionContext=nullptr, QgsSymbol::PreviewFlags flags=QgsSymbol::FlagIncludeCrosshairsForMarkerSymbols) |
Returns a large (roughly 100x100 pixel) preview image for the symbol. More... | |
bool | changeSymbolLayer (int index, QgsSymbolLayer *layer) |
Deletes the current layer at the specified index and replaces it with layer. More... | |
bool | clipFeaturesToExtent () const |
Returns whether features drawn by the symbol will be clipped to the render context's extent. More... | |
virtual QgsSymbol * | clone () const =0 |
Returns a deep copy of this symbol. More... | |
QColor | color () const |
Returns the symbol's color. More... | |
bool | deleteSymbolLayer (int index) |
Removes and deletes the symbol layer at the specified index. More... | |
void | drawPreviewIcon (QPainter *painter, QSize size, QgsRenderContext *customContext=nullptr, bool selected=false, const QgsExpressionContext *expressionContext=nullptr, const QgsLegendPatchShape *patchShape=nullptr) |
Draws an icon of the symbol that occupies an area given by size using the specified painter. More... | |
QString | dump () const |
Returns a string dump of the symbol's properties. More... | |
void | exportImage (const QString &path, const QString &format, QSize size) |
Export the symbol as an image format, to the specified path and with the given size. More... | |
bool | forceRHR () const |
Returns true if polygon features drawn by the symbol will be reoriented to follow the standard right-hand-rule orientation, in which the area that is bounded by the polygon is to the right of the boundary. More... | |
bool | hasDataDefinedProperties () const |
Returns whether the symbol utilizes any data defined properties. More... | |
bool | insertSymbolLayer (int index, QgsSymbolLayer *layer) |
Inserts a symbol layer to specified index. More... | |
Q_DECL_DEPRECATED const QgsVectorLayer * | layer () const |
QgsMapUnitScale | mapUnitScale () const |
Returns the map unit scale for the symbol. More... | |
qreal | opacity () const |
Returns the opacity for the symbol. More... | |
QgsUnitTypes::RenderUnit | outputUnit () const |
Returns the units to use for sizes and widths within the symbol. More... | |
void | renderFeature (const QgsFeature &feature, QgsRenderContext &context, int layer=-1, bool selected=false, bool drawVertexMarker=false, int currentVertexMarkerType=0, double currentVertexMarkerSize=0.0) SIP_THROW(QgsCsException) |
Render a feature. More... | |
RenderHints | renderHints () const |
Returns the rendering hint flags for the symbol. More... | |
void | setClipFeaturesToExtent (bool clipFeaturesToExtent) |
Sets whether features drawn by the symbol should be clipped to the render context's extent. More... | |
void | setColor (const QColor &color) |
Sets the color for the symbol. More... | |
void | setForceRHR (bool force) |
Sets whether polygon features drawn by the symbol should be reoriented to follow the standard right-hand-rule orientation, in which the area that is bounded by the polygon is to the right of the boundary. More... | |
Q_DECL_DEPRECATED void | setLayer (const QgsVectorLayer *layer) |
void | setMapUnitScale (const QgsMapUnitScale &scale) |
Sets the map unit scale for the symbol. More... | |
void | setOpacity (qreal opacity) |
Sets the opacity for the symbol. More... | |
void | setOutputUnit (QgsUnitTypes::RenderUnit unit) |
Sets the units to use for sizes and widths within the symbol. More... | |
void | setRenderHints (RenderHints hints) |
Sets rendering hint flags for the symbol. More... | |
void | startRender (QgsRenderContext &context, const QgsFields &fields=QgsFields()) |
Begins the rendering process for the symbol. More... | |
void | stopRender (QgsRenderContext &context) |
Ends the rendering process. More... | |
QgsSymbolLayer * | symbolLayer (int layer) |
Returns the symbol layer at the specified index. More... | |
const QgsSymbolLayer * | symbolLayer (int layer) const |
Returns the symbol layer at the specified index, const variant. More... | |
int | symbolLayerCount () const |
Returns the total number of symbol layers contained in the symbol. More... | |
QgsSymbolLayerList | symbolLayers () |
Returns the list of symbol layers contained in the symbol. More... | |
QgsSymbolRenderContext * | symbolRenderContext () |
Returns the symbol render context. More... | |
QgsSymbolLayer * | takeSymbolLayer (int index) |
Removes a symbol layer from the list and returns a pointer to it. More... | |
void | toSld (QDomDocument &doc, QDomElement &element, QgsStringMap props) const |
Converts the symbol to a SLD representation. More... | |
SymbolType | type () const |
Returns the symbol's type. More... | |
QSet< QString > | usedAttributes (const QgsRenderContext &context) const |
Returns a list of attributes required to render this feature. More... | |
Static Public Member Functions | |
static QgsSymbol * | defaultSymbol (QgsWkbTypes::GeometryType geomType) |
Returns a new default symbol for the specified geometry type. More... | |
Protected Member Functions | |
QgsSymbol (SymbolType type, const QgsSymbolLayerList &layers) | |
QgsSymbolLayerList | cloneLayers () const |
Retrieve a cloned list of all layers that make up this symbol. More... | |
void | renderUsingLayer (QgsSymbolLayer *layer, QgsSymbolRenderContext &context) |
Renders a context using a particular symbol layer without passing in a geometry. More... | |
void | renderVertexMarker (QPointF pt, QgsRenderContext &context, int currentVertexMarkerType, double currentVertexMarkerSize) |
Render editing vertex marker at specified point. More... | |
Static Protected Member Functions | |
static QPolygonF | _getLineString (QgsRenderContext &context, const QgsCurve &curve, bool clipToExtent=true) |
Creates a line string in screen coordinates from a QgsCurve in map coordinates. More... | |
static QPointF | _getPoint (QgsRenderContext &context, const QgsPoint &point) |
Creates a point in screen coordinates from a QgsPoint in map coordinates. More... | |
static void | _getPolygon (QPolygonF &pts, QVector< QPolygonF > &holes, QgsRenderContext &context, const QgsPolygon &polygon, bool clipToExtent=true, bool correctRingOrientation=false) |
Creates a polygon in screen coordinates from a QgsPolygonXYin map coordinates. More... | |
static QPolygonF | _getPolygonRing (QgsRenderContext &context, const QgsCurve &curve, bool clipToExtent, bool isExteriorRing=false, bool correctRingOrientation=false) |
Creates a polygon ring in screen coordinates from a QgsCurve in map coordinates. More... | |
Protected Attributes | |
bool | mClipFeaturesToExtent = true |
bool | mForceRHR = false |
Q_DECL_DEPRECATED const QgsVectorLayer * | mLayer = nullptr |
QgsSymbolLayerList | mLayers |
qreal | mOpacity = 1.0 |
Symbol opacity (in the range 0 - 1) More... | |
RenderHints | mRenderHints |
SymbolType | mType |
Friends | |
class | QgsFeatureRenderer |
Abstract base class for all rendered symbols.
Definition at line 63 of file qgssymbol.h.
Flags for controlling how symbol preview images are generated.
Enumerator | |
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FlagIncludeCrosshairsForMarkerSymbols | Include a crosshairs reference image in the background of marker symbol previews. |
Definition at line 377 of file qgssymbol.h.
Flags controlling behavior of symbols during rendering.
Enumerator | |
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DynamicRotation | Rotation of symbol may be changed during rendering and symbol should not be cached. |
Definition at line 104 of file qgssymbol.h.
Scale method.
Enumerator | |
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ScaleArea | Calculate scale by the area. |
ScaleDiameter | Calculate scale by the diameter. |
Definition at line 96 of file qgssymbol.h.
Type of the symbol.
Enumerator | |
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Marker | Marker symbol. |
Line | Line symbol. |
Fill | Fill symbol. |
Hybrid | Hybrid symbol. |
Definition at line 85 of file qgssymbol.h.
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Definition at line 251 of file qgssymbol.cpp.
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Definition at line 83 of file qgssymbol.cpp.
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Creates a line string in screen coordinates from a QgsCurve in map coordinates.
Definition at line 104 of file qgssymbol.cpp.
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inlinestaticprotected |
Creates a point in screen coordinates from a QgsPoint in map coordinates.
Definition at line 566 of file qgssymbol.h.
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staticprotected |
Creates a polygon in screen coordinates from a QgsPolygonXYin map coordinates.
If correctRingOrientation is true
then the ring will be oriented to match standard ring orientation, e.g. clockwise for exterior rings and counter-clockwise for interior rings.
Definition at line 236 of file qgssymbol.cpp.
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staticprotected |
Creates a polygon ring in screen coordinates from a QgsCurve in map coordinates.
If correctRingOrientation is true
then the ring will be oriented to match standard ring orientation, e.g. clockwise for exterior rings and counter-clockwise for interior rings.
Definition at line 165 of file qgssymbol.cpp.
bool QgsSymbol::appendSymbolLayer | ( | QgsSymbolLayer * | layer | ) |
Appends a symbol layer at the end of the current symbol layer list.
Ownership of layer is transferred to the symbol.
true
if the layer was successfully added, false
if the layer is not compatible with the symbol's type(). Definition at line 408 of file qgssymbol.cpp.
QImage QgsSymbol::asImage | ( | QSize | size, |
QgsRenderContext * | customContext = nullptr |
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Returns an image of the symbol at the specified size.
Optionally a custom render context may be given in order to ensure that the preview icon exactly matches the settings from that context.
Definition at line 623 of file qgssymbol.cpp.
QImage QgsSymbol::bigSymbolPreviewImage | ( | QgsExpressionContext * | expressionContext = nullptr , |
QgsSymbol::PreviewFlags | flags = QgsSymbol::FlagIncludeCrosshairsForMarkerSymbols |
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Returns a large (roughly 100x100 pixel) preview image for the symbol.
expressionContext | optional expression context, for evaluation of data defined symbol properties |
flags | optional flags to control how preview image is generated |
Definition at line 637 of file qgssymbol.cpp.
bool QgsSymbol::changeSymbolLayer | ( | int | index, |
QgsSymbolLayer * | layer | ||
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Deletes the current layer at the specified index and replaces it with layer.
Ownership of layer is transferred to the symbol.
Returns false
if layer is not compatible with the symbol's type(), or true
if the layer was successfully replaced.
Definition at line 438 of file qgssymbol.cpp.
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Returns whether features drawn by the symbol will be clipped to the render context's extent.
If this option is enabled then features which are partially outside the extent will be clipped. This speeds up rendering of the feature, but may have undesirable side effects for certain symbol types.
true
if features will be clipped Definition at line 499 of file qgssymbol.h.
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Returns a deep copy of this symbol.
Ownership is transferred to the caller.
Implemented in QgsFillSymbol, QgsLineSymbol, and QgsMarkerSymbol.
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Retrieve a cloned list of all layers that make up this symbol.
Ownership is transferred to the caller.
Definition at line 722 of file qgssymbol.cpp.
QColor QgsSymbol::color | ( | ) | const |
Returns the symbol's color.
For multi-layer symbols, this method returns the color of the first unlocked symbol layer.
Definition at line 514 of file qgssymbol.cpp.
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static |
Returns a new default symbol for the specified geometry type.
The caller takes ownership of the returned object.
Definition at line 320 of file qgssymbol.cpp.
bool QgsSymbol::deleteSymbolLayer | ( | int | index | ) |
Removes and deletes the symbol layer at the specified index.
Definition at line 418 of file qgssymbol.cpp.
void QgsSymbol::drawPreviewIcon | ( | QPainter * | painter, |
QSize | size, | ||
QgsRenderContext * | customContext = nullptr , |
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bool | selected = false , |
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const QgsExpressionContext * | expressionContext = nullptr , |
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const QgsLegendPatchShape * | patchShape = nullptr |
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Draws an icon of the symbol that occupies an area given by size using the specified painter.
Optionally a custom render context may be given in order to ensure that the preview icon exactly matches the settings from that context.
painter | destination painter |
size | size of the icon |
customContext | the context in which the rendering happens |
selected | set to true to render the symbol in a selected state |
expressionContext | optional custom expression context |
patchShape | optional patch shape to use for symbol preview. If not specified a default shape will be used instead. |
Definition at line 525 of file qgssymbol.cpp.
QString QgsSymbol::dump | ( | ) | const |
Returns a string dump of the symbol's properties.
Definition at line 683 of file qgssymbol.cpp.
void QgsSymbol::exportImage | ( | const QString & | path, |
const QString & | format, | ||
QSize | size | ||
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Export the symbol as an image format, to the specified path and with the given size.
If format is "SVG" then an SVG file will be created, otherwise a raster image of the specified format will be created.
Definition at line 603 of file qgssymbol.cpp.
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inline |
Returns true
if polygon features drawn by the symbol will be reoriented to follow the standard right-hand-rule orientation, in which the area that is bounded by the polygon is to the right of the boundary.
In particular, the exterior ring is oriented in a clockwise direction and the interior rings in a counter-clockwise direction.
Definition at line 521 of file qgssymbol.h.
bool QgsSymbol::hasDataDefinedProperties | ( | ) | const |
Returns whether the symbol utilizes any data defined properties.
Definition at line 771 of file qgssymbol.cpp.
bool QgsSymbol::insertSymbolLayer | ( | int | index, |
QgsSymbolLayer * | layer | ||
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Inserts a symbol layer to specified index.
Ownership of layer is transferred to the symbol.
index | The index at which the layer should be added |
layer | The symbol layer to add |
true
if the layer is added, false
if the index or the layer is bad Definition at line 395 of file qgssymbol.cpp.
const QgsVectorLayer * QgsSymbol::layer | ( | ) | const |
Definition at line 789 of file qgssymbol.cpp.
QgsMapUnitScale QgsSymbol::mapUnitScale | ( | ) | const |
Returns the map unit scale for the symbol.
If the symbol consists of multiple layers, the map unit scale is only returned if all layers have the same scale settings. If the settings differ, a default constructed map unit scale is returned.
Definition at line 278 of file qgssymbol.cpp.
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Returns the opacity for the symbol.
Definition at line 458 of file qgssymbol.h.
QgsUnitTypes::RenderUnit QgsSymbol::outputUnit | ( | ) | const |
Returns the units to use for sizes and widths within the symbol.
Individual symbol layer definitions will interpret this in different ways, e.g., a marker symbol may use it to specify the units for the marker size, while a line symbol may use it to specify the units for the line width.
Definition at line 257 of file qgssymbol.cpp.
PRIVATE void QgsSymbol::renderFeature | ( | const QgsFeature & | feature, |
QgsRenderContext & | context, | ||
int | layer = -1 , |
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bool | selected = false , |
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bool | drawVertexMarker = false , |
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int | currentVertexMarkerType = 0 , |
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double | currentVertexMarkerSize = 0.0 |
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Render a feature.
Before calling this the startRender() method should be called to initialize the rendering process. After rendering all features stopRender() must be called.
Definition at line 838 of file qgssymbol.cpp.
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Returns the rendering hint flags for the symbol.
Definition at line 477 of file qgssymbol.h.
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Renders a context using a particular symbol layer without passing in a geometry.
This is used as fallback, if the symbol being rendered is not compatible with the specified layer. In such a case, this method can be called and will call the layer's rendering method anyway but the geometry passed to the layer will be empty. This is required for layers that generate their own geometry from other information in the rendering context.
Definition at line 736 of file qgssymbol.cpp.
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Render editing vertex marker at specified point.
Definition at line 1338 of file qgssymbol.cpp.
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Sets whether features drawn by the symbol should be clipped to the render context's extent.
If this option is enabled then features which are partially outside the extent will be clipped. This speeds up rendering of the feature, but may have undesirable side effects for certain symbol types.
clipFeaturesToExtent | set to true to enable clipping (defaults to TRUE) |
Definition at line 488 of file qgssymbol.h.
void QgsSymbol::setColor | ( | const QColor & | color | ) |
Sets the color for the symbol.
Calling this method sets the color for each individual symbol layer contained within the symbol to color.
Locked symbol layers are skipped and are left unchanged.
Definition at line 504 of file qgssymbol.cpp.
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inline |
Sets whether polygon features drawn by the symbol should be reoriented to follow the standard right-hand-rule orientation, in which the area that is bounded by the polygon is to the right of the boundary.
In particular, the exterior ring is oriented in a clockwise direction and the interior rings in a counter-clockwise direction.
Definition at line 510 of file qgssymbol.h.
void QgsSymbol::setLayer | ( | const QgsVectorLayer * | layer | ) |
nullptr
after stopRender Definition at line 782 of file qgssymbol.cpp.
void QgsSymbol::setMapUnitScale | ( | const QgsMapUnitScale & | scale | ) |
Sets the map unit scale for the symbol.
Calling this method sets the scale for all symbol layers contained within the symbol.
Definition at line 311 of file qgssymbol.cpp.
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Sets the opacity for the symbol.
opacity | opacity value between 0 (fully transparent) and 1 (fully opaque) |
Definition at line 465 of file qgssymbol.h.
void QgsSymbol::setOutputUnit | ( | QgsUnitTypes::RenderUnit | unit | ) |
Sets the units to use for sizes and widths within the symbol.
Individual symbol definitions will interpret this in different ways, e.g., a marker symbol may use it to specify the units for the marker size, while a line symbol may use it to specify the units for the line width.
unit | output units |
Definition at line 302 of file qgssymbol.cpp.
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Sets rendering hint flags for the symbol.
Definition at line 471 of file qgssymbol.h.
void QgsSymbol::startRender | ( | QgsRenderContext & | context, |
const QgsFields & | fields = QgsFields() |
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Begins the rendering process for the symbol.
This must be called before renderFeature(), and should be followed by a call to stopRender().
context | render context which symbol will be drawn using |
fields | fields for features to be rendered (usually the associated vector layer's fields). Required for correct calculation of data defined overrides. |
Definition at line 454 of file qgssymbol.cpp.
void QgsSymbol::stopRender | ( | QgsRenderContext & | context | ) |
Ends the rendering process.
This should be called after rendering all desired features.
context | render context, must match the context specified when startRender() was called. |
Definition at line 479 of file qgssymbol.cpp.
QgsSymbolLayer * QgsSymbol::symbolLayer | ( | int | layer | ) |
Returns the symbol layer at the specified index.
Definition at line 385 of file qgssymbol.cpp.
const QgsSymbolLayer * QgsSymbol::symbolLayer | ( | int | layer | ) | const |
Returns the symbol layer at the specified index, const variant.
Definition at line 390 of file qgssymbol.cpp.
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Returns the total number of symbol layers contained in the symbol.
Definition at line 183 of file qgssymbol.h.
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Returns the list of symbol layers contained in the symbol.
Definition at line 133 of file qgssymbol.h.
QgsSymbolRenderContext * QgsSymbol::symbolRenderContext | ( | ) |
Returns the symbol render context.
Only valid between startRender and stopRender calls.
Definition at line 1333 of file qgssymbol.cpp.
QgsSymbolLayer * QgsSymbol::takeSymbolLayer | ( | int | index | ) |
Removes a symbol layer from the list and returns a pointer to it.
Ownership of the layer is handed to the caller.
index | The index of the layer to remove |
Definition at line 429 of file qgssymbol.cpp.
void QgsSymbol::toSld | ( | QDomDocument & | doc, |
QDomElement & | element, | ||
QgsStringMap | props | ||
) | const |
Converts the symbol to a SLD representation.
Definition at line 709 of file qgssymbol.cpp.
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Returns the symbol's type.
Definition at line 122 of file qgssymbol.h.
QSet< QString > QgsSymbol::usedAttributes | ( | const QgsRenderContext & | context | ) | const |
Returns a list of attributes required to render this feature.
This should include any attributes required by the symbology including the ones required by expressions.
Definition at line 757 of file qgssymbol.cpp.
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Definition at line 78 of file qgssymbol.h.
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Definition at line 637 of file qgssymbol.h.
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Definition at line 638 of file qgssymbol.h.
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Definition at line 640 of file qgssymbol.h.
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Definition at line 631 of file qgssymbol.h.
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Symbol opacity (in the range 0 - 1)
Definition at line 634 of file qgssymbol.h.
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Definition at line 636 of file qgssymbol.h.
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Definition at line 630 of file qgssymbol.h.