QGIS API Documentation
3.14.0-Pi (9f7028fd23)
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41 #include <QTextDocument>
42 #include <QTextFragment>
49 , mLayerGeometryType( layer->geometryType() )
50 , mRenderer( layer->renderer() )
51 , mFields( layer->fields() )
52 , mCrs( layer->
crs() )
56 if ( withFeatureLoop )
58 mSource = qgis::make_unique<QgsVectorLayerFeatureSource>(
layer );
67 , mLayerGeometryType( geometryType )
68 , mRenderer( nullptr )
140 QSet<QString> attrNames;
141 if ( !
prepare( ctx, attrNames ) )
142 return QList<QgsLabelFeature *>();
171 if ( !symbols.isEmpty() )
173 symbol = symbols.at( 0 );
205 std::unique_ptr< QgsAbstractGeometry > obstacleGeom;
207 obstacleGeom = qgis::make_unique< QgsMultiPolygon >();
210 for (
int i = 0; i < fet.
geometry().constGet()->nCoordinates(); ++i )
233 const auto constSymbols = symbols;
238 if ( bounds.isValid() )
239 bounds = bounds.united(
static_cast< QgsMarkerSymbol *
>( symbol )->bounds( pt, context, fet ) );
241 bounds =
static_cast< QgsMarkerSymbol *
>( symbol )->bounds( pt, context, fet );
246 QVector< double > bX;
247 bX << bounds.left() << bounds.right() << bounds.right() << bounds.left();
248 QVector< double > bY;
249 bY << bounds.top() << bounds.top() << bounds.bottom() << bounds.bottom();
250 std::unique_ptr< QgsLineString > boundLineString = qgis::make_unique< QgsLineString >( bX, bY );
254 for (
int i = 0; i < boundLineString->numPoints(); ++i )
257 static_cast<int>( boundLineString->yAt( i ) ) );
258 boundLineString->setXAt( i, point.
x() );
259 boundLineString->setYAt( i, point.
y() );
272 boundLineString->close();
277 boundLineString->filterVertices( [](
const QgsPoint & point )->
bool
279 return std::isfinite( point.
x() ) && std::isfinite( point.
y() );
281 if ( !boundLineString->isRing() )
285 std::unique_ptr< QgsPolygon > obstaclePolygon = qgis::make_unique< QgsPolygon >();
286 obstaclePolygon->setExteriorRing( boundLineString.release() );
290 static_cast<QgsMultiPolygon *
>( obstacleGeom.get() )->addGeometry( obstaclePolygon.release() );
294 obstacleGeom = std::move( obstaclePolygon );
309 drawCallout( context, label );
327 QRectF rect( outPt.x(), outPt.y(), outPt2.
x() - outPt.x(), outPt2.
y() - outPt.y() );
350 const QMap< QgsPalLayerSettings::Property, QVariant > &ddValues = lf->
dataDefinedValues();
355 QgsDebugMsgLevel( QStringLiteral(
"PAL font definedFont: %1, Style: %2" ).arg( dFont.toString(), dFont.styleName() ), 4 );
362 format.
setSize( dFont.pixelSize() );
371 case LabelPosition::QuadrantAboveLeft:
372 case LabelPosition::QuadrantLeft:
373 case LabelPosition::QuadrantBelowLeft:
376 case LabelPosition::QuadrantAbove:
377 case LabelPosition::QuadrantOver:
378 case LabelPosition::QuadrantBelow:
381 case LabelPosition::QuadrantAboveRight:
382 case LabelPosition::QuadrantRight:
383 case LabelPosition::QuadrantBelowRight:
390 QgsPalLabeling::dataDefinedTextStyle( tmpLyr, ddValues );
393 QgsPalLabeling::dataDefinedTextBuffer( tmpLyr, ddValues );
396 QgsPalLabeling::dataDefinedTextMask( tmpLyr, ddValues );
399 QgsPalLabeling::dataDefinedTextFormatting( tmpLyr, ddValues );
402 QgsPalLabeling::dataDefinedShapeBackground( tmpLyr, ddValues );
405 QgsPalLabeling::dataDefinedDropShadow( tmpLyr, ddValues );
413 drawCallout( context, label );
474 QPainter *painter = context.
painter();
492 QRectF rect( 0, 0, outPt2.
x() - outPt.x(), outPt2.
y() - outPt.y() );
494 painter->setRenderHint( QPainter::Antialiasing,
false );
495 painter->translate( QPointF( outPt.x(), outPt.y() ) );
496 painter->rotate( -label->
getAlpha() * 180 / M_PI );
500 painter->setBrush( QColor( 255, 0, 0, 100 ) );
501 painter->setPen( QColor( 255, 0, 0, 150 ) );
505 painter->setBrush( QColor( 0, 255, 0, 100 ) );
506 painter->setPen( QColor( 0, 255, 0, 150 ) );
509 painter->drawRect( rect );
518 QgsTextRenderer::Component component;
519 component.dpiRatio = dpiRatio;
520 component.origin = outPt;
521 component.rotation = label->
getAlpha();
526 QPointF centerPt( outPt );
530 double xc = outPt2.
x() - outPt.x();
531 double yc = outPt2.
y() - outPt.y();
533 double angle = -component.rotation;
534 double xd = xc * std::cos(
angle ) - yc * std::sin(
angle );
535 double yd = xc * std::sin(
angle ) + yc * std::cos(
angle );
537 centerPt.setX( centerPt.x() + xd );
538 centerPt.setY( centerPt.y() + yd );
540 component.center = centerPt;
546 component.size = QSizeF( labelWidthPx, labelHeightPx );
571 bool prependSymb =
false;
597 symb = symb + QStringLiteral(
"\n" );
602 symb = QStringLiteral(
"\n" ) + symb;
622 QgsTextRenderer::Component component;
623 component.origin = outPt;
624 component.rotation = label->
getAlpha();
631 for (
const QString line : multiLineList )
639 QgsTextRenderer::drawTextInternal( drawType, context, tmpLyr.
format(), component, document, labelfm,
Flags mFlags
Flags altering drawing and registration of features.
QgsCoordinateTransform ct
QgsTextBufferSettings & buffer()
Returns a reference to the text buffer settings.
const QMap< QgsPalLayerSettings::DataDefinedProperties, QVariant > & dataDefinedValues() const
Gets data-defined values.
double getY(int i=0) const
Returns the down-left y coordinate.
virtual void stopRender(QgsRenderContext &context)
To be called after rendering is complete.
QString text(int partId) const
Returns the text component corresponding to a specified label part.
QString leftDirectionSymbol
String to use for left direction arrows.
double convertToPainterUnits(double size, QgsUnitTypes::RenderUnit unit, const QgsMapUnitScale &scale=QgsMapUnitScale()) const
Converts a size from the specified units to painter units (pixels).
const QgsMapToPixel & mapToPixel() const
Returns the context's map to pixel transform, which transforms between map coordinates and device coo...
TextPart
Components of text.
void registerFeature(const QgsFeature &f, QgsRenderContext &context, QgsLabelFeature **labelFeature=nullptr, QgsGeometry obstacleGeometry=QgsGeometry(), const QgsSymbol *symbol=nullptr)
Register a feature for labeling.
void setFont(const QFont &font)
Sets the font used for rendering text.
QString layerId() const
Returns ID of associated layer, or empty string if no layer is associated with the provider.
bool reverseDirectionSymbol
True if direction symbols should be reversed.
QgsExpressionContext & expressionContext()
Gets the expression context.
QgsExpressionContextScope * popScope()
Removes the last scope from the expression context and return it.
bool enabled() const
Returns whether the background is enabled.
QgsFeatureRenderer * mRenderer
QList< QgsLabelFeature * > labelFeatures(QgsRenderContext &context) override
Returns list of label features (they are owned by the provider and thus deleted on its destruction)
Point geometry type, with support for z-dimension and m-values.
QFontMetricsF * labelFontMetrics()
Metrics of the font for rendering.
@ Background
Background shape.
#define QgsDebugMsgLevel(str, level)
@ ShadowBuffer
Draw shadow under buffer.
@ AlignCenter
Center align.
void drawLabel(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw this label at the position determined by the labeling engine.
@ DrawLabels
Whether the labels should be rendered.
const QgsCoordinateReferenceSystem & crs
QString mName
Name of the layer.
LabelPosition is a candidate feature label position.
QgsTextCharacterFormat characterFormat(int partId) const
Returns the character format corresponding to the specified label part.
QgsExpressionContextScope * lastScope()
Returns the last scope added to the context.
UpsideDownLabels upsidedownLabels
Controls whether upside down labels are displayed and how they are handled.
void setOriginalValueVariable(const QVariant &value)
Sets the original value variable value for the context.
const QgsLabelObstacleSettings & obstacleSettings() const
Returns the label obstacle settings.
QgsAbstractLabelProvider * provider() const
Returns pointer to the associated provider.
bool addDirectionSymbol
If true, '<' or '>' (or custom strings set via leftDirectionSymbol and rightDirectionSymbol) will be ...
bool mergeLines
true if connected line features with identical label text should be merged prior to generating label ...
QPointF toQPointF() const
Converts a point to a QPointF.
QgsTextShadowSettings & shadow()
Returns a reference to the text drop shadow settings.
Quadrant getQuadrant() const
QgsFeatureRequest & setSubsetOfAttributes(const QgsAttributeList &attrs)
Set a subset of attributes that will be fetched.
QgsPointXY toMapCoordinates(int x, int y) const
Transform device coordinates to map (world) coordinates.
@ Line
Arranges candidates parallel to a generalised line representing the feature or parallel to a polygon'...
LabelPosition * nextPart() const
Returns the next part of this label position (i.e.
const QgsRectangle & extent() const
When rendering a map layer, calling this method returns the "clipping" extent for the layer (in the l...
Class that adds extra information to QgsLabelFeature for text labels.
FeaturePart * getFeaturePart() const
Returns the feature corresponding to this labelposition.
std::unique_ptr< QgsAbstractFeatureSource > mSource
Layer's feature source.
bool enabled() const
Returns whether the shadow is enabled.
virtual void stopRender(QgsRenderContext &context)
Must be called when a render cycle has finished, to allow the renderer to clean up.
QString mProviderId
Associated provider ID (one layer may have multiple providers, e.g. in rule-based labeling)
virtual QgsPoint vertexAt(QgsVertexId id) const =0
Returns the point corresponding to a specified vertex id.
Layer * layer()
Returns the layer that feature belongs to.
const QgsPalLayerSettings & settings() const
Returns the layer's settings.
QgsFeatureRequest & setFilterRect(const QgsRectangle &rectangle)
Sets the rectangle from which features will be taken.
bool displayAll
If true, all features will be labelled even when overlaps occur.
const QgsLabelingEngineSettings & engineSettings() const
Gets associated labeling engine settings.
QgsFields mFields
Layer's fields.
QgsCoordinateTransform coordinateTransform() const
Returns the current coordinate transform for the context.
void setColor(const QColor &color)
Sets the color that text will be rendered in.
QgsPalLayerSettings::UpsideDownLabels mUpsidedownLabels
How to handle labels that would be upside down.
bool hasFixedPosition() const
Whether the label should use a fixed position instead of being automatically placed.
@ Curved
Arranges candidates following the curvature of a line feature. Applies to line layers only.
QString mLayerId
Associated layer's ID, if applicable.
@ MergeConnectedLines
Whether adjacent lines (with the same label text) should be merged.
void stopRender(QgsRenderContext &context) override
To be called after rendering is complete.
The QgsAbstractLabelProvider class is an interface class. Implementations return list of labels and t...
const QgsMaskIdProvider * maskIdProvider() const
Returns the mask id provider attached to the context.
bool labelAllParts() const
Returns true if all parts of the feature should be labeled.
@ CentroidMustBeInside
Whether location of centroid must be inside of polygons.
void stopRender(QgsRenderContext &context)
Finalises the label settings after use.
@ SymbolAbove
Place direction symbols on above label.
QString wrapChar
Wrapping character string.
QList< QgsSymbol * > QgsSymbolList
@ ShadowLowest
Draw shadow below all text components.
int autoWrapLength
If non-zero, indicates that label text should be automatically wrapped to (ideally) the specified num...
bool testFlag(Flag f) const
Test whether a particular flag is enabled.
MultiLineAlign multilineAlign
Horizontal alignment of multi-line labels.
virtual QgsSymbolList originalSymbolsForFeature(const QgsFeature &feature, QgsRenderContext &context) const
Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbol...
const QgsTextFormat & format() const
Returns the label text formatting settings, e.g., font settings, buffer settings, etc.
bool allFeaturePartsLabeled
true if all parts of associated feature were labeled
@ CalloutDraw
Show callout.
bool drawLabels
Whether to draw labels for this layer.
void setFormat(const QgsTextFormat &format)
Sets the label text formatting settings, e.g., font settings, buffer settings, etc.
QColor unplacedLabelColor() const
Returns the color to use when rendering unplaced labels.
void startRender(QgsRenderContext &context)
Prepares the label settings for rendering.
bool allowHtmlFormatting() const
Returns true if text should be treated as a HTML document and HTML tags should be used for formatting...
static QStringList splitToLines(const QString &text, const QString &wrapCharacter, int autoWrapLength=0, bool useMaxLineLengthWhenAutoWrapping=true)
Splits a text string to a list of separate lines, using a specified wrap character (wrapCharacter).
virtual DrawOrder drawOrder() const
Returns the desired drawing order (stacking) to use while rendering this callout.
QFont definedFont()
Font to be used for rendering.
QString id() const
Returns the layer's unique ID, which is used to access this layer from QgsProject.
void setShadowPlacement(QgsTextShadowSettings::ShadowPlacement placement)
Sets the placement for the drop shadow.
Multi polygon geometry collection.
virtual int nCoordinates() const
Returns the number of nodes contained in the geometry.
Struct for storing maximum and minimum scales for measurements in map units.
const QgsAbstractGeometry * constGet() const
Returns a non-modifiable (const) reference to the underlying abstract geometry primitive.
void drawUnplacedLabel(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw an unplaced label.
ObstacleType type() const
Returns how features act as obstacles for labels.
const QgsLabelingEngine * mEngine
Associated labeling engine.
QString providerId() const
Returns provider ID - useful in case there is more than one label provider within a layer (e....
ShapeType type() const
Returns the type of background shape (e.g., square, ellipse, SVG).
QgsPointXY transform(const QgsPointXY &p) const
Transform the point from map (world) coordinates to device coordinates.
@ ShadowShape
Draw shadow under background shape.
Single scope for storing variables and functions for use within a QgsExpressionContext....
int maskId(const QString &labelLayerId=QString(), const QString &labelRuleId=QString()) const
Returns the mask id associated with a label layer and its optional label rule.
void appendScope(QgsExpressionContextScope *scope)
Appends a scope to the end of the context.
DirectionSymbols placeDirectionSymbol
Placement option for direction symbols.
virtual void startRender(QgsRenderContext &context)
To be called before rendering of labels begins.
@ DrawAllLabels
Whether all features will be labelled even though overlaps occur.
bool prepare(QgsRenderContext &context, QSet< QString > &attributeNames, const QgsFields &fields, const QgsMapSettings &mapSettings, const QgsCoordinateReferenceSystem &crs)
Prepare for registration of features.
void init()
initialization method - called from constructors
void transformInPlace(double &x, double &y) const
Transform device coordinates to map coordinates.
int priority
Label priority.
bool enabled() const
Returns whether the buffer is enabled.
static QgsExpressionContextScope * updateSymbolScope(const QgsSymbol *symbol, QgsExpressionContextScope *symbolScope=nullptr)
Updates a symbol scope related to a QgsSymbol to an expression context.
QString rightDirectionSymbol
String to use for right direction arrows.
const QgsMapSettings & mapSettings() const
Gets associated map settings.
GeometryType
The geometry types are used to group QgsWkbTypes::Type in a coarse way.
GEOSGeometry * geometry() const
Gets access to the associated geometry.
bool nextFeature(QgsFeature &f)
bool conflictsWithObstacle() const
Returns whether the position is marked as conflicting with an obstacle feature.
void drawLabelPrivate(pal::LabelPosition *label, QgsRenderContext &context, QgsPalLayerSettings &tmpLyr, QgsTextRenderer::TextPart drawType, double dpiRatio=1.0) const
Internal label drawing method.
As part of the API refactoring and improvements which landed in the Processing API was substantially reworked from the x version This was done in order to allow much of the underlying Processing framework to be ported into c
bool valueAsBool(int key, const QgsExpressionContext &context, bool defaultValue=false, bool *ok=nullptr) const
Calculates the current value of the property with the specified key and interprets it as an boolean.
void drawLabelBackground(QgsRenderContext &context, pal::LabelPosition *label) const override
Draw the background for the specified label.
void startRender(QgsRenderContext &context) override
To be called before rendering of labels begins.
QgsLabelingResults * results() const
For internal use by the providers.
bool hasGeometry() const
Returns true if the feature has an associated geometry.
void render(QgsRenderContext &context, QRectF rect, const double angle, const QgsGeometry &anchor, QgsCalloutContext &calloutContext)
Renders the callout onto the specified render context.
@ ShadowText
Draw shadow under text.
double getX(int i=0) const
Returns the down-left x coordinate.
Utility class for identifying a unique vertex within a geometry.
QgsPalLayerSettings mSettings
Layer's labeling configuration.
void append(const QgsTextBlock &block)
Appends a block to the document.
Contains additional contextual information about the context in which a callout is being rendered.
@ DrawLabelRectOnly
Whether to only draw the label rect and not the actual label text (used for unit tests)
QgsTextDocument document() const
Returns the document for the label.
QList< QgsLabelFeature * > mLabels
List of generated.
virtual void registerFeature(const QgsFeature &feature, QgsRenderContext &context, const QgsGeometry &obstacleGeometry=QgsGeometry(), const QgsSymbol *symbol=nullptr)
Register a feature for labeling as one or more QgsLabelFeature objects stored into mLabels.
QgsCallout * callout() const
Returns the label callout renderer, responsible for drawing label callouts.
@ Label
Label-specific draw mode.
QgsMapLayer * layer() const
Returns the associated layer, or nullptr if no layer is associated with the provider.
bool useMaxLineLengthForAutoWrap
If true, indicates that when auto wrapping label text the autoWrapLength length indicates the maximum...
QFont font() const
Returns the font used for rendering text.
QgsTextBackgroundSettings & background()
Returns a reference to the text background settings.
void setSizeUnit(QgsUnitTypes::RenderUnit unit)
Sets the units for the size of rendered text.
static QgsGeometry getPointObstacleGeometry(QgsFeature &fet, QgsRenderContext &context, const QgsSymbolList &symbols)
Returns the geometry for a point feature which should be used as an obstacle for labels.
QgsWkbTypes::GeometryType mLayerGeometryType
Geometry type of layer.
The QgsLabelFeature class describes a feature that should be used within the labeling engine....
virtual bool prepare(QgsRenderContext &context, QSet< QString > &attributeNames)
Prepare for registration of features.
@ Buffer
Buffer component.
QgsLabelObstacleSettings::ObstacleType mObstacleType
Type of the obstacle of feature geometries.
double getAlpha() const
Returns the angle to rotate text (in rad).
QgsVectorLayerLabelProvider(QgsVectorLayer *layer, const QString &providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings, const QString &layerName=QString())
Convenience constructor to initialize the provider from given vector layer.
QPainter * painter()
Returns the destination QPainter for the render operation.
void setSize(double size)
Sets the size for rendered text.
QgsFeatureId featureId() const
Returns the unique ID of the feature.
@ ShapeMarkerSymbol
Marker symbol.
static std::unique_ptr< QgsAbstractGeometry > fromGeos(const GEOSGeometry *geos)
Create a geometry from a GEOSGeometry.
QgsPropertyCollection & dataDefinedProperties()
Returns a reference to the label's property collection, used for data defined overrides.
@ SymbolBelow
Place direction symbols on below label.
QgsTextShadowSettings::ShadowPlacement shadowPlacement() const
Returns the placement for the drop shadow.
bool isActive(int key) const override
Returns true if the collection contains an active property with the specified key.
QgsLabelFeature * feature()
Returns the parent feature.
~QgsVectorLayerLabelProvider() override
virtual void startRender(QgsRenderContext &context, const QgsFields &fields)
Must be called when a new render cycle is started.
QgsWkbTypes::GeometryType type
@ OrderBelowAllLabels
Render callouts below all labels.
void setCurrentMaskId(int id)
Stores a mask id as the "current" one.
@ OrderBelowIndividualLabels
Render callouts below their individual associated labels, some callouts may be drawn over other label...
double ANALYSIS_EXPORT angle(QgsPoint *p1, QgsPoint *p2, QgsPoint *p3, QgsPoint *p4)
Calculates the angle between two segments (in 2 dimension, z-values are ignored)
void setMapRotation(double degrees, double cx, double cy)
Set map rotation in degrees (clockwise)
QgsPalLayerSettings::Placement mPlacement
Placement strategy.
@ RenderMapUnits
Map units.
double mPriority
Default priority of labels.
QString labelText() const
Text of the label.
bool enabled() const
Returns true if the the callout is enabled.
bool centroidInside
true if centroid positioned labels must be placed inside their corresponding feature polygon,...
HAlignment
Horizontal alignment.
QgsCoordinateReferenceSystem mCrs
Layer's CRS.
void setFeature(const QgsFeature &feature)
Convenience function for setting a feature for the context.