QgsTextRenderer Class Reference

#include <qgstextrenderer.h>

Public Types
enum	DrawMode { Rect = 0, Point, Label }
	Draw mode to calculate width and height. More...
enum	HAlignment { AlignLeft = 0, AlignCenter, AlignRight }
	Horizontal alignment. More...
enum	TextPart { Text = 0, Buffer, Background, Shadow }
	Components of text. More...

Static Public Member Functions
static Q_DECL_DEPRECATED void	drawPart (const QRectF &rect, double rotation, HAlignment alignment, const QStringList &textLines, QgsRenderContext &context, const QgsTextFormat &format, TextPart part, bool drawAsOutlines=true)
	Draws a single component of rendered text using the specified settings. More...
static Q_DECL_DEPRECATED void	drawPart (QPointF origin, double rotation, HAlignment alignment, const QStringList &textLines, QgsRenderContext &context, const QgsTextFormat &format, TextPart part, bool drawAsOutlines=true)
	Draws a single component of rendered text using the specified settings. More...
static void	drawText (const QRectF &rect, double rotation, HAlignment alignment, const QStringList &textLines, QgsRenderContext &context, const QgsTextFormat &format, bool drawAsOutlines=true)
	Draws text within a rectangle using the specified settings. More...
static void	drawText (QPointF point, double rotation, HAlignment alignment, const QStringList &textLines, QgsRenderContext &context, const QgsTextFormat &format, bool drawAsOutlines=true)
	Draws text at a point origin using the specified settings. More...
static QFontMetricsF	fontMetrics (QgsRenderContext &context, const QgsTextFormat &format)
	Returns the font metrics for the given text format, when rendered in the specified render context. More...
static int	sizeToPixel (double size, const QgsRenderContext &c, QgsUnitTypes::RenderUnit unit, const QgsMapUnitScale &mapUnitScale=QgsMapUnitScale())
	Calculates pixel size (considering output size should be in pixel or map units, scale factors and optionally oversampling) More...
static double	textHeight (const QgsRenderContext &context, const QgsTextFormat &format, const QStringList &textLines, DrawMode mode=Point, QFontMetricsF *fontMetrics=nullptr)
	Returns the height of a text based on a given format. More...
static double	textWidth (const QgsRenderContext &context, const QgsTextFormat &format, const QStringList &textLines, QFontMetricsF *fontMetrics=nullptr)
	Returns the width of a text based on a given format. More...

Friends
class	QgsLabelPreview
class	QgsVectorLayerLabelProvider

Detailed Description

Handles rendering text using rich formatting options, including drop shadows, buffers and background shapes.

Since

QGIS 3.0

Definition at line 36 of file qgstextrenderer.h.

Member Enumeration Documentation

DrawMode

enum QgsTextRenderer::DrawMode

Draw mode to calculate width and height.

Enumerator
Rect	Text within rectangle draw mode.
Point	Text at point of origin draw mode.
Label	Label-specific draw mode.

Definition at line 41 of file qgstextrenderer.h.

HAlignment

enum QgsTextRenderer::HAlignment

Horizontal alignment.

Enumerator
AlignLeft	Left align.
AlignCenter	Center align.
AlignRight	Right align.

Definition at line 58 of file qgstextrenderer.h.

TextPart

enum QgsTextRenderer::TextPart

Components of text.

Enumerator
Text	Text component.
Buffer	Buffer component.
Background	Background shape.
Shadow	Drop shadow.

Definition at line 49 of file qgstextrenderer.h.

Member Function Documentation

drawPart() [1/2]

void QgsTextRenderer::drawPart ( const QRectF &  rect, double  rotation, HAlignment  alignment, const QStringList &  textLines, QgsRenderContext &  context, const QgsTextFormat &  format, QgsTextRenderer::TextPart  part, bool  drawAsOutlines = true  )

static

Draws a single component of rendered text using the specified settings.

Parameters

rect	destination rectangle for text
rotation	text rotation
alignment	horizontal alignment
textLines	list of lines of text to draw
context	render context
format	text format
part	component of text to draw. Note that Shadow parts cannot be drawn individually and instead are drawn with their associated part (e.g., drawn together with the text or background parts)
drawAsOutlines	set to false to render text as text. This allows outputs to formats like SVG to maintain text as text objects, but at the cost of degraded rendering and may result in side effects like misaligned text buffers. This setting is deprecated and has no effect as of QGIS 3.4.3 and the text format should be set using QgsRenderContext::setTextRenderFormat() instead.

Deprecated:

Private API only, will be removed in 4.0

Definition at line 110 of file qgstextrenderer.cpp.

drawPart() [2/2]

void QgsTextRenderer::drawPart ( QPointF  origin, double  rotation, QgsTextRenderer::HAlignment  alignment, const QStringList &  textLines, QgsRenderContext &  context, const QgsTextFormat &  format, QgsTextRenderer::TextPart  part, bool  drawAsOutlines = true  )

static

Draws a single component of rendered text using the specified settings.

Parameters

origin	origin for start of text. Y coordinate will be used as baseline.
rotation	text rotation
alignment	horizontal alignment
textLines	list of lines of text to draw
context	render context
format	text format
part	component of text to draw. Note that Shadow parts cannot be drawn individually and instead are drawn with their associated part (e.g., drawn together with the text or background parts)
drawAsOutlines	set to false to render text as text. This allows outputs to formats like SVG to maintain text as text objects, but at the cost of degraded rendering and may result in side effects like misaligned text buffers. This setting is deprecated and has no effect as of QGIS 3.4.3 and the text format should be set using QgsRenderContext::setTextRenderFormat() instead.

Deprecated:

Private API only, will be removed in 4.0

Definition at line 181 of file qgstextrenderer.cpp.

drawText() [1/2]

void QgsTextRenderer::drawText ( const QRectF &  rect, double  rotation, QgsTextRenderer::HAlignment  alignment, const QStringList &  textLines, QgsRenderContext &  context, const QgsTextFormat &  format, bool  drawAsOutlines = true  )

static

Draws text within a rectangle using the specified settings.

Parameters

rect	destination rectangle for text
rotation	text rotation
alignment	horizontal alignment
textLines	list of lines of text to draw
context	render context
format	text format
drawAsOutlines	set to false to render text as text. This allows outputs to formats like SVG to maintain text as text objects, but at the cost of degraded rendering and may result in side effects like misaligned text buffers. This setting is deprecated and has no effect as of QGIS 3.4.3 and the text format should be set using QgsRenderContext::setTextRenderFormat() instead.

Definition at line 45 of file qgstextrenderer.cpp.

drawText() [2/2]

void QgsTextRenderer::drawText ( QPointF  point, double  rotation, QgsTextRenderer::HAlignment  alignment, const QStringList &  textLines, QgsRenderContext &  context, const QgsTextFormat &  format, bool  drawAsOutlines = true  )

static

Draws text at a point origin using the specified settings.

Parameters

point	origin of text
rotation	text rotation
alignment	horizontal alignment
textLines	list of lines of text to draw
context	render context
format	text format
drawAsOutlines	set to false to render text as text. This allows outputs to formats like SVG to maintain text as text objects, but at the cost of degraded rendering and may result in side effects like misaligned text buffers. This setting is deprecated and has no effect as of QGIS 3.4.3 and the text format should be set using QgsRenderContext::setTextRenderFormat() instead.

Definition at line 67 of file qgstextrenderer.cpp.

fontMetrics()

QFontMetricsF QgsTextRenderer::fontMetrics ( QgsRenderContext &  context, const QgsTextFormat &  format  )

static

Returns the font metrics for the given text format, when rendered in the specified render context.

The font metrics will take into account all scaling required by the render context.

Since

QGIS 3.2

Definition at line 231 of file qgstextrenderer.cpp.

sizeToPixel()

int QgsTextRenderer::sizeToPixel ( double  size, const QgsRenderContext &  c, QgsUnitTypes::RenderUnit  unit, const QgsMapUnitScale &  mapUnitScale = QgsMapUnitScale()  )

static

Calculates pixel size (considering output size should be in pixel or map units, scale factors and optionally oversampling)

Parameters

size	size to convert
c	rendercontext
unit	size units
mapUnitScale	a mapUnitScale clamper

Returns

font pixel size

Definition at line 40 of file qgstextrenderer.cpp.

textHeight()

double QgsTextRenderer::textHeight ( const QgsRenderContext &  context, const QgsTextFormat &  format, const QStringList &  textLines, DrawMode  mode = Point, QFontMetricsF *  fontMetrics = nullptr  )

static

Returns the height of a text based on a given format.

Parameters

context	render context
format	text format
textLines	list of lines of text to calculate width from
mode	draw mode
fontMetrics	font metrics

Definition at line 515 of file qgstextrenderer.cpp.

textWidth()

double QgsTextRenderer::textWidth ( const QgsRenderContext &  context, const QgsTextFormat &  format, const QStringList &  textLines, QFontMetricsF *  fontMetrics = nullptr  )

static

Returns the width of a text based on a given format.

Parameters

context	render context
format	text format
textLines	list of lines of text to calculate width from
fontMetrics	font metrics

Definition at line 448 of file qgstextrenderer.cpp.

Friends And Related Function Documentation

QgsLabelPreview

friend class QgsLabelPreview

friend

Definition at line 289 of file qgstextrenderer.h.

QgsVectorLayerLabelProvider

friend class QgsVectorLayerLabelProvider

friend

Definition at line 288 of file qgstextrenderer.h.

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

• /build/qgis-3.14.0+99unstable/src/core/textrenderer/qgstextrenderer.h
• /build/qgis-3.14.0+99unstable/src/core/textrenderer/qgstextrenderer.cpp