QgsColorEffect Class Reference

A paint effect which alters the colors (e.g., brightness, contrast) in a source picture. More...

#include <qgscoloreffect.h>

Inheritance diagram for QgsColorEffect:

Public Member Functions
	QgsColorEffect ()
QPainter::CompositionMode	blendMode () const
	Returns the blend mode for the effect. More...
int	brightness () const
	Returns the brightness modification for the effect. More...
QgsColorEffect *	clone () const override
	Duplicates an effect by creating a deep copy of the effect. More...
QColor	colorizeColor () const
	Returns the color used for colorizing a picture. More...
bool	colorizeOn () const
	Returns whether the effect will colorize a picture. More...
int	colorizeStrength () const
	Returns the strength used for colorizing a picture. More...
int	contrast () const
	Returns the contrast modification for the effect. More...
QgsImageOperation::GrayscaleMode	grayscaleMode () const
	Returns whether the effect will convert a picture to grayscale. More...
double	opacity () const
	Returns the opacity for the effect. More...
QVariantMap	properties () const override
	Returns the properties describing the paint effect encoded in a string format. More...
void	readProperties (const QVariantMap &props) override
	Reads a string map of an effect's properties and restores the effect to the state described by the properties map. More...
double	saturation () const
	Returns the saturation modification for the effect. More...
void	setBlendMode (const QPainter::CompositionMode mode)
	Sets the blend mode for the effect. More...
void	setBrightness (int brightness)
	Sets the brightness modification for the effect. More...
void	setColorizeColor (const QColor &colorizeColor)
	Sets the color used for colorizing a picture. More...
void	setColorizeOn (bool colorizeOn)
	Sets whether the effect should colorize a picture. More...
void	setColorizeStrength (int colorizeStrength)
	Sets the strength for colorizing a picture. More...
void	setContrast (int contrast)
	Sets the contrast modification for the effect. More...
void	setGrayscaleMode (QgsImageOperation::GrayscaleMode grayscaleMode)
	Sets whether the effect should convert a picture to grayscale. More...
void	setOpacity (const double opacity)
	Sets the opacity for the effect. More...
void	setSaturation (double saturation)
	Sets the saturation modification for the effect. More...
QString	type () const override
	Returns the effect type. More...
Public Member Functions inherited from QgsPaintEffect
	QgsPaintEffect ()=default
	Constructor for QgsPaintEffect. More...
	QgsPaintEffect (const QgsPaintEffect &other)
virtual	~QgsPaintEffect ()
virtual void	begin (QgsRenderContext &context)
	Begins intercepting paint operations to a render context. More...
virtual QgsPaintEffect *	clone () const =0
	Duplicates an effect by creating a deep copy of the effect. More...
DrawMode	drawMode () const
	Returns the draw mode for the effect. More...
bool	enabled () const
	Returns whether the effect is enabled. More...
virtual void	end (QgsRenderContext &context)
	Ends interception of paint operations to a render context, and draws the result to the render context after being modified by the effect. More...
virtual QVariantMap	properties () const =0
	Returns the properties describing the paint effect encoded in a string format. More...
virtual bool	readProperties (const QDomElement &element)
	Restores the effect to the state described by a DOM element. More...
virtual void	readProperties (const QVariantMap &props)=0
	Reads a string map of an effect's properties and restores the effect to the state described by the properties map. More...
virtual void	render (QPicture &picture, QgsRenderContext &context)
	Renders a picture using the effect. More...
virtual bool	saveProperties (QDomDocument &doc, QDomElement &element) const
	Saves the current state of the effect to a DOM element. More...
void	setDrawMode (DrawMode drawMode)
	Sets the draw mode for the effect. More...
void	setEnabled (bool enabled)
	Sets whether the effect is enabled. More...
virtual QString	type () const =0
	Returns the effect type. More...

Static Public Member Functions
static QgsPaintEffect *	create (const QVariantMap &map)
	Creates a new QgsColorEffect effect from a properties string map. More...

Protected Member Functions
void	draw (QgsRenderContext &context) override
	Handles drawing of the effect's result on to the specified render context. More...
Protected Member Functions inherited from QgsPaintEffect
virtual QRectF	boundingRect (const QRectF &rect, const QgsRenderContext &context) const
	Returns the bounding rect required for drawing the effect. More...
virtual void	draw (QgsRenderContext &context)=0
	Handles drawing of the effect's result on to the specified render context. More...
void	drawSource (QPainter &painter)
	Draws the source QPicture onto the specified painter. More...
void	fixQPictureDpi (QPainter *painter) const
	Applies a workaround to a QPainter to avoid an issue with incorrect scaling when drawing QPictures. More...
QPointF	imageOffset (const QgsRenderContext &context) const
	Returns the offset which should be used when drawing the source image on to a destination render context. More...
const QPicture *	source () const
	Returns the source QPicture. More...
QImage *	sourceAsImage (QgsRenderContext &context)
	Returns the source QPicture rendered to a new QImage. More...

Additional Inherited Members
Public Types inherited from QgsPaintEffect
enum	DrawMode { Modifier , Render , ModifyAndRender }
	Drawing modes for effects. More...
Protected Attributes inherited from QgsPaintEffect
DrawMode	mDrawMode = ModifyAndRender
bool	mEnabled = true
bool	requiresQPainterDpiFix = true

Detailed Description

A paint effect which alters the colors (e.g., brightness, contrast) in a source picture.

Since

QGIS 2.9

Definition at line 35 of file qgscoloreffect.h.

Constructor & Destructor Documentation

QgsColorEffect()

QgsColorEffect::QgsColorEffect

(

)

Definition at line 30 of file qgscoloreffect.cpp.

Member Function Documentation

blendMode()

QPainter::CompositionMode QgsColorEffect::blendMode ( ) const

inline

Returns the blend mode for the effect.

Returns

blend mode used for drawing the effect on to a destination paint device

See also

setBlendMode

Definition at line 210 of file qgscoloreffect.h.

brightness()

int QgsColorEffect::brightness ( ) const

inline

Returns the brightness modification for the effect.

Returns

brightness value. Values are between -255 and 255, where 0 represents no change, negative values indicate darkening and positive values indicate lightening

See also

setBrightness

Definition at line 70 of file qgscoloreffect.h.

clone()

QgsColorEffect * QgsColorEffect::clone ( ) const

overridevirtual

Duplicates an effect by creating a deep copy of the effect.

Returns

clone of paint effect

Implements QgsPaintEffect.

Definition at line 132 of file qgscoloreffect.cpp.

colorizeColor()

QColor QgsColorEffect::colorizeColor ( ) const

inline

Returns the color used for colorizing a picture.

This is only used if colorizeOn() is set to true.

Returns

colorization color

See also

setColorizeColor

colorizeOn

colorizeStrength

Definition at line 158 of file qgscoloreffect.h.

colorizeOn()

bool QgsColorEffect::colorizeOn ( ) const

inline

Returns whether the effect will colorize a picture.

Returns

true if colorization is enabled

See also

setColorizeOn

colorizeColor

colorizeStrength

Definition at line 138 of file qgscoloreffect.h.

colorizeStrength()

int QgsColorEffect::colorizeStrength ( ) const

inline

Returns the strength used for colorizing a picture.

This is only used if setColorizeOn() is set to true.

Returns

colorization strength, between 0 and 100

See also

setColorizeStrength

colorizeOn

colorizeColor

Definition at line 178 of file qgscoloreffect.h.

contrast()

int QgsColorEffect::contrast ( ) const

inline

Returns the contrast modification for the effect.

Returns

contrast value. Values are between -100 and 100, where 0 represents no change, negative values indicate less contrast and positive values indicate greater contrast

See also

setContrast

Definition at line 88 of file qgscoloreffect.h.

create()

QgsPaintEffect * QgsColorEffect::create ( const QVariantMap &  map )

static

Creates a new QgsColorEffect effect from a properties string map.

Parameters

map	encoded properties string map

Returns

new QgsColorEffect

Definition at line 23 of file qgscoloreffect.cpp.

draw()

void QgsColorEffect::draw ( QgsRenderContext &  context )

overrideprotectedvirtual

Handles drawing of the effect's result on to the specified render context.

Derived classes must reimplement this method to apply any transformations to the source QPicture and draw the result using the context's painter.

Parameters

context

destination render context

See also

drawSource

Implements QgsPaintEffect.

Definition at line 36 of file qgscoloreffect.cpp.

grayscaleMode()

QgsImageOperation::GrayscaleMode QgsColorEffect::grayscaleMode ( ) const

inline

Returns whether the effect will convert a picture to grayscale.

Returns

method for grayscale conversion

See also

setGrayscaleMode

Definition at line 120 of file qgscoloreffect.h.

opacity()

double QgsColorEffect::opacity ( ) const

inline

Returns the opacity for the effect.

Returns

opacity value between 0 and 1 inclusive, where 0 is fully transparent and 1 is fully opaque.

See also

setOpacity()

Definition at line 194 of file qgscoloreffect.h.

properties()

QVariantMap QgsColorEffect::properties ( ) const

overridevirtual

Returns the properties describing the paint effect encoded in a string format.

Returns

string map of properties, in the form property key, value

See also

readProperties

saveProperties

Implements QgsPaintEffect.

Definition at line 75 of file qgscoloreffect.cpp.

readProperties()

void QgsColorEffect::readProperties ( const QVariantMap &  props )

overridevirtual

Reads a string map of an effect's properties and restores the effect to the state described by the properties map.

Parameters

props

effect properties encoded in a string map

See also

properties

Implements QgsPaintEffect.

Definition at line 93 of file qgscoloreffect.cpp.

saturation()

double QgsColorEffect::saturation ( ) const

inline

Returns the saturation modification for the effect.

Returns

saturation value. Values are between 0 and 2.0, where 1.0 represents no change, 0.0 represents totally desaturated (grayscale), and positive values indicate greater saturation

See also

setSaturation

Definition at line 106 of file qgscoloreffect.h.

setBlendMode()

void QgsColorEffect::setBlendMode ( const QPainter::CompositionMode  mode )

inline

Sets the blend mode for the effect.

Parameters

mode	blend mode used for drawing the effect on to a destination paint device

See also

blendMode

Definition at line 202 of file qgscoloreffect.h.

setBrightness()

void QgsColorEffect::setBrightness

(

int

brightness

)

Sets the brightness modification for the effect.

Parameters

brightness

Valid values are between -255 and 255, where 0 represents no change, negative values indicate darkening and positive values indicate lightening

See also

setBrightness

Definition at line 138 of file qgscoloreffect.cpp.

setColorizeColor()

void QgsColorEffect::setColorizeColor

(

const QColor &

colorizeColor

)

Sets the color used for colorizing a picture.

This is only used if setColorizeOn() is set to true.

Parameters

colorizeColor

colorization color

See also

colorizeColor

setColorizeOn

setColorizeStrength

Definition at line 148 of file qgscoloreffect.cpp.

setColorizeOn()

void QgsColorEffect::setColorizeOn ( bool  colorizeOn )

inline

Sets whether the effect should colorize a picture.

Parameters

colorizeOn

set to true to enable colorization

See also

colorizeOn

setColorizeColor

setColorizeStrength

Definition at line 129 of file qgscoloreffect.h.

setColorizeStrength()

void QgsColorEffect::setColorizeStrength ( int  colorizeStrength )

inline

Sets the strength for colorizing a picture.

This is only used if setColorizeOn() is set to true.

Parameters

colorizeStrength

colorization strength, between 0 and 100

See also

colorizeStrength

setColorizeOn

setColorizeColor

Definition at line 168 of file qgscoloreffect.h.

setContrast()

void QgsColorEffect::setContrast

(

int

contrast

)

Sets the contrast modification for the effect.

Parameters

contrast

Valid values are between -100 and 100, where 0 represents no change, negative values indicate less contrast and positive values indicate greater contrast

See also

setContrast

Definition at line 143 of file qgscoloreffect.cpp.

setGrayscaleMode()

void QgsColorEffect::setGrayscaleMode ( QgsImageOperation::GrayscaleMode  grayscaleMode )

inline

Sets whether the effect should convert a picture to grayscale.

Parameters

grayscaleMode

method for grayscale conversion

See also

grayscaleMode

Definition at line 113 of file qgscoloreffect.h.

setOpacity()

void QgsColorEffect::setOpacity ( const double  opacity )

inline

Sets the opacity for the effect.

Parameters

opacity

double between 0 and 1 inclusive, where 0 is fully transparent and 1 is fully opaque

See also

opacity()

Definition at line 186 of file qgscoloreffect.h.

setSaturation()

void QgsColorEffect::setSaturation ( double  saturation )

inline

Sets the saturation modification for the effect.

Parameters

saturation

Valid values are between 0 and 2.0, where 1.0 represents no change, 0.0 represents totally desaturated (grayscale), and positive values indicate greater saturation

See also

saturation

Definition at line 97 of file qgscoloreffect.h.

type()

QString QgsColorEffect::type ( ) const

inlineoverridevirtual

Returns the effect type.

Returns

unique string representation of the effect type

Implements QgsPaintEffect.

Definition at line 49 of file qgscoloreffect.h.

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

• /build/qgis-3.28.0+99sid/src/core/effects/qgscoloreffect.h
• /build/qgis-3.28.0+99sid/src/core/effects/qgscoloreffect.cpp