A paint effect which consists of a stack of other chained paint effects. More...

#include <qgseffectstack.h>

Inheritance diagram for QgsEffectStack:

Public Member Functions
	QgsEffectStack ()=default
	Constructor for empty QgsEffectStack. More...

	QgsEffectStack (const QgsEffectStack &other)

	QgsEffectStack (const QgsPaintEffect &effect)
	Creates a new QgsEffectStack effect from a single initial effect. More...

	~QgsEffectStack () override

void	appendEffect (QgsPaintEffect *effect)
	Appends an effect to the end of the stack. More...

bool	changeEffect (int index, QgsPaintEffect *effect)
	Replaces the effect at a specified position within the stack. More...

QgsEffectStack *	clone () const override
	Duplicates an effect by creating a deep copy of the effect. More...

int	count () const
	Returns count of effects contained by the stack. More...

QgsPaintEffect *	effect (int index) const
	Returns a pointer to the effect at a specified index within the stack. More...

QList< QgsPaintEffect >	effectList ()
	Returns a pointer to the list of effects currently contained by the stack. More...

bool	insertEffect (int index, QgsPaintEffect *effect)
	Inserts an effect at a specified index within the stack. More...

QgsEffectStack &	operator= (const QgsEffectStack &rhs)

QgsStringMap	properties () const override
	Unused for QgsEffectStack, will always return an empty string map. More...

bool	readProperties (const QDomElement &element) override
	Restores the effect to the state described by a DOM element. More...

void	readProperties (const QgsStringMap &props) override
	Unused for QgsEffectStack, props parameter will be ignored. More...

bool	saveProperties (QDomDocument &doc, QDomElement &element) const override
	Saves the current state of the effect to a DOM element. More...

QgsPaintEffect *	takeEffect (int index)
	Removes an effect from the stack and returns a pointer to it. 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...

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 void	render (QPicture &picture, QgsRenderContext &context)
	Renders a picture using the effect. More...

void	setDrawMode (DrawMode drawMode)
	Sets the draw mode for the effect. More...

void	setEnabled (bool enabled)
	Sets whether the effect is enabled. More...

Static Public Member Functions
static QgsPaintEffect *	create (const QgsStringMap &map)
	Creates a new QgsEffectStack effect. 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...

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 consists of a stack of other chained paint effects.

Effect stacks can be used to apply multiple paint effects to a QPicture. For instance, an effect stack may blur then apply a drop shadow.

The way in which effects apply to a stack is controlled by the effect's drawMode. Effects can either render their results onto the destination paint device, or just modify the source picture which is drawn by subsequent effects in the stack. For instance, a blur effect with a Modifier drawMode will blur the source picture for the following drop shadow effect without actually drawing the blurred picture to the paint device. If the blur effect had a Render drawMode then the blurred picture will be drawn on the paint device, but the following drop shadow effect will be drawn using the original picture, not the blurred version.

Since: QGIS 2.9

Definition at line 44 of file qgseffectstack.h.

Constructor & Destructor Documentation

◆ QgsEffectStack() [1/3]

QgsEffectStack::QgsEffectStack ( )

default

Constructor for empty QgsEffectStack.

◆ QgsEffectStack() [2/3]

QgsEffectStack::QgsEffectStack ( const QgsEffectStack & other )

Definition at line 24 of file qgseffectstack.cpp.

◆ QgsEffectStack() [3/3]

QgsEffectStack::QgsEffectStack ( const QgsPaintEffect & effect )

explicit

Creates a new QgsEffectStack effect from a single initial effect.

Parameters

effect initial effect to add to the stack. The effect will be cloned, so ownership is not transferred to the stack.

Returns: new QgsEffectStack containing initial effect

Definition at line 34 of file qgseffectstack.cpp.

◆ ~QgsEffectStack()

QgsEffectStack::~QgsEffectStack ( )

override

Definition at line 39 of file qgseffectstack.cpp.

Member Function Documentation

◆ appendEffect()

void QgsEffectStack::appendEffect ( QgsPaintEffect * effect )

Appends an effect to the end of the stack.

Parameters

effect QgsPaintEffect to append. Ownership of the effect will be transferred to the stack object.

See also: insertEffect

Definition at line 204 of file qgseffectstack.cpp.

◆ changeEffect()

bool QgsEffectStack::changeEffect	(	int	index,
		QgsPaintEffect *	effect
	)

Replaces the effect at a specified position within the stack.

Parameters

index	position of effect to replace
effect	QgsPaintEffect to replace with. Ownership of the effect will be transferred to the stack object.

Definition at line 220 of file qgseffectstack.cpp.

◆ clone()

QgsEffectStack * QgsEffectStack::clone ( ) const

overridevirtual

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

Returns: clone of paint effect

Implements QgsPaintEffect.

Definition at line 136 of file qgseffectstack.cpp.

◆ count()

int QgsEffectStack::count ( ) const

inline

Returns count of effects contained by the stack.

Returns: count of effects

Definition at line 131 of file qgseffectstack.h.

◆ create()

QgsPaintEffect * QgsEffectStack::create ( const QgsStringMap & map )

static

Creates a new QgsEffectStack effect.

This method ignores the map parameter, and always returns an empty effect stack.

Parameters

map	unused encoded properties string map

Returns: new QgsEffectStack

Definition at line 59 of file qgseffectstack.cpp.

◆ draw()

void QgsEffectStack::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 66 of file qgseffectstack.cpp.

◆ effect()

QgsPaintEffect * QgsEffectStack::effect ( int index ) const

Returns a pointer to the effect at a specified index within the stack.

Parameters

index position of effect to return

Returns: QgsPaintEffect at specified position

Definition at line 245 of file qgseffectstack.cpp.

◆ effectList()

QList< QgsPaintEffect * > * QgsEffectStack::effectList ( )

Returns a pointer to the list of effects currently contained by the stack.

Returns: list of QgsPaintEffects within the stack

Definition at line 240 of file qgseffectstack.cpp.

◆ insertEffect()

bool QgsEffectStack::insertEffect	(	int	index,
		QgsPaintEffect *	effect
	)

Inserts an effect at a specified index within the stack.

Parameters

index	position to insert the effect
effect	QgsPaintEffect to insert. Ownership of the effect will be transferred to the stack object.

See also: appendEffect

Definition at line 209 of file qgseffectstack.cpp.

◆ operator=()

QgsEffectStack & QgsEffectStack::operator= ( const QgsEffectStack & rhs )

Definition at line 44 of file qgseffectstack.cpp.

◆ properties()

QgsStringMap QgsEffectStack::properties ( ) const

overridevirtual

Unused for QgsEffectStack, will always return an empty string map.

Implements QgsPaintEffect.

Definition at line 187 of file qgseffectstack.cpp.

◆ readProperties() [1/2]

bool QgsEffectStack::readProperties ( const QDomElement & element )

overridevirtual

Restores the effect to the state described by a DOM element.

Parameters

element DOM element describing an effect's state

Returns: true if read was successful

See also: saveProperties

Reimplemented from QgsPaintEffect.

Definition at line 164 of file qgseffectstack.cpp.

◆ readProperties() [2/2]

void QgsEffectStack::readProperties ( const QgsStringMap & props )

overridevirtual

Unused for QgsEffectStack, props parameter will be ignored.

Implements QgsPaintEffect.

Definition at line 193 of file qgseffectstack.cpp.

◆ saveProperties()

bool QgsEffectStack::saveProperties	(	QDomDocument &	doc,
		QDomElement &	element
	)		const

overridevirtual

Saves the current state of the effect to a DOM element.

The default behavior is to save the properties string map returned by properties().

Parameters

doc	destination DOM document
element	destination DOM element

Returns: true if save was successful

See also: readProperties

Reimplemented from QgsPaintEffect.

Definition at line 141 of file qgseffectstack.cpp.

◆ takeEffect()

QgsPaintEffect * QgsEffectStack::takeEffect ( int index )

Removes an effect from the stack and returns a pointer to it.

Parameters

index position of effect to take

Definition at line 232 of file qgseffectstack.cpp.

◆ type()

QString QgsEffectStack::type ( ) const

inlineoverridevirtual

Returns the effect type.

Returns: unique string representation of the effect type

Implements QgsPaintEffect.

Definition at line 74 of file qgseffectstack.h.

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

/tmp/buildd/qgis-3.6.0+99unstable/src/core/effects/qgseffectstack.h
/tmp/buildd/qgis-3.6.0+99unstable/src/core/effects/qgseffectstack.cpp

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsEffectStack() [1/3]

◆ QgsEffectStack() [2/3]

◆ QgsEffectStack() [3/3]

◆ ~QgsEffectStack()

Member Function Documentation

◆ appendEffect()

◆ changeEffect()

◆ clone()

◆ count()

◆ create()

◆ draw()

◆ effect()

◆ effectList()

◆ insertEffect()

◆ operator=()

◆ properties()

◆ readProperties() [1/2]

◆ readProperties() [2/2]

◆ saveProperties()

◆ takeEffect()

◆ type()