QGIS API Documentation  2.18.3-Las Palmas (77b8c3d)
Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions | List of all members
QgsBlurEffect Class Reference

A paint effect which blurs a source picture, using a number of different blur methods. More...

#include <qgsblureffect.h>

Inheritance diagram for QgsBlurEffect:
Inheritance graph
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Public Types

enum  BlurMethod { StackBlur, GaussianBlur }
 Available blur methods (algorithms) More...
 
- Public Types inherited from QgsPaintEffect
enum  DrawMode { Modifier, Render, ModifyAndRender }
 Drawing modes for effects. More...
 

Public Member Functions

 QgsBlurEffect ()
 
virtual ~QgsBlurEffect ()
 
QPainter::CompositionMode blendMode () const
 Returns the blend mode for the effect. More...
 
int blurLevel () const
 Returns the blur level (strength) More...
 
BlurMethod blurMethod () const
 Returns the blur method (algorithm) used for performing the blur. More...
 
virtual QgsBlurEffectclone () const override
 Duplicates an effect by creating a deep copy of the effect. More...
 
virtual QgsStringMap properties () const override
 Returns the properties describing the paint effect encoded in a string format. More...
 
virtual void readProperties (const QgsStringMap &props) override
 Reads a string map of an effect's properties and restores the effect to the state described by the properties map. More...
 
void setBlendMode (const QPainter::CompositionMode mode)
 Sets the blend mode for the effect. More...
 
void setBlurLevel (const int level)
 Sets blur level (strength) More...
 
void setBlurMethod (const BlurMethod method)
 Sets the blur method (algorithm) to use for performing the blur. More...
 
void setTransparency (const double transparency)
 Sets the transparency for the effect. More...
 
double transparency () const
 Returns the transparency for the effect. More...
 
virtual QString type () const override
 Returns the effect type. More...
 
- Public Member Functions inherited from QgsPaintEffect
 QgsPaintEffect ()
 
 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 bool readProperties (const QDomElement &element)
 Restores the effect to the state described by a DOM element. 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 (const DrawMode drawMode)
 Sets the draw mode for the effect. More...
 
void setEnabled (const bool enabled)
 Sets whether the effect is enabled. More...
 

Static Public Member Functions

static QgsPaintEffectcreate (const QgsStringMap &map)
 Creates a new QgsBlurEffect effect from a properties string map. More...
 

Protected Member Functions

virtual QRectF boundingRect (const QRectF &rect, const QgsRenderContext &context) const override
 Returns the bounding rect required for drawing the effect. More...
 
virtual 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
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 QPicturesource () const
 Returns the source QPicture. More...
 
QImagesourceAsImage (QgsRenderContext &context)
 Returns the source QPicture rendered to a new QImage. More...
 

Additional Inherited Members

- Protected Attributes inherited from QgsPaintEffect
DrawMode mDrawMode
 
bool mEnabled
 
bool requiresQPainterDpiFix
 

Detailed Description

A paint effect which blurs a source picture, using a number of different blur methods.

Note
Added in version 2.9

Definition at line 32 of file qgsblureffect.h.

Member Enumeration Documentation

Available blur methods (algorithms)

Enumerator
StackBlur 

stack blur, a fast but low quality blur. Valid blur level values are between 0 - 16.

GaussianBlur 

Gaussian blur, a slower but high quality blur. Blur level values are the distance in pixels for the blur operation.

Definition at line 38 of file qgsblureffect.h.

Constructor & Destructor Documentation

QgsBlurEffect::QgsBlurEffect ( )

Definition at line 28 of file qgsblureffect.cpp.

QgsBlurEffect::~QgsBlurEffect ( )
virtual

Definition at line 38 of file qgsblureffect.cpp.

Member Function Documentation

QPainter::CompositionMode QgsBlurEffect::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 112 of file qgsblureffect.h.

int QgsBlurEffect::blurLevel ( ) const
inline

Returns the blur level (strength)

Returns
blur level. Depending on the current blurMethod, this parameter has different effects
See also
setBlurLevel
blurMethod

Definition at line 72 of file qgsblureffect.h.

BlurMethod QgsBlurEffect::blurMethod ( ) const
inline

Returns the blur method (algorithm) used for performing the blur.

Returns
blur method
See also
setBlurMethod

Definition at line 84 of file qgsblureffect.h.

QRectF QgsBlurEffect::boundingRect ( const QRectF rect,
const QgsRenderContext context 
) const
overrideprotectedvirtual

Returns the bounding rect required for drawing the effect.

This method can be used to expand the bounding rect of a source picture to account for offset or blurring effects.

Parameters
rectoriginal source bounding rect
contextdestination render context
Returns
modified bounding rect
See also
sourceAsImage

Reimplemented from QgsPaintEffect.

Definition at line 130 of file qgsblureffect.cpp.

QgsBlurEffect * QgsBlurEffect::clone ( ) const
overridevirtual

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

Returns
clone of paint effect

Implements QgsPaintEffect.

Definition at line 124 of file qgsblureffect.cpp.

QgsPaintEffect * QgsBlurEffect::create ( const QgsStringMap map)
static

Creates a new QgsBlurEffect effect from a properties string map.

Parameters
mapencoded properties string map
Returns
new QgsBlurEffect

Definition at line 21 of file qgsblureffect.cpp.

void QgsBlurEffect::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
contextdestination render context
See also
drawSource

Implements QgsPaintEffect.

Definition at line 43 of file qgsblureffect.cpp.

QgsStringMap QgsBlurEffect::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 85 of file qgsblureffect.cpp.

void QgsBlurEffect::readProperties ( const QgsStringMap props)
overridevirtual

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

Parameters
propseffect properties encoded in a string map
See also
properties

Implements QgsPaintEffect.

Definition at line 97 of file qgsblureffect.cpp.

void QgsBlurEffect::setBlendMode ( const QPainter::CompositionMode  mode)
inline

Sets the blend mode for the effect.

Parameters
modeblend mode used for drawing the effect on to a destination paint device
See also
blendMode

Definition at line 105 of file qgsblureffect.h.

void QgsBlurEffect::setBlurLevel ( const int  level)
inline

Sets blur level (strength)

Parameters
levelblur level. Depending on the current blurMethod, this parameter has different effects
See also
blurLevel
blurMethod

Definition at line 64 of file qgsblureffect.h.

void QgsBlurEffect::setBlurMethod ( const BlurMethod  method)
inline

Sets the blur method (algorithm) to use for performing the blur.

Parameters
methodblur method
See also
blurMethod

Definition at line 78 of file qgsblureffect.h.

void QgsBlurEffect::setTransparency ( const double  transparency)
inline

Sets the transparency for the effect.

Parameters
transparencydouble between 0 and 1 inclusive, where 0 is fully opaque and 1 is fully transparent
See also
transparency

Definition at line 91 of file qgsblureffect.h.

double QgsBlurEffect::transparency ( ) const
inline

Returns the transparency for the effect.

Returns
transparency value between 0 and 1 inclusive, where 0 is fully opaque and 1 is fully transparent
See also
setTransparency

Definition at line 98 of file qgsblureffect.h.

virtual QString QgsBlurEffect::type ( ) const
inlineoverridevirtual

Returns the effect type.

Returns
unique string representation of the effect type

Implements QgsPaintEffect.

Definition at line 53 of file qgsblureffect.h.


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