Skia
2D Graphics Library
SkDrawLooper Class Referenceabstract

Subclasses of SkDrawLooper can be attached to a SkPaint. More...

#include <SkDrawLooper.h>

Inheritance diagram for SkDrawLooper:

Classes

struct  BlurShadowRec
 
class  Context
 Holds state during a draw. More...
 

Public Types

enum  Type {
  kSkColorFilter_Type, kSkDrawable_Type, kSkDrawLooper_Type, kSkImageFilter_Type,
  kSkMaskFilter_Type, kSkPathEffect_Type, kSkPixelRef_Type, kSkUnused_Type4,
  kSkShaderBase_Type, kSkUnused_Type, kSkUnused_Type2, kSkUnused_Type3
}
 
typedef sk_sp< SkFlattenable >(* Factory) (SkReadBuffer &)
 

Public Member Functions

virtual ContextmakeContext (SkArenaAlloc *) const =0
 Called right before something is being drawn. More...
 
bool canComputeFastBounds (const SkPaint &paint) const
 The fast bounds functions are used to enable the paint to be culled early in the drawing pipeline. More...
 
void computeFastBounds (const SkPaint &paint, const SkRect &src, SkRect *dst) const
 
virtual bool asABlurShadow (BlurShadowRec *) const
 If this looper can be interpreted as having two layers, such that. More...
 
SkFlattenable::Type getFlattenableType () const override
 
void apply (SkCanvas *canvas, const SkPaint &paint, std::function< void(SkCanvas *, const SkPaint &)>)
 
virtual Factory getFactory () const =0
 Implement this to return a factory function pointer that can be called to recreate your class given a buffer (previously written to by your override of flatten(). More...
 
virtual const char * getTypeName () const =0
 Returns the name of the object's class. More...
 
virtual void flatten (SkWriteBuffer &) const
 Override this if your subclass needs to record data that it will need to recreate itself from its CreateProc (returned by getFactory()). More...
 
sk_sp< SkDataserialize (const SkSerialProcs *=nullptr) const
 
size_t serialize (void *memory, size_t memory_size, const SkSerialProcs *=nullptr) const
 
bool unique () const
 May return true if the caller is the only owner. More...
 
void ref () const
 Increment the reference count. More...
 
void unref () const
 Decrement the reference count. More...
 

Static Public Member Functions

static SkFlattenable::Type GetFlattenableType ()
 
static sk_sp< SkDrawLooperDeserialize (const void *data, size_t size, const SkDeserialProcs *procs=nullptr)
 
static Factory NameToFactory (const char name[])
 
static const char * FactoryToName (Factory)
 
static void Register (const char name[], Factory)
 
static sk_sp< SkFlattenableDeserialize (Type, const void *data, size_t length, const SkDeserialProcs *procs=nullptr)
 

Protected Member Functions

 SkDrawLooper ()
 

Detailed Description

Subclasses of SkDrawLooper can be attached to a SkPaint.

Where they are, and something is drawn to a canvas with that paint, the looper subclass will be called, allowing it to modify the canvas and/or paint for that draw call. More than that, via the next() method, the looper can modify the draw to be invoked multiple times (hence the name loop-er), allow it to perform effects like shadows or frame/fills, that require more than one pass.

Member Typedef Documentation

◆ Factory

typedef sk_sp<SkFlattenable>(* SkFlattenable::Factory) (SkReadBuffer &)
inherited

Member Enumeration Documentation

◆ Type

enum SkFlattenable::Type
inherited
Enumerator
kSkColorFilter_Type 
kSkDrawable_Type 
kSkDrawLooper_Type 
kSkImageFilter_Type 
kSkMaskFilter_Type 
kSkPathEffect_Type 
kSkPixelRef_Type 
kSkUnused_Type4 
kSkShaderBase_Type 
kSkUnused_Type 
kSkUnused_Type2 
kSkUnused_Type3 

Constructor & Destructor Documentation

◆ SkDrawLooper()

SkDrawLooper::SkDrawLooper ( )
inlineprotected

Member Function Documentation

◆ apply()

void SkDrawLooper::apply ( SkCanvas canvas,
const SkPaint paint,
std::function< void(SkCanvas *, const SkPaint &)>   
)

◆ asABlurShadow()

virtual bool SkDrawLooper::asABlurShadow ( BlurShadowRec ) const
virtual

If this looper can be interpreted as having two layers, such that.

  1. The first layer (bottom most) just has a blur and translate
  2. The second layer has no modifications to either paint or canvas
  3. No other layers. then return true, and if not null, fill out the BlurShadowRec).

If any of the above are not met, return false and ignore the BlurShadowRec parameter.

Reimplemented in SkLayerDrawLooper.

◆ canComputeFastBounds()

bool SkDrawLooper::canComputeFastBounds ( const SkPaint paint) const

The fast bounds functions are used to enable the paint to be culled early in the drawing pipeline.

If a subclass can support this feature it must return true for the canComputeFastBounds() function. If that function returns false then computeFastBounds behavior is undefined otherwise it is expected to have the following behavior. Given the parent paint and the parent's bounding rect the subclass must fill in and return the storage rect, where the storage rect is with the union of the src rect and the looper's bounding rect.

◆ computeFastBounds()

void SkDrawLooper::computeFastBounds ( const SkPaint paint,
const SkRect src,
SkRect dst 
) const

◆ Deserialize() [1/2]

static sk_sp<SkFlattenable> SkFlattenable::Deserialize ( Type  ,
const void *  data,
size_t  length,
const SkDeserialProcs procs = nullptr 
)
staticinherited

◆ Deserialize() [2/2]

static sk_sp<SkDrawLooper> SkDrawLooper::Deserialize ( const void *  data,
size_t  size,
const SkDeserialProcs procs = nullptr 
)
inlinestatic

◆ FactoryToName()

static const char* SkFlattenable::FactoryToName ( Factory  )
staticinherited

◆ flatten()

virtual void SkFlattenable::flatten ( SkWriteBuffer &  ) const
inlinevirtualinherited

Override this if your subclass needs to record data that it will need to recreate itself from its CreateProc (returned by getFactory()).

DEPRECATED public : will move to protected ... use serialize() instead

Reimplemented in SkPath2DPathEffect, SkLayerDrawLooper, SkLine2DPathEffect, SkPath1DPathEffect, SkLumaColorFilter, SkDiscretePathEffect, Sk2DPathEffect, SkOverdrawColorFilter, and SkCornerPathEffect.

◆ getFactory()

virtual Factory SkFlattenable::getFactory ( ) const
pure virtualinherited

Implement this to return a factory function pointer that can be called to recreate your class given a buffer (previously written to by your override of flatten().

Implemented in SkDrawable.

◆ GetFlattenableType()

static SkFlattenable::Type SkDrawLooper::GetFlattenableType ( )
inlinestatic

◆ getFlattenableType()

SkFlattenable::Type SkDrawLooper::getFlattenableType ( ) const
inlineoverridevirtual

Implements SkFlattenable.

◆ getTypeName()

virtual const char* SkFlattenable::getTypeName ( ) const
pure virtualinherited

Returns the name of the object's class.

Implemented in SkDrawable.

◆ makeContext()

virtual Context* SkDrawLooper::makeContext ( SkArenaAlloc *  ) const
pure virtual

Called right before something is being drawn.

Returns a Context whose next() method should be called until it returns false.

Implemented in SkLayerDrawLooper.

◆ NameToFactory()

static Factory SkFlattenable::NameToFactory ( const char  name[])
staticinherited

◆ ref()

void SkRefCntBase::ref ( ) const
inlineinherited

Increment the reference count.

Must be balanced by a call to unref().

◆ Register()

static void SkFlattenable::Register ( const char  name[],
Factory   
)
staticinherited

◆ serialize() [1/2]

sk_sp<SkData> SkFlattenable::serialize ( const SkSerialProcs = nullptr) const
inherited

◆ serialize() [2/2]

size_t SkFlattenable::serialize ( void *  memory,
size_t  memory_size,
const SkSerialProcs = nullptr 
) const
inherited

◆ unique()

bool SkRefCntBase::unique ( ) const
inlineinherited

May return true if the caller is the only owner.

Ensures that all previous owner's actions are complete.

◆ unref()

void SkRefCntBase::unref ( ) const
inlineinherited

Decrement the reference count.

If the reference count is 1 before the decrement, then delete the object. Note that if this is the case, then the object needs to have been allocated via new, and not on the stack.


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