skia2/include/core/SkPathEffect.h
djsollen@google.com 54924243c1 Cleanup code related to SkFlattenable::flatten()
The following changes were made by this CL:

1. Make flatten() a protected method as callers should use
   SkFlattenableWriteBuffer to flatten an object
2. Make flatten a const method (including subclasses)
3. Mark subclass implementation of flatten with SK_OVERRIDE
4. Ensure overridden flatten impls call their parent
5. Remove no-op implementations of flatten from subclasses

Additionally, if necessary the unflattening constructor was
also moved to the protected section of the subclasses
header if it was not already there.

git-svn-id: http://skia.googlecode.com/svn/trunk@3540 2bbb7eff-a529-9590-31e7-b0007b416f81
2012-03-29 15:18:04 +00:00

135 lines
3.9 KiB
C++

/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPathEffect_DEFINED
#define SkPathEffect_DEFINED
#include "SkFlattenable.h"
class SkPath;
/** \class SkPathEffect
SkPathEffect is the base class for objects in the SkPaint that affect
the geometry of a drawing primitive before it is transformed by the
canvas' matrix and drawn.
Dashing is implemented as a subclass of SkPathEffect.
*/
class SK_API SkPathEffect : public SkFlattenable {
public:
SkPathEffect() {}
/** Given a src path and a width value, return true if the patheffect
has produced a new path (dst) and a new width value. If false is returned,
ignore dst and width.
On input, width >= 0 means the src should be stroked
On output, width >= 0 means the dst should be stroked
*/
virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width) = 0;
protected:
SkPathEffect(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
private:
// illegal
SkPathEffect(const SkPathEffect&);
SkPathEffect& operator=(const SkPathEffect&);
typedef SkFlattenable INHERITED;
};
/** \class SkPairPathEffect
Common baseclass for Compose and Sum. This subclass manages two pathEffects,
including flattening them. It does nothing in filterPath, and is only useful
for managing the lifetimes of its two arguments.
*/
class SkPairPathEffect : public SkPathEffect {
public:
SkPairPathEffect(SkPathEffect* pe0, SkPathEffect* pe1);
virtual ~SkPairPathEffect();
protected:
SkPairPathEffect(SkFlattenableReadBuffer&);
virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
// these are visible to our subclasses
SkPathEffect* fPE0, *fPE1;
private:
typedef SkPathEffect INHERITED;
};
/** \class SkComposePathEffect
This subclass of SkPathEffect composes its two arguments, to create
a compound pathEffect.
*/
class SkComposePathEffect : public SkPairPathEffect {
public:
/** Construct a pathEffect whose effect is to apply first the inner pathEffect
and the the outer pathEffect (e.g. outer(inner(path)))
The reference counts for outer and inner are both incremented in the constructor,
and decremented in the destructor.
*/
SkComposePathEffect(SkPathEffect* outer, SkPathEffect* inner)
: INHERITED(outer, inner) {}
// overrides
virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width);
SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposePathEffect)
protected:
SkComposePathEffect(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
private:
// illegal
SkComposePathEffect(const SkComposePathEffect&);
SkComposePathEffect& operator=(const SkComposePathEffect&);
typedef SkPairPathEffect INHERITED;
};
/** \class SkSumPathEffect
This subclass of SkPathEffect applies two pathEffects, one after the other.
Its filterPath() returns true if either of the effects succeeded.
*/
class SkSumPathEffect : public SkPairPathEffect {
public:
/** Construct a pathEffect whose effect is to apply two effects, in sequence.
(e.g. first(path) + second(path))
The reference counts for first and second are both incremented in the constructor,
and decremented in the destructor.
*/
SkSumPathEffect(SkPathEffect* first, SkPathEffect* second)
: INHERITED(first, second) {}
// overrides
virtual bool filterPath(SkPath* dst, const SkPath& src, SkScalar* width);
SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkSumPathEffect)
protected:
SkSumPathEffect(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
private:
// illegal
SkSumPathEffect(const SkSumPathEffect&);
SkSumPathEffect& operator=(const SkSumPathEffect&);
typedef SkPairPathEffect INHERITED;
};
#endif