gecko-dev/layout/svg/nsSVGEffects.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2012-05-21 11:12:37 +00:00
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef NSSVGEFFECTS_H_
#define NSSVGEFFECTS_H_
#include "mozilla/Attributes.h"
#include "FramePropertyTable.h"
#include "mozilla/dom/Element.h"
#include "nsHashKeys.h"
#include "nsID.h"
#include "nsIFrame.h"
#include "nsIMutationObserver.h"
#include "nsInterfaceHashtable.h"
#include "nsISupportsBase.h"
#include "nsISupportsImpl.h"
#include "nsReferencedElement.h"
#include "nsStubMutationObserver.h"
#include "nsSVGUtils.h"
#include "nsTHashtable.h"
#include "nsURIHashKey.h"
class nsIAtom;
class nsIPresShell;
class nsIURI;
class nsSVGClipPathFrame;
class nsSVGPaintServerFrame;
class nsSVGFilterFrame;
class nsSVGMaskFrame;
/*
* This interface allows us to be notified when a piece of SVG content is
* re-rendered.
*
* Concrete implementations of this interface need to implement
* "GetTarget()" to specify the piece of SVG content that they'd like to
* monitor, and they need to implement "DoUpdate" to specify how we'll react
* when that content gets re-rendered. They also need to implement a
* constructor and destructor, which should call StartListening and
* StopListening, respectively.
*/
class nsSVGRenderingObserver : public nsStubMutationObserver {
protected:
virtual ~nsSVGRenderingObserver()
{}
public:
typedef mozilla::dom::Element Element;
nsSVGRenderingObserver()
: mInObserverList(false)
{}
// nsISupports
NS_DECL_ISUPPORTS
// nsIMutationObserver
NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
void InvalidateViaReferencedElement();
// When a nsSVGRenderingObserver list gets forcibly cleared, it uses this
// callback to notify every observer that's cleared from it, so they can
// react.
void NotifyEvictedFromRenderingObserverList();
bool IsInObserverList() const { return mInObserverList; }
nsIFrame* GetReferencedFrame();
/**
* @param aOK this is only for the convenience of callers. We set *aOK to false
* if the frame is the wrong type
*/
nsIFrame* GetReferencedFrame(nsIAtom* aFrameType, bool* aOK);
Element* GetReferencedElement();
virtual bool ObservesReflow() { return true; }
protected:
// Non-virtual protected methods
void StartListening();
void StopListening();
// Virtual protected methods
virtual void DoUpdate() = 0; // called when the referenced resource changes.
// This is an internally-used version of GetReferencedElement that doesn't
// forcibly add us as an observer. (whereas GetReferencedElement does)
virtual Element* GetTarget() = 0;
// Whether we're in our referenced element's observer list at this time.
bool mInObserverList;
};
/*
* SVG elements reference supporting resources by element ID. We need to
* track when those resources change and when the DOM changes in ways
* that affect which element is referenced by a given ID (e.g., when
* element IDs change). The code here is responsible for that.
*
* When a frame references a supporting resource, we create a property
* object derived from nsSVGIDRenderingObserver to manage the relationship. The
* property object is attached to the referencing frame.
*/
class nsSVGIDRenderingObserver : public nsSVGRenderingObserver {
public:
typedef mozilla::dom::Element Element;
nsSVGIDRenderingObserver(nsIURI* aURI, nsIFrame *aFrame,
bool aReferenceImage);
virtual ~nsSVGIDRenderingObserver();
protected:
Element* GetTarget() MOZ_OVERRIDE { return mElement.get(); }
// This is called when the referenced resource changes.
virtual void DoUpdate() MOZ_OVERRIDE;
class SourceReference : public nsReferencedElement {
public:
SourceReference(nsSVGIDRenderingObserver* aContainer) : mContainer(aContainer) {}
protected:
virtual void ElementChanged(Element* aFrom, Element* aTo) MOZ_OVERRIDE {
mContainer->StopListening();
nsReferencedElement::ElementChanged(aFrom, aTo);
mContainer->StartListening();
mContainer->DoUpdate();
}
/**
* Override IsPersistent because we want to keep tracking the element
* for the ID even when it changes.
*/
virtual bool IsPersistent() MOZ_OVERRIDE { return true; }
private:
nsSVGIDRenderingObserver* mContainer;
};
SourceReference mElement;
// The frame that this property is attached to
nsIFrame *mFrame;
// When a presshell is torn down, we don't delete the properties for
// each frame until after the frames are destroyed. So here we remember
// the presshell for the frames we care about and, before we use the frame,
// we test the presshell to see if it's destroying itself. If it is,
// then the frame pointer is not valid and we know the frame has gone away.
nsIPresShell *mFramePresShell;
};
/**
* In a filter chain, there can be multiple SVG reference filters.
* e.g. filter: url(#svg-filter-1) blur(10px) url(#svg-filter-2);
*
* This class keeps track of one SVG reference filter in a filter chain.
* e.g. url(#svg-filter-1)
*
* It fires invalidations when the SVG filter element's id changes or when
* the SVG filter element's content changes.
*
* The nsSVGFilterProperty class manages a list of nsSVGFilterReferences.
*/
class nsSVGFilterReference MOZ_FINAL :
public nsSVGIDRenderingObserver, public nsISVGFilterReference {
public:
nsSVGFilterReference(nsIURI *aURI, nsIFrame *aFilteredFrame)
: nsSVGIDRenderingObserver(aURI, aFilteredFrame, false) {}
bool ReferencesValidResource() { return GetFilterFrame(); }
/**
* @return the filter frame, or null if there is no filter frame
*/
nsSVGFilterFrame *GetFilterFrame();
// nsISupports
NS_DECL_ISUPPORTS_INHERITED
// nsISVGFilterReference
virtual void Invalidate() MOZ_OVERRIDE { DoUpdate(); };
protected:
virtual ~nsSVGFilterReference() {}
private:
// nsSVGIDRenderingObserver
virtual void DoUpdate() MOZ_OVERRIDE;
};
/**
* This class manages a list of nsSVGFilterReferences, which represent SVG
* reference filters in a filter chain.
* e.g. filter: url(#svg-filter-1) blur(10px) url(#svg-filter-2);
*
* In the above example, the nsSVGFilterProperty will manage two
* nsSVGFilterReferences, one for each SVG reference filter. CSS filters like
* "blur(10px)" don't reference filter elements, so they don't need an
* nsSVGFilterReference. The style system invalidates changes to CSS filters.
*/
class nsSVGFilterProperty : public nsISupports {
public:
nsSVGFilterProperty(const nsTArray<nsStyleFilter> &aFilters,
nsIFrame *aFilteredFrame);
const nsTArray<nsStyleFilter>& GetFilters() { return mFilters; }
bool ReferencesValidResources();
bool IsInObserverLists() const;
void Invalidate();
// nsISupports
NS_DECL_ISUPPORTS
protected:
virtual ~nsSVGFilterProperty();
private:
nsTArray<nsSVGFilterReference*> mReferences;
nsTArray<nsStyleFilter> mFilters;
};
class nsSVGMarkerProperty : public nsSVGIDRenderingObserver {
public:
nsSVGMarkerProperty(nsIURI *aURI, nsIFrame *aFrame, bool aReferenceImage)
: nsSVGIDRenderingObserver(aURI, aFrame, aReferenceImage) {}
protected:
virtual void DoUpdate() MOZ_OVERRIDE;
};
class nsSVGTextPathProperty : public nsSVGIDRenderingObserver {
public:
nsSVGTextPathProperty(nsIURI *aURI, nsIFrame *aFrame, bool aReferenceImage)
: nsSVGIDRenderingObserver(aURI, aFrame, aReferenceImage)
, mValid(true) {}
virtual bool ObservesReflow() MOZ_OVERRIDE { return false; }
protected:
virtual void DoUpdate() MOZ_OVERRIDE;
private:
/**
* Returns true if the target of the textPath is the frame of a 'path' element.
*/
bool TargetIsValid();
bool mValid;
};
class nsSVGPaintingProperty : public nsSVGIDRenderingObserver {
public:
nsSVGPaintingProperty(nsIURI *aURI, nsIFrame *aFrame, bool aReferenceImage)
: nsSVGIDRenderingObserver(aURI, aFrame, aReferenceImage) {}
protected:
virtual void DoUpdate() MOZ_OVERRIDE;
};
/**
* A manager for one-shot nsSVGRenderingObserver tracking.
* nsSVGRenderingObservers can be added or removed. They are not strongly
* referenced so an observer must be removed before it dies.
* When InvalidateAll is called, all outstanding references get
* InvalidateViaReferencedElement()
* called on them and the list is cleared. The intent is that
* the observer will force repainting of whatever part of the document
* is needed, and then at paint time the observer will do a clean lookup
* of the referenced element and [re-]add itself to the element's observer list.
*
* InvalidateAll must be called before this object is destroyed, i.e.
* before the referenced frame is destroyed. This should normally happen
* via nsSVGContainerFrame::RemoveFrame, since only frames in the frame
* tree should be referenced.
*/
class nsSVGRenderingObserverList {
public:
nsSVGRenderingObserverList()
: mObservers(4)
{
MOZ_COUNT_CTOR(nsSVGRenderingObserverList);
}
~nsSVGRenderingObserverList() {
InvalidateAll();
MOZ_COUNT_DTOR(nsSVGRenderingObserverList);
}
void Add(nsSVGRenderingObserver* aObserver)
{ mObservers.PutEntry(aObserver); }
void Remove(nsSVGRenderingObserver* aObserver)
{ mObservers.RemoveEntry(aObserver); }
#ifdef DEBUG
bool Contains(nsSVGRenderingObserver* aObserver)
{ return (mObservers.GetEntry(aObserver) != nullptr); }
#endif
bool IsEmpty()
{ return mObservers.Count() == 0; }
/**
* Drop all our observers, and notify them that we have changed and dropped
* our reference to them.
*/
void InvalidateAll();
/**
* Drop all observers that observe reflow, and notify them that we have changed and dropped
* our reference to them.
*/
void InvalidateAllForReflow();
/**
* Drop all our observers, and notify them that we have dropped our reference
* to them.
*/
void RemoveAll();
private:
nsTHashtable<nsPtrHashKey<nsSVGRenderingObserver> > mObservers;
};
class nsSVGEffects {
public:
typedef mozilla::dom::Element Element;
typedef mozilla::FramePropertyDescriptor FramePropertyDescriptor;
typedef nsInterfaceHashtable<nsURIHashKey, nsIMutationObserver>
URIObserverHashtable;
static void DestroySupports(void* aPropertyValue)
{
(static_cast<nsISupports*>(aPropertyValue))->Release();
}
static void DestroyHashtable(void* aPropertyValue)
{
delete static_cast<URIObserverHashtable*> (aPropertyValue);
}
NS_DECLARE_FRAME_PROPERTY(FilterProperty, DestroySupports)
NS_DECLARE_FRAME_PROPERTY(MaskProperty, DestroySupports)
NS_DECLARE_FRAME_PROPERTY(ClipPathProperty, DestroySupports)
NS_DECLARE_FRAME_PROPERTY(MarkerBeginProperty, DestroySupports)
NS_DECLARE_FRAME_PROPERTY(MarkerMiddleProperty, DestroySupports)
NS_DECLARE_FRAME_PROPERTY(MarkerEndProperty, DestroySupports)
NS_DECLARE_FRAME_PROPERTY(FillProperty, DestroySupports)
NS_DECLARE_FRAME_PROPERTY(StrokeProperty, DestroySupports)
NS_DECLARE_FRAME_PROPERTY(HrefProperty, DestroySupports)
NS_DECLARE_FRAME_PROPERTY(BackgroundImageProperty, DestroyHashtable)
/**
* Get the paint server for a aTargetFrame.
*/
static nsSVGPaintServerFrame *GetPaintServer(nsIFrame *aTargetFrame,
const nsStyleSVGPaint *aPaint,
const FramePropertyDescriptor *aProperty);
struct EffectProperties {
nsSVGFilterProperty* mFilter;
nsSVGPaintingProperty* mMask;
nsSVGPaintingProperty* mClipPath;
/**
* @return the clip-path frame, or null if there is no clip-path frame
* @param aOK if a clip-path was specified and the designated element
* exists but is an element of the wrong type, *aOK is set to false.
* Otherwise *aOK is untouched.
*/
nsSVGClipPathFrame *GetClipPathFrame(bool *aOK);
/**
* @return the mask frame, or null if there is no mask frame
* @param aOK if a mask was specified and the designated element
* exists but is an element of the wrong type, *aOK is set to false.
* Otherwise *aOK is untouched.
*/
nsSVGMaskFrame *GetMaskFrame(bool *aOK);
bool HasValidFilter() {
return mFilter && mFilter->ReferencesValidResources();
}
bool HasNoFilterOrHasValidFilter() {
return !mFilter || mFilter->ReferencesValidResources();
}
};
/**
* @param aFrame should be the first continuation
*/
static EffectProperties GetEffectProperties(nsIFrame *aFrame);
/**
* Called when changes to an element (e.g. CSS property changes) cause its
* frame to start/stop referencing (or reference different) SVG resource
* elements. (_Not_ called for changes to referenced resource elements.)
*
* This function handles such changes by discarding _all_ the frame's SVG
* effects frame properties (causing those properties to stop watching their
* target element). It also synchronously (re)creates the filter and marker
* frame properties (XXX why not the other properties?), which makes it
* useful for initializing those properties during first reflow.
*
* XXX rename to something more meaningful like RefreshResourceReferences?
*/
static void UpdateEffects(nsIFrame *aFrame);
/**
* @param aFrame should be the first continuation
*/
static nsSVGFilterProperty *GetFilterProperty(nsIFrame *aFrame);
/**
* @param aFrame must be a first-continuation.
*/
static void AddRenderingObserver(Element *aElement, nsSVGRenderingObserver *aObserver);
/**
* @param aFrame must be a first-continuation.
*/
static void RemoveRenderingObserver(Element *aElement, nsSVGRenderingObserver *aObserver);
/**
* Removes all rendering observers from aElement.
*/
static void RemoveAllRenderingObservers(Element *aElement);
/**
* This can be called on any frame. We invalidate the observers of aFrame's
* element, if any, or else walk up to the nearest observable SVG parent
* frame with observers and invalidate them instead.
*
* Note that this method is very different to e.g.
* nsNodeUtils::AttributeChanged which walks up the content node tree all the
* way to the root node (not stopping if it encounters a non-container SVG
* node) invalidating all mutation observers (not just
* nsSVGRenderingObservers) on all nodes along the way (not just the first
* node it finds with observers). In other words, by doing all the
* things in parentheses in the preceding sentence, this method uses
* knowledge about our implementation and what can be affected by SVG effects
* to make invalidation relatively lightweight when an SVG effect changes.
*/
static void InvalidateRenderingObservers(nsIFrame *aFrame);
enum {
INVALIDATE_REFLOW = 1
};
/**
* This can be called on any element or frame. Only direct observers of this
* (frame's) element, if any, are invalidated.
*/
static void InvalidateDirectRenderingObservers(Element *aElement, uint32_t aFlags = 0);
static void InvalidateDirectRenderingObservers(nsIFrame *aFrame, uint32_t aFlags = 0);
/**
* Get an nsSVGMarkerProperty for the frame, creating a fresh one if necessary
*/
static nsSVGMarkerProperty *
GetMarkerProperty(nsIURI *aURI, nsIFrame *aFrame,
const FramePropertyDescriptor *aProperty);
/**
* Get an nsSVGTextPathProperty for the frame, creating a fresh one if necessary
*/
static nsSVGTextPathProperty *
GetTextPathProperty(nsIURI *aURI, nsIFrame *aFrame,
const FramePropertyDescriptor *aProperty);
/**
* Get an nsSVGPaintingProperty for the frame, creating a fresh one if necessary
*/
static nsSVGPaintingProperty *
GetPaintingProperty(nsIURI *aURI, nsIFrame *aFrame,
const FramePropertyDescriptor *aProperty);
/**
* Get an nsSVGPaintingProperty for the frame for that URI, creating a fresh
* one if necessary
*/
static nsSVGPaintingProperty *
GetPaintingPropertyForURI(nsIURI *aURI, nsIFrame *aFrame,
const FramePropertyDescriptor *aProp);
};
#endif /*NSSVGEFFECTS_H_*/