gecko-dev/layout/svg/nsISVGChildFrame.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 __NS_ISVGCHILDFRAME_H__
#define __NS_ISVGCHILDFRAME_H__
#include "gfxRect.h"
#include "nsQueryFrame.h"
class gfxContext;
class gfxMatrix;
class nsIFrame;
class SVGBBox;
struct nsPoint;
struct nsRect;
struct nsIntRect;
namespace mozilla {
class SVGAnimatedLengthList;
class SVGAnimatedNumberList;
class SVGLengthList;
class SVGNumberList;
class SVGUserUnitList;
namespace gfx {
class Matrix;
}
}
/**
* This class is not particularly well named. It is inherited by some, but
* not all SVG frame classes that can be descendants of an
* nsSVGOuterSVGFrame in the frame tree. Note specifically that SVG container
* frames that do not inherit nsSVGDisplayContainerFrame do not inherit this
* class (so that's classes that only inherit nsSVGContainerFrame).
*/
class nsISVGChildFrame : public nsQueryFrame
{
public:
typedef mozilla::SVGAnimatedNumberList SVGAnimatedNumberList;
typedef mozilla::SVGNumberList SVGNumberList;
typedef mozilla::SVGAnimatedLengthList SVGAnimatedLengthList;
typedef mozilla::SVGLengthList SVGLengthList;
typedef mozilla::SVGUserUnitList SVGUserUnitList;
NS_DECL_QUERYFRAME_TARGET(nsISVGChildFrame)
/**
* Paint this frame.
*
* SVG is painted using a combination of display lists (trees of
* nsDisplayItem built by BuildDisplayList() implementations) and recursive
* PaintSVG calls. SVG frames with the NS_FRAME_IS_NONDISPLAY bit set are
* always painted using recursive PaintSVG calls since display list painting
* would provide no advantages (they wouldn't be retained for invalidation).
* Displayed SVG is normally painted via a display list tree created under
* nsSVGOuterSVGFrame::BuildDisplayList, unless the
* svg.display-lists.painting.enabled pref has been set to false by the user
* in which case it is done via an nsSVGOuterSVGFrame::PaintSVG() call that
* recurses over the entire SVG frame tree. In future we may use PaintSVG()
* calls on SVG container frames to avoid display list construction when it
* is expensive and unnecessary (see bug 934411).
*
* @param aTransform The transform that has to be multiplied onto the
* DrawTarget in order for drawing to be in this frame's SVG user space.
* Implementations of this method should avoid multiplying aTransform onto
* the DrawTarget when possible and instead just pass a transform down to
* their children. This is preferable because changing the transform is
* very expensive for certain DrawTarget backends so it is best to minimize
* the number of transform changes.
*
* @param aDirtyRect The area being redrawn, in frame offset pixel
* coordinates.
*/
virtual nsresult PaintSVG(gfxContext& aContext,
const gfxMatrix& aTransform,
const nsIntRect* aDirtyRect = nullptr) = 0;
/**
* Returns the frame that should handle pointer events at aPoint. aPoint is
* expected to be in the SVG user space of the frame on which this method is
* called. The frame returned may be the frame on which this method is
* called, any of its descendants or else nullptr.
*/
virtual nsIFrame* GetFrameForPoint(const gfxPoint& aPoint) = 0;
// Get bounds in our nsSVGOuterSVGFrame's coordinates space (in app units)
virtual nsRect GetCoveredRegion()=0;
// Called on SVG child frames (except NS_FRAME_IS_NONDISPLAY frames)
// to update and then invalidate their cached bounds. This method is not
// called until after the nsSVGOuterSVGFrame has had its initial reflow
// (i.e. once the SVG viewport dimensions are known). It should also only
// be called by nsSVGOuterSVGFrame during its reflow.
virtual void ReflowSVG()=0;
// Flags to pass to NotifySVGChange:
//
// DO_NOT_NOTIFY_RENDERING_OBSERVERS - this should only be used when
// updating the descendant frames of a clipPath,
// mask, pattern or marker frame (or other similar
// NS_FRAME_IS_NONDISPLAY frame) immediately
// prior to painting that frame's descendants.
// TRANSFORM_CHANGED - the current transform matrix for this frame has changed
// COORD_CONTEXT_CHANGED - the dimensions of this frame's coordinate context has
// changed (percentage lengths must be reevaluated)
enum SVGChangedFlags {
TRANSFORM_CHANGED = 0x01,
COORD_CONTEXT_CHANGED = 0x02,
FULL_ZOOM_CHANGED = 0x04
};
/**
* This is called on a frame when there has been a change to one of its
* ancestors that might affect the frame too. SVGChangedFlags are passed
* to indicate what changed.
*
* Implementations do not need to invalidate, since the caller will
* invalidate the entire area of the ancestor that changed. However, they
* may need to update their bounds.
*/
virtual void NotifySVGChanged(uint32_t aFlags)=0;
/**
* Get this frame's contribution to the rect returned by a GetBBox() call
* that occurred either on this element, or on one of its ancestors.
*
* SVG defines an element's bbox to be the element's fill bounds in the
* userspace established by that element. By allowing callers to pass in the
* transform from the userspace established by this element to the userspace
* established by an an ancestor, this method allows callers to obtain this
* element's fill bounds in the userspace established by that ancestor
* instead. In that case, since we return the bounds in a different userspace
* (the ancestor's), the bounds we return are not this element's bbox, but
* rather this element's contribution to the bbox of the ancestor.
*
* @param aToBBoxUserspace The transform from the userspace established by
* this element to the userspace established by the ancestor on which
* getBBox was called. This will be the identity matrix if we are the
* element on which getBBox was called.
*
* @param aFlags Flags indicating whether, stroke, for example, should be
* included in the bbox calculation.
*/
virtual SVGBBox GetBBoxContribution(const mozilla::gfx::Matrix &aToBBoxUserspace,
uint32_t aFlags) = 0;
// Are we a container frame?
virtual bool IsDisplayContainer()=0;
};
#endif // __NS_ISVGCHILDFRAME_H__