/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 DOM_SVG_SVGCONTENTUTILS_H_
#define DOM_SVG_SVGCONTENTUTILS_H_
// include math.h to pick up definition of M_ maths defines e.g. M_PI
#include <math.h>
#include "mozilla/gfx/2D.h" // for StrokeOptions
#include "mozilla/gfx/Matrix.h"
#include "nsError.h"
#include "nsStringFwd.h"
#include "nsTArray.h"
#include "gfx2DGlue.h"
#include "nsDependentSubstring.h"
class nsIContent;
class nsIFrame;
class nsPresContext;
namespace mozilla {
class ComputedStyle;
class SVGAnimatedTransformList;
class SVGAnimatedPreserveAspectRatio;
class SVGContextPaint;
class SVGPreserveAspectRatio;
union StyleLengthPercentageUnion;
namespace dom {
class Document;
class Element;
class SVGElement;
class SVGSVGElement;
class SVGViewportElement;
}
// namespace dom
#define SVG_ZERO_LENGTH_PATH_FIX_FACTOR 512
/**
* Functions generally used by SVG Content classes. Functions here
* should not generally depend on layout methods/classes e.g. SVGUtils
*/
class SVGContentUtils {
public:
using Float = gfx::
Float;
using Matrix = gfx::Matrix;
using Rect = gfx::Rect;
using StrokeOptions = gfx::StrokeOptions;
/*
* Get the outer SVG element of an nsIContent
*/
static dom::SVGSVGElement* GetOuterSVGElement(dom::SVGElement* aSVGElement);
/**
* Moz2D's StrokeOptions requires someone else to own its mDashPattern
* buffer, which is a pain when you want to initialize a StrokeOptions object
* in a helper function and pass it out. This sub-class owns the mDashPattern
* buffer so that consumers of such a helper function don't need to worry
* about creating it, passing it in, or deleting it. (An added benefit is
* that in the typical case when stroke-dasharray is short it will avoid
* allocating.)
*/
struct AutoStrokeOptions :
public StrokeOptions {
AutoStrokeOptions() {
MOZ_ASSERT(mDashLength == 0,
"InitDashPattern() depends on this");
}
~AutoStrokeOptions() {
if (mDashPattern && mDashPattern != mSmallArray) {
delete[] mDashPattern;
}
}
/**
* Creates the buffer to store the stroke-dasharray, assuming out-of-memory
* does not occur. The buffer's address is assigned to mDashPattern and
* returned to the caller as a non-const pointer (so that the caller can
* initialize the values in the buffer, since mDashPattern is const).
*/
Float* InitDashPattern(size_t aDashCount) {
if (aDashCount <= std::size(mSmallArray)) {
mDashPattern = mSmallArray;
return mSmallArray;
}
Float* nonConstArray =
new (fallible)
Float[aDashCount];
mDashPattern = nonConstArray;
return nonConstArray;
}
void DiscardDashPattern() {
if (mDashPattern && mDashPattern != mSmallArray) {
delete[] mDashPattern;
}
mDashLength = 0;
mDashPattern = nullptr;
}
private:
// Most dasharrays will fit in this and save us allocating
Float mSmallArray[16];
};
enum StrokeOptionFlags { eAllStrokeOptions, eIgnoreStrokeDashing };
/**
* Note: the linecap style returned in aStrokeOptions is not valid when
* ShapeTypeHasNoCorners(aElement) == true && aFlags == eIgnoreStrokeDashing,
* since when aElement has no corners the rendered linecap style depends on
* whether or not the stroke is dashed.
*/
static void GetStrokeOptions(AutoStrokeOptions* aStrokeOptions,
dom::SVGElement* aElement,
const ComputedStyle* aComputedStyle,
const SVGContextPaint* aContextPaint,
StrokeOptionFlags aFlags = eAllStrokeOptions);
/**
* Returns the current computed value of the CSS property 'stroke-width' for
* the given element. aComputedStyle may be provided as an optimization.
* aContextPaint is also optional.
*
* Note that this function does NOT take account of the value of the 'stroke'
* and 'stroke-opacity' properties to, say, return zero if they are "none" or
* "0", respectively.
*/
static Float GetStrokeWidth(
const dom::SVGElement* aElement,
const ComputedStyle* aComputedStyle,
const SVGContextPaint* aContextPaint);
/*
* Get the number of CSS px (user units) per em (i.e. the em-height in user
* units) for an nsIContent
*
* XXX document the conditions under which these may fail, and what they
* return in those cases.
*/
static float GetFontSize(
const dom::Element* aElement);
static float GetFontSize(
const nsIFrame* aFrame);
static float GetFontSize(
const ComputedStyle*, nsPresContext*);
/*
* Get the number of CSS px (user units) per ex (i.e. the x-height in user
* units) for an nsIContent
*
* XXX document the conditions under which these may fail, and what they
* return in those cases.
*/
static float GetFontXHeight(
const dom::Element* aElement);
static float GetFontXHeight(
const nsIFrame* aFrame);
static float GetFontXHeight(
const ComputedStyle*, nsPresContext*);
/*
* Get the number of CSS px (user units) per lh (i.e. the line-height in
* user units) for an nsIContent.
*
* Requires the element be styled - if not, a default value assuming
* the font-size of 16px and line-height of 1.2 is returned.
*/
static float GetLineHeight(
const dom::Element* aElement);
/*
* Report a localized error message to the error console.
*/
static nsresult ReportToConsole(
const dom::Document* doc,
const char* aWarning,
const nsTArray<nsString>& aParams);
static Matrix GetCTM(dom::SVGElement* aElement);
static Matrix GetNonScalingStrokeCTM(dom::SVGElement* aElement);
static Matrix GetScreenCTM(dom::SVGElement* aElement);
/**
* Gets the tight bounds-space stroke bounds of the non-scaling-stroked rect
* aRect.
* @param aToBoundsSpace transforms from source space to the space aBounds
* should be computed in. Must be rectilinear.
* @param aToNonScalingStrokeSpace transforms from source
* space to the space in which non-scaling stroke should be applied.
* Must be rectilinear.
*/
static void RectilinearGetStrokeBounds(
const Rect& aRect,
const Matrix& aToBoundsSpace,
const Matrix& aToNonScalingStrokeSpace,
float aStrokeWidth, Rect* aBounds);
/**
* Check if this is one of the SVG elements that SVG 1.1 Full says
* establishes a viewport: svg, symbol, image or foreignObject.
*/
static bool EstablishesViewport(
const nsIContent* aContent);
static dom::SVGViewportElement* GetNearestViewportElement(
const nsIContent* aContent);
/* enum for specifying coordinate direction for ObjectSpace/UserSpace */
enum ctxDirection { X, Y, XY };
/**
* Computes sqrt((aWidth^2 + aHeight^2)/2);
*/
static double ComputeNormalizedHypotenuse(
double aWidth,
double aHeight);
/* Returns the angle halfway between the two specified angles */
static float AngleBisect(
float a1,
float a2);
/* Generate a viewbox to viewport transformation matrix */
static Matrix GetViewBoxTransform(
float aViewportWidth,
float aViewportHeight,
float aViewboxX,
float aViewboxY,
float aViewboxWidth,
float aViewboxHeight,
const SVGAnimatedPreserveAspectRatio& aPreserveAspectRatio);
static Matrix GetViewBoxTransform(
float aViewportWidth,
float aViewportHeight,
float aViewboxX,
float aViewboxY,
float aViewboxWidth,
float aViewboxHeight,
const SVGPreserveAspectRatio& aPreserveAspectRatio);
/**
* Parses the sign (+ or -) of a number and moves aIter to the next
* character if a sign is found.
* @param aSignMultiplier [outparam] -1 if the sign is negative otherwise 1
* @return false if we hit the end of the string (i.e. if aIter is initially
* at aEnd, or if we reach aEnd right after the sign character).
*/
static inline bool ParseOptionalSign(nsAString::const_iterator& aIter,
const nsAString::const_iterator& aEnd,
int32_t& aSignMultiplier) {
if (aIter == aEnd) {
return false;
}
aSignMultiplier = *aIter ==
'-' ? -1 : 1;
nsAString::const_iterator iter(aIter);
if (*iter ==
'-' || *iter ==
'+') {
++iter;
if (iter == aEnd) {
return false;
}
}
aIter = iter;
return true;
}
/**
* Parse a number of the form:
* number ::= integer ([Ee] integer)? | [+-]? [0-9]* "." [0-9]+ ([Ee]
* integer)? Parsing fails if the number cannot be represented by a floatType.
* If parsing succeeds, aIter is updated so that it points to the character
* after the end of the number, otherwise it is left unchanged
*/
template <
class floatType>
static bool ParseNumber(nsAString::const_iterator& aIter,
const nsAString::const_iterator& aEnd,
floatType& aValue);
/**
* Parse a number of the form:
* number ::= integer ([Ee] integer)? | [+-]? [0-9]* "." [0-9]+ ([Ee]
* integer)? Parsing fails if there is anything left over after the number, or
* the number cannot be represented by a floatType.
*/
template <
class floatType>
static bool ParseNumber(
const nsAString& aString, floatType& aValue);
/**
* Parse an integer of the form:
* integer ::= [+-]? [0-9]+
* The returned number is clamped to an int32_t if outside that range.
* If parsing succeeds, aIter is updated so that it points to the character
* after the end of the number, otherwise it is left unchanged
*/
static bool ParseInteger(nsAString::const_iterator& aIter,
const nsAString::const_iterator& aEnd,
int32_t& aValue);
/**
* Parse an integer of the form:
* integer ::= [+-]? [0-9]+
* The returned number is clamped to an int32_t if outside that range.
* Parsing fails if there is anything left over after the number.
*/
static bool ParseInteger(
const nsAString& aString, int32_t& aValue);
// XXX This should rather use LengthPercentage instead of
// StyleLengthPercentageUnion, but that's a type alias defined in
// ServoStyleConsts.h, and we don't want to avoid including that large header
// with all its dependencies. If a forwarding header were generated by
// cbindgen, we could include that.
// https://github.com/eqrion/cbindgen/issues/617 addresses this.
/**
* Converts a LengthPercentage into a userspace value, resolving percentage
* values relative to aContent's SVG viewport.
*/
static float CoordToFloat(
const dom::SVGElement* aContent,
const StyleLengthPercentageUnion&,
uint8_t aCtxType = SVGContentUtils::XY);
/**
* Parse the SVG path string
* Returns a path
* string formatted as an SVG path
*/
static already_AddRefed<gfx::Path> GetPath(
const nsACString& aPathString);
/**
* Returns true if aContent is one of the elements whose stroke is guaranteed
* to have no corners: circle or ellipse
*/
static bool ShapeTypeHasNoCorners(
const nsIContent* aContent);
/**
* Return one token in aString, aString may have leading and trailing
* whitespace; aSuccess will be set to false if there is no token or more than
* one token, otherwise it's set to true.
*/
static nsDependentSubstring GetAndEnsureOneToken(
const nsAString& aString,
bool& aSuccess);
};
}
// namespace mozilla
#endif // DOM_SVG_SVGCONTENTUTILS_H_
