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/* -*- Mode: C++; tab-width: 20; 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 _CANVASUTILS_H_
#define _CANVASUTILS_H_
#include "CanvasRenderingContextHelper.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/dom/ToJSValue.h"
#include "jsapi.h"
#include "js/Array.h" // JS::GetArrayLength
#include "js/PropertyAndElement.h" // JS_GetElement
#include "mozilla/FloatingPoint.h"
class nsIPrincipal;
namespace mozilla {
namespace dom {
class Document;
class HTMLCanvasElement;
class OffscreenCanvas;
} // namespace dom
namespace CanvasUtils {
bool GetCanvasContextType(const nsAString& str,
dom::CanvasContextType* const out_type);
// Check that the rectangle [x,y,w,h] is a subrectangle of
// [0,0,realWidth,realHeight]
inline bool CheckSaneSubrectSize(int32_t x, int32_t y, int32_t w, int32_t h,
int32_t realWidth, int32_t realHeight) {
CheckedInt32 checked_xmost = CheckedInt32(x) + w;
CheckedInt32 checked_ymost = CheckedInt32(y) + h;
return w >= 0 && h >= 0 && x >= 0 && y >= 0 && checked_xmost.isValid() &&
checked_xmost.value() <= realWidth && checked_ymost.isValid() &&
checked_ymost.value() <= realHeight;
}
// Flag aCanvasElement as write-only if drawing an image with aPrincipal
// onto it would make it such.
void DoDrawImageSecurityCheck(dom::HTMLCanvasElement* aCanvasElement,
nsIPrincipal* aPrincipal, bool forceWriteOnly,
bool CORSUsed);
void DoDrawImageSecurityCheck(dom::OffscreenCanvas* aOffscreenCanvas,
nsIPrincipal* aPrincipal, bool forceWriteOnly,
bool CORSUsed);
// Check if the context is chrome or has the permission to drawWindow
bool HasDrawWindowPrivilege(JSContext* aCx, JSObject* aObj);
// Check if the context has permission to use OffscreenCanvas.
bool IsOffscreenCanvasEnabled(JSContext* aCx, JSObject* aObj);
// Check site-specific permission and display prompt if appropriate.
bool IsImageExtractionAllowed(dom::Document* aDocument, JSContext* aCx,
nsIPrincipal& aPrincipal);
enum class ImageExtraction {
Unrestricted,
Placeholder,
Randomize,
};
// Returns whether the result of an image extraction should be replaced
// by a placeholder or randomized.
ImageExtraction ImageExtractionResult(dom::HTMLCanvasElement* aCanvasElement,
JSContext* aCx, nsIPrincipal& aPrincipal);
ImageExtraction ImageExtractionResult(dom::OffscreenCanvas* aOffscreenCanvas,
JSContext* aCx, nsIPrincipal& aPrincipal);
// Make a double out of |v|, treating undefined values as 0.0 (for
// the sake of sparse arrays). Return true iff coercion
// succeeded.
bool CoerceDouble(const JS::Value& v, double* d);
/* Float validation stuff */
#define VALIDATE(_f) \
if (!std::isfinite(_f)) return false
inline bool FloatValidate(double f1) {
VALIDATE(f1);
return true;
}
inline bool FloatValidate(double f1, double f2) {
VALIDATE(f1);
VALIDATE(f2);
return true;
}
inline bool FloatValidate(double f1, double f2, double f3) {
VALIDATE(f1);
VALIDATE(f2);
VALIDATE(f3);
return true;
}
inline bool FloatValidate(double f1, double f2, double f3, double f4) {
VALIDATE(f1);
VALIDATE(f2);
VALIDATE(f3);
VALIDATE(f4);
return true;
}
inline bool FloatValidate(double f1, double f2, double f3, double f4,
double f5) {
VALIDATE(f1);
VALIDATE(f2);
VALIDATE(f3);
VALIDATE(f4);
VALIDATE(f5);
return true;
}
inline bool FloatValidate(double f1, double f2, double f3, double f4, double f5,
double f6) {
VALIDATE(f1);
VALIDATE(f2);
VALIDATE(f3);
VALIDATE(f4);
VALIDATE(f5);
VALIDATE(f6);
return true;
}
#undef VALIDATE
template <typename T>
nsresult JSValToDashArray(JSContext* cx, const JS::Value& patternArray,
nsTArray<T>& dashes) {
// The cap is pretty arbitrary. 16k should be enough for
// anybody...
static const uint32_t MAX_NUM_DASHES = 1 << 14;
if (!patternArray.isPrimitive()) {
JS::Rooted<JSObject*> obj(cx, patternArray.toObjectOrNull());
uint32_t length;
if (!JS::GetArrayLength(cx, obj, &length)) {
// Not an array-like thing
return NS_ERROR_INVALID_ARG;
} else if (length > MAX_NUM_DASHES) {
// Too many dashes in the pattern
return NS_ERROR_ILLEGAL_VALUE;
}
bool haveNonzeroElement = false;
for (uint32_t i = 0; i < length; ++i) {
JS::Rooted<JS::Value> elt(cx);
double d;
if (!JS_GetElement(cx, obj, i, &elt)) {
return NS_ERROR_FAILURE;
}
if (!(CoerceDouble(elt, &d) && FloatValidate(d) && d >= 0.0)) {
// Pattern elements must be finite "numbers" >= 0.
return NS_ERROR_INVALID_ARG;
} else if (d > 0.0) {
haveNonzeroElement = true;
}
if (!dashes.AppendElement(d, mozilla::fallible)) {
return NS_ERROR_OUT_OF_MEMORY;
}
}
if (dashes.Length() > 0 && !haveNonzeroElement) {
// An all-zero pattern makes no sense.
return NS_ERROR_ILLEGAL_VALUE;
}
} else if (!(patternArray.isUndefined() || patternArray.isNull())) {
// undefined and null mean "reset to no dash". Any other
// random garbage is a type error.
return NS_ERROR_INVALID_ARG;
}
return NS_OK;
}
template <typename T>
void DashArrayToJSVal(nsTArray<T>& dashes, JSContext* cx,
JS::MutableHandle<JS::Value> retval,
mozilla::ErrorResult& rv) {
if (dashes.IsEmpty()) {
retval.setNull();
return;
}
JS::Rooted<JS::Value> val(cx);
if (!mozilla::dom::ToJSValue(cx, dashes, retval)) {
rv.Throw(NS_ERROR_OUT_OF_MEMORY);
}
}
// returns true if write-only mode must used for this principal based on
// the incumbent global.
bool CheckWriteOnlySecurity(bool aCORSUsed, nsIPrincipal* aPrincipal,
bool aHadCrossOriginRedirects);
} // namespace CanvasUtils
} // namespace mozilla
#endif /* _CANVASUTILS_H_ */
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