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-rw-r--r--dom/canvas/CanvasUtils.h162
1 files changed, 162 insertions, 0 deletions
diff --git a/dom/canvas/CanvasUtils.h b/dom/canvas/CanvasUtils.h
new file mode 100644
index 000000000..a69b8bd72
--- /dev/null
+++ b/dom/canvas/CanvasUtils.h
@@ -0,0 +1,162 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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 "mozilla/FloatingPoint.h"
+
+class nsIPrincipal;
+
+namespace mozilla {
+
+namespace dom {
+class HTMLCanvasElement;
+} // 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);
+
+// 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 (!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);
+ }
+}
+
+} // namespace CanvasUtils
+} // namespace mozilla
+
+#endif /* _CANVASUTILS_H_ */