1 files changed, 169 insertions, 0 deletions
diff --git a/dom/animation/KeyframeEffectParams.cpp b/dom/animation/KeyframeEffectParams.cpp
new file mode 100644
index 000000000..257640691
--- /dev/null
+++ b/dom/animation/KeyframeEffectParams.cpp
@@ -0,0 +1,169 @@
+/* -*- 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/. */
+
+#include "mozilla/KeyframeEffectParams.h"
+
+#include "mozilla/AnimationUtils.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/KeyframeUtils.h"
+#include "mozilla/RangedPtr.h"
+#include "nsReadableUtils.h"
+
+namespace mozilla {
+
+static inline bool
+IsLetter(char16_t aCh)
+{
+  return (0x41 <= aCh && aCh <= 0x5A) || (0x61 <= aCh && aCh <= 0x7A);
+}
+
+static inline bool
+IsDigit(char16_t aCh)
+{
+  return 0x30 <= aCh && aCh <= 0x39;
+}
+
+static inline bool
+IsNameStartCode(char16_t aCh)
+{
+  return IsLetter(aCh) || aCh >= 0x80 || aCh == '_';
+}
+
+static inline bool
+IsNameCode(char16_t aCh)
+{
+  return IsNameStartCode(aCh) || IsDigit(aCh) || aCh == '-';
+}
+
+static inline bool
+IsNewLine(char16_t aCh)
+{
+  // 0x0A (LF), 0x0C (FF), 0x0D (CR), or pairs of CR followed by LF are
+  // replaced by LF.
+  return aCh == 0x0A || aCh == 0x0C || aCh == 0x0D;
+}
+
+static inline bool
+IsValidEscape(char16_t aFirst, char16_t aSecond)
+{
+  return aFirst == '\\' && !IsNewLine(aSecond);
+}
+
+static bool
+IsIdentStart(RangedPtr<const char16_t> aIter,
+             const char16_t* const aEnd)
+{
+  if (aIter == aEnd) {
+    return false;
+  }
+
+  if (*aIter == '-') {
+    if (aIter + 1 == aEnd) {
+      return false;
+    }
+    char16_t second = *(aIter + 1);
+    return IsNameStartCode(second) ||
+           second == '-' ||
+           (aIter + 2 != aEnd && IsValidEscape(second, *(aIter + 2)));
+  }
+  return IsNameStartCode(*aIter) ||
+         (aIter + 1 != aEnd && IsValidEscape(*aIter, *(aIter + 1)));
+}
+
+static void
+ConsumeIdentToken(RangedPtr<const char16_t>& aIter,
+                  const char16_t* const aEnd,
+                  nsAString& aResult)
+{
+  aResult.Truncate();
+
+  // Check if it starts with an identifier.
+  if (!IsIdentStart(aIter, aEnd)) {
+    return;
+  }
+
+  // Start to consume.
+  while (aIter != aEnd) {
+    if (IsNameCode(*aIter)) {
+      aResult.Append(*aIter);
+    } else if (*aIter == '\\') {
+      const RangedPtr<const char16_t> secondChar = aIter + 1;
+      if (secondChar == aEnd || !IsValidEscape(*aIter, *secondChar)) {
+        break;
+      }
+      // Consume '\\' and append the character following this '\\'.
+      ++aIter;
+      aResult.Append(*aIter);
+    } else {
+      break;
+    }
+    ++aIter;
+  }
+}
+
+/* static */ void
+KeyframeEffectParams::ParseSpacing(const nsAString& aSpacing,
+                                   SpacingMode& aSpacingMode,
+                                   nsCSSPropertyID& aPacedProperty,
+                                   nsAString& aInvalidPacedProperty,
+                                   ErrorResult& aRv)
+{
+  aInvalidPacedProperty.Truncate();
+
+  // Ignore spacing if the core API is not enabled since it is not yet ready to
+  // ship.
+  if (!AnimationUtils::IsCoreAPIEnabledForCaller()) {
+    aSpacingMode = SpacingMode::distribute;
+    return;
+  }
+
+  // Parse spacing.
+  // distribute | paced({ident})
+  // https://w3c.github.io/web-animations/#dom-keyframeeffectreadonly-spacing
+  // 1. distribute spacing.
+  if (aSpacing.EqualsLiteral("distribute")) {
+    aSpacingMode = SpacingMode::distribute;
+    return;
+  }
+
+  // 2. paced spacing.
+  static const nsLiteralString kPacedPrefix = NS_LITERAL_STRING("paced(");
+  if (!StringBeginsWith(aSpacing, kPacedPrefix)) {
+    aRv.ThrowTypeError<dom::MSG_INVALID_SPACING_MODE_ERROR>(aSpacing);
+    return;
+  }
+
+  RangedPtr<const char16_t> iter(aSpacing.Data() + kPacedPrefix.Length(),
+                                 aSpacing.Data(), aSpacing.Length());
+  const char16_t* const end = aSpacing.EndReading();
+
+  nsAutoString identToken;
+  ConsumeIdentToken(iter, end, identToken);
+  if (identToken.IsEmpty()) {
+    aRv.ThrowTypeError<dom::MSG_INVALID_SPACING_MODE_ERROR>(aSpacing);
+    return;
+  }
+
+  aPacedProperty =
+    nsCSSProps::LookupProperty(identToken, CSSEnabledState::eForAllContent);
+  if (aPacedProperty == eCSSProperty_UNKNOWN ||
+      aPacedProperty == eCSSPropertyExtra_variable ||
+      !KeyframeUtils::IsAnimatableProperty(aPacedProperty)) {
+    aPacedProperty = eCSSProperty_UNKNOWN;
+    aInvalidPacedProperty = identToken;
+  }
+
+  if (end - iter.get() != 1 || *iter != ')') {
+    aRv.ThrowTypeError<dom::MSG_INVALID_SPACING_MODE_ERROR>(aSpacing);
+    return;
+  }
+
+  aSpacingMode = aPacedProperty == eCSSProperty_UNKNOWN
+                 ? SpacingMode::distribute
+                 : SpacingMode::paced;
+}
+
+} // namespace mozilla