From 0d362ca50335d964a78dbba7e7d32574ee67899a Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 17 Apr 2020 05:01:17 -0400 Subject: Bug 1330843 - Allow JS to create NAC pseudo-elements Tag #1375 --- layout/style/nsCSSPseudoElements.h | 9 +++++++++ layout/style/nsComputedDOMStyle.cpp | 7 +++++-- 2 files changed, 14 insertions(+), 2 deletions(-) (limited to 'layout/style') diff --git a/layout/style/nsCSSPseudoElements.h b/layout/style/nsCSSPseudoElements.h index acf818a2c1..64eb2f00ce 100644 --- a/layout/style/nsCSSPseudoElements.h +++ b/layout/style/nsCSSPseudoElements.h @@ -36,6 +36,10 @@ #define CSS_PSEUDO_ELEMENT_SUPPORTS_USER_ACTION_STATE (1<<3) // Is content prevented from parsing selectors containing this pseudo-element? #define CSS_PSEUDO_ELEMENT_UA_SHEET_ONLY (1<<4) +// Can we use the ChromeOnly document.createElement(..., { pseudo: "::foo" }) +// API for creating pseudo-implementing native anonymous content in JS with this +// pseudo-element? +#define CSS_PSEUDO_ELEMENT_IS_JS_CREATED_NAC (1<<5) namespace mozilla { @@ -98,6 +102,11 @@ public: static bool PseudoElementSupportsUserActionState(const Type aType); + static bool PseudoElementIsJSCreatedNAC(Type aType) + { + return PseudoElementHasFlags(aType, CSS_PSEUDO_ELEMENT_IS_JS_CREATED_NAC); + } + static bool IsEnabled(Type aType, EnabledState aEnabledState) { return !PseudoElementHasFlags(aType, CSS_PSEUDO_ELEMENT_UA_SHEET_ONLY) || diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp index 910c1de8ae..102e0df18c 100644 --- a/layout/style/nsComputedDOMStyle.cpp +++ b/layout/style/nsComputedDOMStyle.cpp @@ -717,7 +717,9 @@ nsComputedDOMStyle::UpdateCurrentStyleSources(bool aNeedsLayoutFlush) // We want to check that going through this path because of // HasPseudoElementData is rare, because it slows us down a good // bit. So check that we're really inside something associated - // with a pseudo-element that contains elements. + // with a pseudo-element that contains elements. (We also allow + // the element to be NAC, just in case some chrome JS calls + // getComputedStyle on a NAC-implemented pseudo.) nsStyleContext* topWithPseudoElementData = mStyleContext; while (topWithPseudoElementData->GetParent()->HasPseudoElementData()) { topWithPseudoElementData = topWithPseudoElementData->GetParent(); @@ -728,7 +730,8 @@ nsComputedDOMStyle::UpdateCurrentStyleSources(bool aNeedsLayoutFlush) NS_LITERAL_STRING("we should be in a pseudo-element that is expected to contain elements (")); assertMsg.Append(nsDependentString(pseudoAtom->GetUTF16String())); assertMsg.Append(')'); - NS_ASSERTION(nsCSSPseudoElements::PseudoElementContainsElements(pseudo), + NS_ASSERTION(nsCSSPseudoElements::PseudoElementContainsElements(pseudo) || + mElement->IsNativeAnonymous(), NS_LossyConvertUTF16toASCII(assertMsg).get()); } #endif -- cgit v1.2.3