gecko-dev/layout/style/nsCSSProps.cpp

/* -*- 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/. */

/*
 * methods for dealing with CSS properties and tables of the keyword
 * values they accept
 */

#include "nsCSSProps.h"

#include "mozilla/ArrayUtils.h"
#include "mozilla/Casting.h"

#include "nsLayoutUtils.h"
#include "nsIWidget.h"
#include "nsStyleConsts.h"  // For system widget appearance types

#include "mozilla/dom/Animation.h"
#include "mozilla/dom/AnimationEffectBinding.h"  // for PlaybackDirection
#include "mozilla/LookAndFeel.h"                 // for system colors

#include "nsString.h"
#include "nsStaticNameTable.h"

#include "mozilla/Preferences.h"
#include "mozilla/StaticPrefs_layout.h"

using namespace mozilla;

static int32_t gPropertyTableRefCount;
static nsStaticCaseInsensitiveNameTable* gFontDescTable;
static nsStaticCaseInsensitiveNameTable* gCounterDescTable;
static nsDataHashtable<nsCStringHashKey, nsCSSPropertyID>*
    gPropertyIDLNameTable;

static const char* const kCSSRawFontDescs[] = {
#define CSS_FONT_DESC(name_, method_) #name_,
#include "nsCSSFontDescList.h"
#undef CSS_FONT_DESC
};

static const char* const kCSSRawCounterDescs[] = {
#define CSS_COUNTER_DESC(name_, method_) #name_,
#include "nsCSSCounterDescList.h"
#undef CSS_COUNTER_DESC
};

static nsStaticCaseInsensitiveNameTable* CreateStaticTable(
    const char* const aRawTable[], int32_t aLength) {
  auto table = new nsStaticCaseInsensitiveNameTable(aRawTable, aLength);
#ifdef DEBUG
  // Partially verify the entries.
  for (int32_t index = 0; index < aLength; ++index) {
    nsAutoCString temp(aRawTable[index]);
    MOZ_ASSERT(-1 == temp.FindChar('_'),
               "underscore char in case insensitive name table");
  }
#endif
  return table;
}

void nsCSSProps::AddRefTable(void) {
  if (0 == gPropertyTableRefCount++) {
    MOZ_ASSERT(!gFontDescTable, "pre existing array!");
    MOZ_ASSERT(!gCounterDescTable, "pre existing array!");
    MOZ_ASSERT(!gPropertyIDLNameTable, "pre existing array!");

    gFontDescTable = CreateStaticTable(kCSSRawFontDescs, eCSSFontDesc_COUNT);
    gCounterDescTable =
        CreateStaticTable(kCSSRawCounterDescs, eCSSCounterDesc_COUNT);

    gPropertyIDLNameTable =
        new nsDataHashtable<nsCStringHashKey, nsCSSPropertyID>;
    for (nsCSSPropertyID p = nsCSSPropertyID(0);
         size_t(p) < ArrayLength(kIDLNameTable); p = nsCSSPropertyID(p + 1)) {
      if (kIDLNameTable[p]) {
        gPropertyIDLNameTable->Put(nsDependentCString(kIDLNameTable[p]), p);
      }
    }

    static bool prefObserversInited = false;
    if (!prefObserversInited) {
      prefObserversInited = true;
      for (const PropertyPref* pref = kPropertyPrefTable;
           pref->mPropID != eCSSProperty_UNKNOWN; pref++) {
        nsCString prefName;
        prefName.AssignLiteral(pref->mPref, strlen(pref->mPref));
        bool* enabled = &gPropertyEnabled[pref->mPropID];
        Preferences::AddBoolVarCache(enabled, prefName);
      }
    }
  }
}

#undef DEBUG_SHORTHANDS_CONTAINING

void nsCSSProps::ReleaseTable(void) {
  if (0 == --gPropertyTableRefCount) {
    delete gFontDescTable;
    gFontDescTable = nullptr;

    delete gCounterDescTable;
    gCounterDescTable = nullptr;

    delete gPropertyIDLNameTable;
    gPropertyIDLNameTable = nullptr;
  }
}

/* static */
bool nsCSSProps::IsCustomPropertyName(const nsACString& aProperty) {
  return aProperty.Length() >= CSS_CUSTOM_NAME_PREFIX_LENGTH &&
         StringBeginsWith(aProperty, NS_LITERAL_CSTRING("--"));
}

nsCSSPropertyID nsCSSProps::LookupPropertyByIDLName(
    const nsACString& aPropertyIDLName, EnabledState aEnabled) {
  MOZ_ASSERT(gPropertyIDLNameTable, "no lookup table, needs addref");
  nsCSSPropertyID res;
  if (!gPropertyIDLNameTable->Get(aPropertyIDLName, &res)) {
    return eCSSProperty_UNKNOWN;
  }
  MOZ_ASSERT(res < eCSSProperty_COUNT);
  if (!IsEnabled(res, aEnabled)) {
    return eCSSProperty_UNKNOWN;
  }
  return res;
}

nsCSSFontDesc nsCSSProps::LookupFontDesc(const nsACString& aFontDesc) {
  MOZ_ASSERT(gFontDescTable, "no lookup table, needs addref");
  nsCSSFontDesc which = nsCSSFontDesc(gFontDescTable->Lookup(aFontDesc));

  if (which == eCSSFontDesc_Display &&
      !StaticPrefs::layout_css_font_display_enabled()) {
    which = eCSSFontDesc_UNKNOWN;
  }
  return which;
}

const nsCString& nsCSSProps::GetStringValue(nsCSSFontDesc aFontDescID) {
  MOZ_ASSERT(gFontDescTable, "no lookup table, needs addref");
  if (gFontDescTable) {
    return gFontDescTable->GetStringValue(int32_t(aFontDescID));
  } else {
    static nsDependentCString sNullStr("");
    return sNullStr;
  }
}

const nsCString& nsCSSProps::GetStringValue(nsCSSCounterDesc aCounterDesc) {
  MOZ_ASSERT(gCounterDescTable, "no lookup table, needs addref");
  if (gCounterDescTable) {
    return gCounterDescTable->GetStringValue(int32_t(aCounterDesc));
  } else {
    static nsDependentCString sNullStr("");
    return sNullStr;
  }
}
const CSSPropFlags nsCSSProps::kFlagsTable[eCSSProperty_COUNT] = {
#define CSS_PROP_LONGHAND(name_, id_, method_, flags_, ...) flags_,
#define CSS_PROP_SHORTHAND(name_, id_, method_, flags_, ...) flags_,
#include "mozilla/ServoCSSPropList.h"
#undef CSS_PROP_SHORTHAND
#undef CSS_PROP_LONGHAND
};

/* static */
bool nsCSSProps::gPropertyEnabled[eCSSProperty_COUNT_with_aliases] = {
// If the property has any "ENABLED_IN" flag set, it is disabled by
// default. Note that, if a property has pref, whatever its default
// value is, it will later be changed in nsCSSProps::AddRefTable().
// If the property has "ENABLED_IN" flags but doesn't have a pref,
// it is an internal property which is disabled elsewhere.
#define IS_ENABLED_BY_DEFAULT(flags_) \
  (!((flags_) & (CSSPropFlags::EnabledMask | CSSPropFlags::Inaccessible)))

#define CSS_PROP_LONGHAND(name_, id_, method_, flags_, ...) \
  IS_ENABLED_BY_DEFAULT(flags_),
#define CSS_PROP_SHORTHAND(name_, id_, method_, flags_, ...) \
  IS_ENABLED_BY_DEFAULT(flags_),
#define CSS_PROP_ALIAS(...) true,
#include "mozilla/ServoCSSPropList.h"
#undef CSS_PROP_ALIAS
#undef CSS_PROP_SHORTHAND
#undef CSS_PROP_LONGHAND

#undef IS_ENABLED_BY_DEFAULT
};

#include "nsCSSPropsGenerated.inc"