gecko-dev/layout/base/StaticPresData.h

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/* -*- 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/. */
#ifndef mozilla_StaticPresData_h
#define mozilla_StaticPresData_h
#include "nsAutoPtr.h"
#include "nsCoord.h"
#include "nsCOMPtr.h"
#include "nsFont.h"
#include "nsIAtom.h"
#include "nsILanguageAtomService.h"
namespace mozilla {
struct LangGroupFontPrefs {
// Font sizes default to zero; they will be set in GetFontPreferences
LangGroupFontPrefs()
: mLangGroup(nullptr)
, mMinimumFontSize(0)
, mDefaultVariableFont(mozilla::eFamily_serif, 0)
, mDefaultFixedFont(mozilla::eFamily_monospace, 0)
, mDefaultSerifFont(mozilla::eFamily_serif, 0)
, mDefaultSansSerifFont(mozilla::eFamily_sans_serif, 0)
, mDefaultMonospaceFont(mozilla::eFamily_monospace, 0)
, mDefaultCursiveFont(mozilla::eFamily_cursive, 0)
, mDefaultFantasyFont(mozilla::eFamily_fantasy, 0)
{}
void Reset()
{
// Throw away any other LangGroupFontPrefs objects:
mNext = nullptr;
// Make GetFontPreferences reinitialize mLangGroupFontPrefs:
mLangGroup = nullptr;
}
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
size_t n = 0;
LangGroupFontPrefs* curr = mNext;
while (curr) {
n += aMallocSizeOf(curr);
// Measurement of the following members may be added later if DMD finds
// it is worthwhile:
// - mLangGroup
// - mDefault*Font
curr = curr->mNext;
}
return n;
}
nsCOMPtr<nsIAtom> mLangGroup;
nscoord mMinimumFontSize;
nsFont mDefaultVariableFont;
nsFont mDefaultFixedFont;
nsFont mDefaultSerifFont;
nsFont mDefaultSansSerifFont;
nsFont mDefaultMonospaceFont;
nsFont mDefaultCursiveFont;
nsFont mDefaultFantasyFont;
nsAutoPtr<LangGroupFontPrefs> mNext;
};
/**
* Some functionality that has historically lived on nsPresContext does not
* actually need to be per-document. This singleton class serves as a host
* for that functionality. We delegate to it from nsPresContext where
* appropriate, and use it standalone in some cases as well.
*/
class StaticPresData
{
public:
// Initialization and shutdown of the singleton. Called exactly once.
static void Init();
static void Shutdown();
// Gets an instance of the singleton. Infallible between the calls to Init
// and Shutdown.
static StaticPresData* Get();
/**
* This table maps border-width enums 'thin', 'medium', 'thick'
* to actual nscoord values.
*/
const nscoord* GetBorderWidthTable() { return mBorderWidthTable; }
/**
* Fetch the user's font preferences for the given aLanguage's
* langugage group.
*
* The original code here is pretty old, and includes an optimization
* whereby language-specific prefs are read per-document, and the
* results are stored in a linked list, which is assumed to be very short
* since most documents only ever use one language.
*
* Storing this per-session rather than per-document would almost certainly
* be fine. But just to be on the safe side, we leave the old mechanism as-is,
* with an additional per-session cache that new callers can use if they don't
* have a PresContext.
*/
const LangGroupFontPrefs* GetFontPrefsForLangHelper(nsIAtom* aLanguage,
const LangGroupFontPrefs* aPrefs) const;
/**
* Get the default font for the given language and generic font ID.
* aLanguage may not be nullptr.
*
* This object is read-only, you must copy the font to modify it.
*
* When aFontID is kPresContext_DefaultVariableFontID or
* kPresContext_DefaultFixedFontID (which equals
* kGenericFont_moz_fixed, which is used for the -moz-fixed generic),
* the nsFont returned has its name as a CSS generic family (serif or
* sans-serif for the former, monospace for the latter), and its size
* as the default font size for variable or fixed fonts for the
* language group.
*
* For aFontID corresponding to a CSS Generic, the nsFont returned has
* its name set to that generic font's name, and its size set to
* the user's preference for font size for that generic and the
* given language.
*/
const nsFont* GetDefaultFontHelper(uint8_t aFontID,
nsIAtom* aLanguage,
const LangGroupFontPrefs* aPrefs) const;
/*
* These versions operate on the font pref cache on StaticPresData.
*/
const nsFont* GetDefaultFont(uint8_t aFontID, nsIAtom* aLanguage) const
{
MOZ_ASSERT(aLanguage);
return GetDefaultFontHelper(aFontID, aLanguage, GetFontPrefsForLang(aLanguage));
}
const LangGroupFontPrefs* GetFontPrefsForLang(nsIAtom* aLanguage) const
{
MOZ_ASSERT(aLanguage);
return GetFontPrefsForLangHelper(aLanguage, &mStaticLangGroupFontPrefs);
}
void ResetCachedFontPrefs() { mStaticLangGroupFontPrefs.Reset(); }
private:
StaticPresData();
~StaticPresData() {}
nsCOMPtr<nsILanguageAtomService> mLangService;
nscoord mBorderWidthTable[3];
LangGroupFontPrefs mStaticLangGroupFontPrefs;
};
} // namespace mozilla
#endif // mozilla_StaticPresData_h