Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 169 insertions, 0 deletions

diff --git a/layout/base/StaticPresData.h b/layout/base/StaticPresData.h
new file mode 100644
index 0000000000..984d97d30c
--- /dev/null
+++ b/layout/base/StaticPresData.h
@@ -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/. */
+
+#ifndef mozilla_StaticPresData_h
+#define mozilla_StaticPresData_h
+
+#include "mozilla/UniquePtr.h"
+#include "nsCoord.h"
+#include "nsCOMPtr.h"
+#include "nsFont.h"
+#include "nsAtom.h"
+#include "nsLanguageAtomService.h"
+
+namespace mozilla {
+
+struct LangGroupFontPrefs {
+  // Font sizes default to zero; they will be set in GetFontPreferences
+  LangGroupFontPrefs()
+      : mLangGroup(nullptr),
+        mMinimumFontSize({0}),
+        mDefaultVariableFont(),
+        mDefaultSerifFont(StyleGenericFontFamily::Serif, {0}),
+        mDefaultSansSerifFont(StyleGenericFontFamily::SansSerif, {0}),
+        mDefaultMonospaceFont(StyleGenericFontFamily::Monospace, {0}),
+        mDefaultCursiveFont(StyleGenericFontFamily::Cursive, {0}),
+        mDefaultFantasyFont(StyleGenericFontFamily::Fantasy, {0}) {
+    mDefaultVariableFont.fontlist.SetDefaultFontType(
+        StyleGenericFontFamily::Serif);
+    // We create mDefaultVariableFont.fontlist with defaultType as the
+    // fallback font, and not as part of the font list proper. This way,
+    // it can be overwritten should there be a language change.
+  }
+
+  void Reset() {
+    // Throw away any other LangGroupFontPrefs objects:
+    mNext = nullptr;
+
+    // Make GetFontPreferences reinitialize mLangGroupFontPrefs:
+    mLangGroup = nullptr;
+  }
+
+  // Initialize this with the data for a given language
+  void Initialize(nsStaticAtom* aLangGroupAtom);
+
+  /**
+   * 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.
+   *
+   * 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* GetDefaultFont(StyleGenericFontFamily aFamily) const {
+    switch (aFamily) {
+      // Special (our default variable width font and fixed width font)
+      case StyleGenericFontFamily::None:
+        return &mDefaultVariableFont;
+      // CSS
+      case StyleGenericFontFamily::Serif:
+        return &mDefaultSerifFont;
+      case StyleGenericFontFamily::SansSerif:
+        return &mDefaultSansSerifFont;
+      case StyleGenericFontFamily::Monospace:
+        return &mDefaultMonospaceFont;
+      case StyleGenericFontFamily::Cursive:
+        return &mDefaultCursiveFont;
+      case StyleGenericFontFamily::Fantasy:
+        return &mDefaultFantasyFont;
+      case StyleGenericFontFamily::MozEmoji:
+        // This shouldn't appear in font family names.
+        break;
+    }
+    MOZ_ASSERT_UNREACHABLE("invalid font id");
+    return nullptr;
+  }
+
+  nsStaticAtom* mLangGroup;
+  Length mMinimumFontSize;
+  nsFont mDefaultVariableFont;
+  nsFont mDefaultSerifFont;
+  nsFont mDefaultSansSerifFont;
+  nsFont mDefaultMonospaceFont;
+  nsFont mDefaultCursiveFont;
+  nsFont mDefaultFantasyFont;
+  UniquePtr<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();
+
+  /**
+   * Given a language, get the language group name, which can
+   * be used as an argument to LangGroupFontPrefs::Initialize()
+   *
+   * aNeedsToCache is used for two things.  If null, it indicates that
+   * the nsLanguageAtomService is safe to cache the result of the
+   * language group lookup, either because we're on the main thread,
+   * or because we're on a style worker thread but the font lock has
+   * been acquired.  If non-null, it indicates that it's not safe to
+   * cache the result of the language group lookup (because we're on
+   * a style worker thread without the lock acquired).  In this case,
+   * GetLanguageGroup will store true in *aNeedsToCache true if we
+   * would have cached the result of a new lookup, and false if we
+   * were able to use an existing cached result.  Thus, callers that
+   * get a true *aNeedsToCache outparam value should make an effort
+   * to re-call GetLanguageGroup when it is safe to cache, to avoid
+   * recomputing the language group again later.
+   */
+  nsStaticAtom* GetLangGroup(nsAtom* aLanguage,
+                             bool* aNeedsToCache = nullptr) const;
+
+  /**
+   * Same as GetLangGroup, but will not cache the result
+   */
+  nsStaticAtom* GetUncachedLangGroup(nsAtom* aLanguage) const;
+
+  /**
+   * 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.
+   *
+   * See comment on GetLangGroup for the usage of aNeedsToCache.
+   */
+  const LangGroupFontPrefs* GetFontPrefsForLang(nsAtom* aLanguage,
+                                                bool* aNeedsToCache = nullptr);
+  const nsFont* GetDefaultFont(uint8_t aFontID, nsAtom* aLanguage,
+                               const LangGroupFontPrefs* aPrefs) const;
+
+  void InvalidateFontPrefs() { mLangGroupFontPrefs.Reset(); }
+
+ private:
+  StaticPresData();
+  ~StaticPresData() = default;
+
+  nsLanguageAtomService* mLangService;
+  LangGroupFontPrefs mLangGroupFontPrefs;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_StaticPresData_h