1 files changed, 160 insertions, 0 deletions
diff --git a/layout/base/StaticPresData.h b/layout/base/StaticPresData.h
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+++ b/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