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gecko-dev/gfx/thebes/gfxFont.h

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* 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 GFX_FONT_H
#define GFX_FONT_H
#include "nsAlgorithm.h"
#include "gfxTypes.h"
#include "nsString.h"
#include "gfxPoint.h"
#include "gfxFontUtils.h"
#include "nsTArray.h"
#include "nsTHashtable.h"
#include "nsHashKeys.h"
#include "gfxSkipChars.h"
#include "gfxRect.h"
#include "nsExpirationTracker.h"
#include "gfxFontConstants.h"
#include "gfxPlatform.h"
#include "nsIAtom.h"
#include "nsISupportsImpl.h"
#include "gfxPattern.h"
#include "mozilla/HashFunctions.h"
#include "nsIMemoryReporter.h"
#include "gfxFontFeatures.h"
#include "mozilla/gfx/Types.h"
#include "mozilla/Attributes.h"
#include <algorithm>
typedef struct _cairo_scaled_font cairo_scaled_font_t;
#ifdef DEBUG
#include <stdio.h>
#endif
class gfxContext;
class gfxTextRun;
class gfxFont;
class gfxFontFamily;
class gfxFontGroup;
class gfxUserFontSet;
class gfxUserFontData;
class gfxShapedText;
class gfxShapedWord;
class gfxSVGGlyphs;
class gfxTextObjectPaint;
class nsILanguageAtomService;
typedef struct hb_blob_t hb_blob_t;
#define FONT_MAX_SIZE 2000.0
#define NO_FONT_LANGUAGE_OVERRIDE 0
struct FontListSizes;
struct gfxTextRunDrawCallbacks;
struct THEBES_API gfxFontStyle {
gfxFontStyle();
gfxFontStyle(uint8_t aStyle, uint16_t aWeight, int16_t aStretch,
gfxFloat aSize, nsIAtom *aLanguage,
float aSizeAdjust, bool aSystemFont,
bool aPrinterFont,
const nsString& aLanguageOverride);
gfxFontStyle(const gfxFontStyle& aStyle);
// the language (may be an internal langGroup code rather than an actual
// language code) specified in the document or element's lang property,
// or inferred from the charset
nsRefPtr<nsIAtom> language;
// custom opentype feature settings
nsTArray<gfxFontFeature> featureSettings;
// The logical size of the font, in pixels
gfxFloat size;
// The aspect-value (ie., the ratio actualsize:actualxheight) that any
// actual physical font created from this font structure must have when
// rendering or measuring a string. A value of 0 means no adjustment
// needs to be done.
float sizeAdjust;
// Language system tag, to override document language;
// an OpenType "language system" tag represented as a 32-bit integer
// (see http://www.microsoft.com/typography/otspec/languagetags.htm).
// Normally 0, so font rendering will use the document or element language
// (see above) to control any language-specific rendering, but the author
// can override this for cases where the options implemented in the font
// do not directly match the actual language. (E.g. lang may be Macedonian,
// but the font in use does not explicitly support this; the author can
// use font-language-override to request the Serbian option in the font
// in order to get correct glyph shapes.)
uint32_t languageOverride;
// The weight of the font: 100, 200, ... 900.
uint16_t weight;
// The stretch of the font (the sum of various NS_FONT_STRETCH_*
// constants; see gfxFontConstants.h).
int8_t stretch;
// Say that this font is a system font and therefore does not
// require certain fixup that we do for fonts from untrusted
// sources.
bool systemFont : 1;
// Say that this font is used for print or print preview.
bool printerFont : 1;
// The style of font (normal, italic, oblique)
uint8_t style : 2;
// Return the final adjusted font size for the given aspect ratio.
// Not meant to be called when sizeAdjust = 0.
gfxFloat GetAdjustedSize(gfxFloat aspect) const {
NS_ASSERTION(sizeAdjust != 0.0, "Not meant to be called when sizeAdjust = 0");
gfxFloat adjustedSize = std::max(NS_round(size*(sizeAdjust/aspect)), 1.0);
return std::min(adjustedSize, FONT_MAX_SIZE);
}
PLDHashNumber Hash() const {
return ((style + (systemFont << 7) +
(weight << 8)) + uint32_t(size*1000) + uint32_t(sizeAdjust*1000)) ^
nsISupportsHashKey::HashKey(language);
}
int8_t ComputeWeight() const;
bool Equals(const gfxFontStyle& other) const {
return
(*reinterpret_cast<const uint64_t*>(&size) ==
*reinterpret_cast<const uint64_t*>(&other.size)) &&
(style == other.style) &&
(systemFont == other.systemFont) &&
(printerFont == other.printerFont) &&
(weight == other.weight) &&
(stretch == other.stretch) &&
(language == other.language) &&
(*reinterpret_cast<const uint32_t*>(&sizeAdjust) ==
*reinterpret_cast<const uint32_t*>(&other.sizeAdjust)) &&
(featureSettings == other.featureSettings) &&
(languageOverride == other.languageOverride);
}
static void ParseFontFeatureSettings(const nsString& aFeatureString,
nsTArray<gfxFontFeature>& aFeatures);
static uint32_t ParseFontLanguageOverride(const nsString& aLangTag);
};
class gfxCharacterMap : public gfxSparseBitSet {
public:
nsrefcnt AddRef() {
NS_PRECONDITION(int32_t(mRefCnt) >= 0, "illegal refcnt");
++mRefCnt;
NS_LOG_ADDREF(this, mRefCnt, "gfxCharacterMap", sizeof(*this));
return mRefCnt;
}
nsrefcnt Release() {
NS_PRECONDITION(0 != mRefCnt, "dup release");
--mRefCnt;
NS_LOG_RELEASE(this, mRefCnt, "gfxCharacterMap");
if (mRefCnt == 0) {
NotifyReleased();
// |this| has been deleted.
return 0;
}
return mRefCnt;
}
gfxCharacterMap() :
mHash(0), mBuildOnTheFly(false), mShared(false)
{ }
void CalcHash() { mHash = GetChecksum(); }
size_t SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf) const {
return gfxSparseBitSet::SizeOfExcludingThis(aMallocSizeOf);
}
// hash of the cmap bitvector
uint32_t mHash;
// if cmap is built on the fly it's never shared
bool mBuildOnTheFly;
// cmap is shared globally
bool mShared;
protected:
void NotifyReleased();
nsAutoRefCnt mRefCnt;
private:
gfxCharacterMap(const gfxCharacterMap&);
gfxCharacterMap& operator=(const gfxCharacterMap&);
};
class gfxFontEntry {
public:
NS_INLINE_DECL_REFCOUNTING(gfxFontEntry)
gfxFontEntry(const nsAString& aName, bool aIsStandardFace = false) :
mName(aName), mItalic(false), mFixedPitch(false),
mIsProxy(false), mIsValid(true),
mIsBadUnderlineFont(false), mIsUserFont(false),
mIsLocalUserFont(false), mStandardFace(aIsStandardFace),
mSymbolFont(false),
mIgnoreGDEF(false),
mIgnoreGSUB(false),
mSVGInitialized(false),
mWeight(500), mStretch(NS_FONT_STRETCH_NORMAL),
mCheckedForGraphiteTables(false),
mHasCmapTable(false),
mUVSOffset(0), mUVSData(nullptr),
mUserFontData(nullptr),
mSVGGlyphs(nullptr),
mLanguageOverride(NO_FONT_LANGUAGE_OVERRIDE)
{ }
virtual ~gfxFontEntry();
// unique name for the face, *not* the family; not necessarily the
// "real" or user-friendly name, may be an internal identifier
const nsString& Name() const { return mName; }
// family name
const nsString& FamilyName() const { return mFamilyName; }
// The following two methods may be relatively expensive, as they
// will (usually, except on Linux) load and parse the 'name' table;
// they are intended only for the font-inspection API, not for
// perf-critical layout/drawing work.
// The "real" name of the face, if available from the font resource;
// returns Name() if nothing better is available.
virtual nsString RealFaceName();
uint16_t Weight() const { return mWeight; }
int16_t Stretch() const { return mStretch; }
bool IsUserFont() const { return mIsUserFont; }
bool IsLocalUserFont() const { return mIsLocalUserFont; }
bool IsFixedPitch() const { return mFixedPitch; }
bool IsItalic() const { return mItalic; }
bool IsBold() const { return mWeight >= 600; } // bold == weights 600 and above
bool IgnoreGDEF() const { return mIgnoreGDEF; }
bool IgnoreGSUB() const { return mIgnoreGSUB; }
virtual bool IsSymbolFont();
inline bool HasGraphiteTables() {
if (!mCheckedForGraphiteTables) {
CheckForGraphiteTables();
mCheckedForGraphiteTables = true;
}
return mHasGraphiteTables;
}
inline bool HasCmapTable() {
if (!mCharacterMap) {
ReadCMAP();
NS_ASSERTION(mCharacterMap, "failed to initialize character map");
}
return mHasCmapTable;
}
inline bool HasCharacter(uint32_t ch) {
if (mCharacterMap && mCharacterMap->test(ch)) {
return true;
}
return TestCharacterMap(ch);
}
virtual bool SkipDuringSystemFallback() { return false; }
virtual bool TestCharacterMap(uint32_t aCh);
nsresult InitializeUVSMap();
uint16_t GetUVSGlyph(uint32_t aCh, uint32_t aVS);
virtual nsresult ReadCMAP();
bool TryGetSVGData();
bool HasSVGGlyph(uint32_t aGlyphId);
bool GetSVGGlyphExtents(gfxContext *aContext, uint32_t aGlyphId,
gfxRect *aResult);
bool RenderSVGGlyph(gfxContext *aContext, uint32_t aGlyphId, int aDrawMode,
gfxTextObjectPaint *aObjectPaint);
virtual bool MatchesGenericFamily(const nsACString& aGeneric) const {
return true;
}
virtual bool SupportsLangGroup(nsIAtom *aLangGroup) const {
return true;
}
virtual nsresult GetFontTable(uint32_t aTableTag, FallibleTArray<uint8_t>& aBuffer) {
return NS_ERROR_FAILURE; // all platform subclasses should reimplement this!
}
already_AddRefed<gfxFont> FindOrMakeFont(const gfxFontStyle *aStyle,
bool aNeedsBold);
// Get an existing font table cache entry in aBlob if it has been
// registered, or return false if not. Callers must call
// hb_blob_destroy on aBlob if true is returned.
//
// Note that some gfxFont implementations may not call this at all,
// if it is more efficient to get the table from the OS at that level.
bool GetExistingFontTable(uint32_t aTag, hb_blob_t** aBlob);
// Elements of aTable are transferred (not copied) to and returned in a
// new hb_blob_t which is registered on the gfxFontEntry, but the initial
// reference is owned by the caller. Removing the last reference
// unregisters the table from the font entry.
//
// Pass NULL for aBuffer to indicate that the table is not present and
// NULL will be returned. Also returns NULL on OOM.
hb_blob_t *ShareFontTableAndGetBlob(uint32_t aTag,
FallibleTArray<uint8_t>* aTable);
// For memory reporting
virtual void SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf,
FontListSizes* aSizes) const;
virtual void SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf,
FontListSizes* aSizes) const;
nsString mName;
nsString mFamilyName;
bool mItalic : 1;
bool mFixedPitch : 1;
bool mIsProxy : 1;
bool mIsValid : 1;
bool mIsBadUnderlineFont : 1;
bool mIsUserFont : 1;
bool mIsLocalUserFont : 1;
bool mStandardFace : 1;
bool mSymbolFont : 1;
bool mIgnoreGDEF : 1;
bool mIgnoreGSUB : 1;
bool mSVGInitialized : 1;
uint16_t mWeight;
int16_t mStretch;
bool mHasGraphiteTables;
bool mCheckedForGraphiteTables;
bool mHasCmapTable;
nsRefPtr<gfxCharacterMap> mCharacterMap;
uint32_t mUVSOffset;
nsAutoArrayPtr<uint8_t> mUVSData;
gfxUserFontData* mUserFontData;
gfxSVGGlyphs *mSVGGlyphs;
nsTArray<gfxFontFeature> mFeatureSettings;
uint32_t mLanguageOverride;
protected:
friend class gfxPlatformFontList;
friend class gfxMacPlatformFontList;
friend class gfxUserFcFontEntry;
friend class gfxFontFamily;
friend class gfxSingleFaceMacFontFamily;
gfxFontEntry() :
mItalic(false), mFixedPitch(false),
mIsProxy(false), mIsValid(true),
mIsBadUnderlineFont(false),
mIsUserFont(false),
mIsLocalUserFont(false),
mStandardFace(false),
mSymbolFont(false),
mIgnoreGDEF(false),
mIgnoreGSUB(false),
mSVGInitialized(false),
mWeight(500), mStretch(NS_FONT_STRETCH_NORMAL),
mCheckedForGraphiteTables(false),
mHasCmapTable(false),
mUVSOffset(0), mUVSData(nullptr),
mUserFontData(nullptr),
mSVGGlyphs(nullptr),
mLanguageOverride(NO_FONT_LANGUAGE_OVERRIDE)
{ }
virtual gfxFont *CreateFontInstance(const gfxFontStyle *aFontStyle, bool aNeedsBold) {
NS_NOTREACHED("oops, somebody didn't override CreateFontInstance");
return nullptr;
}
virtual void CheckForGraphiteTables();
private:
/**
* Font table hashtable, to support GetFontTable for harfbuzz.
*
* The harfbuzz shaper (and potentially other clients) needs access to raw
* font table data. This needs to be cached so that it can be used
* repeatedly (each time we construct a text run; in some cases, for
* each character/glyph within the run) without re-fetching large tables
* every time.
*
* Because we may instantiate many gfxFonts for the same physical font
* file (at different sizes), we should ensure that they can share a
* single cached copy of the font tables. To do this, we implement table
* access and sharing on the fontEntry rather than the font itself.
*
* The default implementation uses GetFontTable() to read font table
* data into byte arrays, and wraps them in blobs which are registered in
* a hashtable. The hashtable can then return pre-existing blobs to
* harfbuzz.
*
* Harfbuzz will "destroy" the blobs when it is finished with them. When
* the last blob reference is removed, the FontTableBlobData user data
* will remove the blob from the hashtable if still registered.
*/
class FontTableBlobData;
/**
* FontTableHashEntry manages the entries of hb_blob_t's containing font
* table data.
*
* This is used to share font tables across fonts with the same
* font entry (but different sizes) for use by HarfBuzz. The hashtable
* does not own a strong reference to the blob, but keeps a weak pointer,
* managed by FontTableBlobData. Similarly FontTableBlobData keeps only a
* weak pointer to the hashtable, managed by FontTableHashEntry.
*/
class FontTableHashEntry : public nsUint32HashKey
{
public:
// Declarations for nsTHashtable
typedef nsUint32HashKey KeyClass;
typedef KeyClass::KeyType KeyType;
typedef KeyClass::KeyTypePointer KeyTypePointer;
FontTableHashEntry(KeyTypePointer aTag)
: KeyClass(aTag), mBlob() { }
// Copying transfers blob association.
FontTableHashEntry(FontTableHashEntry& toCopy)
: KeyClass(toCopy), mBlob(toCopy.mBlob)
{
toCopy.mBlob = nullptr;
}
~FontTableHashEntry() { Clear(); }
// FontTable/Blob API
// Transfer (not copy) elements of aTable to a new hb_blob_t and
// return ownership to the caller. A weak reference to the blob is
// recorded in the hashtable entry so that others may use the same
// table.
hb_blob_t *
ShareTableAndGetBlob(FallibleTArray<uint8_t>& aTable,
nsTHashtable<FontTableHashEntry> *aHashtable);
// Return a strong reference to the blob.
// Callers must hb_blob_destroy the returned blob.
hb_blob_t *GetBlob() const;
void Clear();
static size_t
SizeOfEntryExcludingThis(FontTableHashEntry *aEntry,
nsMallocSizeOfFun aMallocSizeOf,
void* aUserArg);
private:
static void DeleteFontTableBlobData(void *aBlobData);
// not implemented
FontTableHashEntry& operator=(FontTableHashEntry& toCopy);
FontTableBlobData *mSharedBlobData;
hb_blob_t *mBlob;
};
nsTHashtable<FontTableHashEntry> mFontTableCache;
gfxFontEntry(const gfxFontEntry&);
gfxFontEntry& operator=(const gfxFontEntry&);
};
// used when iterating over all fonts looking for a match for a given character
struct GlobalFontMatch {
GlobalFontMatch(const uint32_t aCharacter,
int32_t aRunScript,
const gfxFontStyle *aStyle) :
mCh(aCharacter), mRunScript(aRunScript), mStyle(aStyle),
mMatchRank(0), mCount(0), mCmapsTested(0)
{
}
const uint32_t mCh; // codepoint to be matched
int32_t mRunScript; // Unicode script for the codepoint
const gfxFontStyle* mStyle; // style to match
int32_t mMatchRank; // metric indicating closest match
nsRefPtr<gfxFontEntry> mBestMatch; // current best match
nsRefPtr<gfxFontFamily> mMatchedFamily; // the family it belongs to
uint32_t mCount; // number of fonts matched
uint32_t mCmapsTested; // number of cmaps tested
};
class gfxFontFamily {
public:
NS_INLINE_DECL_REFCOUNTING(gfxFontFamily)
gfxFontFamily(const nsAString& aName) :
mName(aName),
mOtherFamilyNamesInitialized(false),
mHasOtherFamilyNames(false),
mFaceNamesInitialized(false),
mHasStyles(false),
mIsSimpleFamily(false),
mIsBadUnderlineFamily(false),
mFamilyCharacterMapInitialized(false)
{ }
virtual ~gfxFontFamily() { }
const nsString& Name() { return mName; }
virtual void LocalizedName(nsAString& aLocalizedName);
virtual bool HasOtherFamilyNames();
nsTArray<nsRefPtr<gfxFontEntry> >& GetFontList() { return mAvailableFonts; }
void AddFontEntry(nsRefPtr<gfxFontEntry> aFontEntry) {
// bug 589682 - set the IgnoreGDEF flag on entries for Italic faces
// of Times New Roman, because of buggy table in those fonts
if (aFontEntry->IsItalic() && !aFontEntry->IsUserFont() &&
Name().EqualsLiteral("Times New Roman"))
{
aFontEntry->mIgnoreGDEF = true;
}
aFontEntry->mFamilyName = Name();
mAvailableFonts.AppendElement(aFontEntry);
}
// note that the styles for this family have been added
void SetHasStyles(bool aHasStyles) { mHasStyles = aHasStyles; }
// choose a specific face to match a style using CSS font matching
// rules (weight matching occurs here). may return a face that doesn't
// precisely match (e.g. normal face when no italic face exists).
// aNeedsSyntheticBold is set to true when synthetic bolding is
// needed, false otherwise
gfxFontEntry *FindFontForStyle(const gfxFontStyle& aFontStyle,
bool& aNeedsSyntheticBold);
// checks for a matching font within the family
// used as part of the font fallback process
void FindFontForChar(GlobalFontMatch *aMatchData);
// checks all fonts for a matching font within the family
void SearchAllFontsForChar(GlobalFontMatch *aMatchData);
// read in other family names, if any, and use functor to add each into cache
virtual void ReadOtherFamilyNames(gfxPlatformFontList *aPlatformFontList);
// set when other family names have been read in
void SetOtherFamilyNamesInitialized() {
mOtherFamilyNamesInitialized = true;
}
// read in other localized family names, fullnames and Postscript names
// for all faces and append to lookup tables
virtual void ReadFaceNames(gfxPlatformFontList *aPlatformFontList,
bool aNeedFullnamePostscriptNames);
// find faces belonging to this family (platform implementations override this;
// should be made pure virtual once all subclasses have been updated)
virtual void FindStyleVariations() { }
// search for a specific face using the Postscript name
gfxFontEntry* FindFont(const nsAString& aPostscriptName);
// read in cmaps for all the faces
void ReadAllCMAPs() {
uint32_t i, numFonts = mAvailableFonts.Length();
for (i = 0; i < numFonts; i++) {
gfxFontEntry *fe = mAvailableFonts[i];
// don't try to load cmaps for downloadable fonts not yet loaded
if (!fe || fe->mIsProxy) {
continue;
}
fe->ReadCMAP();
mFamilyCharacterMap.Union(*(fe->mCharacterMap));
}
mFamilyCharacterMap.Compact();
mFamilyCharacterMapInitialized = true;
}
bool TestCharacterMap(uint32_t aCh) {
if (!mFamilyCharacterMapInitialized) {
ReadAllCMAPs();
}
return mFamilyCharacterMap.test(aCh);
}
void ResetCharacterMap() {
mFamilyCharacterMap.reset();
mFamilyCharacterMapInitialized = false;
}
// mark this family as being in the "bad" underline offset blacklist
void SetBadUnderlineFamily() {
mIsBadUnderlineFamily = true;
if (mHasStyles) {
SetBadUnderlineFonts();
}
}
bool IsBadUnderlineFamily() const { return mIsBadUnderlineFamily; }
// sort available fonts to put preferred (standard) faces towards the end
void SortAvailableFonts();
// check whether the family fits into the simple 4-face model,
// so we can use simplified style-matching;
// if so set the mIsSimpleFamily flag (defaults to False before we've checked)
void CheckForSimpleFamily();
// For memory reporter
virtual void SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf,
FontListSizes* aSizes) const;
virtual void SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf,
FontListSizes* aSizes) const;
// Only used for debugging checks - does a linear search
bool ContainsFace(gfxFontEntry* aFontEntry) {
uint32_t i, numFonts = mAvailableFonts.Length();
for (i = 0; i < numFonts; i++) {
if (mAvailableFonts[i] == aFontEntry) {
return true;
}
}
return false;
}
protected:
// fills in an array with weights of faces that match style,
// returns whether any matching entries found
virtual bool FindWeightsForStyle(gfxFontEntry* aFontsForWeights[],
bool anItalic, int16_t aStretch);
bool ReadOtherFamilyNamesForFace(gfxPlatformFontList *aPlatformFontList,
FallibleTArray<uint8_t>& aNameTable,
bool useFullName = false);
// set whether this font family is in "bad" underline offset blacklist.
void SetBadUnderlineFonts() {
uint32_t i, numFonts = mAvailableFonts.Length();
for (i = 0; i < numFonts; i++) {
if (mAvailableFonts[i]) {
mAvailableFonts[i]->mIsBadUnderlineFont = true;
}
}
}
nsString mName;
nsTArray<nsRefPtr<gfxFontEntry> > mAvailableFonts;
gfxSparseBitSet mFamilyCharacterMap;
bool mOtherFamilyNamesInitialized : 1;
bool mHasOtherFamilyNames : 1;
bool mFaceNamesInitialized : 1;
bool mHasStyles : 1;
bool mIsSimpleFamily : 1;
bool mIsBadUnderlineFamily : 1;
bool mFamilyCharacterMapInitialized : 1;
enum {
// for "simple" families, the faces are stored in mAvailableFonts
// with fixed positions:
kRegularFaceIndex = 0,
kBoldFaceIndex = 1,
kItalicFaceIndex = 2,
kBoldItalicFaceIndex = 3,
// mask values for selecting face with bold and/or italic attributes
kBoldMask = 0x01,
kItalicMask = 0x02
};
};
struct gfxTextRange {
enum {
// flags for recording the kind of font-matching that was used
kFontGroup = 0x0001,
kPrefsFallback = 0x0002,
kSystemFallback = 0x0004
};
gfxTextRange(uint32_t aStart, uint32_t aEnd,
gfxFont* aFont, uint8_t aMatchType)
: start(aStart),
end(aEnd),
font(aFont),
matchType(aMatchType)
{ }
uint32_t Length() const { return end - start; }
uint32_t start, end;
nsRefPtr<gfxFont> font;
uint8_t matchType;
};
/**
* Font cache design:
*
* The mFonts hashtable contains most fonts, indexed by (gfxFontEntry*, style).
* It does not add a reference to the fonts it contains.
* When a font's refcount decreases to zero, instead of deleting it we
* add it to our expiration tracker.
* The expiration tracker tracks fonts with zero refcount. After a certain
* period of time, such fonts expire and are deleted.
*
* We're using 3 generations with a ten-second generation interval, so
* zero-refcount fonts will be deleted 20-30 seconds after their refcount
* goes to zero, if timer events fire in a timely manner.
*
* The font cache also handles timed expiration of cached ShapedWords
* for "persistent" fonts: it has a repeating timer, and notifies
* each cached font to "age" its shaped words. The words will be released
* by the fonts if they get aged three times without being re-used in the
* meantime.
*
* Note that the ShapedWord timeout is much larger than the font timeout,
* so that in the case of a short-lived font, we'll discard the gfxFont
* completely, with all its words, and avoid the cost of aging the words
* individually. That only happens with longer-lived fonts.
*/
struct FontCacheSizes {
FontCacheSizes()
: mFontInstances(0), mShapedWords(0)
{ }
size_t mFontInstances; // memory used by instances of gfxFont subclasses
size_t mShapedWords; // memory used by the per-font shapedWord caches
};
class THEBES_API gfxFontCache MOZ_FINAL : public nsExpirationTracker<gfxFont,3> {
public:
enum {
FONT_TIMEOUT_SECONDS = 10,
SHAPED_WORD_TIMEOUT_SECONDS = 60
};
gfxFontCache();
~gfxFontCache();
/*
* Get the global gfxFontCache. You must call Init() before
* calling this method --- the result will not be null.
*/
static gfxFontCache* GetCache() {
return gGlobalCache;
}
static nsresult Init();
// It's OK to call this even if Init() has not been called.
static void Shutdown();
// Look up a font in the cache. Returns an addrefed pointer, or null
// if there's nothing matching in the cache
already_AddRefed<gfxFont> Lookup(const gfxFontEntry *aFontEntry,
const gfxFontStyle *aStyle);
// We created a new font (presumably because Lookup returned null);
// put it in the cache. The font's refcount should be nonzero. It is
// allowable to add a new font even if there is one already in the
// cache with the same key; we'll forget about the old one.
void AddNew(gfxFont *aFont);
// The font's refcount has gone to zero; give ownership of it to
// the cache. We delete it if it's not acquired again after a certain
// amount of time.
void NotifyReleased(gfxFont *aFont);
// This gets called when the timeout has expired on a zero-refcount
// font; we just delete it.
virtual void NotifyExpired(gfxFont *aFont);
// Cleans out the hashtable and removes expired fonts waiting for cleanup.
// Other gfxFont objects may be still in use but they will be pushed
// into the expiration queues and removed.
void Flush() {
mFonts.Clear();
AgeAllGenerations();
}
void FlushShapedWordCaches() {
mFonts.EnumerateEntries(ClearCachedWordsForFont, nullptr);
}
void SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf,
FontCacheSizes* aSizes) const;
void SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf,
FontCacheSizes* aSizes) const;
protected:
class MemoryReporter MOZ_FINAL
: public nsIMemoryMultiReporter
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIMEMORYMULTIREPORTER
};
void DestroyFont(gfxFont *aFont);
static gfxFontCache *gGlobalCache;
struct Key {
const gfxFontEntry* mFontEntry;
const gfxFontStyle* mStyle;
Key(const gfxFontEntry* aFontEntry, const gfxFontStyle* aStyle)
: mFontEntry(aFontEntry), mStyle(aStyle) {}
};
class HashEntry : public PLDHashEntryHdr {
public:
typedef const Key& KeyType;
typedef const Key* KeyTypePointer;
// When constructing a new entry in the hashtable, we'll leave this
// blank. The caller of Put() will fill this in.
HashEntry(KeyTypePointer aStr) : mFont(nullptr) { }
HashEntry(const HashEntry& toCopy) : mFont(toCopy.mFont) { }
~HashEntry() { }
bool KeyEquals(const KeyTypePointer aKey) const;
static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
static PLDHashNumber HashKey(const KeyTypePointer aKey) {
return mozilla::HashGeneric(aKey->mStyle->Hash(), aKey->mFontEntry);
}
enum { ALLOW_MEMMOVE = true };
gfxFont* mFont;
};
static size_t SizeOfFontEntryExcludingThis(HashEntry* aHashEntry,
nsMallocSizeOfFun aMallocSizeOf,
void* aUserArg);
nsTHashtable<HashEntry> mFonts;
static PLDHashOperator ClearCachedWordsForFont(HashEntry* aHashEntry, void*);
static PLDHashOperator AgeCachedWordsForFont(HashEntry* aHashEntry, void*);
static void WordCacheExpirationTimerCallback(nsITimer* aTimer, void* aCache);
nsCOMPtr<nsITimer> mWordCacheExpirationTimer;
};
class THEBES_API gfxTextRunFactory {
NS_INLINE_DECL_REFCOUNTING(gfxTextRunFactory)
public:
// Flags in the mask 0xFFFF0000 are reserved for textrun clients
// Flags in the mask 0x0000F000 are reserved for per-platform fonts
// Flags in the mask 0x00000FFF are set by the textrun creator.
enum {
CACHE_TEXT_FLAGS = 0xF0000000,
USER_TEXT_FLAGS = 0x0FFF0000,
PLATFORM_TEXT_FLAGS = 0x0000F000,
TEXTRUN_TEXT_FLAGS = 0x00000FFF,
SETTABLE_FLAGS = CACHE_TEXT_FLAGS | USER_TEXT_FLAGS,
/**
* When set, the text string pointer used to create the text run
* is guaranteed to be available during the lifetime of the text run.
*/
TEXT_IS_PERSISTENT = 0x0001,
/**
* When set, the text is known to be all-ASCII (< 128).
*/
TEXT_IS_ASCII = 0x0002,
/**
* When set, the text is RTL.
*/
TEXT_IS_RTL = 0x0004,
/**
* When set, spacing is enabled and the textrun needs to call GetSpacing
* on the spacing provider.
*/
TEXT_ENABLE_SPACING = 0x0008,
/**
* When set, GetHyphenationBreaks may return true for some character
* positions, otherwise it will always return false for all characters.
*/
TEXT_ENABLE_HYPHEN_BREAKS = 0x0010,
/**
* When set, the text has no characters above 255 and it is stored
* in the textrun in 8-bit format.
*/
TEXT_IS_8BIT = 0x0020,
/**
* When set, the RunMetrics::mBoundingBox field will be initialized
* properly based on glyph extents, in particular, glyph extents that
* overflow the standard font-box (the box defined by the ascent, descent
* and advance width of the glyph). When not set, it may just be the
* standard font-box even if glyphs overflow.
*/
TEXT_NEED_BOUNDING_BOX = 0x0040,
/**
* When set, optional ligatures are disabled. Ligatures that are
* required for legible text should still be enabled.
*/
TEXT_DISABLE_OPTIONAL_LIGATURES = 0x0080,
/**
* When set, the textrun should favour speed of construction over
* quality. This may involve disabling ligatures and/or kerning or
* other effects.
*/
TEXT_OPTIMIZE_SPEED = 0x0100,
/**
* For internal use by the memory reporter when accounting for
* storage used by textruns.
* Because the reporter may visit each textrun multiple times while
* walking the frame trees and textrun cache, it needs to mark
* textruns that have been seen so as to avoid multiple-accounting.
*/
TEXT_RUN_SIZE_ACCOUNTED = 0x0200,
/**
* nsTextFrameThebes sets these, but they're defined here rather than
* in nsTextFrameUtils.h because ShapedWord creation/caching also needs
* to check the _INCOMING flag
*/
TEXT_TRAILING_ARABICCHAR = 0x20000000,
/**
* When set, the previous character for this textrun was an Arabic
* character. This is used for the context detection necessary for
* bidi.numeral implementation.
*/
TEXT_INCOMING_ARABICCHAR = 0x40000000,
TEXT_UNUSED_FLAGS = 0x90000000
};
/**
* This record contains all the parameters needed to initialize a textrun.
*/
struct Parameters {
// A reference context suggesting where the textrun will be rendered
gfxContext *mContext;
// Pointer to arbitrary user data (which should outlive the textrun)
void *mUserData;
// A description of which characters have been stripped from the original
// DOM string to produce the characters in the textrun. May be null
// if that information is not relevant.
gfxSkipChars *mSkipChars;
// A list of where linebreaks are currently placed in the textrun. May
// be null if mInitialBreakCount is zero.
uint32_t *mInitialBreaks;
uint32_t mInitialBreakCount;
// The ratio to use to convert device pixels to application layout units
int32_t mAppUnitsPerDevUnit;
};
virtual ~gfxTextRunFactory() {}
};
/**
* This stores glyph bounds information for a particular gfxFont, at
* a particular appunits-per-dev-pixel ratio (because the compressed glyph
* width array is stored in appunits).
*
* We store a hashtable from glyph IDs to float bounding rects. For the
* common case where the glyph has no horizontal left bearing, and no
* y overflow above the font ascent or below the font descent, and tight
* bounding boxes are not required, we avoid storing the glyph ID in the hashtable
* and instead consult an array of 16-bit glyph XMost values (in appunits).
* This array always has an entry for the font's space glyph --- the width is
* assumed to be zero.
*/
class THEBES_API gfxGlyphExtents {
public:
gfxGlyphExtents(int32_t aAppUnitsPerDevUnit) :
mAppUnitsPerDevUnit(aAppUnitsPerDevUnit) {
MOZ_COUNT_CTOR(gfxGlyphExtents);
mTightGlyphExtents.Init();
}
~gfxGlyphExtents();
enum { INVALID_WIDTH = 0xFFFF };
// returns INVALID_WIDTH => not a contained glyph
// Otherwise the glyph has no before-bearing or vertical bearings,
// and the result is its width measured from the baseline origin, in
// appunits.
uint16_t GetContainedGlyphWidthAppUnits(uint32_t aGlyphID) const {
return mContainedGlyphWidths.Get(aGlyphID);
}
bool IsGlyphKnown(uint32_t aGlyphID) const {
return mContainedGlyphWidths.Get(aGlyphID) != INVALID_WIDTH ||
mTightGlyphExtents.GetEntry(aGlyphID) != nullptr;
}
bool IsGlyphKnownWithTightExtents(uint32_t aGlyphID) const {
return mTightGlyphExtents.GetEntry(aGlyphID) != nullptr;
}
// Get glyph extents; a rectangle relative to the left baseline origin
// Returns true on success. Can fail on OOM or when aContext is null
// and extents were not (successfully) prefetched.
bool GetTightGlyphExtentsAppUnits(gfxFont *aFont, gfxContext *aContext,
uint32_t aGlyphID, gfxRect *aExtents);
void SetContainedGlyphWidthAppUnits(uint32_t aGlyphID, uint16_t aWidth) {
mContainedGlyphWidths.Set(aGlyphID, aWidth);
}
void SetTightGlyphExtents(uint32_t aGlyphID, const gfxRect& aExtentsAppUnits);
int32_t GetAppUnitsPerDevUnit() { return mAppUnitsPerDevUnit; }
size_t SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf) const;
size_t SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf) const;
private:
class HashEntry : public nsUint32HashKey {
public:
// When constructing a new entry in the hashtable, we'll leave this
// blank. The caller of Put() will fill this in.
HashEntry(KeyTypePointer aPtr) : nsUint32HashKey(aPtr) {}
HashEntry(const HashEntry& toCopy) : nsUint32HashKey(toCopy) {
x = toCopy.x; y = toCopy.y; width = toCopy.width; height = toCopy.height;
}
float x, y, width, height;
};
enum { BLOCK_SIZE_BITS = 7, BLOCK_SIZE = 1 << BLOCK_SIZE_BITS }; // 128-glyph blocks
class GlyphWidths {
public:
void Set(uint32_t aIndex, uint16_t aValue);
uint16_t Get(uint32_t aIndex) const {
uint32_t block = aIndex >> BLOCK_SIZE_BITS;
if (block >= mBlocks.Length())
return INVALID_WIDTH;
uintptr_t bits = mBlocks[block];
if (!bits)
return INVALID_WIDTH;
uint32_t indexInBlock = aIndex & (BLOCK_SIZE - 1);
if (bits & 0x1) {
if (GetGlyphOffset(bits) != indexInBlock)
return INVALID_WIDTH;
return GetWidth(bits);
}
uint16_t *widths = reinterpret_cast<uint16_t *>(bits);
return widths[indexInBlock];
}
uint32_t SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf) const;
~GlyphWidths();
private:
static uint32_t GetGlyphOffset(uintptr_t aBits) {
NS_ASSERTION(aBits & 0x1, "This is really a pointer...");
return (aBits >> 1) & ((1 << BLOCK_SIZE_BITS) - 1);
}
static uint32_t GetWidth(uintptr_t aBits) {
NS_ASSERTION(aBits & 0x1, "This is really a pointer...");
return aBits >> (1 + BLOCK_SIZE_BITS);
}
static uintptr_t MakeSingle(uint32_t aGlyphOffset, uint16_t aWidth) {
return (aWidth << (1 + BLOCK_SIZE_BITS)) + (aGlyphOffset << 1) + 1;
}
nsTArray<uintptr_t> mBlocks;
};
GlyphWidths mContainedGlyphWidths;
nsTHashtable<HashEntry> mTightGlyphExtents;
int32_t mAppUnitsPerDevUnit;
};
/**
* gfxFontShaper
*
* This class implements text shaping (character to glyph mapping and
* glyph layout). There is a gfxFontShaper subclass for each text layout
* technology (uniscribe, core text, harfbuzz,....) we support.
*
* The shaper is responsible for setting up glyph data in gfxTextRuns.
*
* A generic, platform-independent shaper relies only on the standard
* gfxFont interface and can work with any concrete subclass of gfxFont.
*
* Platform-specific implementations designed to interface to platform
* shaping APIs such as Uniscribe or CoreText may rely on features of a
* specific font subclass to access native font references
* (such as CTFont, HFONT, DWriteFont, etc).
*/
class gfxFontShaper {
public:
gfxFontShaper(gfxFont *aFont)
: mFont(aFont)
{
NS_ASSERTION(aFont, "shaper requires a valid font!");
}
virtual ~gfxFontShaper() { }
// Shape a piece of text and store the resulting glyph data into
// aShapedText. Parameters aOffset/aLength indicate the range of
// aShapedText to be updated; aLength is also the length of aText.
virtual bool ShapeText(gfxContext *aContext,
const PRUnichar *aText,
uint32_t aOffset,
uint32_t aLength,
int32_t aScript,
gfxShapedText *aShapedText) = 0;
gfxFont *GetFont() const { return mFont; }
// returns true if features exist in output, false otherwise
static bool
MergeFontFeatures(const nsTArray<gfxFontFeature>& aStyleRuleFeatures,
const nsTArray<gfxFontFeature>& aFontFeatures,
bool aDisableLigatures,
nsDataHashtable<nsUint32HashKey,uint32_t>& aMergedFeatures);
protected:
// the font this shaper is working with
gfxFont * mFont;
};
/* a SPECIFIC single font family */
class THEBES_API gfxFont {
public:
nsrefcnt AddRef(void) {
NS_PRECONDITION(int32_t(mRefCnt) >= 0, "illegal refcnt");
if (mExpirationState.IsTracked()) {
gfxFontCache::GetCache()->RemoveObject(this);
}
++mRefCnt;
NS_LOG_ADDREF(this, mRefCnt, "gfxFont", sizeof(*this));
return mRefCnt;
}
nsrefcnt Release(void) {
NS_PRECONDITION(0 != mRefCnt, "dup release");
--mRefCnt;
NS_LOG_RELEASE(this, mRefCnt, "gfxFont");
if (mRefCnt == 0) {
NotifyReleased();
// |this| may have been deleted.
return 0;
}
return mRefCnt;
}
int32_t GetRefCount() { return mRefCnt; }
// options to specify the kind of AA to be used when creating a font
typedef enum {
kAntialiasDefault,
kAntialiasNone,
kAntialiasGrayscale,
kAntialiasSubpixel
} AntialiasOption;
// Options for how the text should be drawn
typedef enum {
// GLYPH_FILL and GLYPH_STROKE draw into the current context
// and may be used together with bitwise OR.
GLYPH_FILL = 1,
// Note: using GLYPH_STROKE will destroy the current path.
GLYPH_STROKE = 2,
// Appends glyphs to the current path. Can NOT be used with
// GLYPH_FILL or GLYPH_STROKE.
GLYPH_PATH = 4,
// When GLYPH_FILL and GLYPH_STROKE are both set, draws the
// stroke underneath the fill.
GLYPH_STROKE_UNDERNEATH = 8
} DrawMode;
protected:
nsAutoRefCnt mRefCnt;
cairo_scaled_font_t *mScaledFont;
void NotifyReleased() {
gfxFontCache *cache = gfxFontCache::GetCache();
if (cache) {
// Don't delete just yet; return the object to the cache for
// possibly recycling within some time limit
cache->NotifyReleased(this);
} else {
// The cache may have already been shut down.
delete this;
}
}
gfxFont(gfxFontEntry *aFontEntry, const gfxFontStyle *aFontStyle,
AntialiasOption anAAOption = kAntialiasDefault,
cairo_scaled_font_t *aScaledFont = nullptr);
public:
virtual ~gfxFont();
bool Valid() const {
return mIsValid;
}
// options for the kind of bounding box to return from measurement
typedef enum {
LOOSE_INK_EXTENTS,
// A box that encloses all the painted pixels, and may
// include sidebearings and/or additional ascent/descent
// within the glyph cell even if the ink is smaller.
TIGHT_INK_EXTENTS,
// A box that tightly encloses all the painted pixels
// (although actually on Windows, at least, it may be
// slightly larger than strictly necessary because
// we can't get precise extents with ClearType).
TIGHT_HINTED_OUTLINE_EXTENTS
// A box that tightly encloses the glyph outline,
// ignoring possible antialiasing pixels that extend
// beyond this.
// NOTE: The default implementation of gfxFont::Measure(),
// which works with the glyph extents cache, does not
// differentiate between this and TIGHT_INK_EXTENTS.
// Whether the distinction is important depends on the
// antialiasing behavior of the platform; currently the
// distinction is only implemented in the gfxWindowsFont
// subclass, because of ClearType's tendency to paint
// outside the hinted outline.
// Also NOTE: it is relatively expensive to request this,
// as it does not use cached glyph extents in the font.
} BoundingBoxType;
const nsString& GetName() const { return mFontEntry->Name(); }
const gfxFontStyle *GetStyle() const { return &mStyle; }
virtual cairo_scaled_font_t* GetCairoScaledFont() { return mScaledFont; }
virtual gfxFont* CopyWithAntialiasOption(AntialiasOption anAAOption) {
// platforms where this actually matters should override
return nullptr;
}
virtual gfxFloat GetAdjustedSize() {
return mAdjustedSize > 0.0 ? mAdjustedSize : mStyle.size;
}
float FUnitsToDevUnitsFactor() const {
// check this was set up during font initialization
NS_ASSERTION(mFUnitsConvFactor > 0.0f, "mFUnitsConvFactor not valid");
return mFUnitsConvFactor;
}
// check whether this is an sfnt we can potentially use with harfbuzz
bool FontCanSupportHarfBuzz() {
return mFontEntry->HasCmapTable();
}
// check whether this is an sfnt we can potentially use with Graphite
bool FontCanSupportGraphite() {
return mFontEntry->HasGraphiteTables();
}
// Access to raw font table data (needed for Harfbuzz):
// returns a pointer to data owned by the fontEntry or the OS,
// which will remain valid until released.
//
// Default implementations forward to the font entry,
// and maintain a shared table.
//
// Subclasses should override this if they can provide more efficient
// access than getting tables with mFontEntry->GetFontTable() and sharing
// them via the entry.
//
// Get pointer to a specific font table, or NULL if
// the table doesn't exist in the font
virtual hb_blob_t *GetFontTable(uint32_t aTag);
// Subclasses may choose to look up glyph ids for characters.
// If they do not override this, gfxHarfBuzzShaper will fetch the cmap
// table and use that.
virtual bool ProvidesGetGlyph() const {
return false;
}
// Map unicode character to glyph ID.
// Only used if ProvidesGetGlyph() returns true.
virtual uint32_t GetGlyph(uint32_t unicode, uint32_t variation_selector) {
return 0;
}
// subclasses may provide (possibly hinted) glyph widths (in font units);
// if they do not override this, harfbuzz will use unhinted widths
// derived from the font tables
virtual bool ProvidesGlyphWidths() {
return false;
}
// The return value is interpreted as a horizontal advance in 16.16 fixed
// point format.
virtual int32_t GetGlyphWidth(gfxContext *aCtx, uint16_t aGID) {
return -1;
}
// Return Azure GlyphRenderingOptions for drawing this font.
virtual mozilla::TemporaryRef<mozilla::gfx::GlyphRenderingOptions>
GetGlyphRenderingOptions() { return nullptr; }
gfxFloat SynthesizeSpaceWidth(uint32_t aCh);
// Font metrics
struct Metrics {
gfxFloat xHeight;
gfxFloat superscriptOffset;
gfxFloat subscriptOffset;
gfxFloat strikeoutSize;
gfxFloat strikeoutOffset;
gfxFloat underlineSize;
gfxFloat underlineOffset;
gfxFloat internalLeading;
gfxFloat externalLeading;
gfxFloat emHeight;
gfxFloat emAscent;
gfxFloat emDescent;
gfxFloat maxHeight;
gfxFloat maxAscent;
gfxFloat maxDescent;
gfxFloat maxAdvance;
gfxFloat aveCharWidth;
gfxFloat spaceWidth;
gfxFloat zeroOrAveCharWidth; // width of '0', or if there is
// no '0' glyph in this font,
// equal to .aveCharWidth
};
virtual const gfxFont::Metrics& GetMetrics() = 0;
/**
* We let layout specify spacing on either side of any
* character. We need to specify both before and after
* spacing so that substring measurement can do the right things.
* These values are in appunits. They're always an integral number of
* appunits, but we specify them in floats in case very large spacing
* values are required.
*/
struct Spacing {
gfxFloat mBefore;
gfxFloat mAfter;
};
/**
* Metrics for a particular string
*/
struct THEBES_API RunMetrics {
RunMetrics() {
mAdvanceWidth = mAscent = mDescent = 0.0;
mBoundingBox = gfxRect(0,0,0,0);
}
void CombineWith(const RunMetrics& aOther, bool aOtherIsOnLeft);
// can be negative (partly due to negative spacing).
// Advance widths should be additive: the advance width of the
// (offset1, length1) plus the advance width of (offset1 + length1,
// length2) should be the advance width of (offset1, length1 + length2)
gfxFloat mAdvanceWidth;
// For zero-width substrings, these must be zero!
gfxFloat mAscent; // always non-negative
gfxFloat mDescent; // always non-negative
// Bounding box that is guaranteed to include everything drawn.
// If a tight boundingBox was requested when these metrics were
// generated, this will tightly wrap the glyphs, otherwise it is
// "loose" and may be larger than the true bounding box.
// Coordinates are relative to the baseline left origin, so typically
// mBoundingBox.y == -mAscent
gfxRect mBoundingBox;
};
/**
* Draw a series of glyphs to aContext. The direction of aTextRun must
* be honoured.
* @param aStart the first character to draw
* @param aEnd draw characters up to here
* @param aBaselineOrigin the baseline origin; the left end of the baseline
* for LTR textruns, the right end of the baseline for RTL textruns. On return,
* this should be updated to the other end of the baseline. In application
* units, really!
* @param aSpacing spacing to insert before and after characters (for RTL
* glyphs, before-spacing is inserted to the right of characters). There
* are aEnd - aStart elements in this array, unless it's null to indicate
* that there is no spacing.
* @param aDrawMode specifies whether the fill or stroke of the glyph should be
* drawn, or if it should be drawn into the current path
* @param aObjectPaint information about how to construct the fill and
* stroke pattern. Can be NULL if we are not stroking the text, which
* indicates that the current source from aContext should be used for filling
*
* Callers guarantee:
* -- aStart and aEnd are aligned to cluster and ligature boundaries
* -- all glyphs use this font
*
* The default implementation builds a cairo glyph array and
* calls cairo_show_glyphs or cairo_glyph_path.
*/
virtual void Draw(gfxTextRun *aTextRun, uint32_t aStart, uint32_t aEnd,
gfxContext *aContext, DrawMode aDrawMode, gfxPoint *aBaselineOrigin,
Spacing *aSpacing, gfxTextObjectPaint *aObjectPaint,
gfxTextRunDrawCallbacks *aCallbacks);
/**
* Measure a run of characters. See gfxTextRun::Metrics.
* @param aTight if false, then return the union of the glyph extents
* with the font-box for the characters (the rectangle with x=0,width=
* the advance width for the character run,y=-(font ascent), and height=
* font ascent + font descent). Otherwise, we must return as tight as possible
* an approximation to the area actually painted by glyphs.
* @param aContextForTightBoundingBox when aTight is true, this must
* be non-null.
* @param aSpacing spacing to insert before and after glyphs. The bounding box
* need not include the spacing itself, but the spacing affects the glyph
* positions. null if there is no spacing.
*
* Callers guarantee:
* -- aStart and aEnd are aligned to cluster and ligature boundaries
* -- all glyphs use this font
*
* The default implementation just uses font metrics and aTextRun's
* advances, and assumes no characters fall outside the font box. In
* general this is insufficient, because that assumption is not always true.
*/
virtual RunMetrics Measure(gfxTextRun *aTextRun,
uint32_t aStart, uint32_t aEnd,
BoundingBoxType aBoundingBoxType,
gfxContext *aContextForTightBoundingBox,
Spacing *aSpacing);
/**
* Line breaks have been changed at the beginning and/or end of a substring
* of the text. Reshaping may be required; glyph updating is permitted.
* @return true if anything was changed, false otherwise
*/
bool NotifyLineBreaksChanged(gfxTextRun *aTextRun,
uint32_t aStart, uint32_t aLength)
{ return false; }
// Expiration tracking
nsExpirationState *GetExpirationState() { return &mExpirationState; }
// Get the glyphID of a space
virtual uint32_t GetSpaceGlyph() = 0;
gfxGlyphExtents *GetOrCreateGlyphExtents(int32_t aAppUnitsPerDevUnit);
// You need to call SetupCairoFont on the aCR just before calling this
virtual void SetupGlyphExtents(gfxContext *aContext, uint32_t aGlyphID,
bool aNeedTight, gfxGlyphExtents *aExtents);
// This is called by the default Draw() implementation above.
virtual bool SetupCairoFont(gfxContext *aContext) = 0;
virtual bool AllowSubpixelAA() { return true; }
bool IsSyntheticBold() { return mApplySyntheticBold; }
// Amount by which synthetic bold "fattens" the glyphs:
// For size S up to a threshold size T, we use (0.25 + 3S / 4T),
// so that the result ranges from 0.25 to 1.0; thereafter,
// simply use (S / T).
gfxFloat GetSyntheticBoldOffset() {
gfxFloat size = GetAdjustedSize();
const gfxFloat threshold = 48.0;
return size < threshold ? (0.25 + 0.75 * size / threshold) :
(size / threshold);
}
gfxFontEntry *GetFontEntry() { return mFontEntry.get(); }
bool HasCharacter(uint32_t ch) {
if (!mIsValid)
return false;
return mFontEntry->HasCharacter(ch);
}
uint16_t GetUVSGlyph(uint32_t aCh, uint32_t aVS) {
if (!mIsValid) {
return 0;
}
return mFontEntry->GetUVSGlyph(aCh, aVS);
}
// call the (virtual) InitTextRun method to do glyph generation/shaping,
// limiting the length of text passed by processing the run in multiple
// segments if necessary
template<typename T>
bool SplitAndInitTextRun(gfxContext *aContext,
gfxTextRun *aTextRun,
const T *aString,
uint32_t aRunStart,
uint32_t aRunLength,
int32_t aRunScript);
// Get a ShapedWord representing the given text (either 8- or 16-bit)
// for use in setting up a gfxTextRun.
template<typename T>
gfxShapedWord* GetShapedWord(gfxContext *aContext,
const T *aText,
uint32_t aLength,
uint32_t aHash,
int32_t aRunScript,
int32_t aAppUnitsPerDevUnit,
uint32_t aFlags);
// Ensure the ShapedWord cache is initialized. This MUST be called before
// any attempt to use GetShapedWord().
void InitWordCache() {
if (!mWordCache.IsInitialized()) {
mWordCache.Init();
}
}
// Called by the gfxFontCache timer to increment the age of all the words,
// so that they'll expire after a sufficient period of non-use
void AgeCachedWords() {
if (mWordCache.IsInitialized()) {
(void)mWordCache.EnumerateEntries(AgeCacheEntry, this);
}
}
// Discard all cached word records; called on memory-pressure notification.
void ClearCachedWords() {
if (mWordCache.IsInitialized()) {
mWordCache.Clear();
}
}
virtual void SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf,
FontCacheSizes* aSizes) const;
virtual void SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf,
FontCacheSizes* aSizes) const;
typedef enum {
FONT_TYPE_DWRITE,
FONT_TYPE_GDI,
FONT_TYPE_FT2,
FONT_TYPE_MAC,
FONT_TYPE_OS2,
FONT_TYPE_CAIRO
} FontType;
virtual FontType GetType() const = 0;
virtual mozilla::TemporaryRef<mozilla::gfx::ScaledFont> GetScaledFont(mozilla::gfx::DrawTarget *aTarget)
{ return gfxPlatform::GetPlatform()->GetScaledFontForFont(aTarget, this); }
protected:
// For 8-bit text, expand to 16-bit and then call the following method.
bool ShapeText(gfxContext *aContext,
const uint8_t *aText,
uint32_t aOffset, // dest offset in gfxShapedText
uint32_t aLength,
int32_t aScript,
gfxShapedText *aShapedText, // where to store the result
bool aPreferPlatformShaping = false);
// Call the appropriate shaper to generate glyphs for aText and store
// them into aShapedText.
virtual bool ShapeText(gfxContext *aContext,
const PRUnichar *aText,
uint32_t aOffset,
uint32_t aLength,
int32_t aScript,
gfxShapedText *aShapedText,
bool aPreferPlatformShaping = false);
// Helper to adjust for synthetic bold and set character-type flags
// in the shaped text; implementations of ShapeText should call this
// after glyph shaping has been completed.
void PostShapingFixup(gfxContext *aContext,
const PRUnichar *aText,
uint32_t aOffset, // position within aShapedText
uint32_t aLength,
gfxShapedText *aShapedText);
// Shape text directly into a range within a textrun, without using the
// font's word cache. Intended for use when the font has layout features
// that involve space, and therefore require shaping complete runs rather
// than isolated words, or for long strings that are inefficient to cache.
// This will split the text on "invalid" characters (tab/newline) that are
// not handled via normal shaping, but does not otherwise divide up the
// text.
template<typename T>
bool ShapeTextWithoutWordCache(gfxContext *aContext,
const T *aText,
uint32_t aOffset,
uint32_t aLength,
int32_t aScript,
gfxTextRun *aTextRun);
// Shape a fragment of text (a run that is known to contain only
// "valid" characters, no newlines/tabs/other control chars).
// All non-wordcache shaping goes through here; this is the function
// that will ensure we don't pass excessively long runs to the various
// platform shapers.
template<typename T>
bool ShapeFragmentWithoutWordCache(gfxContext *aContext,
const T *aText,
uint32_t aOffset,
uint32_t aLength,
int32_t aScript,
gfxTextRun *aTextRun);
nsRefPtr<gfxFontEntry> mFontEntry;
struct CacheHashKey {
union {
const uint8_t *mSingle;
const PRUnichar *mDouble;
} mText;
uint32_t mLength;
uint32_t mFlags;
int32_t mScript;
int32_t mAppUnitsPerDevUnit;
PLDHashNumber mHashKey;
bool mTextIs8Bit;
CacheHashKey(const uint8_t *aText, uint32_t aLength,
uint32_t aStringHash,
int32_t aScriptCode, int32_t aAppUnitsPerDevUnit,
uint32_t aFlags)
: mLength(aLength),
mFlags(aFlags),
mScript(aScriptCode),
mAppUnitsPerDevUnit(aAppUnitsPerDevUnit),
mHashKey(aStringHash + aScriptCode +
aAppUnitsPerDevUnit * 0x100 + aFlags * 0x10000),
mTextIs8Bit(true)
{
NS_ASSERTION(aFlags & gfxTextRunFactory::TEXT_IS_8BIT,
"8-bit flag should have been set");
mText.mSingle = aText;
}
CacheHashKey(const PRUnichar *aText, uint32_t aLength,
uint32_t aStringHash,
int32_t aScriptCode, int32_t aAppUnitsPerDevUnit,
uint32_t aFlags)
: mLength(aLength),
mFlags(aFlags),
mScript(aScriptCode),
mAppUnitsPerDevUnit(aAppUnitsPerDevUnit),
mHashKey(aStringHash + aScriptCode +
aAppUnitsPerDevUnit * 0x100 + aFlags * 0x10000),
mTextIs8Bit(false)
{
// We can NOT assert that TEXT_IS_8BIT is false in aFlags here,
// because this might be an 8bit-only word from a 16-bit textrun,
// in which case the text we're passed is still in 16-bit form,
// and we'll have to use an 8-to-16bit comparison in KeyEquals.
mText.mDouble = aText;
}
};
class CacheHashEntry : public PLDHashEntryHdr {
public:
typedef const CacheHashKey &KeyType;
typedef const CacheHashKey *KeyTypePointer;
// When constructing a new entry in the hashtable, the caller of Put()
// will fill us in.
CacheHashEntry(KeyTypePointer aKey) { }
CacheHashEntry(const CacheHashEntry& toCopy) { NS_ERROR("Should not be called"); }
~CacheHashEntry() { }
bool KeyEquals(const KeyTypePointer aKey) const;
static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
static PLDHashNumber HashKey(const KeyTypePointer aKey) {
return aKey->mHashKey;
}
enum { ALLOW_MEMMOVE = true };
nsAutoPtr<gfxShapedWord> mShapedWord;
};
static size_t
WordCacheEntrySizeOfExcludingThis(CacheHashEntry* aHashEntry,
nsMallocSizeOfFun aMallocSizeOf,
void* aUserArg);
nsTHashtable<CacheHashEntry> mWordCache;
static PLDHashOperator AgeCacheEntry(CacheHashEntry *aEntry, void *aUserData);
static const uint32_t kShapedWordCacheMaxAge = 3;
bool mIsValid;
// use synthetic bolding for environments where this is not supported
// by the platform
bool mApplySyntheticBold;
nsExpirationState mExpirationState;
gfxFontStyle mStyle;
nsAutoTArray<gfxGlyphExtents*,1> mGlyphExtentsArray;
gfxFloat mAdjustedSize;
float mFUnitsConvFactor; // conversion factor from font units to dev units
// the AA setting requested for this font - may affect glyph bounds
AntialiasOption mAntialiasOption;
// a copy of the font without antialiasing, if needed for separate
// measurement by mathml code
nsAutoPtr<gfxFont> mNonAAFont;
// we may switch between these shapers on the fly, based on the script
// of the text run being shaped
nsAutoPtr<gfxFontShaper> mPlatformShaper;
nsAutoPtr<gfxFontShaper> mHarfBuzzShaper;
nsAutoPtr<gfxFontShaper> mGraphiteShaper;
mozilla::RefPtr<mozilla::gfx::ScaledFont> mAzureScaledFont;
// Create a default platform text shaper for this font.
// (TODO: This should become pure virtual once all font backends have
// been updated.)
virtual void CreatePlatformShaper() { }
// Helper for subclasses that want to initialize standard metrics from the
// tables of sfnt (TrueType/OpenType) fonts.
// This will use mFUnitsConvFactor if it is already set, else compute it
// from mAdjustedSize and the unitsPerEm in the font's 'head' table.
// Returns TRUE and sets mIsValid=TRUE if successful;
// Returns TRUE but leaves mIsValid=FALSE if the font seems to be broken.
// Returns FALSE if the font does not appear to be an sfnt at all,
// and should be handled (if possible) using other APIs.
bool InitMetricsFromSfntTables(Metrics& aMetrics);
// Helper to calculate various derived metrics from the results of
// InitMetricsFromSfntTables or equivalent platform code
void CalculateDerivedMetrics(Metrics& aMetrics);
// some fonts have bad metrics, this method sanitize them.
// if this font has bad underline offset, aIsBadUnderlineFont should be true.
void SanitizeMetrics(gfxFont::Metrics *aMetrics, bool aIsBadUnderlineFont);
bool RenderSVGGlyph(gfxContext *aContext, gfxPoint aPoint, DrawMode aDrawMode,
uint32_t aGlyphId, gfxTextObjectPaint *aObjectPaint);
bool RenderSVGGlyph(gfxContext *aContext, gfxPoint aPoint, DrawMode aDrawMode,
uint32_t aGlyphId, gfxTextObjectPaint *aObjectPaint,
gfxTextRunDrawCallbacks *aCallbacks,
bool& aEmittedGlyphs);
// Bug 674909. When synthetic bolding text by drawing twice, need to
// render using a pixel offset in device pixels, otherwise text
// doesn't appear bolded, it appears as if a bad text shadow exists
// when a non-identity transform exists. Use an offset factor so that
// the second draw occurs at a constant offset in device pixels.
// This helper calculates the scale factor we need to apply to the
// synthetic-bold offset.
static double CalcXScale(gfxContext *aContext);
};
// proportion of ascent used for x-height, if unable to read value from font
#define DEFAULT_XHEIGHT_FACTOR 0.56f
/*
* gfxShapedText is an abstract superclass for gfxShapedWord and gfxTextRun.
* These are objects that store a list of zero or more glyphs for each character.
* For each glyph we store the glyph ID, the advance, and possibly x/y-offsets.
* The idea is that a string is rendered by a loop that draws each glyph
* at its designated offset from the current point, then advances the current
* point by the glyph's advance in the direction of the textrun (LTR or RTL).
* Each glyph advance is always rounded to the nearest appunit; this ensures
* consistent results when dividing the text in a textrun into multiple text
* frames (frame boundaries are always aligned to appunits). We optimize
* for the case where a character has a single glyph and zero xoffset and yoffset,
* and the glyph ID and advance are in a reasonable range so we can pack all
* necessary data into 32 bits.
*
* gfxFontShaper can shape text into either a gfxShapedWord (cached by a gfxFont)
* or directly into a gfxTextRun (for cases where we want to shape textruns in
* their entirety rather than using cached words, because there may be layout
* features that depend on the inter-word spaces).
*/
class gfxShapedText
{
public:
gfxShapedText(uint32_t aLength, uint32_t aFlags,
int32_t aAppUnitsPerDevUnit)
: mLength(aLength)
, mFlags(aFlags)
, mAppUnitsPerDevUnit(aAppUnitsPerDevUnit)
{ }
virtual ~gfxShapedText() { }
/**
* This class records the information associated with a character in the
* input string. It's optimized for the case where there is one glyph
* representing that character alone.
*
* A character can have zero or more associated glyphs. Each glyph
* has an advance width and an x and y offset.
* A character may be the start of a cluster.
* A character may be the start of a ligature group.
* A character can be "missing", indicating that the system is unable
* to render the character.
*
* All characters in a ligature group conceptually share all the glyphs
* associated with the characters in a group.
*/
class CompressedGlyph {
public:
CompressedGlyph() { mValue = 0; }
enum {
// Indicates that a cluster and ligature group starts at this
// character; this character has a single glyph with a reasonable
// advance and zero offsets. A "reasonable" advance
// is one that fits in the available bits (currently 12) (specified
// in appunits).
FLAG_IS_SIMPLE_GLYPH = 0x80000000U,
// Indicates whether a linebreak is allowed before this character;
// this is a two-bit field that holds a FLAG_BREAK_TYPE_xxx value
// indicating the kind of linebreak (if any) allowed here.
FLAGS_CAN_BREAK_BEFORE = 0x60000000U,
FLAGS_CAN_BREAK_SHIFT = 29,
FLAG_BREAK_TYPE_NONE = 0,
FLAG_BREAK_TYPE_NORMAL = 1,
FLAG_BREAK_TYPE_HYPHEN = 2,
FLAG_CHAR_IS_SPACE = 0x10000000U,
// The advance is stored in appunits
ADVANCE_MASK = 0x0FFF0000U,
ADVANCE_SHIFT = 16,
GLYPH_MASK = 0x0000FFFFU,
// Non-simple glyphs may or may not have glyph data in the
// corresponding mDetailedGlyphs entry. They have the following
// flag bits:
// When NOT set, indicates that this character corresponds to a
// missing glyph and should be skipped (or possibly, render the character
// Unicode value in some special way). If there are glyphs,
// the mGlyphID is actually the UTF16 character code. The bit is
// inverted so we can memset the array to zero to indicate all missing.
FLAG_NOT_MISSING = 0x01,
FLAG_NOT_CLUSTER_START = 0x02,
FLAG_NOT_LIGATURE_GROUP_START = 0x04,
FLAG_CHAR_IS_TAB = 0x08,
FLAG_CHAR_IS_NEWLINE = 0x10,
FLAG_CHAR_IS_LOW_SURROGATE = 0x20,
CHAR_IDENTITY_FLAGS_MASK = 0x38,
GLYPH_COUNT_MASK = 0x00FFFF00U,
GLYPH_COUNT_SHIFT = 8
};
// "Simple glyphs" have a simple glyph ID, simple advance and their
// x and y offsets are zero. Also the glyph extents do not overflow
// the font-box defined by the font ascent, descent and glyph advance width.
// These case is optimized to avoid storing DetailedGlyphs.
// Returns true if the glyph ID aGlyph fits into the compressed representation
static bool IsSimpleGlyphID(uint32_t aGlyph) {
return (aGlyph & GLYPH_MASK) == aGlyph;
}
// Returns true if the advance aAdvance fits into the compressed representation.
// aAdvance is in appunits.
static bool IsSimpleAdvance(uint32_t aAdvance) {
return (aAdvance & (ADVANCE_MASK >> ADVANCE_SHIFT)) == aAdvance;
}
bool IsSimpleGlyph() const { return (mValue & FLAG_IS_SIMPLE_GLYPH) != 0; }
uint32_t GetSimpleAdvance() const { return (mValue & ADVANCE_MASK) >> ADVANCE_SHIFT; }
uint32_t GetSimpleGlyph() const { return mValue & GLYPH_MASK; }
bool IsMissing() const { return (mValue & (FLAG_NOT_MISSING|FLAG_IS_SIMPLE_GLYPH)) == 0; }
bool IsClusterStart() const {
return (mValue & FLAG_IS_SIMPLE_GLYPH) || !(mValue & FLAG_NOT_CLUSTER_START);
}
bool IsLigatureGroupStart() const {
return (mValue & FLAG_IS_SIMPLE_GLYPH) || !(mValue & FLAG_NOT_LIGATURE_GROUP_START);
}
bool IsLigatureContinuation() const {
return (mValue & FLAG_IS_SIMPLE_GLYPH) == 0 &&
(mValue & (FLAG_NOT_LIGATURE_GROUP_START | FLAG_NOT_MISSING)) ==
(FLAG_NOT_LIGATURE_GROUP_START | FLAG_NOT_MISSING);
}
// Return true if the original character was a normal (breakable,
// trimmable) space (U+0020). Not true for other characters that
// may happen to map to the space glyph (U+00A0).
bool CharIsSpace() const {
return (mValue & FLAG_CHAR_IS_SPACE) != 0;
}
bool CharIsTab() const {
return !IsSimpleGlyph() && (mValue & FLAG_CHAR_IS_TAB) != 0;
}
bool CharIsNewline() const {
return !IsSimpleGlyph() && (mValue & FLAG_CHAR_IS_NEWLINE) != 0;
}
bool CharIsLowSurrogate() const {
return !IsSimpleGlyph() && (mValue & FLAG_CHAR_IS_LOW_SURROGATE) != 0;
}
uint32_t CharIdentityFlags() const {
return IsSimpleGlyph() ? 0 : (mValue & CHAR_IDENTITY_FLAGS_MASK);
}
void SetClusterStart(bool aIsClusterStart) {
NS_ASSERTION(!IsSimpleGlyph(),
"can't call SetClusterStart on simple glyphs");
if (aIsClusterStart) {
mValue &= ~FLAG_NOT_CLUSTER_START;
} else {
mValue |= FLAG_NOT_CLUSTER_START;
}
}
uint8_t CanBreakBefore() const {
return (mValue & FLAGS_CAN_BREAK_BEFORE) >> FLAGS_CAN_BREAK_SHIFT;
}
// Returns FLAGS_CAN_BREAK_BEFORE if the setting changed, 0 otherwise
uint32_t SetCanBreakBefore(uint8_t aCanBreakBefore) {
NS_ASSERTION(aCanBreakBefore <= 2,
"Bogus break-before value!");
uint32_t breakMask = (uint32_t(aCanBreakBefore) << FLAGS_CAN_BREAK_SHIFT);
uint32_t toggle = breakMask ^ (mValue & FLAGS_CAN_BREAK_BEFORE);
mValue ^= toggle;
return toggle;
}
CompressedGlyph& SetSimpleGlyph(uint32_t aAdvanceAppUnits, uint32_t aGlyph) {
NS_ASSERTION(IsSimpleAdvance(aAdvanceAppUnits), "Advance overflow");
NS_ASSERTION(IsSimpleGlyphID(aGlyph), "Glyph overflow");
NS_ASSERTION(!CharIdentityFlags(), "Char identity flags lost");
mValue = (mValue & (FLAGS_CAN_BREAK_BEFORE | FLAG_CHAR_IS_SPACE)) |
FLAG_IS_SIMPLE_GLYPH |
(aAdvanceAppUnits << ADVANCE_SHIFT) | aGlyph;
return *this;
}
CompressedGlyph& SetComplex(bool aClusterStart, bool aLigatureStart,
uint32_t aGlyphCount) {
mValue = (mValue & (FLAGS_CAN_BREAK_BEFORE | FLAG_CHAR_IS_SPACE)) |
FLAG_NOT_MISSING |
CharIdentityFlags() |
(aClusterStart ? 0 : FLAG_NOT_CLUSTER_START) |
(aLigatureStart ? 0 : FLAG_NOT_LIGATURE_GROUP_START) |
(aGlyphCount << GLYPH_COUNT_SHIFT);
return *this;
}
/**
* Missing glyphs are treated as ligature group starts; don't mess with
* the cluster-start flag (see bugs 618870 and 619286).
*/
CompressedGlyph& SetMissing(uint32_t aGlyphCount) {
mValue = (mValue & (FLAGS_CAN_BREAK_BEFORE | FLAG_NOT_CLUSTER_START |
FLAG_CHAR_IS_SPACE)) |
CharIdentityFlags() |
(aGlyphCount << GLYPH_COUNT_SHIFT);
return *this;
}
uint32_t GetGlyphCount() const {
NS_ASSERTION(!IsSimpleGlyph(), "Expected non-simple-glyph");
return (mValue & GLYPH_COUNT_MASK) >> GLYPH_COUNT_SHIFT;
}
void SetIsSpace() {
mValue |= FLAG_CHAR_IS_SPACE;
}
void SetIsTab() {
NS_ASSERTION(!IsSimpleGlyph(), "Expected non-simple-glyph");
mValue |= FLAG_CHAR_IS_TAB;
}
void SetIsNewline() {
NS_ASSERTION(!IsSimpleGlyph(), "Expected non-simple-glyph");
mValue |= FLAG_CHAR_IS_NEWLINE;
}
void SetIsLowSurrogate() {
NS_ASSERTION(!IsSimpleGlyph(), "Expected non-simple-glyph");
mValue |= FLAG_CHAR_IS_LOW_SURROGATE;
}
private:
uint32_t mValue;
};
// Accessor for the array of CompressedGlyph records, which will be in
// a different place in gfxShapedWord vs gfxTextRun
virtual CompressedGlyph *GetCharacterGlyphs() = 0;
/**
* When the glyphs for a character don't fit into a CompressedGlyph record
* in SimpleGlyph format, we use an array of DetailedGlyphs instead.
*/
struct DetailedGlyph {
/** The glyphID, or the Unicode character
* if this is a missing glyph */
uint32_t mGlyphID;
/** The advance, x-offset and y-offset of the glyph, in appunits
* mAdvance is in the text direction (RTL or LTR)
* mXOffset is always from left to right
* mYOffset is always from top to bottom */
int32_t mAdvance;
float mXOffset, mYOffset;
};
void SetGlyphs(uint32_t aCharIndex, CompressedGlyph aGlyph,
const DetailedGlyph *aGlyphs);
void SetMissingGlyph(uint32_t aIndex, uint32_t aChar, gfxFont *aFont);
void SetIsSpace(uint32_t aIndex) {
GetCharacterGlyphs()[aIndex].SetIsSpace();
}
void SetIsLowSurrogate(uint32_t aIndex) {
SetGlyphs(aIndex, CompressedGlyph().SetComplex(false, false, 0), nullptr);
GetCharacterGlyphs()[aIndex].SetIsLowSurrogate();
}
bool HasDetailedGlyphs() const {
return mDetailedGlyphs != nullptr;
}
bool IsClusterStart(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return GetCharacterGlyphs()[aPos].IsClusterStart();
}
bool IsLigatureGroupStart(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return GetCharacterGlyphs()[aPos].IsLigatureGroupStart();
}
// NOTE that this must not be called for a character offset that does
// not have any DetailedGlyph records; callers must have verified that
// GetCharacterGlyphs()[aCharIndex].GetGlyphCount() is greater than zero.
DetailedGlyph *GetDetailedGlyphs(uint32_t aCharIndex) {
NS_ASSERTION(GetCharacterGlyphs() && HasDetailedGlyphs() &&
!GetCharacterGlyphs()[aCharIndex].IsSimpleGlyph() &&
GetCharacterGlyphs()[aCharIndex].GetGlyphCount() > 0,
"invalid use of GetDetailedGlyphs; check the caller!");
return mDetailedGlyphs->Get(aCharIndex);
}
void AdjustAdvancesForSyntheticBold(float aSynBoldOffset,
uint32_t aOffset, uint32_t aLength);
// Mark clusters in the CompressedGlyph records, starting at aOffset,
// based on the Unicode properties of the text in aString.
// This is also responsible to set the IsSpace flag for space characters.
void SetupClusterBoundaries(uint32_t aOffset,
const PRUnichar *aString,
uint32_t aLength);
// In 8-bit text, there won't actually be any clusters, but we still need
// the space-marking functionality.
void SetupClusterBoundaries(uint32_t aOffset,
const uint8_t *aString,
uint32_t aLength);
uint32_t Flags() const {
return mFlags;
}
bool IsRightToLeft() const {
return (Flags() & gfxTextRunFactory::TEXT_IS_RTL) != 0;
}
float GetDirection() const {
return IsRightToLeft() ? -1.0f : 1.0f;
}
bool DisableLigatures() const {
return (Flags() & gfxTextRunFactory::TEXT_DISABLE_OPTIONAL_LIGATURES) != 0;
}
bool TextIs8Bit() const {
return (Flags() & gfxTextRunFactory::TEXT_IS_8BIT) != 0;
}
int32_t GetAppUnitsPerDevUnit() const {
return mAppUnitsPerDevUnit;
}
uint32_t GetLength() const {
return mLength;
}
bool FilterIfIgnorable(uint32_t aIndex, uint32_t aCh);
protected:
// Allocate aCount DetailedGlyphs for the given index
DetailedGlyph *AllocateDetailedGlyphs(uint32_t aCharIndex,
uint32_t aCount);
// For characters whose glyph data does not fit the "simple" glyph criteria
// in CompressedGlyph, we use a sorted array to store the association
// between the source character offset and an index into an array
// DetailedGlyphs. The CompressedGlyph record includes a count of
// the number of DetailedGlyph records that belong to the character,
// starting at the given index.
class DetailedGlyphStore {
public:
DetailedGlyphStore()
: mLastUsed(0)
{ }
// This is optimized for the most common calling patterns:
// we rarely need random access to the records, access is most commonly
// sequential through the textRun, so we record the last-used index
// and check whether the caller wants the same record again, or the
// next; if not, it's most likely we're starting over from the start
// of the run, so we check the first entry before resorting to binary
// search as a last resort.
// NOTE that this must not be called for a character offset that does
// not have any DetailedGlyph records; callers must have verified that
// mCharacterGlyphs[aOffset].GetGlyphCount() is greater than zero
// before calling this, otherwise the assertions here will fire (in a
// debug build), and we'll probably crash.
DetailedGlyph* Get(uint32_t aOffset) {
NS_ASSERTION(mOffsetToIndex.Length() > 0,
"no detailed glyph records!");
DetailedGlyph* details = mDetails.Elements();
// check common cases (fwd iteration, initial entry, etc) first
if (mLastUsed < mOffsetToIndex.Length() - 1 &&
aOffset == mOffsetToIndex[mLastUsed + 1].mOffset) {
++mLastUsed;
} else if (aOffset == mOffsetToIndex[0].mOffset) {
mLastUsed = 0;
} else if (aOffset == mOffsetToIndex[mLastUsed].mOffset) {
// do nothing
} else if (mLastUsed > 0 &&
aOffset == mOffsetToIndex[mLastUsed - 1].mOffset) {
--mLastUsed;
} else {
mLastUsed =
mOffsetToIndex.BinaryIndexOf(aOffset, CompareToOffset());
}
NS_ASSERTION(mLastUsed != nsTArray<DGRec>::NoIndex,
"detailed glyph record missing!");
return details + mOffsetToIndex[mLastUsed].mIndex;
}
DetailedGlyph* Allocate(uint32_t aOffset, uint32_t aCount) {
uint32_t detailIndex = mDetails.Length();
DetailedGlyph *details = mDetails.AppendElements(aCount);
if (!details) {
return nullptr;
}
// We normally set up glyph records sequentially, so the common case
// here is to append new records to the mOffsetToIndex array;
// test for that before falling back to the InsertElementSorted
// method.
if (mOffsetToIndex.Length() == 0 ||
aOffset > mOffsetToIndex[mOffsetToIndex.Length() - 1].mOffset) {
if (!mOffsetToIndex.AppendElement(DGRec(aOffset, detailIndex))) {
return nullptr;
}
} else {
if (!mOffsetToIndex.InsertElementSorted(DGRec(aOffset, detailIndex),
CompareRecordOffsets())) {
return nullptr;
}
}
return details;
}
size_t SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf) {
return aMallocSizeOf(this) +
mDetails.SizeOfExcludingThis(aMallocSizeOf) +
mOffsetToIndex.SizeOfExcludingThis(aMallocSizeOf);
}
private:
struct DGRec {
DGRec(const uint32_t& aOffset, const uint32_t& aIndex)
: mOffset(aOffset), mIndex(aIndex) { }
uint32_t mOffset; // source character offset in the textrun
uint32_t mIndex; // index where this char's DetailedGlyphs begin
};
struct CompareToOffset {
bool Equals(const DGRec& a, const uint32_t& b) const {
return a.mOffset == b;
}
bool LessThan(const DGRec& a, const uint32_t& b) const {
return a.mOffset < b;
}
};
struct CompareRecordOffsets {
bool Equals(const DGRec& a, const DGRec& b) const {
return a.mOffset == b.mOffset;
}
bool LessThan(const DGRec& a, const DGRec& b) const {
return a.mOffset < b.mOffset;
}
};
// Concatenated array of all the DetailedGlyph records needed for the
// textRun; individual character offsets are associated with indexes
// into this array via the mOffsetToIndex table.
nsTArray<DetailedGlyph> mDetails;
// For each character offset that needs DetailedGlyphs, we record the
// index in mDetails where the list of glyphs begins. This array is
// sorted by mOffset.
nsTArray<DGRec> mOffsetToIndex;
// Records the most recently used index into mOffsetToIndex, so that
// we can support sequential access more quickly than just doing
// a binary search each time.
nsTArray<DGRec>::index_type mLastUsed;
};
nsAutoPtr<DetailedGlyphStore> mDetailedGlyphs;
// Number of PRUnichar characters and CompressedGlyph glyph records
uint32_t mLength;
// Shaping flags (direction, ligature-suppression)
uint32_t mFlags;
int32_t mAppUnitsPerDevUnit;
};
/*
* gfxShapedWord: an individual (space-delimited) run of text shaped with a
* particular font, without regard to external context.
*
* The glyph data is copied into gfxTextRuns as needed from the cache of
* ShapedWords associated with each gfxFont instance.
*/
class gfxShapedWord : public gfxShapedText
{
public:
static const uint32_t kMaxLength = 32;
// Create a ShapedWord that can hold glyphs for aLength characters,
// with mCharacterGlyphs sized appropriately.
//
// Returns null on allocation failure (does NOT use infallible alloc)
// so caller must check for success.
//
// This does NOT perform shaping, so the returned word contains no
// glyph data; the caller must call gfxFont::ShapeText() with appropriate
// parameters to set up the glyphs.
static gfxShapedWord* Create(const uint8_t *aText, uint32_t aLength,
int32_t aRunScript,
int32_t aAppUnitsPerDevUnit,
uint32_t aFlags) {
NS_ASSERTION(aLength <= kMaxLength, "excessive length for gfxShapedWord!");
// Compute size needed including the mCharacterGlyphs array
// and a copy of the original text
uint32_t size =
offsetof(gfxShapedWord, mCharGlyphsStorage) +
aLength * (sizeof(CompressedGlyph) + sizeof(uint8_t));
void *storage = moz_malloc(size);
if (!storage) {
return nullptr;
}
// Construct in the pre-allocated storage, using placement new
return new (storage) gfxShapedWord(aText, aLength, aRunScript,
aAppUnitsPerDevUnit, aFlags);
}
static gfxShapedWord* Create(const PRUnichar *aText, uint32_t aLength,
int32_t aRunScript,
int32_t aAppUnitsPerDevUnit,
uint32_t aFlags) {
NS_ASSERTION(aLength <= kMaxLength, "excessive length for gfxShapedWord!");
// In the 16-bit version of Create, if the TEXT_IS_8BIT flag is set,
// then we convert the text to an 8-bit version and call the 8-bit
// Create function instead.
if (aFlags & gfxTextRunFactory::TEXT_IS_8BIT) {
nsAutoCString narrowText;
LossyAppendUTF16toASCII(nsDependentSubstring(aText, aLength),
narrowText);
return Create((const uint8_t*)(narrowText.BeginReading()),
aLength, aRunScript, aAppUnitsPerDevUnit, aFlags);
}
uint32_t size =
offsetof(gfxShapedWord, mCharGlyphsStorage) +
aLength * (sizeof(CompressedGlyph) + sizeof(PRUnichar));
void *storage = moz_malloc(size);
if (!storage) {
return nullptr;
}
return new (storage) gfxShapedWord(aText, aLength, aRunScript,
aAppUnitsPerDevUnit, aFlags);
}
// Override operator delete to properly free the object that was
// allocated via moz_malloc.
void operator delete(void* p) {
moz_free(p);
}
CompressedGlyph *GetCharacterGlyphs() {
return &mCharGlyphsStorage[0];
}
const uint8_t* Text8Bit() const {
NS_ASSERTION(TextIs8Bit(), "invalid use of Text8Bit()");
return reinterpret_cast<const uint8_t*>(mCharGlyphsStorage + GetLength());
}
const PRUnichar* TextUnicode() const {
NS_ASSERTION(!TextIs8Bit(), "invalid use of TextUnicode()");
return reinterpret_cast<const PRUnichar*>(mCharGlyphsStorage + GetLength());
}
PRUnichar GetCharAt(uint32_t aOffset) const {
NS_ASSERTION(aOffset < GetLength(), "aOffset out of range");
return TextIs8Bit() ?
PRUnichar(Text8Bit()[aOffset]) : TextUnicode()[aOffset];
}
int32_t Script() const {
return mScript;
}
void ResetAge() {
mAgeCounter = 0;
}
uint32_t IncrementAge() {
return ++mAgeCounter;
}
private:
// so that gfxTextRun can share our DetailedGlyphStore class
friend class gfxTextRun;
// Construct storage for a ShapedWord, ready to receive glyph data
gfxShapedWord(const uint8_t *aText, uint32_t aLength,
int32_t aRunScript, int32_t aAppUnitsPerDevUnit,
uint32_t aFlags)
: gfxShapedText(aLength, aFlags | gfxTextRunFactory::TEXT_IS_8BIT,
aAppUnitsPerDevUnit)
, mScript(aRunScript)
, mAgeCounter(0)
{
memset(mCharGlyphsStorage, 0, aLength * sizeof(CompressedGlyph));
uint8_t *text = reinterpret_cast<uint8_t*>(&mCharGlyphsStorage[aLength]);
memcpy(text, aText, aLength * sizeof(uint8_t));
}
gfxShapedWord(const PRUnichar *aText, uint32_t aLength,
int32_t aRunScript, int32_t aAppUnitsPerDevUnit,
uint32_t aFlags)
: gfxShapedText(aLength, aFlags, aAppUnitsPerDevUnit)
, mScript(aRunScript)
, mAgeCounter(0)
{
memset(mCharGlyphsStorage, 0, aLength * sizeof(CompressedGlyph));
PRUnichar *text = reinterpret_cast<PRUnichar*>(&mCharGlyphsStorage[aLength]);
memcpy(text, aText, aLength * sizeof(PRUnichar));
SetupClusterBoundaries(0, aText, aLength);
}
int32_t mScript;
uint32_t mAgeCounter;
// The mCharGlyphsStorage array is actually a variable-size member;
// when the ShapedWord is created, its size will be increased as necessary
// to allow the proper number of glyphs to be stored.
// The original text, in either 8-bit or 16-bit form, will be stored
// immediately following the CompressedGlyphs.
CompressedGlyph mCharGlyphsStorage[1];
};
/**
* Callback for Draw() to use when drawing text with mode
* gfxFont::GLYPH_PATH.
*/
struct gfxTextRunDrawCallbacks {
/**
* Constructs a new DrawCallbacks object.
*
* @param aShouldPaintSVGGlyphs If true, SVG glyphs will be
* painted and the NotifyBeforeSVGGlyphPainted/NotifyAfterSVGGlyphPainted
* callbacks will be invoked for each SVG glyph. If false, SVG glyphs
* will not be painted; fallback plain glyphs are not emitted either.
*/
gfxTextRunDrawCallbacks(bool aShouldPaintSVGGlyphs = false)
: mShouldPaintSVGGlyphs(aShouldPaintSVGGlyphs)
{
}
/**
* Called when a path has been emitted to the gfxContext when
* painting a text run. This can be called any number of times,
* due to partial ligatures and intervening SVG glyphs.
*/
virtual void NotifyGlyphPathEmitted() = 0;
/**
* Called just before an SVG glyph has been painted to the gfxContext.
*/
virtual void NotifyBeforeSVGGlyphPainted() { }
/**
* Called just after an SVG glyph has been painted to the gfxContext.
*/
virtual void NotifyAfterSVGGlyphPainted() { }
bool mShouldPaintSVGGlyphs;
};
/**
* gfxTextRun is an abstraction for drawing and measuring substrings of a run
* of text. It stores runs of positioned glyph data, each run having a single
* gfxFont. The glyphs are associated with a string of source text, and the
* gfxTextRun APIs take parameters that are offsets into that source text.
*
* gfxTextRuns are not refcounted. They should be deleted when no longer required.
*
* gfxTextRuns are mostly immutable. The only things that can change are
* inter-cluster spacing and line break placement. Spacing is always obtained
* lazily by methods that need it, it is not cached. Line breaks are stored
* persistently (insofar as they affect the shaping of glyphs; gfxTextRun does
* not actually do anything to explicitly account for line breaks). Initially
* there are no line breaks. The textrun can record line breaks before or after
* any given cluster. (Line breaks specified inside clusters are ignored.)
*
* It is important that zero-length substrings are handled correctly. This will
* be on the test!
*/
class THEBES_API gfxTextRun : public gfxShapedText {
public:
// Override operator delete to properly free the object that was
// allocated via moz_malloc.
void operator delete(void* p) {
moz_free(p);
}
virtual ~gfxTextRun();
typedef gfxFont::RunMetrics Metrics;
// Public textrun API for general use
bool IsClusterStart(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return mCharacterGlyphs[aPos].IsClusterStart();
}
bool IsLigatureGroupStart(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return mCharacterGlyphs[aPos].IsLigatureGroupStart();
}
bool CanBreakLineBefore(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return mCharacterGlyphs[aPos].CanBreakBefore() ==
CompressedGlyph::FLAG_BREAK_TYPE_NORMAL;
}
bool CanHyphenateBefore(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return mCharacterGlyphs[aPos].CanBreakBefore() ==
CompressedGlyph::FLAG_BREAK_TYPE_HYPHEN;
}
bool CharIsSpace(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return mCharacterGlyphs[aPos].CharIsSpace();
}
bool CharIsTab(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return mCharacterGlyphs[aPos].CharIsTab();
}
bool CharIsNewline(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return mCharacterGlyphs[aPos].CharIsNewline();
}
bool CharIsLowSurrogate(uint32_t aPos) {
NS_ASSERTION(aPos < GetLength(), "aPos out of range");
return mCharacterGlyphs[aPos].CharIsLowSurrogate();
}
uint32_t GetLength() { return mLength; }
// All uint32_t aStart, uint32_t aLength ranges below are restricted to
// grapheme cluster boundaries! All offsets are in terms of the string
// passed into MakeTextRun.
// All coordinates are in layout/app units
/**
* Set the potential linebreaks for a substring of the textrun. These are
* the "allow break before" points. Initially, there are no potential
* linebreaks.
*
* This can change glyphs and/or geometry! Some textruns' shapes
* depend on potential line breaks (e.g., title-case-converting textruns).
* This function is virtual so that those textruns can reshape themselves.
*
* @return true if this changed the linebreaks, false if the new line
* breaks are the same as the old
*/
virtual bool SetPotentialLineBreaks(uint32_t aStart, uint32_t aLength,
uint8_t *aBreakBefore,
gfxContext *aRefContext);
/**
* Layout provides PropertyProvider objects. These allow detection of
* potential line break points and computation of spacing. We pass the data
* this way to allow lazy data acquisition; for example BreakAndMeasureText
* will want to only ask for properties of text it's actually looking at.
*
* NOTE that requested spacing may not actually be applied, if the textrun
* is unable to apply it in some context. Exception: spacing around a
* whitespace character MUST always be applied.
*/
class PropertyProvider {
public:
// Detect hyphenation break opportunities in the given range; breaks
// not at cluster boundaries will be ignored.
virtual void GetHyphenationBreaks(uint32_t aStart, uint32_t aLength,
bool *aBreakBefore) = 0;
// Returns the provider's hyphenation setting, so callers can decide
// whether it is necessary to call GetHyphenationBreaks.
// Result is an NS_STYLE_HYPHENS_* value.
virtual int8_t GetHyphensOption() = 0;
// Returns the extra width that will be consumed by a hyphen. This should
// be constant for a given textrun.
virtual gfxFloat GetHyphenWidth() = 0;
typedef gfxFont::Spacing Spacing;
/**
* Get the spacing around the indicated characters. Spacing must be zero
* inside clusters. In other words, if character i is not
* CLUSTER_START, then character i-1 must have zero after-spacing and
* character i must have zero before-spacing.
*/
virtual void GetSpacing(uint32_t aStart, uint32_t aLength,
Spacing *aSpacing) = 0;
};
class ClusterIterator {
public:
ClusterIterator(gfxTextRun *aTextRun);
void Reset();
bool NextCluster();
uint32_t Position() const {
return mCurrentChar;
}
uint32_t ClusterLength() const;
gfxFloat ClusterAdvance(PropertyProvider *aProvider) const;
private:
gfxTextRun *mTextRun;
uint32_t mCurrentChar;
};
/**
* Draws a substring. Uses only GetSpacing from aBreakProvider.
* The provided point is the baseline origin on the left of the string
* for LTR, on the right of the string for RTL.
* @param aAdvanceWidth if non-null, the advance width of the substring
* is returned here.
*
* Drawing should respect advance widths in the sense that for LTR runs,
* Draw(ctx, pt, offset1, length1, dirty, &provider, &advance) followed by
* Draw(ctx, gfxPoint(pt.x + advance, pt.y), offset1 + length1, length2,
* dirty, &provider, nullptr) should have the same effect as
* Draw(ctx, pt, offset1, length1+length2, dirty, &provider, nullptr).
* For RTL runs the rule is:
* Draw(ctx, pt, offset1 + length1, length2, dirty, &provider, &advance) followed by
* Draw(ctx, gfxPoint(pt.x + advance, pt.y), offset1, length1,
* dirty, &provider, nullptr) should have the same effect as
* Draw(ctx, pt, offset1, length1+length2, dirty, &provider, nullptr).
*
* Glyphs should be drawn in logical content order, which can be significant
* if they overlap (perhaps due to negative spacing).
*/
void Draw(gfxContext *aContext, gfxPoint aPt,
gfxFont::DrawMode aDrawMode,
uint32_t aStart, uint32_t aLength,
PropertyProvider *aProvider,
gfxFloat *aAdvanceWidth, gfxTextObjectPaint *aObjectPaint,
gfxTextRunDrawCallbacks *aCallbacks = nullptr);
/**
* Computes the ReflowMetrics for a substring.
* Uses GetSpacing from aBreakProvider.
* @param aBoundingBoxType which kind of bounding box (loose/tight)
*/
Metrics MeasureText(uint32_t aStart, uint32_t aLength,
gfxFont::BoundingBoxType aBoundingBoxType,
gfxContext *aRefContextForTightBoundingBox,
PropertyProvider *aProvider);
/**
* Computes just the advance width for a substring.
* Uses GetSpacing from aBreakProvider.
*/
gfxFloat GetAdvanceWidth(uint32_t aStart, uint32_t aLength,
PropertyProvider *aProvider);
/**
* Clear all stored line breaks for the given range (both before and after),
* and then set the line-break state before aStart to aBreakBefore and
* after the last cluster to aBreakAfter.
*
* We require that before and after line breaks be consistent. For clusters
* i and i+1, we require that if there is a break after cluster i, a break
* will be specified before cluster i+1. This may be temporarily violated
* (e.g. after reflowing line L and before reflowing line L+1); to handle
* these temporary violations, we say that there is a break betwen i and i+1
* if a break is specified after i OR a break is specified before i+1.
*
* This can change textrun geometry! The existence of a linebreak can affect
* the advance width of the cluster before the break (when kerning) or the
* geometry of one cluster before the break or any number of clusters
* after the break. (The one-cluster-before-the-break limit is somewhat
* arbitrary; if some scripts require breaking it, then we need to
* alter nsTextFrame::TrimTrailingWhitespace, perhaps drastically becase
* it could affect the layout of frames before it...)
*
* We return true if glyphs or geometry changed, false otherwise. This
* function is virtual so that gfxTextRun subclasses can reshape
* properly.
*
* @param aAdvanceWidthDelta if non-null, returns the change in advance
* width of the given range.
*/
virtual bool SetLineBreaks(uint32_t aStart, uint32_t aLength,
bool aLineBreakBefore, bool aLineBreakAfter,
gfxFloat *aAdvanceWidthDelta,
gfxContext *aRefContext);
/**
* Finds the longest substring that will fit into the given width.
* Uses GetHyphenationBreaks and GetSpacing from aBreakProvider.
* Guarantees the following:
* -- 0 <= result <= aMaxLength
* -- result is the maximal value of N such that either
* N < aMaxLength && line break at N && GetAdvanceWidth(aStart, N) <= aWidth
* OR N < aMaxLength && hyphen break at N && GetAdvanceWidth(aStart, N) + GetHyphenWidth() <= aWidth
* OR N == aMaxLength && GetAdvanceWidth(aStart, N) <= aWidth
* where GetAdvanceWidth assumes the effect of
* SetLineBreaks(aStart, N, aLineBreakBefore, N < aMaxLength, aProvider)
* -- if no such N exists, then result is the smallest N such that
* N < aMaxLength && line break at N
* OR N < aMaxLength && hyphen break at N
* OR N == aMaxLength
*
* The call has the effect of
* SetLineBreaks(aStart, result, aLineBreakBefore, result < aMaxLength, aProvider)
* and the returned metrics and the invariants above reflect this.
*
* @param aMaxLength this can be UINT32_MAX, in which case the length used
* is up to the end of the string
* @param aLineBreakBefore set to true if and only if there is an actual
* line break at the start of this string.
* @param aSuppressInitialBreak if true, then we assume there is no possible
* linebreak before aStart. If false, then we will check the internal
* line break opportunity state before deciding whether to return 0 as the
* character to break before.
* @param aTrimWhitespace if non-null, then we allow a trailing run of
* spaces to be trimmed; the width of the space(s) will not be included in
* the measured string width for comparison with the limit aWidth, and
* trimmed spaces will not be included in returned metrics. The width
* of the trimmed spaces will be returned in aTrimWhitespace.
* Trimmed spaces are still counted in the "characters fit" result.
* @param aMetrics if non-null, we fill this in for the returned substring.
* If a hyphenation break was used, the hyphen is NOT included in the returned metrics.
* @param aBoundingBoxType whether to make the bounding box in aMetrics tight
* @param aRefContextForTightBoundingBox a reference context to get the
* tight bounding box, if requested
* @param aUsedHyphenation if non-null, records if we selected a hyphenation break
* @param aLastBreak if non-null and result is aMaxLength, we set this to
* the maximal N such that
* N < aMaxLength && line break at N && GetAdvanceWidth(aStart, N) <= aWidth
* OR N < aMaxLength && hyphen break at N && GetAdvanceWidth(aStart, N) + GetHyphenWidth() <= aWidth
* or UINT32_MAX if no such N exists, where GetAdvanceWidth assumes
* the effect of
* SetLineBreaks(aStart, N, aLineBreakBefore, N < aMaxLength, aProvider)
*
* @param aCanWordWrap true if we can break between any two grapheme
* clusters. This is set by word-wrap: break-word
*
* @param aBreakPriority in/out the priority of the break opportunity
* saved in the line. If we are prioritizing break opportunities, we will
* not set a break with a lower priority. @see gfxBreakPriority.
*
* Note that negative advance widths are possible especially if negative
* spacing is provided.
*/
uint32_t BreakAndMeasureText(uint32_t aStart, uint32_t aMaxLength,
bool aLineBreakBefore, gfxFloat aWidth,
PropertyProvider *aProvider,
bool aSuppressInitialBreak,
gfxFloat *aTrimWhitespace,
Metrics *aMetrics,
gfxFont::BoundingBoxType aBoundingBoxType,
gfxContext *aRefContextForTightBoundingBox,
bool *aUsedHyphenation,
uint32_t *aLastBreak,
bool aCanWordWrap,
gfxBreakPriority *aBreakPriority);
/**
* Update the reference context.
* XXX this is a hack. New text frame does not call this. Use only
* temporarily for old text frame.
*/
void SetContext(gfxContext *aContext) {}
// Utility getters
gfxFloat GetDirection() const { return (mFlags & gfxTextRunFactory::TEXT_IS_RTL) ? -1.0 : 1.0; }
void *GetUserData() const { return mUserData; }
void SetUserData(void *aUserData) { mUserData = aUserData; }
uint32_t GetFlags() const { return mFlags; }
void SetFlagBits(uint32_t aFlags) {
NS_ASSERTION(!(aFlags & ~gfxTextRunFactory::SETTABLE_FLAGS),
"Only user flags should be mutable");
mFlags |= aFlags;
}
void ClearFlagBits(uint32_t aFlags) {
NS_ASSERTION(!(aFlags & ~gfxTextRunFactory::SETTABLE_FLAGS),
"Only user flags should be mutable");
mFlags &= ~aFlags;
}
const gfxSkipChars& GetSkipChars() const { return mSkipChars; }
gfxFontGroup *GetFontGroup() const { return mFontGroup; }
// Call this, don't call "new gfxTextRun" directly. This does custom
// allocation and initialization
static gfxTextRun *Create(const gfxTextRunFactory::Parameters *aParams,
uint32_t aLength, gfxFontGroup *aFontGroup,
uint32_t aFlags);
// The text is divided into GlyphRuns as necessary
struct GlyphRun {
nsRefPtr<gfxFont> mFont; // never null
uint32_t mCharacterOffset; // into original UTF16 string
uint8_t mMatchType;
};
class THEBES_API GlyphRunIterator {
public:
GlyphRunIterator(gfxTextRun *aTextRun, uint32_t aStart, uint32_t aLength)
: mTextRun(aTextRun), mStartOffset(aStart), mEndOffset(aStart + aLength) {
mNextIndex = mTextRun->FindFirstGlyphRunContaining(aStart);
}
bool NextRun();
GlyphRun *GetGlyphRun() { return mGlyphRun; }
uint32_t GetStringStart() { return mStringStart; }
uint32_t GetStringEnd() { return mStringEnd; }
private:
gfxTextRun *mTextRun;
GlyphRun *mGlyphRun;
uint32_t mStringStart;
uint32_t mStringEnd;
uint32_t mNextIndex;
uint32_t mStartOffset;
uint32_t mEndOffset;
};
class GlyphRunOffsetComparator {
public:
bool Equals(const GlyphRun& a,
const GlyphRun& b) const
{
return a.mCharacterOffset == b.mCharacterOffset;
}
bool LessThan(const GlyphRun& a,
const GlyphRun& b) const
{
return a.mCharacterOffset < b.mCharacterOffset;
}
};
friend class GlyphRunIterator;
friend class FontSelector;
// API for setting up the textrun glyphs. Should only be called by
// things that construct textruns.
/**
* We've found a run of text that should use a particular font. Call this
* only during initialization when font substitution has been computed.
* Call it before setting up the glyphs for the characters in this run;
* SetMissingGlyph requires that the correct glyphrun be installed.
*
* If aForceNewRun, a new glyph run will be added, even if the
* previously added run uses the same font. If glyph runs are
* added out of strictly increasing aStartCharIndex order (via
* force), then SortGlyphRuns must be called after all glyph runs
* are added before any further operations are performed with this
* TextRun.
*/
nsresult AddGlyphRun(gfxFont *aFont, uint8_t aMatchType,
uint32_t aStartCharIndex, bool aForceNewRun);
void ResetGlyphRuns() { mGlyphRuns.Clear(); }
void SortGlyphRuns();
void SanitizeGlyphRuns();
CompressedGlyph* GetCharacterGlyphs() {
NS_ASSERTION(mCharacterGlyphs, "failed to initialize mCharacterGlyphs");
return mCharacterGlyphs;
}
void SetSpaceGlyph(gfxFont *aFont, gfxContext *aContext, uint32_t aCharIndex);
// Set the glyph data for the given character index to the font's
// space glyph, IF this can be done as a "simple" glyph record
// (not requiring a DetailedGlyph entry). This avoids the need to call
// the font shaper and go through the shaped-word cache for most spaces.
//
// The parameter aSpaceChar is the original character code for which
// this space glyph is being used; if this is U+0020, we need to record
// that it could be trimmed at a run edge, whereas other kinds of space
// (currently just U+00A0) would not be trimmable/breakable.
//
// Returns true if it was able to set simple glyph data for the space;
// if it returns false, the caller needs to fall back to some other
// means to create the necessary (detailed) glyph data.
bool SetSpaceGlyphIfSimple(gfxFont *aFont, gfxContext *aContext,
uint32_t aCharIndex, PRUnichar aSpaceChar);
// Record the positions of specific characters that layout may need to
// detect in the textrun, even though it doesn't have an explicit copy
// of the original text. These are recorded using flag bits in the
// CompressedGlyph record; if necessary, we convert "simple" glyph records
// to "complex" ones as the Tab and Newline flags are not present in
// simple CompressedGlyph records.
void SetIsTab(uint32_t aIndex) {
CompressedGlyph *g = &mCharacterGlyphs[aIndex];
if (g->IsSimpleGlyph()) {
DetailedGlyph *details = AllocateDetailedGlyphs(aIndex, 1);
details->mGlyphID = g->GetSimpleGlyph();
details->mAdvance = g->GetSimpleAdvance();
details->mXOffset = details->mYOffset = 0;
SetGlyphs(aIndex, CompressedGlyph().SetComplex(true, true, 1), details);
}
g->SetIsTab();
}
void SetIsNewline(uint32_t aIndex) {
CompressedGlyph *g = &mCharacterGlyphs[aIndex];
if (g->IsSimpleGlyph()) {
DetailedGlyph *details = AllocateDetailedGlyphs(aIndex, 1);
details->mGlyphID = g->GetSimpleGlyph();
details->mAdvance = g->GetSimpleAdvance();
details->mXOffset = details->mYOffset = 0;
SetGlyphs(aIndex, CompressedGlyph().SetComplex(true, true, 1), details);
}
g->SetIsNewline();
}
void SetIsLowSurrogate(uint32_t aIndex) {
SetGlyphs(aIndex, CompressedGlyph().SetComplex(false, false, 0), nullptr);
mCharacterGlyphs[aIndex].SetIsLowSurrogate();
}
/**
* Prefetch all the glyph extents needed to ensure that Measure calls
* on this textrun not requesting tight boundingBoxes will succeed. Note
* that some glyph extents might not be fetched due to OOM or other
* errors.
*/
void FetchGlyphExtents(gfxContext *aRefContext);
uint32_t CountMissingGlyphs();
const GlyphRun *GetGlyphRuns(uint32_t *aNumGlyphRuns) {
*aNumGlyphRuns = mGlyphRuns.Length();
return mGlyphRuns.Elements();
}
// Returns the index of the GlyphRun containing the given offset.
// Returns mGlyphRuns.Length() when aOffset is mCharacterCount.
uint32_t FindFirstGlyphRunContaining(uint32_t aOffset);
// Copy glyph data from a ShapedWord into this textrun.
void CopyGlyphDataFrom(gfxShapedWord *aSource, uint32_t aStart);
// Copy glyph data for a range of characters from aSource to this
// textrun.
void CopyGlyphDataFrom(gfxTextRun *aSource, uint32_t aStart,
uint32_t aLength, uint32_t aDest);
nsExpirationState *GetExpirationState() { return &mExpirationState; }
struct LigatureData {
// textrun offsets of the start and end of the containing ligature
uint32_t mLigatureStart;
uint32_t mLigatureEnd;
// appunits advance to the start of the ligature part within the ligature;
// never includes any spacing
gfxFloat mPartAdvance;
// appunits width of the ligature part; includes before-spacing
// when the part is at the start of the ligature, and after-spacing
// when the part is as the end of the ligature
gfxFloat mPartWidth;
bool mClipBeforePart;
bool mClipAfterPart;
};
// return storage used by this run, for memory reporter;
// nsTransformedTextRun needs to override this as it holds additional data
virtual NS_MUST_OVERRIDE size_t
SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf);
virtual NS_MUST_OVERRIDE size_t
SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf);
// Get the size, if it hasn't already been gotten, marking as it goes.
size_t MaybeSizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf) {
if (mFlags & gfxTextRunFactory::TEXT_RUN_SIZE_ACCOUNTED) {
return 0;
}
mFlags |= gfxTextRunFactory::TEXT_RUN_SIZE_ACCOUNTED;
return SizeOfIncludingThis(aMallocSizeOf);
}
void ResetSizeOfAccountingFlags() {
mFlags &= ~gfxTextRunFactory::TEXT_RUN_SIZE_ACCOUNTED;
}
#ifdef DEBUG
void Dump(FILE* aOutput);
#endif
protected:
/**
* Create a textrun, and set its mCharacterGlyphs to point immediately
* after the base object; this is ONLY used in conjunction with placement
* new, after allocating a block large enough for the glyph records to
* follow the base textrun object.
*/
gfxTextRun(const gfxTextRunFactory::Parameters *aParams,
uint32_t aLength, gfxFontGroup *aFontGroup, uint32_t aFlags);
/**
* Helper for the Create() factory method to allocate the required
* glyph storage for a textrun object with the basic size aSize,
* plus room for aLength glyph records.
*/
static void* AllocateStorageForTextRun(size_t aSize, uint32_t aLength);
// Pointer to the array of CompressedGlyph records; must be initialized
// when the object is constructed.
CompressedGlyph *mCharacterGlyphs;
private:
// **** general helpers ****
// Allocate aCount DetailedGlyphs for the given index
DetailedGlyph *AllocateDetailedGlyphs(uint32_t aCharIndex, uint32_t aCount);
// Get the total advance for a range of glyphs.
int32_t GetAdvanceForGlyphs(uint32_t aStart, uint32_t aEnd);
// Spacing for characters outside the range aSpacingStart/aSpacingEnd
// is assumed to be zero; such characters are not passed to aProvider.
// This is useful to protect aProvider from being passed character indices
// it is not currently able to handle.
bool GetAdjustedSpacingArray(uint32_t aStart, uint32_t aEnd,
PropertyProvider *aProvider,
uint32_t aSpacingStart, uint32_t aSpacingEnd,
nsTArray<PropertyProvider::Spacing> *aSpacing);
// **** ligature helpers ****
// (Platforms do the actual ligaturization, but we need to do a bunch of stuff
// to handle requests that begin or end inside a ligature)
// if aProvider is null then mBeforeSpacing and mAfterSpacing are set to zero
LigatureData ComputeLigatureData(uint32_t aPartStart, uint32_t aPartEnd,
PropertyProvider *aProvider);
gfxFloat ComputePartialLigatureWidth(uint32_t aPartStart, uint32_t aPartEnd,
PropertyProvider *aProvider);
void DrawPartialLigature(gfxFont *aFont, gfxContext *aCtx,
uint32_t aStart, uint32_t aEnd, gfxPoint *aPt,
PropertyProvider *aProvider,
gfxTextRunDrawCallbacks *aCallbacks);
// Advance aStart to the start of the nearest ligature; back up aEnd
// to the nearest ligature end; may result in *aStart == *aEnd
void ShrinkToLigatureBoundaries(uint32_t *aStart, uint32_t *aEnd);
// result in appunits
gfxFloat GetPartialLigatureWidth(uint32_t aStart, uint32_t aEnd, PropertyProvider *aProvider);
void AccumulatePartialLigatureMetrics(gfxFont *aFont,
uint32_t aStart, uint32_t aEnd,
gfxFont::BoundingBoxType aBoundingBoxType,
gfxContext *aRefContext,
PropertyProvider *aProvider,
Metrics *aMetrics);
// **** measurement helper ****
void AccumulateMetricsForRun(gfxFont *aFont, uint32_t aStart, uint32_t aEnd,
gfxFont::BoundingBoxType aBoundingBoxType,
gfxContext *aRefContext,
PropertyProvider *aProvider,
uint32_t aSpacingStart, uint32_t aSpacingEnd,
Metrics *aMetrics);
// **** drawing helper ****
void DrawGlyphs(gfxFont *aFont, gfxContext *aContext,
gfxFont::DrawMode aDrawMode, gfxPoint *aPt,
gfxTextObjectPaint *aObjectPaint, uint32_t aStart,
uint32_t aEnd, PropertyProvider *aProvider,
uint32_t aSpacingStart, uint32_t aSpacingEnd,
gfxTextRunDrawCallbacks *aCallbacks);
// XXX this should be changed to a GlyphRun plus a maybe-null GlyphRun*,
// for smaller size especially in the super-common one-glyphrun case
nsAutoTArray<GlyphRun,1> mGlyphRuns;
void *mUserData;
gfxFontGroup *mFontGroup; // addrefed
gfxSkipChars mSkipChars;
nsExpirationState mExpirationState;
bool mSkipDrawing; // true if the font group we used had a user font
// download that's in progress, so we should hide text
// until the download completes (or timeout fires)
};
class THEBES_API gfxFontGroup : public gfxTextRunFactory {
public:
class FamilyFace {
public:
FamilyFace() { }
FamilyFace(gfxFontFamily* aFamily, gfxFont* aFont)
: mFamily(aFamily), mFont(aFont)
{
NS_ASSERTION(aFont, "font pointer must not be null");
NS_ASSERTION(!aFamily ||
aFamily->ContainsFace(aFont->GetFontEntry()),
"font is not a member of the given family");
}
gfxFontFamily* Family() const { return mFamily.get(); }
gfxFont* Font() const { return mFont.get(); }
private:
nsRefPtr<gfxFontFamily> mFamily;
nsRefPtr<gfxFont> mFont;
};
static void Shutdown(); // platform must call this to release the languageAtomService
gfxFontGroup(const nsAString& aFamilies, const gfxFontStyle *aStyle, gfxUserFontSet *aUserFontSet = nullptr);
virtual ~gfxFontGroup();
virtual gfxFont *GetFontAt(int32_t i) {
// If it turns out to be hard for all clients that cache font
// groups to call UpdateFontList at appropriate times, we could
// instead consider just calling UpdateFontList from someplace
// more central (such as here).
NS_ASSERTION(!mUserFontSet || mCurrGeneration == GetGeneration(),
"Whoever was caching this font group should have "
"called UpdateFontList on it");
NS_ASSERTION(mFonts.Length() > uint32_t(i) && mFonts[i].Font(),
"Requesting a font index that doesn't exist");
return mFonts[i].Font();
}
uint32_t FontListLength() const {
return mFonts.Length();
}
bool Equals(const gfxFontGroup& other) const {
return mFamilies.Equals(other.mFamilies) &&
mStyle.Equals(other.mStyle);
}
const gfxFontStyle *GetStyle() const { return &mStyle; }
virtual gfxFontGroup *Copy(const gfxFontStyle *aStyle);
/**
* The listed characters should be treated as invisible and zero-width
* when creating textruns.
*/
static bool IsInvalidChar(uint8_t ch);
static bool IsInvalidChar(PRUnichar ch);
/**
* Make a textrun for a given string.
* If aText is not persistent (aFlags & TEXT_IS_PERSISTENT), the
* textrun will copy it.
* This calls FetchGlyphExtents on the textrun.
*/
virtual gfxTextRun *MakeTextRun(const PRUnichar *aString, uint32_t aLength,
const Parameters *aParams, uint32_t aFlags);
/**
* Make a textrun for a given string.
* If aText is not persistent (aFlags & TEXT_IS_PERSISTENT), the
* textrun will copy it.
* This calls FetchGlyphExtents on the textrun.
*/
virtual gfxTextRun *MakeTextRun(const uint8_t *aString, uint32_t aLength,
const Parameters *aParams, uint32_t aFlags);
/**
* Textrun creation helper for clients that don't want to pass
* a full Parameters record.
*/
template<typename T>
gfxTextRun *MakeTextRun(const T *aString, uint32_t aLength,
gfxContext *aRefContext,
int32_t aAppUnitsPerDevUnit,
uint32_t aFlags)
{
gfxTextRunFactory::Parameters params = {
aRefContext, nullptr, nullptr, nullptr, 0, aAppUnitsPerDevUnit
};
return MakeTextRun(aString, aLength, &params, aFlags);
}
/* helper function for splitting font families on commas and
* calling a function for each family to fill the mFonts array
*/
typedef bool (*FontCreationCallback) (const nsAString& aName,
const nsACString& aGenericName,
bool aUseFontSet,
void *closure);
bool ForEachFont(const nsAString& aFamilies,
nsIAtom *aLanguage,
FontCreationCallback fc,
void *closure);
bool ForEachFont(FontCreationCallback fc, void *closure);
/**
* Check whether a given font (specified by its gfxFontEntry)
* is already in the fontgroup's list of actual fonts
*/
bool HasFont(const gfxFontEntry *aFontEntry);
const nsString& GetFamilies() { return mFamilies; }
// This returns the preferred underline for this font group.
// Some CJK fonts have wrong underline offset in its metrics.
// If this group has such "bad" font, each platform's gfxFontGroup initialized mUnderlineOffset.
// The value should be lower value of first font's metrics and the bad font's metrics.
// Otherwise, this returns from first font's metrics.
enum { UNDERLINE_OFFSET_NOT_SET = INT16_MAX };
virtual gfxFloat GetUnderlineOffset() {
if (mUnderlineOffset == UNDERLINE_OFFSET_NOT_SET)
mUnderlineOffset = GetFontAt(0)->GetMetrics().underlineOffset;
return mUnderlineOffset;
}
virtual already_AddRefed<gfxFont>
FindFontForChar(uint32_t ch, uint32_t prevCh, int32_t aRunScript,
gfxFont *aPrevMatchedFont,
uint8_t *aMatchType);
// search through pref fonts for a character, return nullptr if no matching pref font
virtual already_AddRefed<gfxFont> WhichPrefFontSupportsChar(uint32_t aCh);
virtual already_AddRefed<gfxFont>
WhichSystemFontSupportsChar(uint32_t aCh, int32_t aRunScript);
template<typename T>
void ComputeRanges(nsTArray<gfxTextRange>& mRanges,
const T *aString, uint32_t aLength,
int32_t aRunScript);
gfxUserFontSet* GetUserFontSet();
// With downloadable fonts, the composition of the font group can change as fonts are downloaded
// for each change in state of the user font set, the generation value is bumped to avoid picking up
// previously created text runs in the text run word cache. For font groups based on stylesheets
// with no @font-face rule, this always returns 0.
uint64_t GetGeneration();
// If there is a user font set, check to see whether the font list or any
// caches need updating.
virtual void UpdateFontList();
bool ShouldSkipDrawing() const {
return mSkipDrawing;
}
protected:
nsString mFamilies;
gfxFontStyle mStyle;
nsTArray<FamilyFace> mFonts;
gfxFloat mUnderlineOffset;
gfxUserFontSet* mUserFontSet;
uint64_t mCurrGeneration; // track the current user font set generation, rebuild font list if needed
// cache the most recent pref font to avoid general pref font lookup
nsRefPtr<gfxFontFamily> mLastPrefFamily;
nsRefPtr<gfxFont> mLastPrefFont;
eFontPrefLang mLastPrefLang; // lang group for last pref font
eFontPrefLang mPageLang;
bool mLastPrefFirstFont; // is this the first font in the list of pref fonts for this lang group?
bool mSkipDrawing; // hide text while waiting for a font
// download to complete (or fallback
// timer to fire)
/**
* Textrun creation short-cuts for special cases where we don't need to
* call a font shaper to generate glyphs.
*/
gfxTextRun *MakeEmptyTextRun(const Parameters *aParams, uint32_t aFlags);
gfxTextRun *MakeSpaceTextRun(const Parameters *aParams, uint32_t aFlags);
gfxTextRun *MakeBlankTextRun(uint32_t aLength,
const Parameters *aParams, uint32_t aFlags);
// Used for construction/destruction. Not intended to change the font set
// as invalidation of font lists and caches is not considered.
void SetUserFontSet(gfxUserFontSet *aUserFontSet);
// Initialize the list of fonts
void BuildFontList();
// Init this font group's font metrics. If there no bad fonts, you don't need to call this.
// But if there are one or more bad fonts which have bad underline offset,
// you should call this with the *first* bad font.
void InitMetricsForBadFont(gfxFont* aBadFont);
// Set up the textrun glyphs for an entire text run:
// find script runs, and then call InitScriptRun for each
template<typename T>
void InitTextRun(gfxContext *aContext,
gfxTextRun *aTextRun,
const T *aString,
uint32_t aLength);
// InitTextRun helper to handle a single script run, by finding font ranges
// and calling each font's InitTextRun() as appropriate
template<typename T>
void InitScriptRun(gfxContext *aContext,
gfxTextRun *aTextRun,
const T *aString,
uint32_t aScriptRunStart,
uint32_t aScriptRunEnd,
int32_t aRunScript);
/* If aResolveGeneric is true, then CSS/Gecko generic family names are
* replaced with preferred fonts.
*
* If aResolveFontName is true then fc() is called only for existing fonts
* and with actual font names. If false then fc() is called with each
* family name in aFamilies (after resolving CSS/Gecko generic family names
* if aResolveGeneric).
* If aUseFontSet is true, the fontgroup's user font set is checked;
* if false then it is skipped.
*/
bool ForEachFontInternal(const nsAString& aFamilies,
nsIAtom *aLanguage,
bool aResolveGeneric,
bool aResolveFontName,
bool aUseFontSet,
FontCreationCallback fc,
void *closure);
// Helper for font-matching:
// see if aCh is supported in any of the faces from aFamily;
// if so return the best style match, else return null.
already_AddRefed<gfxFont> TryAllFamilyMembers(gfxFontFamily* aFamily,
uint32_t aCh);
static bool FontResolverProc(const nsAString& aName, void *aClosure);
static bool FindPlatformFont(const nsAString& aName,
const nsACString& aGenericName,
bool aUseFontSet,
void *closure);
static NS_HIDDEN_(nsILanguageAtomService*) gLangService;
};
#endif
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