gecko-dev/gfx/thebes/gfxPlatformFontList.h

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 *   Jonathan Kew <jfkthame@gmail.com>
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#ifndef GFXPLATFORMFONTLIST_H_
#define GFXPLATFORMFONTLIST_H_

#include "nsDataHashtable.h"
#include "nsRefPtrHashtable.h"
#include "nsHashSets.h"

#include "gfxFontUtils.h"
#include "gfxFont.h"
#include "gfxPlatform.h"

#include "mozilla/FunctionTimer.h"

// gfxPlatformFontList is an abstract class for the global font list on the system;
// concrete subclasses for each platform implement the actual interface to the system fonts.
// This class exists because we cannot rely on the platform font-finding APIs to behave
// in sensible/similar ways, particularly with rich, complex OpenType families,
// so we do our own font family/style management here instead.

// Much of this is based on the old gfxQuartzFontCache, but adapted for use on all platforms.

class gfxPlatformFontList : protected gfxFontInfoLoader
{
public:
    static gfxPlatformFontList* PlatformFontList() {
        return sPlatformFontList;
    }

    static nsresult Init() {
        NS_TIME_FUNCTION;

        NS_ASSERTION(!sPlatformFontList, "What's this doing here?");
        sPlatformFontList = gfxPlatform::GetPlatform()->CreatePlatformFontList();
        if (!sPlatformFontList) return NS_ERROR_OUT_OF_MEMORY;
        sPlatformFontList->InitFontList();
        return NS_OK;
    }

    static void Shutdown() {
        delete sPlatformFontList;
        sPlatformFontList = nsnull;
    }

    void GetFontList (nsIAtom *aLangGroup,
                      const nsACString& aGenericFamily,
                      nsTArray<nsString>& aListOfFonts);

    virtual PRBool ResolveFontName(const nsAString& aFontName,
                                   nsAString& aResolvedFontName);

    void UpdateFontList() { InitFontList(); }

    void ClearPrefFonts() { mPrefFonts.Clear(); }

    void GetFontFamilyList(nsTArray<nsRefPtr<gfxFontFamily> >& aFamilyArray);

    gfxFontEntry* FindFontForChar(const PRUint32 aCh, gfxFont *aPrevFont);

    // TODO: make this virtual, for lazily adding to the font list
    gfxFontFamily* FindFamily(const nsAString& aFamily);

    gfxFontEntry* FindFontForFamily(const nsAString& aFamily, const gfxFontStyle* aStyle, PRBool& aNeedsBold);

    PRBool GetPrefFontFamilyEntries(eFontPrefLang aLangGroup, nsTArray<nsRefPtr<gfxFontFamily> > *array);
    void SetPrefFontFamilyEntries(eFontPrefLang aLangGroup, nsTArray<nsRefPtr<gfxFontFamily> >& array);

    // name lookup table methods

    void AddOtherFamilyName(gfxFontFamily *aFamilyEntry, nsAString& aOtherFamilyName);

    void AddFullname(gfxFontEntry *aFontEntry, nsAString& aFullname);

    void AddPostscriptName(gfxFontEntry *aFontEntry, nsAString& aPostscriptName);

    PRBool NeedFullnamePostscriptNames() { return mNeedFullnamePostscriptNames; }

    // pure virtual functions, to be provided by concrete subclasses

    // get the system default font
    virtual gfxFontEntry* GetDefaultFont(const gfxFontStyle* aStyle,
                                         PRBool& aNeedsBold) = 0;

    // look up a font by name on the host platform
    virtual gfxFontEntry* LookupLocalFont(const gfxProxyFontEntry *aProxyEntry,
                                          const nsAString& aFontName) = 0;

    // create a new platform font from downloaded data (@font-face)
    // this method is responsible to ensure aFontData is NS_Free()'d
    virtual gfxFontEntry* MakePlatformFont(const gfxProxyFontEntry *aProxyEntry,
                                           const PRUint8 *aFontData,
                                           PRUint32 aLength) = 0;

    // get the standard family name on the platform for a given font name
    // (platforms may override, eg Mac)
    virtual PRBool GetStandardFamilyName(const nsAString& aFontName, nsAString& aFamilyName);

protected:
    gfxPlatformFontList(PRBool aNeedFullnamePostscriptNames = PR_TRUE);

    static gfxPlatformFontList *sPlatformFontList;

    static PLDHashOperator FindFontForCharProc(nsStringHashKey::KeyType aKey,
                                               nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                               void* userArg);

    // initialize font lists
    virtual void InitFontList();

    // separate initialization for reading in name tables, since this is expensive
    void InitOtherFamilyNames();

    static PLDHashOperator InitOtherFamilyNamesProc(nsStringHashKey::KeyType aKey,
                                                    nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                                    void* userArg);

    // read in all fullname/Postscript names for all font faces
    void InitFaceNameLists();

    static PLDHashOperator InitFaceNameListsProc(nsStringHashKey::KeyType aKey,
                                                 nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                                 void* userArg);

    // commonly used fonts for which the name table should be loaded at startup
    virtual void PreloadNamesList();

    // load the bad underline blacklist from pref.
    void LoadBadUnderlineList();

    // explicitly set fixed-pitch flag for all faces
    void SetFixedPitch(const nsAString& aFamilyName);

    void GenerateFontListKey(const nsAString& aKeyName, nsAString& aResult);

    static PLDHashOperator
        HashEnumFuncForFamilies(nsStringHashKey::KeyType aKey,
                                nsRefPtr<gfxFontFamily>& aFamilyEntry,
                                void* aUserArg);

    // gfxFontInfoLoader overrides, used to load in font cmaps
    virtual void InitLoader();
    virtual PRBool RunLoader();
    virtual void FinishLoader();

    // canonical family name ==> family entry (unique, one name per family entry)
    nsRefPtrHashtable<nsStringHashKey, gfxFontFamily> mFontFamilies;

    // other family name ==> family entry (not unique, can have multiple names per
    // family entry, only names *other* than the canonical names are stored here)
    nsRefPtrHashtable<nsStringHashKey, gfxFontFamily> mOtherFamilyNames;

    // flag set after InitOtherFamilyNames is called upon first name lookup miss
    PRPackedBool mOtherFamilyNamesInitialized;

    // flag set after fullname and Postcript name lists are populated
    PRPackedBool mFaceNamesInitialized;

    // whether these are needed for a given platform
    PRPackedBool mNeedFullnamePostscriptNames;

    // fullname ==> font entry (unique, one name per font entry)
    nsRefPtrHashtable<nsStringHashKey, gfxFontEntry> mFullnames;

    // Postscript name ==> font entry (unique, one name per font entry)
    nsRefPtrHashtable<nsStringHashKey, gfxFontEntry> mPostscriptNames;

    // cached pref font lists
    // maps list of family names ==> array of family entries, one per lang group
    nsDataHashtable<nsUint32HashKey, nsTArray<nsRefPtr<gfxFontFamily> > > mPrefFonts;

    // when system-wide font lookup fails for a character, cache it to skip future searches
    gfxSparseBitSet mCodepointsWithNoFonts;

    // the family to use for U+FFFD fallback, to avoid expensive search every time
    // on pages with lots of problems
    nsString mReplacementCharFallbackFamily;

    nsStringHashSet mBadUnderlineFamilyNames;

    // data used as part of the font cmap loading process
    nsTArray<nsRefPtr<gfxFontFamily> > mFontFamiliesToLoad;
    PRUint32 mStartIndex;
    PRUint32 mIncrement;
    PRUint32 mNumFamilies;
};

#endif /* GFXPLATFORMFONTLIST_H_ */