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gecko/gfx/thebes/public/gfxFontUtils.h

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Foundation code.
*
* The Initial Developer of the Original Code is Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2005-2009
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Stuart Parmenter <stuart@mozilla.com>
* John Daggett <jdaggett@mozilla.com>
* Jonathan Kew <jfkthame@gmail.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef GFX_FONT_UTILS_H
#define GFX_FONT_UTILS_H
#include "gfxTypes.h"
#include "prtypes.h"
#include "prcpucfg.h"
#include "nsDataHashtable.h"
#include "nsITimer.h"
#include "nsCOMPtr.h"
#include "nsIRunnable.h"
#include "nsThreadUtils.h"
#include "nsComponentManagerUtils.h"
#include "nsTArray.h"
#include "nsAutoPtr.h"
#include "nsIStreamBufferAccess.h"
/* Bug 341128 - w32api defines min/max which causes problems with <bitset> */
#ifdef __MINGW32__
#undef min
#undef max
#endif
class gfxSparseBitSet {
private:
enum { BLOCK_SIZE = 32 }; // ==> 256 codepoints per block
enum { BLOCK_SIZE_BITS = BLOCK_SIZE * 8 };
enum { BLOCK_INDEX_SHIFT = 8 };
struct Block {
Block(const Block& aBlock) { memcpy(mBits, aBlock.mBits, sizeof(mBits)); }
Block(unsigned char memsetValue = 0) { memset(mBits, memsetValue, BLOCK_SIZE); }
PRUint8 mBits[BLOCK_SIZE];
};
public:
gfxSparseBitSet() { }
gfxSparseBitSet(const gfxSparseBitSet& aBitset) {
PRUint32 len = aBitset.mBlocks.Length();
mBlocks.AppendElements(len);
for (PRUint32 i = 0; i < len; ++i) {
Block *block = aBitset.mBlocks[i];
if (block)
mBlocks[i] = new Block(*block);
}
}
PRBool test(PRUint32 aIndex) const {
NS_ASSERTION(mBlocks.DebugGetHeader(), "mHdr is null, this is bad");
PRUint32 blockIndex = aIndex/BLOCK_SIZE_BITS;
if (blockIndex >= mBlocks.Length())
return PR_FALSE;
Block *block = mBlocks[blockIndex];
if (!block)
return PR_FALSE;
return ((block->mBits[(aIndex>>3) & (BLOCK_SIZE - 1)]) & (1 << (aIndex & 0x7))) != 0;
}
PRBool TestRange(PRUint32 aStart, PRUint32 aEnd) {
PRUint32 startBlock, endBlock, blockLen;
// start point is beyond the end of the block array? return false immediately
startBlock = aStart >> BLOCK_INDEX_SHIFT;
blockLen = mBlocks.Length();
if (startBlock >= blockLen) return PR_FALSE;
// check for blocks in range, if none, return false
PRUint32 blockIndex;
PRBool hasBlocksInRange = PR_FALSE;
endBlock = aEnd >> BLOCK_INDEX_SHIFT;
blockIndex = startBlock;
for (blockIndex = startBlock; blockIndex <= endBlock; blockIndex++) {
if (blockIndex < blockLen && mBlocks[blockIndex])
hasBlocksInRange = PR_TRUE;
}
if (!hasBlocksInRange) return PR_FALSE;
Block *block;
PRUint32 i, start, end;
// first block, check bits
if ((block = mBlocks[startBlock])) {
start = aStart;
end = PR_MIN(aEnd, ((startBlock+1) << BLOCK_INDEX_SHIFT) - 1);
for (i = start; i <= end; i++) {
if ((block->mBits[(i>>3) & (BLOCK_SIZE - 1)]) & (1 << (i & 0x7)))
return PR_TRUE;
}
}
if (endBlock == startBlock) return PR_FALSE;
// [2..n-1] blocks check bytes
for (blockIndex = startBlock + 1; blockIndex < endBlock; blockIndex++) {
PRUint32 index;
if (blockIndex >= blockLen || !(block = mBlocks[blockIndex])) continue;
for (index = 0; index < BLOCK_SIZE; index++) {
if (block->mBits[index])
return PR_TRUE;
}
}
// last block, check bits
if (endBlock < blockLen && (block = mBlocks[endBlock])) {
start = endBlock << BLOCK_INDEX_SHIFT;
end = aEnd;
for (i = start; i <= end; i++) {
if ((block->mBits[(i>>3) & (BLOCK_SIZE - 1)]) & (1 << (i & 0x7)))
return PR_TRUE;
}
}
return PR_FALSE;
}
void set(PRUint32 aIndex) {
PRUint32 blockIndex = aIndex/BLOCK_SIZE_BITS;
if (blockIndex >= mBlocks.Length()) {
nsAutoPtr<Block> *blocks = mBlocks.AppendElements(blockIndex + 1 - mBlocks.Length());
if (NS_UNLIKELY(!blocks)) // OOM
return;
}
Block *block = mBlocks[blockIndex];
if (!block) {
block = new Block;
if (NS_UNLIKELY(!block)) // OOM
return;
mBlocks[blockIndex] = block;
}
block->mBits[(aIndex>>3) & (BLOCK_SIZE - 1)] |= 1 << (aIndex & 0x7);
}
void set(PRUint32 aIndex, PRBool aValue) {
if (aValue)
set(aIndex);
else
clear(aIndex);
}
void SetRange(PRUint32 aStart, PRUint32 aEnd) {
const PRUint32 startIndex = aStart/BLOCK_SIZE_BITS;
const PRUint32 endIndex = aEnd/BLOCK_SIZE_BITS;
if (endIndex >= mBlocks.Length()) {
PRUint32 numNewBlocks = endIndex + 1 - mBlocks.Length();
nsAutoPtr<Block> *blocks = mBlocks.AppendElements(numNewBlocks);
if (NS_UNLIKELY(!blocks)) // OOM
return;
}
for (PRUint32 i = startIndex; i <= endIndex; ++i) {
const PRUint32 blockFirstBit = i * BLOCK_SIZE_BITS;
const PRUint32 blockLastBit = blockFirstBit + BLOCK_SIZE_BITS - 1;
Block *block = mBlocks[i];
if (!block) {
PRBool fullBlock = PR_FALSE;
if (aStart <= blockFirstBit && aEnd >= blockLastBit)
fullBlock = PR_TRUE;
block = new Block(fullBlock ? 0xFF : 0);
if (NS_UNLIKELY(!block)) // OOM
return;
mBlocks[i] = block;
if (fullBlock)
continue;
}
const PRUint32 start = aStart > blockFirstBit ? aStart - blockFirstBit : 0;
const PRUint32 end = PR_MIN(aEnd - blockFirstBit, BLOCK_SIZE_BITS - 1);
for (PRUint32 bit = start; bit <= end; ++bit) {
block->mBits[bit>>3] |= 1 << (bit & 0x7);
}
}
}
void clear(PRUint32 aIndex) {
PRUint32 blockIndex = aIndex/BLOCK_SIZE_BITS;
if (blockIndex >= mBlocks.Length()) {
nsAutoPtr<Block> *blocks = mBlocks.AppendElements(blockIndex + 1 - mBlocks.Length());
if (NS_UNLIKELY(!blocks)) // OOM
return;
}
Block *block = mBlocks[blockIndex];
if (!block) {
block = new Block;
if (NS_UNLIKELY(!block)) // OOM
return;
mBlocks[blockIndex] = block;
}
block->mBits[(aIndex>>3) & (BLOCK_SIZE - 1)] &= ~(1 << (aIndex & 0x7));
}
void ClearRange(PRUint32 aStart, PRUint32 aEnd) {
const PRUint32 startIndex = aStart/BLOCK_SIZE_BITS;
const PRUint32 endIndex = aEnd/BLOCK_SIZE_BITS;
if (endIndex >= mBlocks.Length()) {
PRUint32 numNewBlocks = endIndex + 1 - mBlocks.Length();
nsAutoPtr<Block> *blocks = mBlocks.AppendElements(numNewBlocks);
if (NS_UNLIKELY(!blocks)) // OOM
return;
}
for (PRUint32 i = startIndex; i <= endIndex; ++i) {
const PRUint32 blockFirstBit = i * BLOCK_SIZE_BITS;
const PRUint32 blockLastBit = blockFirstBit + BLOCK_SIZE_BITS - 1;
Block *block = mBlocks[i];
if (!block) {
PRBool fullBlock = PR_FALSE;
if (aStart <= blockFirstBit && aEnd >= blockLastBit)
fullBlock = PR_TRUE;
block = new Block(fullBlock ? 0xFF : 0);
if (NS_UNLIKELY(!block)) // OOM
return;
mBlocks[i] = block;
if (fullBlock)
continue;
}
const PRUint32 start = aStart > blockFirstBit ? aStart - blockFirstBit : 0;
const PRUint32 end = PR_MIN(aEnd - blockFirstBit, BLOCK_SIZE_BITS - 1);
for (PRUint32 bit = start; bit <= end; ++bit) {
block->mBits[bit>>3] &= ~(1 << (bit & 0x7));
}
}
}
PRUint32 GetSize() {
PRUint32 size = 0;
for (PRUint32 i = 0; i < mBlocks.Length(); i++) {
if (mBlocks[i])
size += sizeof(Block);
size += sizeof(nsAutoPtr<Block>);
}
return size;
}
// clear out all blocks in the array
void reset() {
PRUint32 i;
for (i = 0; i < mBlocks.Length(); i++)
mBlocks[i] = nsnull;
}
nsTArray< nsAutoPtr<Block> > mBlocks;
};
#define TRUETYPE_TAG(a, b, c, d) ((a) << 24 | (b) << 16 | (c) << 8 | (d))
namespace mozilla {
// Byte-swapping types and name table structure definitions moved from
// gfxFontUtils.cpp to .h file so that gfxFont.cpp can also refer to them
#pragma pack(1)
struct AutoSwap_PRUint16 {
#ifdef __SUNPRO_CC
AutoSwap_PRUint16& operator = (const PRUint16 aValue)
{ this->value = NS_SWAP16(aValue); return *this; }
#else
AutoSwap_PRUint16(PRUint16 aValue) { value = NS_SWAP16(aValue); }
#endif
operator PRUint16() const { return NS_SWAP16(value); }
operator PRUint32() const { return NS_SWAP16(value); }
operator PRUint64() const { return NS_SWAP16(value); }
PRUint16 value;
};
struct AutoSwap_PRInt16 {
#ifdef __SUNPRO_CC
AutoSwap_PRInt16& operator = (const PRInt16 aValue)
{ this->value = NS_SWAP16(aValue); return *this; }
#else
AutoSwap_PRInt16(PRInt16 aValue) { value = NS_SWAP16(aValue); }
#endif
operator PRInt16() const { return NS_SWAP16(value); }
operator PRUint32() const { return NS_SWAP16(value); }
PRInt16 value;
};
struct AutoSwap_PRUint32 {
#ifdef __SUNPRO_CC
AutoSwap_PRUint32& operator = (const PRUint32 aValue)
{ this->value = NS_SWAP32(aValue); return *this; }
#else
AutoSwap_PRUint32(PRUint32 aValue) { value = NS_SWAP32(aValue); }
#endif
operator PRUint32() const { return NS_SWAP32(value); }
PRUint32 value;
};
struct AutoSwap_PRUint64 {
#ifdef __SUNPRO_CC
AutoSwap_PRUint64& operator = (const PRUint64 aValue)
{ this->value = NS_SWAP64(aValue); return *this; }
#else
AutoSwap_PRUint64(PRUint64 aValue) { value = NS_SWAP64(aValue); }
#endif
operator PRUint64() const { return NS_SWAP64(value); }
PRUint64 value;
};
#pragma pack()
} // namespace mozilla
// used for overlaying name changes without touching original font data
struct FontDataOverlay {
// overlaySrc != 0 ==> use overlay
PRUint32 overlaySrc; // src offset from start of font data
PRUint32 overlaySrcLen; // src length
PRUint32 overlayDest; // dest offset from start of font data
};
enum gfxUserFontType {
GFX_USERFONT_UNKNOWN = 0,
GFX_USERFONT_OPENTYPE = 1,
GFX_USERFONT_SVG = 2,
GFX_USERFONT_WOFF = 3
};
class THEBES_API gfxFontUtils {
public:
// these are public because gfxFont.cpp also looks into the name table
enum {
NAME_ID_FAMILY = 1,
NAME_ID_STYLE = 2,
NAME_ID_UNIQUE = 3,
NAME_ID_FULL = 4,
NAME_ID_VERSION = 5,
NAME_ID_POSTSCRIPT = 6,
NAME_ID_PREFERRED_FAMILY = 16,
NAME_ID_PREFERRED_STYLE = 17,
PLATFORM_ALL = -1,
PLATFORM_ID_UNICODE = 0, // Mac OS uses this typically
PLATFORM_ID_MAC = 1,
PLATFORM_ID_ISO = 2,
PLATFORM_ID_MICROSOFT = 3,
ENCODING_ID_MAC_ROMAN = 0, // traditional Mac OS script manager encodings
ENCODING_ID_MAC_JAPANESE = 1, // (there are others defined, but some were never
ENCODING_ID_MAC_TRAD_CHINESE = 2, // implemented by Apple, and I have never seen them
ENCODING_ID_MAC_KOREAN = 3, // used in font names)
ENCODING_ID_MAC_ARABIC = 4,
ENCODING_ID_MAC_HEBREW = 5,
ENCODING_ID_MAC_GREEK = 6,
ENCODING_ID_MAC_CYRILLIC = 7,
ENCODING_ID_MAC_DEVANAGARI = 9,
ENCODING_ID_MAC_GURMUKHI = 10,
ENCODING_ID_MAC_GUJARATI = 11,
ENCODING_ID_MAC_SIMP_CHINESE = 25,
ENCODING_ID_MICROSOFT_SYMBOL = 0, // Microsoft platform encoding IDs
ENCODING_ID_MICROSOFT_UNICODEBMP = 1,
ENCODING_ID_MICROSOFT_SHIFTJIS = 2,
ENCODING_ID_MICROSOFT_PRC = 3,
ENCODING_ID_MICROSOFT_BIG5 = 4,
ENCODING_ID_MICROSOFT_WANSUNG = 5,
ENCODING_ID_MICROSOFT_JOHAB = 6,
ENCODING_ID_MICROSOFT_UNICODEFULL = 10,
LANG_ALL = -1,
LANG_ID_MAC_ENGLISH = 0, // many others are defined, but most don't affect
LANG_ID_MAC_HEBREW = 10, // the charset; should check all the central/eastern
LANG_ID_MAC_JAPANESE = 11, // european codes, though
LANG_ID_MAC_ARABIC = 12,
LANG_ID_MAC_ICELANDIC = 15,
LANG_ID_MAC_TURKISH = 17,
LANG_ID_MAC_TRAD_CHINESE = 19,
LANG_ID_MAC_URDU = 20,
LANG_ID_MAC_KOREAN = 23,
LANG_ID_MAC_POLISH = 25,
LANG_ID_MAC_FARSI = 31,
LANG_ID_MAC_SIMP_CHINESE = 33,
LANG_ID_MAC_ROMANIAN = 37,
LANG_ID_MAC_CZECH = 38,
LANG_ID_MAC_SLOVAK = 39,
LANG_ID_MICROSOFT_EN_US = 0x0409, // with Microsoft platformID, EN US lang code
CMAP_MAX_CODEPOINT = 0x10ffff // maximum possible Unicode codepoint
// contained in a cmap
};
// name table has a header, followed by name records, followed by string data
struct NameHeader {
mozilla::AutoSwap_PRUint16 format; // Format selector (=0).
mozilla::AutoSwap_PRUint16 count; // Number of name records.
mozilla::AutoSwap_PRUint16 stringOffset; // Offset to start of string storage
// (from start of table)
};
struct NameRecord {
mozilla::AutoSwap_PRUint16 platformID; // Platform ID
mozilla::AutoSwap_PRUint16 encodingID; // Platform-specific encoding ID
mozilla::AutoSwap_PRUint16 languageID; // Language ID
mozilla::AutoSwap_PRUint16 nameID; // Name ID.
mozilla::AutoSwap_PRUint16 length; // String length (in bytes).
mozilla::AutoSwap_PRUint16 offset; // String offset from start of storage
// (in bytes).
};
// for reading big-endian font data on either big or little-endian platforms
static inline PRUint16
ReadShortAt(const PRUint8 *aBuf, PRUint32 aIndex)
{
return (aBuf[aIndex] << 8) | aBuf[aIndex + 1];
}
static inline PRUint16
ReadShortAt16(const PRUint16 *aBuf, PRUint32 aIndex)
{
const PRUint8 *buf = reinterpret_cast<const PRUint8*>(aBuf);
PRUint32 index = aIndex << 1;
return (buf[index] << 8) | buf[index+1];
}
static inline PRUint32
ReadLongAt(const PRUint8 *aBuf, PRUint32 aIndex)
{
return ((aBuf[aIndex] << 24) | (aBuf[aIndex + 1] << 16) |
(aBuf[aIndex + 2] << 8) | (aBuf[aIndex + 3]));
}
static nsresult
ReadCMAPTableFormat12(PRUint8 *aBuf, PRUint32 aLength,
gfxSparseBitSet& aCharacterMap);
static nsresult
ReadCMAPTableFormat4(PRUint8 *aBuf, PRUint32 aLength,
gfxSparseBitSet& aCharacterMap);
static PRUint32
FindPreferredSubtable(PRUint8 *aBuf, PRUint32 aBufLength,
PRUint32 *aTableOffset, PRBool *aSymbolEncoding);
static nsresult
ReadCMAP(PRUint8 *aBuf, PRUint32 aBufLength, gfxSparseBitSet& aCharacterMap,
PRPackedBool& aUnicodeFont, PRPackedBool& aSymbolFont);
static PRUint32
MapCharToGlyphFormat4(const PRUint8 *aBuf, PRUnichar aCh);
static PRUint32
MapCharToGlyph(PRUint8 *aBuf, PRUint32 aBufLength, PRUnichar aCh);
#ifdef XP_WIN
// given a TrueType/OpenType data file, produce a EOT-format header
// for use with Windows T2Embed API AddFontResource type API's
// effectively hide existing fonts with matching names aHeaderLen is
// the size of the header buffer on input, the actual size of the
// EOT header on output
static nsresult
MakeEOTHeader(const PRUint8 *aFontData, PRUint32 aFontDataLength,
nsTArray<PRUint8> *aHeader, FontDataOverlay *aOverlay);
// determine whether a font (which has already passed ValidateSFNTHeaders)
// is CFF format rather than TrueType
static PRBool
IsCffFont(const PRUint8* aFontData);
#endif
// determine the format of font data
static gfxUserFontType
DetermineFontDataType(const PRUint8 *aFontData, PRUint32 aFontDataLength);
// checks for valid SFNT table structure, returns true if valid
// does *not* guarantee that all font data is valid
static PRBool
ValidateSFNTHeaders(const PRUint8 *aFontData, PRUint32 aFontDataLength);
// create a new name table and build a new font with that name table
// appended on the end, returns true on success
static nsresult
RenameFont(const nsAString& aName, const PRUint8 *aFontData,
PRUint32 aFontDataLength, nsTArray<PRUint8> *aNewFont);
// read all names matching aNameID, returning in aNames array
static nsresult
ReadNames(nsTArray<PRUint8>& aNameTable, PRUint32 aNameID,
PRInt32 aPlatformID, nsTArray<nsString>& aNames);
// reads English or first name matching aNameID, returning in aName
// platform based on OS
static nsresult
ReadCanonicalName(nsTArray<PRUint8>& aNameTable, PRUint32 aNameID,
nsString& aName);
// convert a name from the raw name table data into an nsString,
// provided we know how; return PR_TRUE if successful, or PR_FALSE
// if we can't handle the encoding
static PRBool
DecodeFontName(const PRUint8 *aBuf, PRInt32 aLength,
PRUint32 aPlatformCode, PRUint32 aScriptCode,
PRUint32 aLangCode, nsAString& dest);
static inline bool IsJoinCauser(PRUint32 ch) {
return (ch == 0x200D);
}
static inline bool IsInvalid(PRUint32 ch) {
return (ch == 0xFFFD);
}
// Font code may want to know if there is the potential for bidi behavior
// to be triggered by any of the characters in a text run; this can be
// used to test that possibility.
enum {
kUnicodeBidiScriptsStart = 0x0590,
kUnicodeBidiScriptsEnd = 0x08FF,
kUnicodeBidiPresentationStart = 0xFB1D,
kUnicodeBidiPresentationEnd = 0xFEFC,
kUnicodeFirstHighSurrogateBlock = 0xD800,
kUnicodeRLM = 0x200F,
kUnicodeRLE = 0x202B,
kUnicodeRLO = 0x202E
};
static inline PRBool PotentialRTLChar(PRUnichar aCh) {
if (aCh >= kUnicodeBidiScriptsStart && aCh <= kUnicodeBidiScriptsEnd)
// bidi scripts Hebrew, Arabic, Syriac, Thaana, N'Ko are all encoded together
return PR_TRUE;
if (aCh == kUnicodeRLM || aCh == kUnicodeRLE || aCh == kUnicodeRLO)
// directional controls that trigger bidi layout
return PR_TRUE;
if (aCh >= kUnicodeBidiPresentationStart &&
aCh <= kUnicodeBidiPresentationEnd)
// presentation forms of Arabic and Hebrew letters
return PR_TRUE;
if ((aCh & 0xFF00) == kUnicodeFirstHighSurrogateBlock)
// surrogate that could be part of a bidi supplementary char
// (Cypriot, Aramaic, Phoenecian, etc)
return PR_TRUE;
// otherwise we know this char cannot trigger bidi reordering
return PR_FALSE;
}
static PRUint8 CharRangeBit(PRUint32 ch);
// for a given font list pref name, set up a list of font names
static void GetPrefsFontList(const char *aPrefName,
nsTArray<nsString>& aFontList);
// generate a unique font name
static nsresult MakeUniqueUserFontName(nsAString& aName);
protected:
static nsresult
ReadNames(nsTArray<PRUint8>& aNameTable, PRUint32 aNameID,
PRInt32 aLangID, PRInt32 aPlatformID, nsTArray<nsString>& aNames);
// convert opentype name-table platform/encoding/language values to a charset name
// we can use to convert the name data to unicode, or "" if data is UTF16BE
static const char*
GetCharsetForFontName(PRUint16 aPlatform, PRUint16 aScript, PRUint16 aLanguage);
struct MacFontNameCharsetMapping {
PRUint16 mEncoding;
PRUint16 mLanguage;
const char *mCharsetName;
bool operator<(const MacFontNameCharsetMapping& rhs) const {
return (mEncoding < rhs.mEncoding) ||
((mEncoding == rhs.mEncoding) && (mLanguage < rhs.mLanguage));
}
};
static const MacFontNameCharsetMapping gMacFontNameCharsets[];
static const char* gISOFontNameCharsets[];
static const char* gMSFontNameCharsets[];
};
// helper class for loading in font info spaced out at regular intervals
class gfxFontInfoLoader {
public:
// state transitions:
// initial ---StartLoader with delay---> timer on delay
// initial ---StartLoader without delay---> timer on interval
// timer on delay ---LoaderTimerFire---> timer on interval
// timer on delay ---CancelLoader---> timer off
// timer on interval ---CancelLoader---> timer off
// timer off ---StartLoader with delay---> timer on delay
// timer off ---StartLoader without delay---> timer on interval
typedef enum {
stateInitial,
stateTimerOnDelay,
stateTimerOnInterval,
stateTimerOff
} TimerState;
gfxFontInfoLoader() :
mInterval(0), mState(stateInitial)
{
}
virtual ~gfxFontInfoLoader() {}
// start timer with an initial delay, then call Run method at regular intervals
void StartLoader(PRUint32 aDelay, PRUint32 aInterval) {
mInterval = aInterval;
// sanity check
if (mState != stateInitial && mState != stateTimerOff)
CancelLoader();
// set up timer
if (!mTimer) {
mTimer = do_CreateInstance("@mozilla.org/timer;1");
if (!mTimer) {
NS_WARNING("Failure to create font info loader timer");
return;
}
}
// need an initial delay?
PRUint32 timerInterval;
if (aDelay) {
mState = stateTimerOnDelay;
timerInterval = aDelay;
} else {
mState = stateTimerOnInterval;
timerInterval = mInterval;
}
InitLoader();
// start timer
mTimer->InitWithFuncCallback(LoaderTimerCallback, this, aDelay,
nsITimer::TYPE_REPEATING_SLACK);
}
// cancel the timer and cleanup
void CancelLoader() {
if (mState == stateInitial)
return;
mState = stateTimerOff;
if (mTimer) {
mTimer->Cancel();
}
FinishLoader();
}
protected:
// Init - initialization at start time after initial delay
virtual void InitLoader() = 0;
// Run - called at intervals, return true to indicate done
virtual PRBool RunLoader() = 0;
// Finish - cleanup after done
virtual void FinishLoader() = 0;
static void LoaderTimerCallback(nsITimer *aTimer, void *aThis) {
gfxFontInfoLoader *loader = static_cast<gfxFontInfoLoader*>(aThis);
loader->LoaderTimerFire();
}
// start the timer, interval callbacks
void LoaderTimerFire() {
if (mState == stateTimerOnDelay) {
mState = stateTimerOnInterval;
mTimer->SetDelay(mInterval);
}
PRBool done = RunLoader();
if (done) {
CancelLoader();
}
}
nsCOMPtr<nsITimer> mTimer;
PRUint32 mInterval;
TimerState mState;
};
#endif /* GFX_FONT_UTILS_H */
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