/**
Generate a Huffman code.
This generates a Huffman code for a given set of code frequencies. The output is a table of
code lengths which can be used to build canonincal encoding tables or decoding trees for use
with the TBitInput and TBitOutput classes.
Entries in the table with a frequency of zero will have a zero code length and thus no
associated huffman encoding. If each such symbol should have a maximum length encoding, they
must be given at least a frequency of 1.
For an alphabet of n symbols, this algorithm has a transient memory overhead of 8n, and a
time complexity of O(n*log(n)).
@param "const TUint32 aFrequency[]" The table of code frequencies
@param "TInt aNumCodes" The number of codes in the table
@param "TUint32 aHuffman[]" The table for the output code-length table. This must be the same
size as the frequency table, and can safely be the same table
@leave "KErrNoMemory" If memory used for code generation cannot be allocated
@panic "USER ???" If the number of codes exceeds Huffman::KMaxCodes
*/
void Huffman::HuffmanL(const TUint32 aFrequency[],TInt aNumCodes,TUint32 aHuffman[])
{
if(TUint(aNumCodes)>TUint(KMaxCodes))
throw E32ImageCompressionError(E32ImageCompressionError::HUFFMANTOOMANYCODESERROR);
// Sort the values into decreasing order of frequency
TNode* nodes = new TNode[aNumCodes];
TInt lCount=0;
for (TInt ii=0;ii<aNumCodes;++ii)
{
TInt c=aFrequency[ii];
if (c!=0)
InsertInOrder(nodes,lCount++,c,ii|KLeaf);
}
// default code length is zero
memset(aHuffman,0,aNumCodes*sizeof(TUint32));
if (lCount==0)
{
// no codes with frequency>0. No code has a length
}
else if (lCount==1)
{
// special case for a single value (always encode as "0")
aHuffman[nodes[0].iRight&~KLeaf]=1;
}
else
{
// Huffman algorithm: pair off least frequent nodes and reorder
do
{
--lCount;
TUint c=nodes[lCount].iCount + nodes[lCount-1].iCount;
nodes[lCount].iLeft=nodes[lCount-1].iRight;
// re-order the leaves now to reflect new combined frequency 'c'
InsertInOrder(nodes,lCount-1,c,lCount);
} while (lCount>1);
// generate code lengths in aHuffman[]
HuffmanLengthsL(aHuffman,nodes,1,0);
}
delete [] nodes;
if(!IsValid(aHuffman,aNumCodes))
throw E32ImageCompressionError(E32ImageCompressionError::HUFFMANINVALIDCODINGERROR);
}
int RTFcolourtbl::AddColour (RTFcolourdef& cd)
{
// Only add if not already present.
int iSize = (x64_int_cast)the_RTFcolourdef.size();
if((iSize == 0) && (!cd.IsAuto()))
{
RTFcolourdef cda;
cda.MakeAuto();
InsertInOrder(cda);
return 0;
}
for(int i = 0; i < iSize; i++)
{
if(cd == the_RTFcolourdef[i])
return i;
}
InsertInOrder(cd);
return iSize;
}
ERTFToken RTFcolourtbl::ReadToken(ERTFToken Token, RTFParser* Parser)
{
switch(Token)
{
case ';':
InsertInOrder(cd);
cd.MakeAuto();
break;
default:
return cd.ReadToken(Token, Parser);
}
return rtferr_OK;
}
void CUrlRichEditCtrl::ParseAndFormatText(BOOL bForceReformat)
{
KillTimer(TIMER_REPARSE);
AF_NOREENTRANT // prevent reentrancy
// parse the control content
CString sText;
GetWindowText(sText);
// richedit2 uses '\r\n' whereas richedit uses just '\n'
if (!CWinClasses::IsClass(*this, WC_RICHEDIT))
sText.Replace(_T("\r\n"), _T("\n"));
// parse the text into an array of URLPOS
CUrlArray aUrls;
LPCTSTR szText = sText;
BOOL bPrevDelim = TRUE;
int nPos = 0;
BOOL bBracedFile = FALSE;
while (*szText)
{
// if nChar < 0 then its a multibyte char and can't be part
// of a url, so we bump the text buffer by 2 but the pos by 1
#ifndef _UNICODE
TCHAR nChar = *szText;
if (IsDBCSLeadByte(nChar))
{
szText++;
szText++;
nPos++;
continue;
}
#endif
// if the previous item was not a delimiter then there's no
// point checking for a protocol match so we just update the
// value of bPrevDelim for the current char
if (!bPrevDelim)
{
bPrevDelim = IsDelim(szText);
szText++;
nPos++;
continue;
}
// if the current char is a delim then this can't be the start
// of a url either
else if (IsDelim(szText))
{
bPrevDelim = TRUE;
szText++;
nPos++;
continue;
}
// now check for a protocol
int nProt = MatchProtocol(szText);
// if no match then increment pos and go to next char
if (nProt == -1)
{
bPrevDelim = FALSE;
szText++;
nPos++;
continue;
}
// check for braces (<...>)
if (nPos > 0)
bBracedFile = (szText[-1] == '<');
else
bBracedFile = FALSE;
// find the end of the url (URLDELIMS)
int nLen = 0;
LPCTSTR szStart = szText;
if (bBracedFile)
{
while (*szText && *szText != '>')
{
szText++;
nLen++;
}
}
else
{
while (!IsDelim(szText))
{
szText++;
nLen++;
}
}
bPrevDelim = TRUE;
// save the result
URLITEM urli;
urli.cr.cpMin = nPos;
urli.cr.cpMax = urli.cr.cpMin + nLen;
nPos += nLen;
// make sure the url does not end in a punctuation mark
while (ENDPUNCTUATION.Find(szStart[nLen - 1]) != -1)
{
nLen--;
urli.cr.cpMax--;
}
// Only save if the link is more than just the protocol
if (nLen > m_aProtocols[nProt].sProtocol.GetLength())
{
urli.sUrl = CString(szStart, nLen);
urli.bWantNotify = m_aProtocols[nProt].bWantNotify;
InsertInOrder(urli, aUrls);
}
}
// compare aUrls with m_aUrls to see if anything has changed
BOOL bReformat = !sText.IsEmpty() && (bForceReformat || !UrlsMatch(aUrls));
// then overwrite (always)
m_aUrls.Copy(aUrls);
if (bReformat)
{
BOOL bVisible = IsWindowVisible();
CRePauseUndo rep(*this);
if (bVisible)
SetRedraw(FALSE);
// save current selection
CHARRANGE crSel;
GetSel(crSel);
// and first line
int nFirstLine = GetFirstVisibleLine();
// save/reset event mask
DWORD dwEventMask = SetEventMask(0);
// retrieve default character attribs
CHARFORMAT cf;
cf.cbSize = sizeof(cf);
cf.dwMask = CFM_LINK;
// format urls
int nUrls = aUrls.GetSize();
CHARRANGE cr = { 0, 0 };
for (int nUrl = 0; nUrl < nUrls; nUrl++)
{
// clear formatting from the end of the previous
// url to the start of this url
cr.cpMax = aUrls[nUrl].cr.cpMin;
cf.dwEffects = 0;
SetSel(cr);
SetSelectionCharFormat(cf);
// update for next url
cr.cpMin = aUrls[nUrl].cr.cpMax;
// then format url
cf.dwEffects = CFM_LINK;
SetSel(aUrls[nUrl].cr);
SetSelectionCharFormat(cf);
}
// clear formatting for whatever's left
cr.cpMax = -1;
cf.dwEffects = 0;
SetSel(cr);
SetSelectionCharFormat(cf);
// restore selection
SetSel(crSel);
// and first line
SetFirstVisibleLine(nFirstLine);
// restore event mask
SetEventMask(dwEventMask);
if (bVisible)
{
SetRedraw(TRUE);
Invalidate(FALSE);
}
}
}
