gecko/editor/libeditor/text/nsInternetCiter.cpp
2011-10-17 10:59:28 -04:00

430 lines
14 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** 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.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Pierre Phaneuf <pp@ludusdesign.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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 ***** */
#include "nsString.h"
#include "nsReadableUtils.h"
#include "nsInternetCiter.h"
#include "nsCRT.h"
#include "nsCOMPtr.h"
// Line breaker stuff
#include "nsIServiceManager.h"
#include "nsLWBrkCIID.h"
#include "nsILineBreaker.h"
const PRUnichar gt ('>');
const PRUnichar space (' ');
const PRUnichar nbsp (0xa0);
const PRUnichar nl ('\n');
const PRUnichar cr('\r');
/** Mail citations using the Internet style: > This is a citation
*/
nsresult
nsInternetCiter::GetCiteString(const nsAString& aInString, nsAString& aOutString)
{
aOutString.Truncate();
PRUnichar uch = nl;
// Strip trailing new lines which will otherwise turn up
// as ugly quoted empty lines.
nsReadingIterator <PRUnichar> beginIter,endIter;
aInString.BeginReading(beginIter);
aInString.EndReading(endIter);
while(beginIter!= endIter &&
(*endIter == cr ||
*endIter == nl))
{
--endIter;
}
// Loop over the string:
while (beginIter != endIter)
{
if (uch == nl)
{
aOutString.Append(gt);
// No space between >: this is ">>> " style quoting, for
// compatibility with RFC 2646 and format=flowed.
if (*beginIter != gt)
aOutString.Append(space);
}
uch = *beginIter;
++beginIter;
aOutString += uch;
}
if (uch != nl)
aOutString += nl;
return NS_OK;
}
nsresult
nsInternetCiter::StripCitesAndLinebreaks(const nsAString& aInString,
nsAString& aOutString,
bool aLinebreaksToo,
PRInt32* aCiteLevel)
{
if (aCiteLevel)
*aCiteLevel = 0;
aOutString.Truncate();
nsReadingIterator <PRUnichar> beginIter,endIter;
aInString.BeginReading(beginIter);
aInString.EndReading(endIter);
while (beginIter!= endIter) // loop over lines
{
// Clear out cites first, at the beginning of the line:
PRInt32 thisLineCiteLevel = 0;
while (beginIter!= endIter && (*beginIter == gt || nsCRT::IsAsciiSpace(*beginIter)))
{
if (*beginIter == gt) ++thisLineCiteLevel;
++beginIter;
}
// Now copy characters until line end:
while (beginIter != endIter && (*beginIter != '\r' && *beginIter != '\n'))
{
aOutString.Append(*beginIter);
++beginIter;
}
if (aLinebreaksToo)
aOutString.Append(PRUnichar(' '));
else
aOutString.Append(PRUnichar('\n')); // DOM linebreaks, not NS_LINEBREAK
// Skip over any more consecutive linebreak-like characters:
while (beginIter != endIter && (*beginIter == '\r' || *beginIter == '\n'))
++beginIter;
// Done with this line -- update cite level
if (aCiteLevel && (thisLineCiteLevel > *aCiteLevel))
*aCiteLevel = thisLineCiteLevel;
}
return NS_OK;
}
nsresult
nsInternetCiter::StripCites(const nsAString& aInString, nsAString& aOutString)
{
return StripCitesAndLinebreaks(aInString, aOutString, false, 0);
}
static void AddCite(nsAString& aOutString, PRInt32 citeLevel)
{
for (PRInt32 i = 0; i < citeLevel; ++i)
aOutString.Append(gt);
if (citeLevel > 0)
aOutString.Append(space);
}
static inline void
BreakLine(nsAString& aOutString, PRUint32& outStringCol,
PRUint32 citeLevel)
{
aOutString.Append(nl);
if (citeLevel > 0)
{
AddCite(aOutString, citeLevel);
outStringCol = citeLevel + 1;
}
else
outStringCol = 0;
}
static inline bool IsSpace(PRUnichar c)
{
return (nsCRT::IsAsciiSpace(c) || (c == nl) || (c == cr) || (c == nbsp));
}
nsresult
nsInternetCiter::Rewrap(const nsAString& aInString,
PRUint32 aWrapCol, PRUint32 aFirstLineOffset,
bool aRespectNewlines,
nsAString& aOutString)
{
// There shouldn't be returns in this string, only dom newlines.
// Check to make sure:
#ifdef DEBUG
PRInt32 cr = aInString.FindChar(PRUnichar('\r'));
NS_ASSERTION((cr < 0), "Rewrap: CR in string gotten from DOM!\n");
#endif /* DEBUG */
aOutString.Truncate();
nsresult rv;
nsCOMPtr<nsILineBreaker> lineBreaker = do_GetService(NS_LBRK_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
// Loop over lines in the input string, rewrapping each one.
PRUint32 length;
PRUint32 posInString = 0;
PRUint32 outStringCol = 0;
PRUint32 citeLevel = 0;
const nsPromiseFlatString &tString = PromiseFlatString(aInString);
length = tString.Length();
#ifdef DEBUG_wrapping
int loopcount = 0;
#endif
while (posInString < length)
{
#ifdef DEBUG_wrapping
printf("Outer loop: '%s'\n",
NS_LossyConvertUTF16toASCII(Substring(tString, posInString,
length-posInString)).get());
printf("out string is now: '%s'\n",
NS_LossyConvertUTF16toASCII(aOutString).get());
#endif
// Get the new cite level here since we're at the beginning of a line
PRUint32 newCiteLevel = 0;
while (posInString < length && tString[posInString] == gt)
{
++newCiteLevel;
++posInString;
while (posInString < length && tString[posInString] == space)
++posInString;
}
if (posInString >= length)
break;
// Special case: if this is a blank line, maintain a blank line
// (retain the original paragraph breaks)
if (tString[posInString] == nl && !aOutString.IsEmpty())
{
if (aOutString.Last() != nl)
aOutString.Append(nl);
AddCite(aOutString, newCiteLevel);
aOutString.Append(nl);
++posInString;
outStringCol = 0;
continue;
}
// If the cite level has changed, then start a new line with the
// new cite level (but if we're at the beginning of the string,
// don't bother).
if (newCiteLevel != citeLevel && posInString > newCiteLevel+1
&& outStringCol != 0)
{
BreakLine(aOutString, outStringCol, 0);
}
citeLevel = newCiteLevel;
// Prepend the quote level to the out string if appropriate
if (outStringCol == 0)
{
AddCite(aOutString, citeLevel);
outStringCol = citeLevel + (citeLevel ? 1 : 0);
}
// If it's not a cite, and we're not at the beginning of a line in
// the output string, add a space to separate new text from the
// previous text.
else if (outStringCol > citeLevel)
{
aOutString.Append(space);
++outStringCol;
}
// find the next newline -- don't want to go farther than that
PRInt32 nextNewline = tString.FindChar(nl, posInString);
if (nextNewline < 0) nextNewline = length;
// For now, don't wrap unquoted lines at all.
// This is because the plaintext edit window has already wrapped them
// by the time we get them for rewrap, yet when we call the line
// breaker, it will refuse to break backwards, and we'll end up
// with a line that's too long and gets displayed as a lone word
// on a line by itself. Need special logic to detect this case
// and break it ourselves without resorting to the line breaker.
if (citeLevel == 0)
{
aOutString.Append(Substring(tString, posInString,
nextNewline-posInString));
outStringCol += nextNewline - posInString;
if (nextNewline != (PRInt32)length)
{
aOutString.Append(nl);
outStringCol = 0;
}
posInString = nextNewline+1;
continue;
}
// Otherwise we have to use the line breaker and loop
// over this line of the input string to get all of it:
while ((PRInt32)posInString < nextNewline)
{
#ifdef DEBUG_wrapping
if (++loopcount > 1000)
NS_ASSERTION(false, "possible infinite loop in nsInternetCiter\n");
printf("Inner loop: '%s'\n",
NS_LossyConvertUTF16toASCII(Substring(tString, posInString,
nextNewline-posInString)).get());
#endif
// Skip over initial spaces:
while ((PRInt32)posInString < nextNewline
&& nsCRT::IsAsciiSpace(tString[posInString]))
++posInString;
// If this is a short line, just append it and continue:
if (outStringCol + nextNewline - posInString <= aWrapCol-citeLevel-1)
{
// If this short line is the final one in the in string,
// then we need to include the final newline, if any:
if (nextNewline+1 == (PRInt32)length && tString[nextNewline-1] == nl)
++nextNewline;
// Trim trailing spaces:
PRInt32 lastRealChar = nextNewline;
while ((PRUint32)lastRealChar > posInString
&& nsCRT::IsAsciiSpace(tString[lastRealChar-1]))
--lastRealChar;
aOutString += Substring(tString,
posInString, lastRealChar - posInString);
outStringCol += lastRealChar - posInString;
posInString = nextNewline + 1;
continue;
}
PRInt32 eol = posInString + aWrapCol - citeLevel - outStringCol;
// eol is the prospective end of line.
// We'll first look backwards from there for a place to break.
// If it's already less than our current position,
// then our line is already too long, so break now.
if (eol <= (PRInt32)posInString)
{
BreakLine(aOutString, outStringCol, citeLevel);
continue; // continue inner loop, with outStringCol now at bol
}
PRInt32 breakPt = 0;
rv = NS_ERROR_BASE;
if (lineBreaker)
{
breakPt = lineBreaker->Prev(tString.get() + posInString,
length - posInString, eol + 1 - posInString);
if (breakPt == NS_LINEBREAKER_NEED_MORE_TEXT)
{
// if we couldn't find a breakpoint looking backwards,
// and we're not starting a new line, then end this line
// and loop around again:
if (outStringCol > citeLevel + 1)
{
BreakLine(aOutString, outStringCol, citeLevel);
continue; // continue inner loop, with outStringCol now at bol
}
// Else try looking forwards:
breakPt = lineBreaker->Next(tString.get() + posInString,
length - posInString, eol - posInString);
if (breakPt == NS_LINEBREAKER_NEED_MORE_TEXT) rv = NS_ERROR_BASE;
else rv = NS_OK;
}
else rv = NS_OK;
}
// If rv is okay, then breakPt is the place to break.
// If we get out here and rv is set, something went wrong with line
// breaker. Just break the line, hard.
if (NS_FAILED(rv))
{
#ifdef DEBUG_akkana
printf("nsInternetCiter: LineBreaker not working -- breaking hard\n");
#endif
breakPt = eol;
}
// Special case: maybe we should have wrapped last time.
// If the first breakpoint here makes the current line too long,
// then if we already have text on the current line,
// break and loop around again.
// If we're at the beginning of the current line, though,
// don't force a break since the long word might be a url
// and breaking it would make it unclickable on the other end.
const int SLOP = 6;
if (outStringCol + breakPt > aWrapCol + SLOP
&& outStringCol > citeLevel+1)
{
BreakLine(aOutString, outStringCol, citeLevel);
continue;
}
nsAutoString sub (Substring(tString, posInString, breakPt));
// skip newlines or whitespace at the end of the string
PRInt32 subend = sub.Length();
while (subend > 0 && IsSpace(sub[subend-1]))
--subend;
sub.Left(sub, subend);
aOutString += sub;
outStringCol += sub.Length();
// Advance past the whitespace which caused the wrap:
posInString += breakPt;
while (posInString < length && IsSpace(tString[posInString]))
++posInString;
// Add a newline and the quote level to the out string
if (posInString < length) // not for the last line, though
BreakLine(aOutString, outStringCol, citeLevel);
} // end inner loop within one line of aInString
#ifdef DEBUG_wrapping
printf("---------\nEnd inner loop: out string is now '%s'\n-----------\n",
NS_LossyConvertUTF16toASCII(aOutString).get());
#endif
} // end outer loop over lines of aInString
#ifdef DEBUG_wrapping
printf("Final out string is now: '%s'\n",
NS_LossyConvertUTF16toASCII(aOutString).get());
#endif
return NS_OK;
}