gecko-dev/editor/libeditor/InternetCiter.cpp

315 строки
10 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
#include "InternetCiter.h"
#include "nsAString.h"
#include "nsCOMPtr.h"
#include "nsCRT.h"
#include "nsDebug.h"
#include "nsDependentSubstring.h"
#include "nsError.h"
#include "mozilla/intl/LineBreaker.h"
#include "nsServiceManagerUtils.h"
#include "nsString.h"
#include "nsStringIterator.h"
namespace mozilla {
const char16_t gt ('>');
const char16_t space (' ');
const char16_t nl ('\n');
const char16_t cr('\r');
/**
* Mail citations using the Internet style: > This is a citation.
*/
nsresult
InternetCiter::GetCiteString(const nsAString& aInString,
nsAString& aOutString)
{
aOutString.Truncate();
char16_t uch = nl;
// Strip trailing new lines which will otherwise turn up
// as ugly quoted empty lines.
nsReadingIterator <char16_t> 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;
}
static void AddCite(nsAString& aOutString, int32_t citeLevel)
{
for (int32_t i = 0; i < citeLevel; ++i) {
aOutString.Append(gt);
}
if (citeLevel > 0) {
aOutString.Append(space);
}
}
static inline void
BreakLine(nsAString& aOutString, uint32_t& outStringCol,
uint32_t citeLevel)
{
aOutString.Append(nl);
if (citeLevel > 0) {
AddCite(aOutString, citeLevel);
outStringCol = citeLevel + 1;
} else {
outStringCol = 0;
}
}
static inline bool IsSpace(char16_t c)
{
const char16_t nbsp (0xa0);
return (nsCRT::IsAsciiSpace(c) || (c == nl) || (c == cr) || (c == nbsp));
}
nsresult
InternetCiter::Rewrap(const nsAString& aInString,
uint32_t aWrapCol,
uint32_t aFirstLineOffset,
bool aRespectNewlines,
nsAString& aOutString)
{
// There shouldn't be returns in this string, only dom newlines.
// Check to make sure:
#ifdef DEBUG
int32_t cr = aInString.FindChar(char16_t('\r'));
NS_ASSERTION((cr < 0), "Rewrap: CR in string gotten from DOM!\n");
#endif /* DEBUG */
aOutString.Truncate();
nsresult rv;
RefPtr<mozilla::intl::LineBreaker> lineBreaker =
mozilla::intl::LineBreaker::Create();
MOZ_ASSERT(lineBreaker);
// Loop over lines in the input string, rewrapping each one.
uint32_t length;
uint32_t posInString = 0;
uint32_t outStringCol = 0;
uint32_t citeLevel = 0;
const nsPromiseFlatString &tString = PromiseFlatString(aInString);
length = tString.Length();
while (posInString < length) {
// Get the new cite level here since we're at the beginning of a line
uint32_t 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) {
BreakLine(aOutString, outStringCol, 0);
}
citeLevel = newCiteLevel;
// Prepend the quote level to the out string if appropriate
if (!outStringCol) {
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
int32_t 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) {
aOutString.Append(Substring(tString, posInString,
nextNewline-posInString));
outStringCol += nextNewline - posInString;
if (nextNewline != (int32_t)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 ((int32_t)posInString < nextNewline) {
// Skip over initial spaces:
while ((int32_t)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 == (int32_t)length && tString[nextNewline-1] == nl) {
++nextNewline;
}
// Trim trailing spaces:
int32_t lastRealChar = nextNewline;
while ((uint32_t)lastRealChar > posInString &&
nsCRT::IsAsciiSpace(tString[lastRealChar-1])) {
--lastRealChar;
}
aOutString += Substring(tString,
posInString, lastRealChar - posInString);
outStringCol += lastRealChar - posInString;
posInString = nextNewline + 1;
continue;
}
int32_t 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 <= (int32_t)posInString) {
BreakLine(aOutString, outStringCol, citeLevel);
continue; // continue inner loop, with outStringCol now at bol
}
int32_t breakPt = 0;
// XXX Why this uses NS_ERROR_"BASE"?
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);
rv = breakPt == NS_LINEBREAKER_NEED_MORE_TEXT ? NS_ERROR_BASE :
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)) {
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
int32_t 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
} // end outer loop over lines of aInString
return NS_OK;
}
} // namespace mozilla