Mozilla/mozilla/xpcom/string/src/nsDependentSubstring.cpp
jaggernaut%netscape.com 39042c626f Use typedefs throughout the string code. r=dbaron, sr=scc
git-svn-id: svn://10.0.0.236/trunk@105374 18797224-902f-48f8-a5cc-f745e15eee43
2001-10-13 15:01:21 +00:00

124 lines
4.3 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* 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.
*
* The Initial Developer of the Original Code is Netscape
* Communications. Portions created by Netscape Communications are
* Copyright (C) 2001 by Netscape Communications. All
* Rights Reserved.
*
* Contributor(s):
* Scott Collins <scc@mozilla.org> (original author)
*/
#include "nsDependentSubstring.h"
PRUint32
nsDependentSubstring::Length() const
{
return mLength;
}
const nsDependentSubstring::char_type*
nsDependentSubstring::GetReadableFragment( const_fragment_type& aFragment, nsFragmentRequest aRequest, PRUint32 aPosition ) const
{
// Offset any request for a specific position (First, Last, At) by our
// substrings startpos within the owning string
if ( aRequest == kFirstFragment )
{
aPosition = mStartPos;
aRequest = kFragmentAt;
}
else if ( aRequest == kLastFragment )
{
aPosition = mStartPos + mLength;
aRequest = kFragmentAt;
}
else if ( aRequest == kFragmentAt )
aPosition += mStartPos;
// requests for |kNextFragment| or |kPrevFragment| are just relayed down into the string we're slicing
const char_type* position_ptr = mString.GetReadableFragment(aFragment, aRequest, aPosition);
// If |GetReadableFragment| returns |0|, then we are off the string, the contents of the
// fragment are garbage.
// Therefore, only need to fix up the fragment boundaries when |position_ptr| is not null
if ( position_ptr )
{
// if there's more physical data in the returned fragment than I logically have left...
size_t logical_size_backward = aPosition - mStartPos;
if ( size_t(position_ptr - aFragment.mStart) > logical_size_backward )
aFragment.mStart = position_ptr - logical_size_backward;
size_t logical_size_forward = mLength - logical_size_backward;
if ( size_t(aFragment.mEnd - position_ptr) > logical_size_forward )
aFragment.mEnd = position_ptr + logical_size_forward;
}
return position_ptr;
}
PRUint32
nsDependentCSubstring::Length() const
{
return mLength;
}
const nsDependentCSubstring::char_type*
nsDependentCSubstring::GetReadableFragment( const_fragment_type& aFragment, nsFragmentRequest aRequest, PRUint32 aPosition ) const
{
// Offset any request for a specific position (First, Last, At) by our
// substrings startpos within the owning string
if ( aRequest == kFirstFragment )
{
aPosition = mStartPos;
aRequest = kFragmentAt;
}
else if ( aRequest == kLastFragment )
{
aPosition = mStartPos + mLength;
aRequest = kFragmentAt;
}
else if ( aRequest == kFragmentAt )
aPosition += mStartPos;
// requests for |kNextFragment| or |kPrevFragment| are just relayed down into the string we're slicing
const char_type* position_ptr = mString.GetReadableFragment(aFragment, aRequest, aPosition);
// If |GetReadableFragment| returns |0|, then we are off the string, the contents of the
// fragment are garbage.
// Therefore, only need to fix up the fragment boundaries when |position_ptr| is not null
if ( position_ptr )
{
// if there's more physical data in the returned fragment than I logically have left...
size_t logical_size_backward = aPosition - mStartPos;
if ( size_t(position_ptr - aFragment.mStart) > logical_size_backward )
aFragment.mStart = position_ptr - logical_size_backward;
size_t logical_size_forward = mLength - logical_size_backward;
if ( size_t(aFragment.mEnd - position_ptr) > logical_size_forward )
aFragment.mEnd = position_ptr + logical_size_forward;
}
return position_ptr;
}