gecko/content/base/src/nsTextFragment.h

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/* -*- 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 Communicator client 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):
*
* 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 ***** */
/*
* A class which represents a fragment of text (eg inside a text
* node); if only codepoints below 256 are used, the text is stored as
* a char*; otherwise the text is stored as a PRUnichar*
*/
#ifndef nsTextFragment_h___
#define nsTextFragment_h___
#include "nsAString.h"
class nsString;
class nsCString;
// XXX should this normalize the code to keep a \u0000 at the end?
// XXX nsTextFragmentPool?
// XXX these need I18N spankage
#define XP_IS_SPACE(_ch) \
(((_ch) == ' ') || ((_ch) == '\t') || ((_ch) == '\n'))
#define XP_IS_UPPERCASE(_ch) \
(((_ch) >= 'A') && ((_ch) <= 'Z'))
#define XP_IS_LOWERCASE(_ch) \
(((_ch) >= 'a') && ((_ch) <= 'z'))
#define XP_TO_LOWER(_ch) ((_ch) | 32)
#define XP_TO_UPPER(_ch) ((_ch) & ~32)
#define XP_IS_SPACE_W XP_IS_SPACE
/**
* A fragment of text. If mIs2b is 1 then the m2b pointer is valid
* otherwise the m1b pointer is valid. If m1b is used then each byte
* of data represents a single ucs2 character with the high byte being
* zero.
*
* This class does not have a virtual destructor therefore it is not
* meant to be subclassed.
*/
class nsTextFragment {
public:
static nsresult Init();
static void Shutdown();
/**
* Default constructor. Initialize the fragment to be empty.
*/
nsTextFragment()
: m1b(nsnull), mAllBits(0)
{
NS_ASSERTION(sizeof(FragmentBits) == 4, "Bad field packing!");
}
~nsTextFragment();
/**
* Change the contents of this fragment to be a copy of the
* the argument fragment.
*/
nsTextFragment& operator=(const nsTextFragment& aOther);
/**
* Return PR_TRUE if this fragment is represented by PRUnichar data
*/
PRBool Is2b() const
{
return mState.mIs2b;
}
/**
* Return PR_TRUE if this fragment contains Bidi text
* For performance reasons this flag is not set automatically, but
* requires an explicit call to SetBidiFlag()
*/
PRBool IsBidi() const
{
return mState.mIsBidi;
}
/**
* Get a pointer to constant PRUnichar data.
*/
const PRUnichar *Get2b() const
{
NS_ASSERTION(Is2b(), "not 2b text");
return m2b;
}
/**
* Get a pointer to constant char data.
*/
const char *Get1b() const
{
NS_ASSERTION(!Is2b(), "not 1b text");
return (const char *)m1b;
}
/**
* Get the length of the fragment. The length is the number of logical
* characters, not the number of bytes to store the characters.
*/
PRUint32 GetLength() const
{
return mState.mLength;
}
/**
* Change the contents of this fragment to be a copy of the given
* buffer.
*/
void SetTo(const PRUnichar* aBuffer, PRInt32 aLength);
/**
* Append aData to the end of this fragment.
*/
void Append(const PRUnichar* aBuffer, PRUint32 aLength);
/**
* Append the contents of this string fragment to aString
*/
void AppendTo(nsAString& aString) const;
/**
* Append a substring of the contents of this string fragment to aString.
* @param aOffset where to start the substring in this text fragment
* @param aLength the length of the substring
*/
void AppendTo(nsAString& aString, PRInt32 aOffset, PRInt32 aLength) const;
/**
* Make a copy of the fragments contents starting at offset for
* count characters. The offset and count will be adjusted to
* lie within the fragments data. The fragments data is converted if
* necessary.
*/
void CopyTo(PRUnichar *aDest, PRInt32 aOffset, PRInt32 aCount);
/**
* Return the character in the text-fragment at the given
* index. This always returns a PRUnichar.
*/
PRUnichar CharAt(PRInt32 aIndex) const
{
NS_ASSERTION(PRUint32(aIndex) < mState.mLength, "bad index");
return mState.mIs2b ? m2b[aIndex] : static_cast<unsigned char>(m1b[aIndex]);
}
/**
* Scan the contents of the fragment and turn on mState.mIsBidi if it
* includes any Bidi characters.
*/
void SetBidiFlag();
struct FragmentBits {
// PRUint32 to ensure that the values are unsigned, because we
// want 0/1, not 0/-1!
// Making these PRPackedBool causes Windows to not actually pack them,
// which causes crashes because we assume this structure is no more than
// 32 bits!
PRUint32 mInHeap : 1;
PRUint32 mIs2b : 1;
PRUint32 mIsBidi : 1;
PRUint32 mLength : 29;
};
private:
void ReleaseText();
union {
PRUnichar *m2b;
const char *m1b; // This is const since it can point to shared data
};
union {
PRUint32 mAllBits;
FragmentBits mState;
};
};
#endif /* nsTextFragment_h___ */