Source/WebCore/platform/text/StringWithDirection.h

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
 * Copyright (C) 2017 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
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 * notice, this list of conditions and the following disclaimer.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 */

#pragma once

#include "WritingMode.h"
#include <wtf/text/WTFString.h>

namespace WebCore {

// In some circumstances we want to store a String along with the TextDirection
// of the String as learned from the context of the String. For example,
// consider storing the title derived from <title dir='rtl'>some title</title>
// in the history.
//
// Note that is explicitly *not* the direction of the string as learned
// from the characters of the string; it's extra metadata we have external
// to the string.

struct StringWithDirection {
    StringWithDirection() = default;
    StringWithDirection(const String& string, TextDirection direction) : string { string }, direction { direction } { }
    StringWithDirection(String&& string, TextDirection direction) : string { WTFMove(string) }, direction { direction } { }
    String string;
    TextDirection direction { LTR };
};

inline bool operator==(const StringWithDirection& a, const StringWithDirection& b)
{
    return a.string == b.string && a.direction == b.direction;
}

inline bool operator!=(const StringWithDirection& a, const StringWithDirection& b)
{
    return !(a == b);
}

inline StringWithDirection truncateFromEnd(const StringWithDirection& string, unsigned maxLength)
{
    if (string.direction == LTR)
        return StringWithDirection(string.string.left(maxLength), LTR);
    return StringWithDirection(string.string.right(maxLength), RTL);
}

}