RebalanceWhitespaceCommand.cpp   [plain text]

/*
 * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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#include "config.h"
#include "RebalanceWhitespaceCommand.h"

#include "Document.h"
#include "htmlediting.h"
#include "TextIterator.h"
#include <wtf/Assertions.h>

namespace WebCore {

RebalanceWhitespaceCommand::RebalanceWhitespaceCommand(Document *document, const Position &pos)
    : EditCommand(document), m_position(pos), m_upstreamOffset(InvalidOffset)
{
}

static inline bool isWhitespace(UChar c)
{
    return c == 0xa0 || isCollapsibleWhitespace(c);
}

// FIXME: This doesn't go into adjacent text in siblings, cousins, etc.
// FIXME: This turns preserved newlines into nbsps.
void RebalanceWhitespaceCommand::doApply()
{
    if (m_position.isNull() || !m_position.node()->isTextNode())
        return;

    Text* textNode = static_cast<Text*>(m_position.node());
    String text = textNode->data();
    ASSERT(!text.isEmpty());
    ASSERT(!textNode->renderer() || textNode->renderer()->style()->collapseWhiteSpace());

    int offset = m_position.offset();
    // If neither text[offset] nor text[offset - 1] are some form of whitespace, do nothing.
    if (!isWhitespace(text[offset])) {
        offset--;
        if (offset < 0 || !isWhitespace(text[offset]))
            return;
    }
    
    // Set upstream and downstream to define the extent of the whitespace surrounding text[offset].
    int upstream = offset;
    while (upstream > 0 && isWhitespace(text[upstream - 1]))
        upstream--;
    m_upstreamOffset = upstream; // Save m_upstreamOffset, it will be used during an Undo
    
    int downstream = offset;
    while ((unsigned)downstream + 1 < text.length() && isWhitespace(text[downstream + 1]))
        downstream++;
    
    int length = downstream - upstream + 1;
    ASSERT(length > 0);
    
    m_beforeString = text.substring(upstream, length);
    rebalanceWhitespaceInTextNode(textNode, upstream, length);
    m_afterString = text.substring(upstream, length);
}

void RebalanceWhitespaceCommand::doUnapply()
{
    if (m_upstreamOffset == InvalidOffset)
        return;
    
    ASSERT(m_position.node()->isTextNode());
    
    Text* node = static_cast<Text*>(m_position.node());
    ExceptionCode ec = 0;
    node->deleteData(m_upstreamOffset, m_afterString.length(), ec);
    ASSERT(!ec);
    node->insertData(m_upstreamOffset, m_beforeString, ec);
    ASSERT(!ec);
}

bool RebalanceWhitespaceCommand::preservesTypingStyle() const
{
    return true;
}

} // namespace WebCore