/*

 * Copyright (C) 2006 Apple Computer, 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:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#include "config.h"

#include "Element.h"

#include "FormatBlockCommand.h"

#include "Document.h"

#include "htmlediting.h"

#include "HTMLElement.h"

#include "HTMLNames.h"

#include "visible_units.h"

namespace WebCore {

using namespace HTMLNames;

FormatBlockCommand::FormatBlockCommand(Document* document, const AtomicString& tagName) 

    : CompositeEditCommand(document), m_tagName(tagName)

{

}

bool FormatBlockCommand::modifyRange()

{

    ASSERT(endingSelection().isRange());

    VisiblePosition visibleStart = endingSelection().visibleStart();

    VisiblePosition visibleEnd = endingSelection().visibleEnd();

    VisiblePosition startOfLastParagraph = startOfParagraph(visibleEnd);

    if (startOfParagraph(visibleStart) == startOfLastParagraph)

        return false;

    setEndingSelection(visibleStart);

    doApply();

    visibleStart = endingSelection().visibleStart();

    VisiblePosition nextParagraph = endOfParagraph(visibleStart).next();

    while (nextParagraph.isNotNull() && nextParagraph != startOfLastParagraph) {

        setEndingSelection(nextParagraph);

        doApply();

        nextParagraph = endOfParagraph(endingSelection().visibleStart()).next();

    }

    setEndingSelection(visibleEnd);

    doApply();

    visibleEnd = endingSelection().visibleEnd();

    setEndingSelection(VisibleSelection(visibleStart.deepEquivalent(), visibleEnd.deepEquivalent(), DOWNSTREAM));

    return true;

}

void FormatBlockCommand::doApply()

{

    if (endingSelection().isNone())

        return;

    if (!endingSelection().rootEditableElement())

        return;

    VisiblePosition visibleEnd = endingSelection().visibleEnd();

    VisiblePosition visibleStart = endingSelection().visibleStart();

    // When a selection ends at the start of a paragraph, we rarely paint 

    // the selection gap before that paragraph, because there often is no gap.  

    // In a case like this, it's not obvious to the user that the selection 

    // ends "inside" that paragraph, so it would be confusing if FormatBlock

    // operated on that paragraph.

    // FIXME: We paint the gap before some paragraphs that are indented with left 

    // margin/padding, but not others.  We should make the gap painting more consistent and 

    // then use a left margin/padding rule here.

    if (visibleEnd != visibleStart && isStartOfParagraph(visibleEnd))

        setEndingSelection(VisibleSelection(visibleStart, visibleEnd.previous(true)));

    if (endingSelection().isRange() && modifyRange())

        return;

    ExceptionCode ec;

    String localName, prefix;

    if (!Document::parseQualifiedName(m_tagName, prefix, localName, ec))

        return;

    QualifiedName qTypeOfBlock(prefix, localName, xhtmlNamespaceURI);

    Node* refNode = enclosingBlockFlowElement(endingSelection().visibleStart());

    if (refNode->hasTagName(qTypeOfBlock))

        // We're already in a block with the format we want, so we don't have to do anything

        return;

    VisiblePosition paragraphStart = startOfParagraph(endingSelection().visibleStart());

    VisiblePosition paragraphEnd = endOfParagraph(endingSelection().visibleStart());

    VisiblePosition blockStart = startOfBlock(endingSelection().visibleStart());

    VisiblePosition blockEnd = endOfBlock(endingSelection().visibleStart());

    RefPtr<Element> blockNode = createHTMLElement(document(), m_tagName);

    RefPtr<Element> placeholder = createBreakElement(document());

    Node* root = endingSelection().start().node()->rootEditableElement();

    if (validBlockTag(refNode->nodeName().lower()) && 

        paragraphStart == blockStart && paragraphEnd == blockEnd && 

        refNode != root && !root->isDescendantOf(refNode))

        // Already in a valid block tag that only contains the current paragraph, so we can swap with the new tag

        insertNodeBefore(blockNode, refNode);

    else {

        // Avoid inserting inside inline elements that surround paragraphStart with upstream().

        // This is only to avoid creating bloated markup.

        insertNodeAt(blockNode, paragraphStart.deepEquivalent().upstream());

    }

    appendNode(placeholder, blockNode);

    VisiblePosition destination(Position(placeholder.get(), 0));

    if (paragraphStart == paragraphEnd && !lineBreakExistsAtVisiblePosition(paragraphStart)) {

        setEndingSelection(destination);

        return;

    }

    moveParagraph(paragraphStart, paragraphEnd, destination, true, false);

}

}