/*

 * Copyright (C) 2004, 2008 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:

 * 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. 

 */

#ifndef VisiblePosition_h

#define VisiblePosition_h

#include "Node.h"

#include "Position.h"

#include "TextDirection.h"

namespace WebCore {

// VisiblePosition default affinity is downstream because

// the callers do not really care (they just want the

// deep position without regard to line position), and this

// is cheaper than UPSTREAM

#define VP_DEFAULT_AFFINITY DOWNSTREAM

// Callers who do not know where on the line the position is,

// but would like UPSTREAM if at a line break or DOWNSTREAM

// otherwise, need a clear way to specify that.  The

// constructors auto-correct UPSTREAM to DOWNSTREAM if the

// position is not at a line break.

#define VP_UPSTREAM_IF_POSSIBLE UPSTREAM

class InlineBox;

enum StayInEditableContent { MayLeaveEditableContent, MustStayInEditableContent };

class VisiblePosition {

public:

    // NOTE: UPSTREAM affinity will be used only if pos is at end of a wrapped line,

    // otherwise it will be converted to DOWNSTREAM

    VisiblePosition() : m_affinity(VP_DEFAULT_AFFINITY) { }

    VisiblePosition(Node*, int offset, EAffinity);

    VisiblePosition(const Position&, EAffinity = VP_DEFAULT_AFFINITY);

    void clear() { m_deepPosition.clear(); }

    bool isNull() const { return m_deepPosition.isNull(); }

    bool isNotNull() const { return m_deepPosition.isNotNull(); }

    bool isOrphan() const { return m_deepPosition.isOrphan(); }

    Position deepEquivalent() const { return m_deepPosition; }

    EAffinity affinity() const { ASSERT(m_affinity == UPSTREAM || m_affinity == DOWNSTREAM); return m_affinity; }

    void setAffinity(EAffinity affinity) { m_affinity = affinity; }

    // FIXME: Change the following functions' parameter from a boolean to StayInEditableContent.

    // next() and previous() will increment/decrement by a character cluster.

    VisiblePosition next(bool stayInEditableContent = false) const;

    VisiblePosition previous(bool stayInEditableContent = false) const;

    VisiblePosition honorEditableBoundaryAtOrBefore(const VisiblePosition&) const;

    VisiblePosition honorEditableBoundaryAtOrAfter(const VisiblePosition&) const;

    VisiblePosition left(bool stayInEditableContent = false) const;

    VisiblePosition right(bool stayInEditableContent = false) const;

    UChar32 characterAfter() const;

    UChar32 characterBefore() const { return previous().characterAfter(); }

    void debugPosition(const char* msg = "") const;

    Element* rootEditableElement() const { return m_deepPosition.isNotNull() ? m_deepPosition.node()->rootEditableElement() : 0; }

    void getInlineBoxAndOffset(InlineBox*& inlineBox, int& caretOffset) const

    {

        m_deepPosition.getInlineBoxAndOffset(m_affinity, inlineBox, caretOffset);

    }

    void getInlineBoxAndOffset(TextDirection primaryDirection, InlineBox*& inlineBox, int& caretOffset) const

    {

        m_deepPosition.getInlineBoxAndOffset(m_affinity, primaryDirection, inlineBox, caretOffset);

    }

    // Rect is local to the returned renderer

    IntRect localCaretRect(RenderObject*&) const;

    // Bounds of (possibly transformed) caret in absolute coords

    IntRect absoluteCaretBounds() const;

    // Abs x position of the caret ignoring transforms.

    // FIXME: navigation with transforms should be smarter.

    int xOffsetForVerticalNavigation() const;

#ifndef NDEBUG

    void formatForDebugger(char* buffer, unsigned length) const;

    void showTreeForThis() const;

#endif

private:

    void init(const Position&, EAffinity);

    Position canonicalPosition(const Position&);

    Position leftVisuallyDistinctCandidate() const;

    Position rightVisuallyDistinctCandidate() const;

    Position m_deepPosition;

    EAffinity m_affinity;

};

// FIXME: This shouldn't ignore affinity.

inline bool operator==(const VisiblePosition& a, const VisiblePosition& b)

{

    return a.deepEquivalent() == b.deepEquivalent();

}

inline bool operator!=(const VisiblePosition& a, const VisiblePosition& b)

{

    return !(a == b);

}

PassRefPtr<Range> makeRange(const VisiblePosition&, const VisiblePosition&);

bool setStart(Range*, const VisiblePosition&);

bool setEnd(Range*, const VisiblePosition&);

VisiblePosition startVisiblePosition(const Range*, EAffinity);

VisiblePosition endVisiblePosition(const Range*, EAffinity);

Node *enclosingBlockFlowElement(const VisiblePosition&);

bool isFirstVisiblePositionInNode(const VisiblePosition&, const Node*);

bool isLastVisiblePositionInNode(const VisiblePosition&, const Node*);

} // namespace WebCore

#ifndef NDEBUG

// Outside the WebCore namespace for ease of invocation from gdb.

void showTree(const WebCore::VisiblePosition*);

void showTree(const WebCore::VisiblePosition&);

#endif

#endif // VisiblePosition_h