source: trunk/src/gui/graphicsview/qgridlayoutengine_p.h@ 256

/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information ([email protected])
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at [email protected].
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef QGRIDLAYOUTENGINE_P_H
#define QGRIDLAYOUTENGINE_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of the graphics view layout classes.  This header
// file may change from version to version without notice, or even be removed.
//
// We mean it.
//

#include "qalgorithms.h"
#include "qbitarray.h"
#include "qlist.h"
#include "qmap.h"
#include "qpair.h"
#include "qvector.h"

#include <float.h>

QT_BEGIN_NAMESPACE

class QGraphicsLayoutItem;
class QStyle;
class QWidget;

// ### deal with Descent in a similar way
enum {
    MinimumSize = Qt::MinimumSize,
    PreferredSize = Qt::PreferredSize,
    MaximumSize = Qt::MaximumSize,
    NSizes
};

// do not reorder
enum {
    Hor,
    Ver,
    NOrientations
};

// do not reorder
enum LayoutSide {
    Left,
    Top,
    Right,
    Bottom
};

template <typename T>
class QLayoutParameter
{
public:
    enum State { Default, User, Cached };

    inline QLayoutParameter() : q_value(T()), q_state(Default) {}
    inline QLayoutParameter(T value, State state = Default) : q_value(value), q_state(state) {}

    inline void setUserValue(T value) {
        q_value = value;
        q_state = User;
    }
    inline void setCachedValue(T value) const {
        if (q_state != User) {
            q_value = value;
            q_state = Cached;
        }
    }
    inline T value() const { return q_value; }
    inline T value(T defaultValue) const { return isUser() ? q_value : defaultValue; }
    inline bool isDefault() const { return q_state == Default; }
    inline bool isUser() const { return q_state == User; }
    inline bool isCached() const { return q_state == Cached; }

private:
    mutable T q_value;
    mutable State q_state;
};

class QStretchParameter : public QLayoutParameter<int>
{
public:
    QStretchParameter() : QLayoutParameter<int>(-1) {}

};

class QLayoutStyleInfo
{
public:
    inline QLayoutStyleInfo() { invalidate(); }
    inline QLayoutStyleInfo(QStyle *style, QWidget *widget)
        : q_valid(true), q_style(style), q_widget(widget) {}

    inline void invalidate() { q_valid = false; q_style = 0; q_widget = 0; }

    inline QStyle *style() const { return q_style; }
    inline QWidget *widget() const { return q_widget; }

    inline bool operator==(const QLayoutStyleInfo &other)
        { return q_style == other.q_style && q_widget == other.q_widget; }
    inline bool operator!=(const QLayoutStyleInfo &other)
        { return !(*this == other); }

private:
    bool q_valid;
    QStyle *q_style;
    QWidget *q_widget;
};

class QGridLayoutBox
{
public:
    inline QGridLayoutBox()
        : q_minimumSize(0), q_preferredSize(0), q_maximumSize(FLT_MAX),
          q_minimumDescent(-1), q_minimumAscent(-1) {}

    void add(const QGridLayoutBox &other, int stretch, qreal spacing);
    void combine(const QGridLayoutBox &other);
    void normalize();