/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtWidgets module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia. For licensing terms and
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** use the contact form at http://qt.digia.com/contact-us.
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** 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 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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** $QT_END_LICENSE$
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****************************************************************************/

#ifndef QLAYOUT_H
#define QLAYOUT_H

#include <QtCore/qobject.h>
#include <QtWidgets/qlayoutitem.h>
#include <QtWidgets/qsizepolicy.h>
#include <QtCore/qrect.h>
#include <QtCore/qmargins.h>

#include <limits.h>

QT_BEGIN_NAMESPACE


class QLayout;
class QSize;


class QLayoutPrivate;

class Q_WIDGETS_EXPORT QLayout : public QObject, public QLayoutItem
{
    Q_OBJECT
    Q_DECLARE_PRIVATE(QLayout)

    Q_ENUMS(SizeConstraint)
    Q_PROPERTY(int margin READ margin WRITE setMargin)
    Q_PROPERTY(int spacing READ spacing WRITE setSpacing)
    Q_PROPERTY(SizeConstraint sizeConstraint READ sizeConstraint WRITE setSizeConstraint)
public:
    enum SizeConstraint {
        SetDefaultConstraint,
        SetNoConstraint,
        SetMinimumSize,
        SetFixedSize,
        SetMaximumSize,
        SetMinAndMaxSize
    };

    QLayout(QWidget *parent);
    QLayout();
    ~QLayout();

    int margin() const;
    int spacing() const;

    void setMargin(int);
    void setSpacing(int);

    void setContentsMargins(int left, int top, int right, int bottom);
    void setContentsMargins(const QMargins &margins);
    void getContentsMargins(int *left, int *top, int *right, int *bottom) const;
    QMargins contentsMargins() const;
    QRect contentsRect() const;

    bool setAlignment(QWidget *w, Qt::Alignment alignment);
    bool setAlignment(QLayout *l, Qt::Alignment alignment);
#ifdef Q_NO_USING_KEYWORD
    inline void setAlignment(Qt::Alignment alignment) { QLayoutItem::setAlignment(alignment); }
#else
    using QLayoutItem::setAlignment;
#endif

    void setSizeConstraint(SizeConstraint);
    SizeConstraint sizeConstraint() const;
    void setMenuBar(QWidget *w);
    QWidget *menuBar() const;

    QWidget *parentWidget() const;

    void invalidate();
    QRect geometry() const;
    bool activate();
    void update();

    void addWidget(QWidget *w);
    virtual void addItem(QLayoutItem *) = 0;

    void removeWidget(QWidget *w);
    void removeItem(QLayoutItem *);

    Qt::Orientations expandingDirections() const;
    QSize minimumSize() const;
    QSize maximumSize() const;
    virtual void setGeometry(const QRect&);
    virtual QLayoutItem *itemAt(int index) const = 0;
    virtual QLayoutItem *takeAt(int index) = 0;
    virtual int indexOf(QWidget *) const;
    virtual int count() const = 0;
    bool isEmpty() const;
    QSizePolicy::ControlTypes controlTypes() const;

    // ### Qt 6 make this function virtual
    QLayoutItem *replaceWidget(QWidget *from, QWidget *to, Qt::FindChildOptions options = Qt::FindChildrenRecursively);

    int totalHeightForWidth(int w) const;
    QSize totalMinimumSize() const;
    QSize totalMaximumSize() const;
    QSize totalSizeHint() const;
    QLayout *layout();

    void setEnabled(bool);
    bool isEnabled() const;


    static QSize closestAcceptableSize(const QWidget *w, const QSize &s);

protected:
    void widgetEvent(QEvent *);
    void childEvent(QChildEvent *e);
    void addChildLayout(QLayout *l);
    void addChildWidget(QWidget *w);
    bool adoptLayout(QLayout *layout);

    QRect alignmentRect(const QRect&) const;
protected:
    QLayout(QLayoutPrivate &d, QLayout*, QWidget*);

private:
    Q_DISABLE_COPY(QLayout)

    static void activateRecursiveHelper(QLayoutItem *item);

    friend class QApplicationPrivate;
    friend class QWidget;

};

QT_END_NAMESPACE

//### support old includes
#include <QtWidgets/qboxlayout.h>
#include <QtWidgets/qgridlayout.h>

#endif // QLAYOUT_H
