/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtGui module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#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 "qgraphicslayout_p.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 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();

#ifdef QT_DEBUG

    void dump(int indent = 0) const;

#endif

    // This code could use the union-struct-array trick, but a compiler

    // bug prevents this from working.

    qreal q_minimumSize;

    qreal q_preferredSize;

    qreal q_maximumSize;

    qreal q_minimumDescent;

    qreal q_minimumAscent;

    inline qreal &q_sizes(int which)

    {

        qreal *t;

        switch (which) {

        case Qt::MinimumSize:

            t = &q_minimumSize;

            break;

        case Qt::PreferredSize:

            t = &q_preferredSize;

            break;

        case Qt::MaximumSize:

            t = &q_maximumSize;

            break;

        case Qt::MinimumDescent:

            t = &q_minimumDescent;

            break;

        case (Qt::MinimumDescent + 1):

            t = &q_minimumAscent;

            break;

        default:

            t = 0;

            break;

        }

        return *t;

    }

    inline const qreal &q_sizes(int which) const

    {

        const qreal *t;

        switch (which) {

        case Qt::MinimumSize:

            t = &q_minimumSize;

            break;

        case Qt::PreferredSize:

            t = &q_preferredSize;

            break;

        case Qt::MaximumSize:

            t = &q_maximumSize;

            break;

        case Qt::MinimumDescent:

            t = &q_minimumDescent;

            break;

        case (Qt::MinimumDescent + 1):

            t = &q_minimumAscent;

            break;

        default:

            t = 0;

            break;

        }

        return *t;

    }

};

bool operator==(const QGridLayoutBox &box1, const QGridLayoutBox &box2);

inline bool operator!=(const QGridLayoutBox &box1, const QGridLayoutBox &box2)

    { return !operator==(box1, box2); }

class QGridLayoutMultiCellData

{

public:

    inline QGridLayoutMultiCellData() : q_stretch(-1) {}

    QGridLayoutBox q_box;

    int q_stretch;

};

typedef QMap<QPair<int, int>, QGridLayoutMultiCellData> MultiCellMap;

class QGridLayoutRowData

{

public:

    void reset(int count);

    void distributeMultiCells();

    void calculateGeometries(int start, int end, qreal targetSize, qreal *positions, qreal *sizes,

                             qreal *descents, const QGridLayoutBox &totalBox);

    QGridLayoutBox totalBox(int start, int end) const;

    void stealBox(int start, int end, int which, qreal *positions, qreal *sizes);

#ifdef QT_DEBUG

    void dump(int indent = 0) const;

#endif

    QBitArray ignore;   // ### rename q_

    QVector<QGridLayoutBox> boxes;

    MultiCellMap multiCellMap;

    QVector<int> stretches;

    QVector<qreal> spacings;

    bool hasIgnoreFlag;

};

class QGridLayoutEngine;

class QGridLayoutItem

{

public:

    QGridLayoutItem(QGridLayoutEngine *engine, QGraphicsLayoutItem *layoutItem, int row, int column,

                    int rowSpan = 1, int columnSpan = 1, Qt::Alignment alignment = 0,

                    int itemAtIndex = -1);

    inline int firstRow() const { return q_firstRows[Ver]; }

    inline int firstColumn() const { return q_firstRows[Hor]; }

    inline int rowSpan() const { return q_rowSpans[Ver]; }

    inline int columnSpan() const { return q_rowSpans[Hor]; }

    inline int lastRow() const { return firstRow() + rowSpan() - 1; }

    inline int lastColumn() const { return firstColumn() + columnSpan() - 1; }

    int firstRow(Qt::Orientation orientation) const;

    int firstColumn(Qt::Orientation orientation) const;

    int lastRow(Qt::Orientation orientation) const;

    int lastColumn(Qt::Orientation orientation) const;

    int rowSpan(Qt::Orientation orientation) const;

    int columnSpan(Qt::Orientation orientation) const;

    void setFirstRow(int row, Qt::Orientation orientation = Qt::Vertical);

    void setRowSpan(int rowSpan, Qt::Orientation orientation = Qt::Vertical);

    int stretchFactor(Qt::Orientation orientation) const;

    void setStretchFactor(int stretch, Qt::Orientation orientation);

    inline Qt::Alignment alignment() const { return q_alignment; }

    inline void setAlignment(Qt::Alignment alignment) { q_alignment = alignment; }

    QSizePolicy::Policy sizePolicy(Qt::Orientation orientation) const;

    QSizePolicy::ControlTypes controlTypes(LayoutSide side) const;

    QSizeF sizeHint(Qt::SizeHint which, const QSizeF &constraint = QSizeF()) const;

    QGridLayoutBox box(Qt::Orientation orientation, qreal constraint = -1.0) const;

    QRectF geometryWithin(qreal x, qreal y, qreal width, qreal height, qreal rowDescent) const;

    QGraphicsLayoutItem *layoutItem() const { return q_layoutItem; }

    void setGeometry(const QRectF &rect);

    void transpose();

    void insertOrRemoveRows(int row, int delta, Qt::Orientation orientation = Qt::Vertical);

    QSizeF effectiveMaxSize() const;

#ifdef QT_DEBUG

    void dump(int indent = 0) const;

#endif

private:

    QGridLayoutEngine *q_engine;   // ### needed?

    QGraphicsLayoutItem *q_layoutItem;

    int q_firstRows[NOrientations];

    int q_rowSpans[NOrientations];

    int q_stretches[NOrientations];

    Qt::Alignment q_alignment;

};

class QGridLayoutRowInfo

{

public:

    inline QGridLayoutRowInfo() : count(0) {}

    void insertOrRemoveRows(int row, int delta);

#ifdef QT_DEBUG

    void dump(int indent = 0) const;

#endif

    int count;

    QVector<QStretchParameter> stretches;

    QVector<QLayoutParameter<qreal> > spacings;

    QVector<Qt::Alignment> alignments;

    QVector<QGridLayoutBox> boxes;

};

class QGridLayoutEngine

{

public:

    QGridLayoutEngine();

    inline ~QGridLayoutEngine() { qDeleteAll(q_items); }

    int rowCount(Qt::Orientation orientation) const;

    int columnCount(Qt::Orientation orientation) const;

    inline int rowCount() const { return q_infos[Ver].count; }

    inline int columnCount() const { return q_infos[Hor].count; }

    // returns the number of items inserted, which may be less than (rowCount * columnCount)

    int itemCount() const;

    QGridLayoutItem *itemAt(int index) const;

    int effectiveFirstRow(Qt::Orientation orientation = Qt::Vertical) const;

    int effectiveLastRow(Qt::Orientation orientation = Qt::Vertical) const;

    void setSpacing(qreal spacing, Qt::Orientations orientations);

    qreal spacing(const QLayoutStyleInfo &styleInfo, Qt::Orientation orientation) const;

    // ### setSpacingAfterRow(), spacingAfterRow()

    void setRowSpacing(int row, qreal spacing, Qt::Orientation orientation = Qt::Vertical);

    qreal rowSpacing(int row, Qt::Orientation orientation = Qt::Vertical) const;

    void setRowStretchFactor(int row, int stretch, Qt::Orientation orientation = Qt::Vertical);

    int rowStretchFactor(int row, Qt::Orientation orientation = Qt::Vertical) const;

    void setStretchFactor(QGraphicsLayoutItem *layoutItem, int stretch,

                          Qt::Orientation orientation);

    int stretchFactor(QGraphicsLayoutItem *layoutItem, Qt::Orientation orientation) const;

    void setRowSizeHint(Qt::SizeHint which, int row, qreal size,

                        Qt::Orientation orientation = Qt::Vertical);

    qreal rowSizeHint(Qt::SizeHint which, int row,

                      Qt::Orientation orientation = Qt::Vertical) const;

    void setRowAlignment(int row, Qt::Alignment alignment, Qt::Orientation orientation);

    Qt::Alignment rowAlignment(int row, Qt::Orientation orientation) const;

    void setAlignment(QGraphicsLayoutItem *layoutItem, Qt::Alignment alignment);

    Qt::Alignment alignment(QGraphicsLayoutItem *layoutItem) const;

    Qt::Alignment effectiveAlignment(const QGridLayoutItem *layoutItem) const;

    void insertItem(QGridLayoutItem *item, int index);

    void addItem(QGridLayoutItem *item);

    void removeItem(QGridLayoutItem *item);

    QGridLayoutItem *findLayoutItem(QGraphicsLayoutItem *layoutItem) const;

    QGridLayoutItem *itemAt(int row, int column, Qt::Orientation orientation = Qt::Vertical) const;

    inline void insertRow(int row, Qt::Orientation orientation = Qt::Vertical)

        { insertOrRemoveRows(row, +1, orientation); }

    inline void removeRow(int row, Qt::Orientation orientation = Qt::Vertical)

        { insertOrRemoveRows(row, -1, orientation); }

    void invalidate();

    void setGeometries(const QLayoutStyleInfo &styleInfo, const QRectF &contentsGeometry);

    QRectF cellRect(const QLayoutStyleInfo &styleInfo, const QRectF &contentsGeometry, int row,

                    int column, int rowSpan, int columnSpan) const;

    QSizeF sizeHint(const QLayoutStyleInfo &styleInfo, Qt::SizeHint which,

                    const QSizeF &constraint) const;

    QSizePolicy::ControlTypes controlTypes(LayoutSide side) const;

    void transpose();

    void setVisualDirection(Qt::LayoutDirection direction);

    Qt::LayoutDirection visualDirection() const;

#ifdef QT_DEBUG

    void dump(int indent = 0) const;

#endif

private:

    static int grossRoundUp(int n) { return ((n + 2) | 0x3) - 2; }

    void maybeExpandGrid(int row, int column, Qt::Orientation orientation = Qt::Vertical);

    void regenerateGrid();

    inline int internalGridRowCount() const { return grossRoundUp(rowCount()); }

    inline int internalGridColumnCount() const { return grossRoundUp(columnCount()); }

    void setItemAt(int row, int column, QGridLayoutItem *item);

    void insertOrRemoveRows(int row, int delta, Qt::Orientation orientation = Qt::Vertical);

    void fillRowData(QGridLayoutRowData *rowData, const QLayoutStyleInfo &styleInfo,

                     Qt::Orientation orientation = Qt::Vertical) const;

    void ensureEffectiveFirstAndLastRows() const;

    void ensureColumnAndRowData(const QLayoutStyleInfo &styleInfo) const;

    void ensureGeometries(const QLayoutStyleInfo &styleInfo, const QSizeF &size) const;

    // User input

    QVector<QGridLayoutItem *> q_grid;

    QList<QGridLayoutItem *> q_items;

    QLayoutParameter<qreal> q_defaultSpacings[NOrientations];

    QGridLayoutRowInfo q_infos[NOrientations];

    Qt::LayoutDirection m_visualDirection;

    // Lazily computed from the above user input

    mutable int q_cachedEffectiveFirstRows[NOrientations];

    mutable int q_cachedEffectiveLastRows[NOrientations];

    // Layout item input

    mutable QLayoutStyleInfo q_cachedDataForStyleInfo;

    mutable QGridLayoutRowData q_columnData;

    mutable QGridLayoutRowData q_rowData;

    mutable QGridLayoutBox q_totalBoxes[NOrientations];

    // Output

    mutable QSizeF q_cachedSize;

    mutable QVector<qreal> q_xx;

    mutable QVector<qreal> q_yy;

    mutable QVector<qreal> q_widths;

    mutable QVector<qreal> q_heights;

    mutable QVector<qreal> q_descents;

    friend class QGridLayoutItem;

};

QT_END_NAMESPACE

#endif