QskLayoutEngine2D.h

/******************************************************************************
 * QSkinny - Copyright (C) The authors
 *           SPDX-License-Identifier: BSD-3-Clause
 *****************************************************************************/
 
#ifndef QSK_LAYOUT_ENGINE_2D_H
#define QSK_LAYOUT_ENGINE_2D_H
 
#include "QskGlobal.h"
#include "QskLayoutChain.h"
#include "QskSizePolicy.h"
 
#include <qnamespace.h>
#include <memory>
 
class QskLayoutElement;
 
class QSK_EXPORT QskLayoutEngine2D
{
  public:
    QskLayoutEngine2D();
    virtual ~QskLayoutEngine2D();
 
    virtual int count() const = 0;
 
    int rowCount() const;
    int columnCount() const;
 
    bool setVisualDirection( Qt::LayoutDirection );
    Qt::LayoutDirection visualDirection() const;
 
    bool setDefaultAlignment( Qt::Alignment );
    Qt::Alignment defaultAlignment() const;
 
    bool setExtraSpacingAt( Qt::Edges edges );
    Qt::Edges extraSpacingAt() const;
 
    bool setSpacing( qreal spacing, Qt::Orientations );
    qreal spacing( Qt::Orientation ) const;
 
    qreal defaultSpacing( Qt::Orientation ) const;
 
    void invalidate();
 
    qreal widthForHeight( qreal height ) const;
    qreal heightForWidth( qreal width ) const;
 
    QSizeF sizeHint( Qt::SizeHint, const QSizeF& constraint ) const;
 
    void setGeometries( const QRectF& );
 
  protected:
    QRectF geometryAt( const QskLayoutElement*, const QRect& grid ) const;
 
    enum
    {
        ElementCache = 1 << 0,
        LayoutCache  = 1 << 1
    };
 
    void invalidate( int what );
 
  private:
    Q_DISABLE_COPY( QskLayoutEngine2D )
 
    void updateSegments( const QSizeF& ) const;
 
    virtual void layoutItems() = 0;
    virtual int effectiveCount( Qt::Orientation ) const = 0;
 
    virtual void invalidateElementCache() = 0;
    QskSizePolicy::ConstraintType constraintType() const;
 
    virtual QskSizePolicy sizePolicyAt( int index ) const = 0;
 
    void setupChain( Qt::Orientation ) const;
    void setupChain( Qt::Orientation, const QskLayoutChain::Segments& ) const;
 
    virtual void setupChain( Qt::Orientation,
        const QskLayoutChain::Segments&, QskLayoutChain& ) const = 0;
 
    class PrivateData;
    std::unique_ptr< PrivateData > m_data;
};
 
inline void QskLayoutEngine2D::invalidate()
{
    invalidate( ElementCache | LayoutCache );
}
 
inline int QskLayoutEngine2D::rowCount() const
{
    return effectiveCount( Qt::Vertical );
}
 
inline int QskLayoutEngine2D::columnCount() const
{
    return effectiveCount( Qt::Horizontal );
}
 
#endif