14.1.161. tablet_qt/layouts/flowlayouthfw.h

// As per http://doc.qt.io/qt-5/qtwidgets-layouts-flowlayout-example.html

/*===========================================================================
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===========================================================================*/

#pragma once
#include <QLayout>
#include <QMap>  // RNC
#include <QRect>
#include <QStyle>

class FlowLayoutHfw : public QLayout
{
    // Flow layout, as per FlowLayout Qt demo, but modified to support
    // height-for-width better (better as in: word-wrapping labels etc. get the
    // maximum width allowed, aiming for the minimum height).

    Q_OBJECT  // RNC
public:
    explicit FlowLayoutHfw(QWidget* parent, int margin = -1,
                           int h_spacing = -1, int v_spacing = -1);
    explicit FlowLayoutHfw(int margin = -1,
                           int h_spacing = -1, int v_spacing = -1);
    ~FlowLayoutHfw() override;

    // QLayout supplies: void addWidget(QWidget* w);  // no alignment option
    // QVBoxLayout/QHBoxLayout supply:
    //    void addWidget(QWidget* widget, int stretch, Qt::Alignment alignment);
    // Alignment does make sense, specifically top alignment.
    void addWidget(QWidget* w);  // RNC: just routes to QLayout version (for disambiguating conversions)
    void addWidget(QWidget* w, Qt::Alignment alignment);  // RNC
    virtual void addItem(QLayoutItem* item) override;

    void setHorizontalAlignmentOfContents(Qt::Alignment halign);
    virtual int horizontalSpacing() const;
    virtual int verticalSpacing() const;
    virtual Qt::Orientations expandingDirections() const override;
    virtual bool hasHeightForWidth() const override;
    virtual int heightForWidth(int) const override;
    virtual int count() const override;
    virtual QLayoutItem* itemAt(int index) const override;
    virtual QSize minimumSize() const override;
    virtual void setGeometry(const QRect& rect) override;
    virtual QSize sizeHint() const override;
    virtual QLayoutItem* takeAt(int index) override;
    virtual void invalidate() override;  // RNC

protected:  // RNC (was private)
    virtual QSize doLayout(const QRect& rect, bool test_only) const;
    int smartSpacing(QStyle::PixelMetric pm) const;
    int itemTop(int row_top, int item_height, int row_height,
                Qt::Alignment valignment) const;  // RNC
    int rowShiftToRight(int layout_width, int width_of_all_items) const;  // RNC

    QVector<QLayoutItem*> m_item_list;
    int m_h_space;
    int m_v_space;
    mutable QSize m_size_hint;
    mutable QMap<int, int> m_width_to_height;  // RNC
    Qt::Alignment m_halign;  // RNC

    struct ItemCalc {
        QLayoutItem* item;
        QWidget* widget;
        int layout_row;
        QSize item_size;
        QPoint layout_cell_top_left;
    };
};