scroll_bar.hpp

#pragma once
 
#include "qml_material/control/scroll_indicator.hpp"
 
namespace qml_material
{
class ScrollBarAttached;
 
class QML_MATERIAL_API ScrollBar : public ScrollIndicator {
    Q_OBJECT
    QML_NAMED_ELEMENT(ScrollBarBase)
    QML_ATTACHED(ScrollBarAttached)
    Q_PROPERTY(qreal stepSize READ stepSize WRITE setStepSize NOTIFY stepSizeChanged FINAL)
    Q_PROPERTY(bool pressed READ pressed WRITE setPressed NOTIFY pressedChanged FINAL)
    Q_PROPERTY(bool interactive READ interactive WRITE setInteractive RESET resetInteractive NOTIFY
                   interactiveChanged FINAL)
    Q_PROPERTY(SnapMode snapMode READ snapMode WRITE setSnapMode NOTIFY snapModeChanged FINAL)
    Q_PROPERTY(Policy policy READ policy WRITE setPolicy NOTIFY policyChanged FINAL)
public:
    enum SnapMode
    {
        NoSnap,
        SnapAlways,
        SnapOnRelease
    };
    Q_ENUM(SnapMode)
    enum Policy
    {
        AsNeeded  = Qt::ScrollBarAsNeeded,
        AlwaysOff = Qt::ScrollBarAlwaysOff,
        AlwaysOn  = Qt::ScrollBarAlwaysOn
    };
    Q_ENUM(Policy)
    explicit ScrollBar(QQuickItem* parent = nullptr);
    ~ScrollBar() override;
    static ScrollBarAttached* qmlAttachedProperties(QObject*);
    qreal                     stepSize() const { return m_step; }
    bool                      pressed() const { return m_pressed; }
    bool                      interactive() const { return m_interactive; }
    SnapMode                  snapMode() const { return m_snap; }
    Policy                    policy() const { return m_policy; }
    void                      setStepSize(qreal);
    void                      setPressed(bool);
    void                      setInteractive(bool);
    void                      resetInteractive();
    void                      setSnapMode(SnapMode);
    void                      setPolicy(Policy);
    Q_INVOKABLE void          increase();
    Q_INVOKABLE void          decrease();
    Q_SIGNAL void             stepSizeChanged();
    Q_SIGNAL void             pressedChanged();
    Q_SIGNAL void             interactiveChanged();
    Q_SIGNAL void             snapModeChanged();
    Q_SIGNAL void             policyChanged();
 
protected:
    void setMoving(bool) override;
    void disconnectFlickable() override;
    void mousePressEvent(QMouseEvent*) override;
    void mouseMoveEvent(QMouseEvent*) override;
    void mouseReleaseEvent(QMouseEvent*) override;
    void mouseUngrabEvent() override;
    void touchEvent(QTouchEvent*) override;
    void touchUngrabEvent() override;
    void itemChange(ItemChange, const ItemChangeData&) override;
 
private:
    void                    updateActive();
    void                    cancel();
    void                    begin(const QPointF&);
    void                    move(const QPointF&, bool release);
    void                    step(qreal);
    qreal                   logicalPosition(qreal) const;
    qreal                   positionAt(const QPointF&) const;
    void                    observeWindow();
    qreal                   m_step        = 0;
    qreal                   m_offset      = 0;
    bool                    m_pressed     = false;
    bool                    m_interactive = true;
    bool                    m_moving      = false;
    bool                    m_mouse       = false;
    int                     m_touch_id    = -1;
    SnapMode                m_snap        = NoSnap;
    Policy                  m_policy      = AsNeeded;
    QMetaObject::Connection m_window_connection;
};
 
class QML_MATERIAL_API ScrollBarAttached : public QObject {
    Q_OBJECT
    Q_PROPERTY(
        ScrollBar* horizontal READ horizontal WRITE setHorizontal NOTIFY horizontalChanged FINAL)
    Q_PROPERTY(ScrollBar* vertical READ vertical WRITE setVertical NOTIFY verticalChanged FINAL)
public:
    explicit ScrollBarAttached(QObject* parent);
    ScrollBar*    horizontal() const;
    ScrollBar*    vertical() const;
    void          setHorizontal(ScrollBar*);
    void          setVertical(ScrollBar*);
    Q_SIGNAL void horizontalChanged();
    Q_SIGNAL void verticalChanged();
 
private:
    ScrollIndicatorAttached* m_attachment;
};
} // namespace qml_material
 
QML_DECLARE_TYPEINFO(qml_material::ScrollBar, QML_HAS_ATTACHED_PROPERTIES)