tgscrollarea.h

#pragma once
 
#include <widgets/tgwidget.h>
 
#include <QPointer>
 
namespace Tg {
class ScrollBar;
 
class ScrollArea : public Widget
{
    Q_OBJECT
 
    Q_PROPERTY(QPoint contentsPosition READ contentsPosition WRITE setContentsPosition NOTIFY contentsPositionChanged)
 
    friend class ListView;
 
public:
    enum class ScrollBarPolicy {
        AlwaysShow,
        ShowWhenNeeded,
        NeverShow
    };
    Q_ENUM(ScrollBarPolicy)
 
    ScrollArea(Widget *parent);
    ScrollArea(Screen *screen);
 
    QPoint contentsPosition() const;
 
public slots:
    void setContentsPosition(const QPoint &contentsPosition);
 
signals:
    void contentsPositionChanged(const QPoint &contentsPosition) const;
 
protected:
    void init() override;
    void consumeKeyboardBuffer(const QString &keyboardBuffer) override;
    QString drawPixel(const QPoint &pixel) const override;
    virtual QString drawAreaContents(const QPoint &pixel) const;
 
    QPoint childPixel(const QPoint &pixel) const;
 
    int childrenWidth() const;
    int childrenHeight() const;
    QRect scrollableArea() const;
 
    void updateScrollBarStates();
    void updateScrollBarPositions();
 
    int _childrenWidth = 0;
    int _childrenHeight = 0;
 
protected slots:
    virtual void updateChildrenDimensions();
    void connectChild(Widget *child);
 
private:
    QPointer<ScrollBar> _verticalScrollBar;
    ScrollBarPolicy _verticalScrollBarPolicy = ScrollBarPolicy::ShowWhenNeeded;
    QPointer<ScrollBar> _horizontalScrollBar;
    ScrollBarPolicy _horizontalScrollBarPolicy = ScrollBarPolicy::ShowWhenNeeded;
 
    QPoint _contentsPosition;
};
}