Upsilon/escher/include/escher/scroll_view_indicator.h

#ifndef ESCHER_SCROLL_VIEW_INDICATOR_H
#define ESCHER_SCROLL_VIEW_INDICATOR_H

#include <escher/view.h>

class ScrollViewIndicator : public View {
public:
  ScrollViewIndicator();
  void setMargin(KDCoordinate m) { m_margin = m; }
  KDCoordinate margin() const { return m_margin; }
protected:
#if ESCHER_VIEW_LOGGING
  const char * className() const override;
  void logAttributes(std::ostream &os) const override;
#endif
  KDColor m_color;
  KDCoordinate m_margin;
};

class ScrollViewBar : public ScrollViewIndicator {
public:
  ScrollViewBar();
  bool update(KDCoordinate totalContentLength, KDCoordinate contentOffset, KDCoordinate visibleContentLength);
  bool visible() const { return 0 < m_offset || m_visibleLength < 1; }
protected:
  constexpr static KDCoordinate k_indicatorThickness = 4;
  float m_offset;
  float m_visibleLength;
  KDColor m_trackColor;
};

class ScrollViewHorizontalBar : public ScrollViewBar {
public:
  void drawRect(KDContext * ctx, KDRect rect) const override;
private:
  KDCoordinate totalLength() const { return m_frame.width() - 2*m_margin; }
};

class ScrollViewVerticalBar : public ScrollViewBar {
public:
  void drawRect(KDContext * ctx, KDRect rect) const override;
private:
  KDCoordinate totalLength() const { return m_frame.height() - 2*m_margin; }
};

class ScrollViewArrow : public ScrollViewIndicator {
public:
  enum Side : char { //FIXME
    Top = 't',
    Right = '>',
    Bottom = 'b',
    Left = '<'
  };
  ScrollViewArrow(Side side);
  bool update(bool visible);
  void setBackgroundColor(KDColor c) { m_backgroundColor = c; }
  void drawRect(KDContext * ctx, KDRect rect) const override;
private:
  bool m_visible;
  const char m_arrow;
  KDColor m_backgroundColor;
};

#endif