Method scrollAndDrawLog

examples/allevents.cpp:147–191

  void recalcMaxLines() { m_maxlines = (m_window->height() - m_lineHeight) / m_lineHeight; }

  void scrollAndDrawLog(const int newlines)
  {
    Surface* surface = m_window->surface();
    const gfx::Rect rc = surface->bounds();

    Paint p;
    p.style(Paint::Fill);
    p.color(gfx::rgba(0, 0, 0, 8));

    // Scroll old lines
    int i;
    if (m_textLog.size() >= m_maxlines) {
      int h = m_lineHeight * newlines;
      surface->scrollTo(rc, 0, -h);

      surface->drawRect(gfx::Rect(rc.x, rc.y, rc.w, rc.h - h), p);
      p.color(gfx::rgba(0, 0, 0));
      surface->drawRect(gfx::Rect(rc.x, rc.y + rc.h - h, rc.w, h), p);

      i = (m_textLog.size() - newlines);
    }
    // First lines without scroll
    else {
      i = m_oldLogSize;
      surface->drawRect(gfx::Rect(rc.x, rc.y, rc.w, i * m_lineHeight), p);
    }

    Paint paint;
    paint.color(gfx::rgba(255, 255, 255));
    for (; i < m_textLog.size(); ++i) {
      // Use shaper so we can paint emojis in the log
      draw_text(surface, m_textLog[i], gfx::PointF(0, i * m_lineHeight), &paint);
    }

    gfx::Rgb rgb(gfx::Hsv(m_hue, 1.0, 1.0));
    paint.color(gfx::rgba(rgb.red(), rgb.green(), rgb.blue()));
    paint.antialias(true);
    surface->drawCircle(m_mousePos.x, m_mousePos.y, m_brushSize, paint);

    // Invalidates the whole window to show it on the screen.
    if (m_window->isVisible())
      m_window->invalidateRegion(gfx::Region(rc));
    else
      m_window->setVisible(true);
  }

  void logMouseEvent(const Event& ev, const char* eventName)
  {