ScrollBarContainer.c

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// -----------------------------------------------------------
class ScrollBarContainer : ScriptedWidgetEventHandler
{
  reference bool Invert;
  protected Widget Content;
  protected Widget ScrollBar;
  protected Widget Scroller;
  protected Widget m_root;
 
  const int WHEEL_STEP = 20;
  protected float m_root_height;
  protected float m_content_height;
  protected float m_position;
  protected bool m_scrolling;
  protected float m_scrolling_start_pos;
  protected int m_scrolling_mouse_pos;
 
  void ~ScrollBarContainer()
  {
    //if(GetGame() != NULL)
    //GetGame().GetDragQueue().RemoveCalls(this);
  }
 
  void ScrollFixedAmount(bool down, float amount)
  {
    m_root.Update();
    Content.Update();
    float width;
 
    m_root.GetScreenSize(width, m_root_height);
    Content.GetScreenSize(width, m_content_height);
 
    float diff = m_root_height / m_content_height;
    float one_percent = diff / 100;
    float percents = amount / m_content_height;
    //float step = (1.0 / (m_content_height - m_root_height)) * WHEEL_STEP;
    float step = (percents / 100);
    if (down)
      m_position += 1 * (percents + 0.05);
    else
      m_position -= 1 * (percents + 0.05);
 
    if (m_position < 0) m_position = 0;
    if (m_position > 1 - diff) m_position = 1 - diff;
    UpdateScroller();
  }
 
  void ScrollToPos(float pos)
  {
    m_root.Update();
    Content.Update();
    float width;
 
    m_root.GetScreenSize(width, m_root_height);
    Content.GetScreenSize(width, m_content_height);
 
    float diff = m_root_height / m_content_height;
    float percents = pos / m_content_height;
 
    m_position = percents;
 
    if (m_position < 0)
      m_position = 0;
    if (m_position > 1 - diff)
      m_position = 1 - diff;
    UpdateScroller();
  }
 
  void ScrollToBottom()
  {
    m_root.Update();
    Content.Update();
    float width;
 
    m_root.GetScreenSize(width, m_root_height);
    Content.GetScreenSize(width, m_content_height);
 
    float diff = m_root_height / m_content_height;
    m_position = 1 - diff;
    UpdateScroller();
  }
 
  void ScrollToTop()
  {
    if (m_position != 0)
    {
      m_position = 0;
      UpdateScroller();
    }
  }
 
  float GetContentYPos()
  {
    float x, y;
    Content.GetPos(x, y);
    return y;
  }
 
  float GetRootHeight()
  {
    return m_root_height;
  }
 
  void UpdateScroller()
  {
    m_root.Update();
    Content.Update();
    float width;
    float height;
    float diff;
    float scroller_height;
 
    m_root.GetScreenSize(width, m_root_height);
    Content.GetScreenSize(width, m_content_height);
 
    diff = m_content_height - m_root_height;
    if (diff <= 0)
    {
      Content.SetPos(0, 0);
      Scroller.Show(false);
      ScrollBar.Show(false);
      m_position = 0;
      return;
    }
 
    scroller_height = (m_root_height / m_content_height) * m_root_height;
 
    ScrollBar.Show(true);
    Scroller.Show(true);
    Scroller.GetSize(width, height);
    Scroller.SetSize(width, scroller_height);
 
    float pos = (-m_content_height * m_position);
 
    if (pos <= -diff)
      pos = -diff;
 
    Scroller.SetPos(0, -pos);
 
    if (Invert)
      Content.SetPos(0, -(diff + (-diff * m_position)));
    else
      Content.SetPos(0, pos);
  }
 
  void OnWidgetScriptInit(Widget w)
  {
    m_root = w;
    m_root.SetHandler(this);
    m_root.SetFlags(WidgetFlags.VEXACTPOS);
    m_scrolling = false;
    UpdateScroller();
  }
 
  protected void StopScrolling()
  {
    if (m_scrolling)
    {
      GetGame().GetDragQueue().RemoveCalls(this);
      m_scrolling = false;
    }
  }
 
  protected void UpdateScroll(int mouse_x, int mouse_y, bool is_dragging)
  {
    m_root.Update();
    Content.Update();
    float width;
 
    m_root.GetScreenSize(width, m_root_height);
    Content.GetScreenSize(width, m_content_height);
 
    if (m_scrolling)
    {
      if (is_dragging)
      {
        float diff = (mouse_y - m_scrolling_mouse_pos);
        float scroller_height = (m_root_height / m_content_height) * m_root_height;
        m_position = m_scrolling_start_pos + (diff / (m_root_height - scroller_height));
        if (m_position < 0) m_position = 0;
        if (m_position > 1) m_position = 1;
      }
      else
      {
        m_scrolling = false;
        StopScrolling();
      }
    }
 
    UpdateScroller();
  }
 
 
  // ScriptedWidgetEventHandler override
  //--------------------------------------------------------------------------
  override bool OnMouseButtonDown(Widget w, int x, int y, int button)
  {
    if (button == MouseState.LEFT && w == Scroller && !m_scrolling)
    {
      m_scrolling = true;
      m_scrolling_start_pos = m_position;
      int mouse_x;
      GetMousePos(mouse_x, m_scrolling_mouse_pos);
      GetGame().GetDragQueue().Call(this, "UpdateScroll");
      return true;
    }
 
    return false;
  }
 
  //--------------------------------------------------------------------------
  override bool OnMouseButtonUp(Widget w, int x, int y, int button)
  {
    StopScrolling();
    return false;
  }
 
  //--------------------------------------------------------------------------
  override bool OnMouseWheel(Widget w, int x, int y, int wheel)
  {
    if (m_scrolling || m_content_height <= m_root_height) return false;
 
    float step = (1.0 / (m_content_height - m_root_height)) * WHEEL_STEP;
    m_position -= wheel * step;
 
    if (m_position < 0) m_position = 0;
    if (m_position > 1) m_position = 1;
    UpdateScroller();
    return true;
  }
 
  override bool OnResize(Widget w, int x, int y)
  {
    if (w == m_root || w == Content)
      UpdateScroller();
    return false;
  }
};