ScrollBarContainer.c

См. документацию.

// -----------------------------------------------------------
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;
    }
};