GUIScrollBar.h

#pragma once
#include "GUIBase.h"

// Minimum scroll bar thumb size
#define SCROLLBAR_MINTHUMBSIZE 8

namespace ParaEngine
{
    enum GUI_SCROLL_TYPE{
        NONE = 0,
        HSCROLL = 1,
        VSCROLL = 2
    };

    class CGUIScrollBar : public CGUIBase
    {
    public:
        CGUIScrollBar();
        virtual ~CGUIScrollBar();

        //virtual bool  MsgProc(CGUIEvent *event=NULL);
        virtual bool    MsgProc(MSG *event);

        virtual HRESULT Render(GUIState* pGUIState, float fElapsedTime);
        virtual void    UpdateRects();
        virtual void    InitObject(const char * strObjectName, const char * alignment, int x, int y, int width, int height);
        virtual bool    OnMouseLeave();
        virtual bool    OnChange(const char* code = NULL);

        void SetTrackRange(int nStart, int nEnd);

        int GetTrackPos() { return m_nPosition; }

        int GetTrackStart(){ return m_nStart; };
        int GetTrackEnd(){ return m_nEnd; };

        void SetValue(int nValue) { SetTrackPos(nValue); };

        int  GetValue() const { return m_nPosition; };

        void SetTrackPos(int nPosition) { m_nPosition = nPosition; Cap(); UpdateThumbRect(); }

        int GetPageSize() { return m_nPageSize; }

        void SetPageSize(int nPageSize) { m_nPageSize = nPageSize; Cap(); UpdateThumbRect(); }

        void SetStep(int nDelta){ m_nDelta = nDelta; }

        int GetStep(){ return m_nDelta; }

        void Scroll(int nDelta);

        void ShowItem(int nIndex);

        void SetFixedThumb(bool bFixed);
        bool GetFixedThumb()const{ return m_bFixedThumb; }

        void SetThumbSize(int size){ m_nThumbSize = SCROLLBAR_MINTHUMBSIZE > size ? SCROLLBAR_MINTHUMBSIZE : size; m_bNeedUpdate = true; }
        int GetThumbSize()const { return m_nThumbSize; }

        void SetLinkedObject(CGUIBase* obj){ m_Linked = obj; }

        void                    SetScrollbarWidth(int width);
        int                     GetScrollbarWidth()const;
        //      virtual void SetSize(int width, int height );
        //      virtual void SetWidth(int width );
        //      virtual void SetHeight(int height );

        static void StaticInit();
        virtual void Clone(IObject* pobj)const;
        virtual IObject *Clone()const;
        virtual const IType* GetType()const{ return m_type; }

    protected:
        static const IType* m_type;
        // ARROWSTATE indicates the state of the arrow buttons.
        // CLEAR            No arrow is down.
        // CLICKED_UP       Up arrow is clicked.
        // CLICKED_DOWN     Down arrow is clicked.
        // HELD_UP          Up arrow is held down for sustained period.
        // HELD_DOWN        Down arrow is held down for sustained period.
        enum ARROWSTATE { CLEAR, CLICKED_UP, CLICKED_DOWN, HELD_UP, HELD_DOWN, CLICKED, HELD };

        void UpdateThumbRect();

        void UpdateThumbRectNineElement();

        void Cap();  // Clips position at boundaries. Ensures it stays within legal range.

        bool m_bShowThumb;
        int m_nPosition;  // Position of the first displayed item
        int m_nOldPosition;
        int m_nPageSize;  // How many items are displayable in one page
        int m_nStart;     // First item
        int m_nEnd;       // The index after the last item
        int m_nDelta;     // How many items are scrolled in one click
        //      POINT m_LastMouse;// Last mouse position
        ARROWSTATE m_Arrow; // State of the arrows
        DWORD m_dArrowTS;  // Timestamp of last arrow event.
        int m_ScrollType;
        bool m_bFixedThumb;//if the thumb has fixed size, default is true
        CGUIBase* m_Linked;
        int m_nThumbSize;//thumb size if m_bFixedThumb=true, default is 20;
    };
}