Graphics Plus/Graphics Plus.iso/msdos/plotting/pcgplots/gptscrol.cpp

C/C++ Source or Header | 1992-04-24 | 5KB | 194 lines

// GptScroll.cpp
// copyright 1992 Pittsburgh Supercomputing Center
#include "gpt.h"

 // Scroller Constructor
Scroller::Scroller(WindowPt win, short xMax, short yMax)
    {
    RECT rect;
    FullSize = FALSE;
    nVscrollPos  = nHscrollPos = 0;
    MaxX = xMax;
    MaxY = yMax;
    XRatio = 1.0;
   YRatio = 1.0;
    this->win = win;
    this->hWnd  = win->GetHandle();
    GetClientRect( hWnd, (LPRECT) &rect );
    ixMax        = MaxX - rect.right;
    iyMax        = MaxY - rect.bottom;
    ixMin = 0;
    iyMin = 0;
    //GetClipBox(hDC, lpRect)
    SetScrollRange(hWnd,SB_HORZ,ixMin,ixMax,FALSE);    // triggers size message
    SetScrollPos(hWnd,SB_HORZ,nHscrollPos, FALSE);
    SetScrollRange(hWnd,SB_VERT,iyMin,iyMax,FALSE);
    SetScrollPos(hWnd,SB_VERT,nVscrollPos, FALSE);


    }
/* *****************
void Scroller::NewSize(short x, short y)
    {
    //MaxX=1024; MaxY = 714;
    ixMax        = MaxX - x;
    iyMax        = MaxY - y;

    BOOL repaint;
    repaint = FALSE;
    if (iyMax  < GetSystemMetrics(SM_CYHSCROLL)*XRatio && iyMax > 0)
        {repaint = TRUE; iyMax = 0; }
    nVscrollPos = max(0, min(nVscrollPos, iyMax));
    SetScrollRange(hWnd,SB_VERT,0,iyMax,repaint);
    SetScrollPos(hWnd,SB_HORZ,nHscrollPos, repaint);

    repaint = FALSE;
    if (ixMax  < GetSystemMetrics(SM_CXVSCROLL)*YRatio && ixMax > 0)
        { repaint = TRUE; ixMax = 0; }

    nHscrollPos = max(0, min(nHscrollPos, ixMax));
    SetScrollRange(hWnd,SB_HORZ,0,ixMax, repaint);
    SetScrollPos(hWnd,SB_HORZ,nHscrollPos, repaint);
    if (ixMax== 0 && iyMax == 0) FullSize = TRUE;
    else FullSize = FALSE;
    }
*********************************** */
 void Scroller::NewSize(short x, short y)
    {
    float XPRat = 1.0;
    float YPRat = 1.0;
    if ( ixMax)
        XPRat = (float)(ixMax - nHscrollPos ) /(ixMax -ixMin);
        // P = max - (max - min)*R
        // R = (max - P) / (max - min)
    if (iyMax)
        YPRat = (float)(iyMax - nVscrollPos ) /(iyMax - iyMin);
    int SizeX = MaxX - x;     // Scroll Range in X ( == 0 at full size )
    int SizeY = MaxY - y;     // Scroll Range in Y ( == 0 at full size )

    // Siz = Max - Min
    // Rat = (Pos - Min) / Siz
    // Min = Pos - Rat*Siz
    if (ixMax == ixMin) nHscrollPos = 0;
    else  nHscrollPos = (float)nHscrollPos/(ixMax - ixMin) * SizeX;
    if (iyMax == iyMin) nVscrollPos = 0;
    else  nVscrollPos = (float)nVscrollPos/(iyMax - iyMin) * SizeY;

    ixMax = nHscrollPos  + (XPRat*SizeX);
    iyMax = nVscrollPos  + (YPRat*SizeY);
    if (ixMax > SizeX)  ixMax = SizeX;
    if (iyMax > SizeY) iyMax = SizeY;
    ixMin = ixMax - SizeX;
    iyMin = iyMax - SizeY;
    if (ixMin < 0) ixMin = 0;
    if (iyMin < 0) iyMin = 0;
    BOOL repaint;
    repaint = FALSE;
    if (iyMax  < GetSystemMetrics(SM_CYHSCROLL)*XRatio )
        {repaint = TRUE; iyMax = 0; }
    // Determine where position currently is relative to size
    nVscrollPos = max(0, min(nVscrollPos, iyMax));
    nVscrollPos = min( max(nVscrollPos, iyMin), iyMax);
    SetScrollRange(hWnd,SB_VERT,iyMin,iyMax,repaint);
    SetScrollPos(hWnd,SB_VERT,nVscrollPos, repaint);

    repaint = FALSE;
    if (ixMax  < GetSystemMetrics(SM_CXVSCROLL)*YRatio )
        { repaint = TRUE; ixMax = 0; }

    nHscrollPos = max(0, min(nHscrollPos, ixMax));
    nHscrollPos = min( max(nHscrollPos, ixMin), ixMax);
    SetScrollRange(hWnd,SB_HORZ,ixMin,ixMax, repaint);
    SetScrollPos(hWnd,SB_HORZ,nHscrollPos, repaint);
    if (!SizeX && !SizeY) FullSize = TRUE;
    else FullSize = FALSE;
    }


 void Scroller::SetPos(short horz, short vert)
    {
    if (horz > ixMax) horz = ixMax;
    if (horz < ixMin) horz = ixMin;
    if (vert > iyMax) vert = iyMax;
    if (vert < iyMin) vert = iyMin;

    //nHscrollPos = max(0, min(horz, ixMax));
    //nVscrollPos = max(0, min(vert, ixMax));
    nHscrollPos = horz;
    nVscrollPos = vert;
    SetScrollPos(hWnd,SB_VERT, nVscrollPos,TRUE);
    SetScrollPos(hWnd,SB_HORZ, nHscrollPos,TRUE);
    }
 void Scroller::Scroll()
    {
    WORD wScrollType      = ((FrameWindowPt)win)->GetwParam();
    WORD wScrollDirection = ((FrameWindowPt)win)->GetiMessage();
    WORD wThumbPosition   = LOWORD(((FrameWindowPt)win)->GetlParam() );
    short iPos;
    short inc;
    RECT rect;
    GetClientRect( hWnd, (LPRECT) &rect );

    if (wScrollDirection == WM_VSCROLL)
        {
        iPos = nVscrollPos;
        inc  = (iyMax - iyMin)/10+1;
        }
    else
        {
        iPos = nHscrollPos;
        inc  = (ixMax - ixMin)/10+1;
        }
    switch ( wScrollType)
        {
        case SB_LINEUP:
        iPos -=inc;
        break;

        case SB_LINEDOWN:
        iPos +=inc;
        break;

        case SB_PAGEUP:
        iPos -= inc*3;
        break;

        case SB_PAGEDOWN:
        iPos += inc*3;
        break;

        case SB_THUMBPOSITION:
        iPos = wThumbPosition;
        break;

        default:
        break;
        }
    if (wScrollDirection == WM_VSCROLL)
        {
        if (iPos > iyMax) iPos = iyMax;
        if (iPos < iyMin) iPos = iyMin;
        nVscrollPos = iPos;
        if (nVscrollPos != GetScrollPos(hWnd, SB_VERT))
            {
            SetScrollPos(hWnd,SB_VERT, nVscrollPos,TRUE);
            InvalidateRect(hWnd, NULL, TRUE);
            //ScrollWindow(hWnd,0,nVscrollPos, NULL,NULL);
            //UpdateWindow(hWnd);
            }
        }
    else
        {
        if (iPos > ixMax) iPos = ixMax;
        if (iPos < ixMin) iPos = ixMin;
        nHscrollPos = iPos;
        if (nHscrollPos != GetScrollPos(hWnd, SB_HORZ))
            {
            SetScrollPos(hWnd,SB_HORZ, nHscrollPos, TRUE);
            InvalidateRect(hWnd, NULL, TRUE);
            //ScrollWindow(hWnd,nHscrollPos,0, NULL,NULL);
          //    UpdateWindow(hWnd);
            }
        }
    }