/*--------------------------------------------------------
HELLOWIN.C -- System Metrics Display Program No .1
(c) Charles Petzold,1998
----------------------------------------------------------*/

#include <Windows.h>
#include "SYSMETS.h"

LRESULT CALLBACK WndProc (HWND,UINT, WPARAM,LPARAM);

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine,
    int iCmdShow)
{
    static TCHAR szAppName[] = TEXT ("SysMets4");
    HWND hwnd;
    MSG msg;
    WNDCLASS   wndclass;

    wndclass.style   = CS_HREDRAW | CS_VREDRAW;
    wndclass.lpfnWndProc  = WndProc;
    wndclass.cbClsExtra  = 0 ;
    wndclass.cbWndExtra = 0 ;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(NULL,IDI_APPLICATION);
    wndclass.hCursor = LoadCursor(NULL,IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH);
    wndclass.lpszMenuName = NULL;
    wndclass.lpszClassName = szAppName;

    if(!RegisterClass(&wndclass))
    {
        MessageBox(NULL,TEXT("This program requires Windows NT!"),
            szAppName,MB_ICONERROR);
return 0;
    }
    //RegisterClass(&wndclass);
    hwnd = CreateWindow(szAppName, //window class name
           TEXT("Get System Metrics No.4"),//window caption
           WS_OVERLAPPEDWINDOW,//window style
           CW_USEDEFAULT,//initial x position
           CW_USEDEFAULT,//initial y position
           CW_USEDEFAULT,//initial x size
           CW_USEDEFAULT,//initial y size
           NULL,//parent window handle
           NULL,//window menu handle
           hInstance,//program instance handle
           NULL);//creation parameters

    ShowWindow(hwnd,iCmdShow);
    UpdateWindow(hwnd);

    while (GetMessage(&msg,NULL,0,0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
    static int cxChar,cxCaps,cyChar,cxClient,cyClient,iMaxWidth;
    HDC hdc;
    int i,x,y,iVertPos,iHorzPos,iPaintBeg,iPaintEnd;
    PAINTSTRUCT ps;
    SCROLLINFO si;
    TCHAR szBuffer[10];
    TEXTMETRIC tm;

    switch(message)
    {
    case WM_CREATE:
           hdc = GetDC(hwnd);
           GetTextMetrics(hdc,&tm);
           cxChar = tm.tmAveCharWidth;
           cxCaps = (tm.tmPitchAndFamily &1?3:2)*cxChar/2;
           cyChar = tm.tmHeight + tm.tmExternalLeading;

           ReleaseDC(hwnd,hdc);
         /*  SetScrollRange(hwnd,SB_VERT,0,NUMLINES -1 ,FALSE);
           SetScrollPos(hwnd,SB_VERT,iVscrollPos,TRUE);
*/
    //SAVE the width of the three columns
           
           iMaxWidth=40*cxChar+22*cxCaps;
           return 0;

    case WM_SIZE:
        cxClient = LOWORD(lParam);
        cyClient = HIWORD(lParam);

        //Set vertical scroll bar range and page size

        si.cbSize = sizeof(si);
        si.fMask = SIF_RANGE | SIF_PAGE;
        si.nMin = 0;
        si.nMax = NUMLINES - 1;
        si.nPage = cyClient / cyChar ;
        SetScrollInfo(hwnd , SB_VERT,&si,TRUE);


        //Set horizontal scroll bar range and page size

        si.cbSize = sizeof(si);
        si.fMask  = SIF_RANGE|SIF_PAGE;
        si.nMin  = 0;
        si.nMax = 2+iMaxWidth/cxChar;
        si.nPage = cxClient / cxChar;
        SetScrollInfo(hwnd,SB_HORZ,&si,TRUE);
        return 0;

    case WM_VSCROLL:
        //Get all the vertical scroll bar information
        
        si.cbSize = sizeof(si);
        si.fMask = SIF_ALL;
        GetScrollInfo(hwnd,SB_VERT,&si);

        //Save the position for comparison later on

        iVertPos = si.nPos ;

        switch(LOWORD(wParam))
        {
        
        case SB_TOP:
            si.nPos = si.nMin ;
            break;

        case SB_BOTTOM:
            si.nPos = si.nMax ;
            break;

        case SB_LINEDOWN:
            si.nPos +=1;
            break;

        case SB_PAGEUP:
            si.nPos -= si.nPage;
            break;

        case SB_PAGEDOWN:
            si.nPos += si.nPage;
            break;

        case SB_THUMBTRACK:
            si.nPos = si.nTrackPos;
            break;
        }

        //Set the position and then retrieve it.Due to adjustments
        //by Windows it might not be the same as the value set.

        si.fMask = SIF_POS;
        SetScrollInfo(hwnd,SB_VERT,&si,TRUE);
        GetScrollInfo(hwnd,SB_VERT,&si);

        //if the position has changed,scroll the window and update it

        if (si.nPos != iVertPos)
        {
            ScrollWindow(hwnd,0,cyChar*(iVertPos - si.nPos),NULL,NULL);
            UpdateWindow(hwnd);
        }
        return 0;

    case WM_HSCROLL:
        //get all the vertical scroll bar information
        si.cbSize = sizeof(si);
        si.fMask = SIF_ALL;

        //Save the position for comparision later on

        GetScrollInfo(hwnd,SB_HORZ,&si);

        iHorzPos = si.nPos;

        switch(LOWORD(wParam))
        {
        case SB_LINELEFT:
            si.nPos -= 1;
            break;

        case SB_LINERIGHT:
            si.nPos += 1;
            break;

        case SB_PAGERIGHT:
            si.nPos += si.nPage;
            break;

        case SB_THUMBPOSITION:
            si.nPos = si.nTrackPos;
            break;

        default:
            break;
        }

        //Set the position and then retrieve it .Due to adjustments
        //by windows it might not be the same as the value set.

        si.fMask = SIF_POS;
        SetScrollInfo(hwnd , SB_HORZ,&si,TRUE);
        GetScrollInfo(hwnd,SB_HORZ,&si);

        //If the position has changed,scroll the window

        if(si.nPos != iHorzPos)
        {
            ScrollWindow (hwnd,cxChar*(iHorzPos - si.nPos),0,NULL,NULL);
        }
        return 0;

    case WM_KEYDOWN:
        switch (wParam)
        {
        case VK_HOME:
            SendMessage(hwnd,WM_VSCROLL,SB_TOP,0);
            break;

        case VK_END:
            SendMessage(hwnd,WM_VSCROLL,SB_BOTTOM,0);
            break;

        case VK_PRIOR:
            SendMessage(hwnd,WM_VSCROLL,SB_PAGEUP,0);
            break;

        case VK_NEXT:
            SendMessage(hwnd,WM_VSCROLL,SB_PAGEDOWN,0);
            break;

        case VK_UP:
            SendMessage(hwnd,WM_VSCROLL,SB_LINEUP,0);
            break;

        case VK_DOWN:
            SendMessage(hwnd,WM_VSCROLL,SB_LINEDOWN,0);
            break;

        case VK_LEFT:
            SendMessage(hwnd,WM_HSCROLL,SB_PAGEUP,0);
            break;

        case VK_RIGHT:
            SendMessage(hwnd,WM_HSCROLL,SB_PAGEDOWN,0);
                break;
        }
        return 0;

    case WM_PAINT:
        hdc = BeginPaint(hwnd,&ps);
        //Get vertical scroll bar position
        si.cbSize = sizeof(si);
        si.fMask = SIF_POS;

        GetScrollInfo(hwnd,SB_VERT,&si);
        iVertPos = si.nPos;

        //Get horizontal scroll bar psoition
        GetScrollInfo(hwnd,SB_HORZ,&si);
        iHorzPos = si.nPos;

        //Find painting limits

        iPaintBeg = max(0,iVertPos + ps.rcPaint.top / cyChar);
        iPaintEnd = min(NUMLINES - 1,iVertPos + ps.rcPaint.bottom / cyChar);

        for (i = iPaintBeg ; i<= iPaintEnd ; i++)
        {
            x = cxChar* (1 - iHorzPos);
            y = cyChar*(i - iVertPos);

            TextOut (hdc,x,y ,sysmetrics[i].szLabel, lstrlen(sysmetrics[i].szLabel));

            TextOut (hdc,x + 22 * cxCaps , y, sysmetrics[i].szDesc,lstrlen(sysmetrics[i].szDesc));

            SetTextAlign(hdc,TA_RIGHT | TA_TOP);

            TextOut(hdc, x+22 *cxCaps + 40* cxChar,y,szBuffer,wsprintf(szBuffer,TEXT("%5d"),GetSystemMetrics(sysmetrics[i].Index)));

            SetTextAlign(hdc,TA_LEFT|TA_TOP);
        }


            EndPaint(hwnd,&ps);
        return 0 ;

    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd,message,wParam,lParam);
}