;-scroll.asm-----------------------------------------------------------------
;          x86 - Dos & Win32 - Assembly Language Programming                ;
;                                                                           ;
; Written by: John A Lyons                                                  ;
; Email     : sysop@megablast.8k.com                                        ;
; Page      : http://www.asmsource.8k.com/                                  ;
; Compiler  : Masm32 v6.13 Microsoft Macro Assembler                        ;
; Date      : 21-1-2001                                                     ;
; Purpose   : How to use the vertical scrollbar (things are very similar for;
;             the horizontal scrollbar).Illustrates procedure calls         ;
;             ShowScrollBar and SetScrollInfo.                              ;
;                                                                           ;
;----------------------------------------------------------------------------
; Compile with nmake


.386
.MODEL  FLAT , STDCALL

include windows.inc
include user32.inc
include kernel32.inc
include gdi32.inc
includelib user32.lib
includelib kernel32.lib
includelib gdi32.lib



EXTRN wsprintfA:PROC


.data
ClassName       db "SimpleWinClass",0
AppName         db "Vertical Scrollbar",0

hInstance       HINSTANCE ?
CommandLine     LPSTR ?
hwnd            HWND ?
scrollpos       DWORD ?

counter         DWORD ?
buff            db 200 dup(0)
num             db "%lu     ",0
hdc             DWORD ?

.code

WinMain proc hInst:HINSTANCE,hPrevInst:HINSTANCE,CmdLine:LPSTR,CmdShow:SDWORD
	LOCAL wc:WNDCLASSEX
	LOCAL msg:MSG
        LOCAL scr:SCROLLINFO

                        ;typedef struct tagSCROLLINFO {  // si
                        ;
                        ;    UINT cbSize;
                        ;    UINT fMask;
                        ;    int  nMin;
                        ;    int  nMax;
                        ;    UINT nPage;
                        ;    int  nPos;
                        ;    int  nTrackPos;
                        ;}   SCROLLINFO;


	mov   wc.cbSize,SIZEOF WNDCLASSEX
	mov   wc.style, CS_HREDRAW or CS_VREDRAW
	mov   wc.lpfnWndProc, OFFSET WndProc
	mov   wc.cbClsExtra,NULL
	mov   wc.cbWndExtra,NULL
        push  hInstance
        pop   wc.hInstance
	mov   wc.hbrBackground,COLOR_WINDOW+1
	mov   wc.lpszMenuName,NULL
	mov   wc.lpszClassName,OFFSET ClassName
        invoke LoadIcon,NULL,IDI_APPLICATION

	mov   wc.hIcon,eax
        mov   wc.hIconSm,0
        invoke LoadCursor,NULL,IDC_ARROW

	mov   wc.hCursor,eax
        invoke RegisterClassEx, addr wc

        INVOKE CreateWindowEx,NULL,ADDR ClassName,ADDR AppName,\
           WS_OVERLAPPEDWINDOW,
           CW_USEDEFAULT,CW_USEDEFAULT,
          300,168,            ;size
          NULL,NULL,\
           hInst,NULL
        mov   hwnd,eax

        invoke ShowScrollBar,hwnd,SB_VERT,TRUE

        mov scr.cbSize,SIZEOF scr
;        mov scr.fMask,SIF_POS     ;SIF_RANGE
        mov scr.fMask,SIF_POS + SIF_RANGE + SIF_PAGE
        mov scr.nMin,0
        mov scr.nMax,100
        mov scr.nPos,5
        mov scrollpos,5
        mov scr.nPage,10
        invoke SetScrollInfo,hwnd,SB_VERT,addr scr,TRUE


        INVOKE ShowWindow, hwnd,SW_SHOWNORMAL
        INVOKE UpdateWindow, hwnd

        .WHILE TRUE
                INVOKE GetMessage, ADDR msg,NULL,0,0
                .BREAK .IF (!eax)
                INVOKE TranslateMessage, ADDR msg
                INVOKE DispatchMessage, ADDR msg
        .ENDW
        mov     eax,msg.wParam
        ret
WinMain endp
WndProc proc hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParam:LPARAM
        LOCAL ps:PAINTSTRUCT

	mov   eax,uMsg
	.IF eax==WM_DESTROY
		invoke PostQuitMessage,NULL
        .ELSEIF eax==WM_PAINT
                invoke BeginPaint,hWnd, ADDR ps
                mov    hdc,eax

;                invoke TextOut,hdc,0,0,ADDR TestString,(SIZEOF TestString) -1
                call shownum

                invoke EndPaint,hWnd, ADDR ps

        .ELSEIF eax==WM_VSCROLL
                invoke GetDC,hWnd
                mov    hdc,eax

                mov eax,wParam
                and eax,0ffffh

                mov ebx,wParam
                shr ebx,16
                mov ecx,scrollpos

                .IF eax==SB_THUMBTRACK
                        mov scrollpos,ebx
                        call updatescroll

                .ELSEIF eax==SB_THUMBPOSITION

                .ELSEIF eax==SB_LINEUP
                        mov ebx,scrollpos
                        cmp ebx,0
                        je nosr1

                        dec ebx
                        mov scrollpos,ebx
                        call updatescroll
                .ELSEIF eax==SB_LINEUP
                        cmp ecx,0
                        je nosr1

                        dec ecx
                        mov scrollpos,ecx
                        call updatescroll
                .ELSEIF eax==SB_LINEDOWN
                        cmp ecx,91
                        jae nosr1

                        inc ecx
                        mov scrollpos,ecx
                        call updatescroll
                .ELSEIF eax==SB_PAGEUP
                        cmp ecx,0
                        je nosr1
                        cmp ecx,10
                        ja sub1
                        mov ecx,0
                        jmp sub1a

sub1:
                        sub ecx,10
sub1a:
                        mov scrollpos,ecx
                        call updatescroll
                .ELSEIF eax==SB_PAGEDOWN
                        cmp ecx,91
                        jae nosr1
                        cmp ecx,81
                        jb sub2
                        mov ecx,91
                        jmp sub2a
sub2:
                        add ecx,10
sub2a:

                        mov scrollpos,ecx
                        call updatescroll


                .ENDIF
nosr1:

                call shownum


                invoke EndPaint,hWnd, ADDR ps
        .ELSE
                invoke DefWindowProc,hWnd,uMsg,wParam,lParam
                ret
	.ENDIF
        xor    eax,eax
	ret
WndProc endp
count proc
        push esi
           mov eax,0
noc2:
          cmp [esi],byte ptr 0
          je noc1
          inc esi
          inc eax
          jmp noc2
noc1:
        mov [counter],eax

        pop esi

        ret
count endp
shownum proc
                push edi
                mov eax,scrollpos
                mov ecx,10
                mov edi,0
listo:
                push eax
                push ecx
                push edi

                push eax
                push offset num
                push offset buff
                call wsprintfA
                add esp,0ch
                lea esi,buff
                call count
                invoke TextOut,hdc,0,edi,esi,counter

                pop edi
                pop ecx
                pop eax
                inc eax

                add edi,14
                loop listo

                pop edi

                ret
shownum         endp
updatescroll    proc
                LOCAL scr:SCROLLINFO

                mov ebx,scrollpos
                mov scr.cbSize,SIZEOF scr
                mov scr.fMask,SIF_POS
                mov scr.nPos,ebx
                invoke SetScrollInfo,hwnd,SB_VERT,addr scr,TRUE

                ret
updatescroll    endp

start:

	invoke GetModuleHandle, NULL
	mov    hInstance,eax
	invoke GetCommandLine
        invoke WinMain, hInstance,NULL,CommandLine, SW_SHOWDEFAULT
	invoke ExitProcess,eax

        end start