locals
.386
.model flat,stdcall
include win32.asi
include win32.ase
include fdui.asi

	public handlesb,scrollkeys,DisplayWindowBars,SetBarRanges, ShiftState
	extrn  Translate : PROC, Dispatch : PROC
.data
ShiftState	db	?

.code

;-----------------------------------------------------------------------------
;
; this routine calculates the new scroll bar position, then redraws
; the scroll bar and invalidates the screen
;
handlesb	PROC	hwnd : dword, sbdata : dword, \
			sbmsg : dword, newpos : dword

		mov	ebx,[sbdata]
		mov	eax,[sbmsg]
		call	Dispatch
		dd	8
		dd	SB_BOTTOM,offset sbbot
		dd	SB_TOP,offset sbtop
		dd	SB_THUMBPOSITION,offset sbtpos
		dd	SB_THUMBTRACK,offset sbttrack
		dd	SB_PAGEUP,offset sbpup
		dd	SB_PAGEDOWN,offset sbpdown
		dd	SB_LINEUP,offset sblup
		dd	SB_LINEDOWN,offset sbldown
		jc	badbx
		call	SetScrollPos,[hwnd],[ebx + sbinfo.sbstyle],\
					[ebx + sbinfo.sbpos],1
                call    InvalidateRect,[hwnd],0,0,0,0
badbx:
		ret

sbbot	PROC
		mov	[ebx + sbinfo.sbpos],0
		ret
sbbot	ENDP
sbtop	PROC
		mov	eax,[ebx + sbinfo.sbheight]
		mov	[ebx + sbinfo.sbpos],eax
		ret
sbtop	ENDP
sbtpos	PROC
		mov	eax,[newpos]
		mov	dword ptr [ebx + sbinfo.sbpos],eax
		ret
sbtpos	ENDP
sbttrack	PROC
		; intercept the tunhmbtrack message if you want to give
		; feedback while they ard dragging the scrollbar
		
		mov	eax,[newpos]
		mov	dword ptr [ebx + sbinfo.sbpos],eax
		ret
sbttrack	ENDP
sbpup	PROC
		
		mov	eax,[ebx + sbinfo.sbpaging]
		sub	dword ptr [ebx + sbinfo.sbpos],eax
		jns	sbpupx
		mov	dword ptr [ebx + sbinfo.sbpos],0
sbpupx:
		ret
sbpup	ENDP
sbpdown	PROC
		mov	eax,[ebx + sbinfo.sbpaging]
		add	dword ptr [ebx + sbinfo.sbpos],eax
		mov     eax,[ebx + sbinfo.sbheight]
		cmp	dword ptr [ebx + sbinfo.sbpos],eax
		jc	sbpdownx
		mov	dword ptr [ebx + sbinfo.sbpos],eax
sbpdownx:
		ret
sbpdown	ENDP
sblup	PROC
		dec	dword ptr [ebx + sbinfo.sbpos]
		jns	sblupx
		mov	dword ptr [ebx + sbinfo.sbpos],0
sblupx:
		ret
sblup	ENDP
sbldown	PROC
		inc	dword ptr [ebx + sbinfo.sbpos]
		mov	eax,[ebx + sbinfo.sbheight]
		cmp	dword ptr [ebx + sbinfo.sbpos],eax
		jc	sbldownx
		mov	dword ptr [ebx + sbinfo.sbpos],eax
sbldownx:
		ret
sbldown	ENDP
handlesb	ENDP
;-----------------------------------------------------------------------------
;
; this function translates a keypress into something handlesb can
; use
;
; we are using shift-right and shift-left here to do page-right and page-left
;
scrollkeys	proc	hwnd : dword, key : dword, dwdata : dword
		mov	eax,key
		mov	ebx,[dwdata]
		test	[ShiftState],1
		jnz	isshifted
		call	Translate
		dd	4
		dd	VK_NEXT,SB_PAGEDOWN
		dd	VK_PRIOR,SB_PAGEUP
		dd	VK_UP,SB_LINEUP
		dd	VK_DOWN,SB_LINEDOWN
		jc	sk_chkhorz
		lea	ebx,[ebx + dwinfo.pvsb]
		call	handlesb,[hwnd],ebx,eax,0
		ret
sk_chkhorz:
		call	Translate
		dd	2
		dd	VK_LEFT,SB_LINEUP
		dd	VK_RIGHT,SB_LINEDOWN
		jnc	skhorz
		ret
isshifted:
		call	Translate
		dd	2
		dd	VK_LEFT,SB_PAGEUP
		dd	VK_RIGHT,SB_PAGEDOWN
		jc	sk_noredraw
skhorz:
		lea	ebx,[ebx + dwinfo.phsb]
		call	handlesb,[hwnd],ebx,eax,0
sk_noredraw:
		ret
scrollkeys	endp
;-----------------------------------------------------------------------------
DisplayWindowBars PROC hwnd : dword, flag : dword

		call   ShowScrollBar,[hwnd],SB_BOTH,[flag]
		ret
DisplayWindowBars ENDP

SetBarRanges PROC hwnd : dword, sbr_vert : dword, sbr_horiz : dword
		 mov	ebx,[sbr_horiz]
		 call	SetScrollRange,[hwnd],SB_HORZ, \
				0,[ebx + sbinfo.sbpos],[ebx + sbinfo.sbheight],1
		 mov	ebx,[sbr_vert]
		 call	SetScrollRange,[hwnd],SB_VERT, \
				0,[ebx + sbinfo.sbpos],[ebx + sbinfo.sbheight],1
                call    InvalidateRect,[hwnd],0,0,0,0
		ret
SetBarRanges ENDP
end