程式語言 - Wine - Assembly (ARM 32) - Set Scrollbar

參考資訊：
http://www.winprog.org/tutorial/
http://winapi.freetechsecrets.com/win32/
https://github.com/gammasoft71/Examples_Win32
http://masm32.com/board/index.php?topic=3584.0
https://learn.microsoft.com/en-us/windows/win32/winmsg/window-styles

當視窗的可視區域(如：300x300像素)小於顯示圖片大小(如：640x480像素)時，這時可以使用Windows視窗元件Scrollbar，用來做顯示位置調整的動作，Scrollbar元件有垂直和水平兩種方向並且提供視窗事件回報機制(WM_VSCROLL、WM_HSCROLL)，因此，這裡的Scrollbar元件並不能夠自動幫忙做顯示位置調整的動作，取而代之的是，在收到WM_VSCROLL、WM_HSCROLL事件時，使用者必須自己決定哪些東西要顯示在視窗的可視區域上

main.s

    .include "head.inc"
  
    .text
WndProc:
    push { r4, lr }
    mov r4, #WM_VSCROLL
    cmp r1, r4
    beq handle_vscroll
    cmp r1, #WM_CLOSE
    beq handle_close
    cmp r1, #WM_DESTROY
    beq handle_destroy
    b handle_default
 
handle_vscroll:
    mov r4, #0xffff
    and r2, r2, r4
    cmp r2, #SB_LINEUP
    beq handle_sb_line_up
    cmp r2, #SB_LINEDOWN
    beq handle_sb_line_down
    cmp r2, #SB_PAGEUP
    beq handle_sb_page_up
    cmp r2, #SB_PAGEDOWN
    beq handle_sb_page_down
    b finish

handle_sb_line_up:
    ldr r1, =SLUP
    bl SetWindowTextA
    b finish
 
handle_sb_line_down:
    ldr r1, =SLDN
    bl SetWindowTextA
    b finish
 
handle_sb_page_up:
    ldr r1, =SPUP
    bl SetWindowTextA
    b finish
 
handle_sb_page_down:
    ldr r1, =SPDN
    bl SetWindowTextA
    b finish

handle_close:
    bl DestroyWindow
    eor r0, r0
    b finish
  
handle_destroy:
    ldr r0, =0
    bl PostQuitMessage
    eor r0, r0
    b finish
  
handle_default:
    push { r3 }
    mov r3, r2
    mov r2, r1
    mov r1, r0
    ldr r0, =pDefWndProc
    ldr r0, [r0]
    bl CallWindowProcA
    add sp, sp, #4
    b finish
  
finish:
    pop { r4, pc }
  
WinMain:
    push { lr }
  
    ldr r3, =0
    ldr r2, =0
    ldr r1, =0
    ldr r0, =0
    push { r0, r1, r2, r3 }
    ldr r3, =300
    ldr r2, =300
    ldr r1, =0
    ldr r0, =0
    push { r0, r1, r2, r3 }
    ldr r3, =WS_OVERLAPPEDWINDOW | WS_VISIBLE | WS_VSCROLL
    ldr r2, =szAppName
    ldr r1, =WC_DIALOG
    ldr r0, =WS_EX_LEFT
    bl CreateWindowExA
    add sp, sp, #32
    ldr r1, =hWin
    str r0, [r1]
  
    ldr r2, =WndProc
    ldr r1, =GWL_WNDPROC
    bl SetWindowLongA
    ldr r1, =pDefWndProc
    str r0, [r1]

    mov r0, #0
    push { r0 }
    mov r3, #100
    mov r2, #0
    mov r1, #SB_VERT
    ldr r0, =hWin
    ldr r0, [r0]
    bl SetScrollRange
    add sp, sp, #4

    mov r3, #1
    mov r2, #50
    mov r1, #SB_VERT
    ldr r0, =hWin
    ldr r0, [r0]
    bl SetScrollPos

loop:
    ldr r3, =0
    ldr r2, =0
    ldr r1, =0
    ldr r0, =szMsg
    bl GetMessageA
  
    cmp r0, #0
    beq exit
    
    ldr r0, =szMsg
    bl DispatchMessageA
    b loop
  
exit:
    mov r0, #0
    bl ExitProcess
   
    pop { pc }

Line 15~46：處理Scrollbar訊息並且顯示在視窗標題
Line 86：WS_VSCROLL是垂直的Scrollbar，WS_HSCROLL則是水平的Scrollbar
Line 101~108：設定Scrollbar最大的範圍
Line 111~116：設定Scrollbar目前的位置

編譯、執行

$ winegcc main.s -o main
$ wine ./main.exe