Configure the Zoom key to do a page up / page down

Microsoft_Zoom_In_Out_4000_Keyboard.ahk

;~ https://autohotkey.com/board/topic/36304-hidextended-input-devices-ms-natural-keyboard-4000-etc/page-2
; Capture input from the "Zoom" slider on the Natural Keyboard 4000  and use it to scroll up and scroll down
; The HID top level collection for the Natural Keyboard 4000 is:;   Usage 1 ; Usage Page   12
;~ #NoTrayIcon
#SingleInstance force ; Replace any previous instance

DetectHiddenWindows, on
OnMessage(0x00FF, "InputMessage")
SizeofRawInputDeviceList := 8, SizeofRidDeviceInfo := 32, RIM_TYPEMOUSE := 0, RIM_TYPEKEYBOARD := 1, RIM_TYPEHID := 2, RIDI_DEVICENAME := 0x20000007
RIDI_DEVICEINFO := 0x2000000b, RIDEV_INPUTSINK := 0x00000100, RID_INPUT := 0x10000003, Usage := 1, UsagePage := 12

Gui, Show, Hide, NaturalCapture
HWND := WinExist("NaturalCapture")

; Keyboards are always Usage 6, Usage Page 1, Mice are Usage 2, Usage Page 1, HID devices specify their top level collection in the info block   
VarSetCapacity(RawDevice, 12),NumPut(RIDEV_INPUTSINK, RawDevice, 4),NumPut(HWND, RawDevice, 8),NumPut(UsagePage, RawDevice, 0, "UShort"),NumPut(Usage, RawDevice, 2, "UShort")     

Res := DllCall("RegisterRawInputDevices", "UInt", &RawDevice, UInt, 1, UInt, 12)
if (Res = 0)
	MsgBox, Failed to register for Natural Keyboard

InputMessage(wParam, lParam, msg, hwnd){
	global DoCapture, RIM_TYPEMOUSE, RIM_TYPEKEYBOARD, RIM_TYPEHID, RID_INPUT
	if (DoCapture = 0)
		return
	
	Res := DllCall("GetRawInputData", UInt, lParam, UInt, RID_INPUT, UInt, 0, "UInt *", Size, UInt, 16),VarSetCapacity(Buffer, Size)
	Res := DllCall("GetRawInputData", UInt, lParam, UInt, RID_INPUT, UInt, &Buffer, "UInt *", Size, UInt, 16)
	Type := NumGet(Buffer, 0 * 4),Size := NumGet(Buffer, 1 * 4), Handle := NumGet(Buffer, 2 * 4) 
	
	if (Type = RIM_TYPEHID){
		SizeHid := NumGet(Buffer, (16 + 0)),InputCount := NumGet(Buffer, (16 + 4))  
		Loop %InputCount% {
			Addr := &Buffer + 24 + ((A_Index - 1) * SizeHid),	BAddr := &Buffer ,Input := Mem2Hex(Addr, SizeHid)
			if (IsLabel(Input)) 
				Gosub, %Input%
		}
	}
	return
}
return

DoScroll:
ControlGetFocus, fcontrol, A ; WM_VSCROLL = 0x115, SB_LINEUP = 0, SB_LINEDOWN = 1
;********************What to do...***********************************
if (ScrollDir = 1) { ;If zoom is up
	Send {PgUp}	;Scrolling up	
}else{ ;If Zoom is down
	Send {PgDn}  ;Scrolling down
}
Return

012E020000010000: ; Zoom down
ScrollDir := 2
GoSub, DoScroll
SetTimer, DoScroll, 1080
return

012D020000010000: ; Zoom up
ScrollDir := 1
GoSub, DoScroll
SetTimer, DoScroll, 1080
return

0100000000010000: ; All up
ScrollDir := 0
SetTimer, DoScroll, Off
return

Mem2Hex( pointer, len ){
	A_FI := A_FormatInteger
	SetFormat, Integer, Hex
	Loop, %len%  {
		Hex := *Pointer+0
		StringReplace, Hex, Hex, 0x, 0x0
		StringRight Hex, Hex, 2           
		hexDump := hexDump . hex
		Pointer ++
	}
	SetFormat, Integer, %A_FI%
	StringUpper, hexDump, hexDump
	Return hexDump
}