Mouse Wheel Emulator

How many people out there are stuck with a laptop with no scroll wheel, or an old but comfortable two-button mouse they refuse to let go? Here's a treat for you.

This script combines the functionality of TheGood's AHKHID and ManaUser's MakeChord libraries to provide emulated middle-click and scroll wheel abilities to users of mice, trackpads and trackballs without a scroll wheel.

I've included this script, along with the necessary AHK libraries in the ZIP file linked above. Extract all 3 files to the same folder and run MouseWheelEmulator.ahk. You can also use AHK's script compiler to make an EXE out of it that you can run from any folder without the library dependencies.

For more information and instructions see the comments in the script. Enjoy!

;; MouseWheelEmulator.ahk



/*



MouseWheelEmulator

Created by Blahman (blah238 at gmail dot com)

v1.0

10/18/2009



Summary: This script combines the functionality of TheGood's AHKHID and ManaUser's MakeChord libraries to provide emulated middle-click and scroll wheel abilities to users of mice, trackpads and trackballs without a scroll wheel.



Features:

-Allows middle clicks and mouse wheel scrolling to be performed on hardware without a physical scroll wheel

-Freezes the mouse cursor in place during virtual mouse wheel scrolling

-Sends scroll wheel messages to window or control under cursor, not just the active window (in supported applications; see note about different scroll modes below)



Installation:

1) Download the AHKHID and MakeChord libraries and place the AHKHID.ahk and MakeChord.ahk files in the same folder as this script.

AHKHID: http://www.autohotkey.com/forum/topic41397.html

MakeChord (just the second half that starts with the MakeChord() function): http://www.autohotkey.com/forum/topic44399.html

2) Run this script.



Usage:

By default there are two ways to activate a middle click or scroll the virtual mouse wheel:

To perform middle-click:

Click the left and right mouse buttons simultaneously (often referred to as "chording").

-or-

Hold Alt and right click.



To scroll the virtual mouse wheel:

Click and hold the left and right mouse buttons simultaneously and move the mouse in the direction you wish to scroll.

-or-

Hold Alt, click and hold the right mouse button, and move the mouse in the direction you wish to scroll.



Note: If you need to terminate the script you can use Ctrl-Alt-Break.



About the different scroll modes:

There are several different ways that any given program may implement mouse scrolling. AHK has built-in WheelUp and WheelDown functions, but not all applications respond to them.

Some applications respond to WM_VSCROLL/WM_HSCROLL messages, while others respond to WM_MOUSEWHEEL/WM_HSCROLL messages.

If you find an application you use doesn't work with this script out of the box, you can probably fix it yourself by adding that application's process name to the conditional statements in the GetScrollMode() function.

The default scroll mode, 0, is AHK's built-in WheelUp and WheelDown commands. This does not support horizontal scrolling or scrolling the window or control under the cursor, while the other two modes do.

Some applications respond to more than one scroll mode, so you can try them all and decide which works best for you.

Finally, to further muddy the waters, some applications have frames within them that respond to scroll messages differently to the rest of the application. An example of this is the AHK help file, which uses the Internet Explorer_Server1 control to display HTML pages in one frame, and standard Windows controls to display the table of contents, index, etc. in another frame, and each responds to different scroll modes. I have tried to account for this in the GetScrollMode() function as well, but there may be other implementations I have not covered. You can use AHK's Window Spy to determine the name of the non-conforming control and write an exception for it, similar to the examples I have provided.



*/



;; Configuration



mouse_Threshold = 3 ; the number of pixels the mouse must move for a scroll tick to occur

MakeChord("LButton", "RButton", "scrollChord", 20) ; Chord to activate middle click or scrolling. See MakeChord.ahk for instructions

scroll_Hotkey = !RButton ; Hotkey to activate middle click or scrolling



;; End Configuration



#SingleInstance Force

#NoEnv

#Persistent

SendMode Input

Process, Priority, , Realtime

#Include %A_ScriptDir%\AHKHID.ahk



;Create GUI to receive messages

Gui, +LastFound

hGui := WinExist()



;Intercept WM_INPUT messages

OnMessage(0x00FF, "InputMsg")



SetDefaultMouseSpeed, 0

scrollMode = 0 ; 0 = MouseClick, WheelUp/WheelDown, 1 = WM_VSCROLL/WM_HSCROLL, 2 = WM_MOUSEWHEEL/WM_HSCROLL

CoordMode, Mouse, Screen





HotKey, %scroll_Hotkey%, scrollChord

HotKey, %scroll_Hotkey% Up, scrollChord_Up

return



scrollChord:

mouse_Moved = n

BlockInput, MouseMove

MouseGetPos, m_x, m_y, winID, control

WinGet, procName, ProcessName, ahk_id %winID%

hw_m_target := DllCall( "WindowFromPoint", "int", m_x, "int", m_y )

GetScrollMode()

HID_Register(1, 2, hGui, RIDEV_INPUTSINK)

return



scrollChord_Up:

ToolTip

BlockInput, MouseMoveOff

HID_Register(1,2,0,RIDEV_REMOVE)

if mouse_Moved = n

MouseClick, Middle

return



InputMsg(wParam, lParam) {

local x, y

Critical



x := HID_GetInputInfo(lParam, II_MSE_LASTX)

y := HID_GetInputInfo(lParam, II_MSE_LASTY)

If ((Abs(x) > 0.0) or (Abs(y) > 0.0))

mouse_Moved = y

if y > %mouse_Threshold%

{

ScrollDown()

}

else if y < -%mouse_Threshold%

ScrollUp()

if x > %mouse_Threshold%

{

ScrollRight()

}

else if x < -%mouse_Threshold%

ScrollLeft()

;ToolTip, % "dX = " . x . " " . "dY = " . y . a_tab . winID . a_tab . control . a_tab . procName . a_tab . hw_m_target . a_tab . scrollMode

;; Uncomment the above line for handy debug info shown while scrolling

}



GetScrollMode()

{

global

local ctl_x, ctl_y, ctl_w, ctl_h, ctl_hwnd, win_x, win_y

if (procName = "hh.exe" or procName = "iexplore.exe" or procName = "dexplore.exe" or procName = "OUTLOOK.EXE")

{

scrollMode = 1

WinGetPos, win_x, win_y, , , ahk_id %WinID%

ControlGetPos, ctl_x, ctl_y, ctl_w, ctl_h, Internet Explorer_Server1, ahk_id %WinID%

if (((m_x >= win_x + ctl_x) and (m_x <= win_x + ctl_x + ctl_w)) and ((m_y >= win_y + ctl_y) and (m_y <= win_y + ctl_y + ctl_h)))

control = Internet Explorer_Server1

else

{

ControlGetPos, ctl_x, ctl_y, ctl_w, ctl_h, NETUIHWND1, ahk_id %WinID%

if (((m_x >= win_x + ctl_x) and (m_x <= win_x + ctl_x + ctl_w)) and ((m_y >= win_y + ctl_y) and (m_y <= win_y + ctl_y + ctl_h)))

scrollMode = 2

}

}

else if (procName = "firefox.exe" or procName = "notepad.exe" or procName = "explorer.exe" or procName = "EXCEL.exe")

scrollMode = 2

else

scrollMode = 0

return

}



ScrollDown()

{

global

if (scrollMode = 0)

MouseClick, WheelDown

else if (scrollMode = 1)

PostMessage, 0x115, 1, 0, %control%, ahk_id %winID%

else

{

; WM_MOUSEWHEEL

; WHEEL_DELTA = 120

PostMessage, 0x20A, -120 << 16, ( m_y << 16 )|m_x,, ahk_id %hw_m_target%

}

}



ScrollUp()

{

global

if (scrollMode = 0)

MouseClick, WheelUp

else if (scrollMode = 1)

{

PostMessage, 0x115, 0, 0, %control%, ahk_id %winID%

}

else if (scrollMode = 2)

{

; WM_MOUSEWHEEL

; WHEEL_DELTA = 120

PostMessage, 0x20A, 120 << 16, ( m_y << 16 )|m_x,, ahk_id %hw_m_target%

}

}



ScrollRight()

{

global

if (scrollMode <> 0)

loop, 2

SendMessage, 0x114, 1, 0, %control%, ahk_id %winID%

}



ScrollLeft()

{

global

if (scrollMode <> 0)

loop, 2

SendMessage, 0x114, 0, 0, %control%, ahk_id %winID%

}



^!CtrlBreak::ExitApp



#Include %A_ScriptDir%\MakeChord.ahk

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