Automatic keyboard layout change on window focus using AutoHotkey

AutoKeyboardLayout.ahk

; How to use:
; 1. Install AuthotKey: https://www.autohotkey.com
; 2. Save this script in `My Documents`
; 3. Create a shortcut in the Startup folder (`Win`+`R`, `shell:startup`)
; 4. Change the configurations below
; 5. Start and test the script!

; Configuration

	; Cultures can be fetched from here: https://msdn.microsoft.com/en-us/library/windows/desktop/dd318693(v=vs.85).aspx
	; They must be set twice in the language ID;
	;   en-US: 0x04090409
	;   fr-CA: 0x0C0C0C0C

global DefaultLanguage := "fr-CA"
global DefaultLanguageIndentifier := "0x0C0C0C0C"
global SecondaryLanguage := "en-US"
global SecondaryLanguageIndentifier := "0x04090409"
global SecondaryLanguageWindowTitles := "VIM,Visual Studio,PowerShell,cmd.exe,ConEmu"

; And the code itself (you should not have to change this)

Gui +LastFound 
hWnd := WinExist()
DllCall( "RegisterShellHookWindow", UInt,Hwnd )
MsgNum := DllCall( "RegisterWindowMessage", Str,"SHELLHOOK" )
OnMessage( MsgNum, "ShellMessage" )
Return

ShellMessage( wParam,lParam )
{
 WinGetTitle, title, ahk_id %lParam%
; 4 is HSHELL_WINDOWACTIVATED, 32772 is HSHELL_RUDEAPPACTIVATED
 If (wParam=4 || wParam=32772) {
	If title contains %SecondaryLanguageWindowTitles%
		SetKeyboard( title, SecondaryLanguage )
	Else
		SetKeyboard( title, DefaultLanguage )
 }
}

SetKeyboard( title, culture )
{
	; 0x50 is WM_INPUTLANGCHANGEREQUEST.
	Try
	{
		If (culture = SecondaryLanguage)
		{
			PostMessage, 0x50, 0, %SecondaryLanguageIndentifier%,, A
			; To debug:
			; ToolTip, Using secondary language %SecondaryLanguage%
			; Sleep 1000
			; ToolTip
		}
		Else If (culture = DefaultLanguage)
		{
			PostMessage, 0x50, 0, %DefaultLanguageIndentifier%,, A
			; To debug:
			; ToolTip, Using default language %DefaultLanguage%
			; Sleep 1000
			; ToolTip
		}
		Else
		{
			; To debug:
			; ToolTip, Unknown culture: %culture%
			; Sleep 1000
			; ToolTip
		}
	}
	Catch e
	{
		ToolTip, Could not switch to %culture%`n%e%
		Sleep 1000
		ToolTip
	}
}

Thank you!

Works great thanks! I had to dig a bit deeper than that link to get the Language Identifiers, here's the link: https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-lcid/70feba9f-294e-491e-b6eb-56532684c37f

I'm not maintaining this anymore but I'll gladly include contributions :)

You should find this information in AHK's docs: https://www.autohotkey.com/docs/v2/

And I'm overwhelmed by projects and life :) Sorry, you'll need to figure this one out. <3