Borderless window mode which cleans up after itself

F11-Fullscreen.ahk

;;; Known issues:
;;;
;;; - Weird results for windows with custom decorations such as
;;; Chrome, or programs with a Ribbon interface.
;;; - Emacs will be maximized behind instead of in front of
;;; the taskbar. Workaround: WinHide ahk_class Shell_TrayWnd

global id2undoer := Object()

#SingleInstance force

; #notrayicon ; uncomment if you don't want an H in you tasktray

#Warn All
#NoEnv

Class Undoer {
	__New(id) {
		;MsgBox "In __New, id is ", %id%
		this.id := id
		WinGet, s, Style, A
		this.s := s
		WinGetPos, x, y, w, h, ahk_id %id%
		this.x := x, this.y := y, this.w := w, this.h := h
		return this
	}
	
	; Originally, this was __Delete, but sadly, it
	; does not get called when I wanted it to.
	Undo() {
		id := this.id
		;MsgBox, "In Undo, id is ", %id%
		s := this.s
		WinSet, Style, %s%, ahk_id %id%
		x := this.x, y := this.y, w := this.w, h := this.h
		WinMove, ahk_id %id%,, %x%, %y%, %w%, %h%
	}
}

ToggleFakeFullscreen()
{
	CoordMode Screen, Window
	static UNDECORATED := -0xC40000
	WinGet, id, ID, A
	if ( id2undoer.HasKey(id) )
	{
		id2undoer[id].Undo()
		id2undoer.Delete(id)
	}
	else
	{
		id2undoer[id] := new Undoer(id)
		
		WinSet, Style, %UNDECORATED%, ahk_id %id%
		SysGet, mon, Monitor, % GetMonitorActiveWindow()
		
		WinMove, A,, %monLeft%, %monTop%, % monRight-monLeft, % monBottom-monTop
	}
}

GetMonitorAtPos(x,y)
{
	;; Monitor number at position x,y or -1 if x,y outside monitors.
	SysGet monitorCount, MonitorCount
	i := 0
	while(i < monitorCount)
	{
		SysGet area, Monitor, %i%
		if ( areaLeft <= x && x <= areaRight && areaTop <= y && y <= areaBottom )
		{
			return i
		}
		msgbox "x", x, "L", areaLeft, "R", areaRight
		msgbox "y", y, "T", areaTop, "B", areaBottom
		i := i+1
	}
	msgbox "fallthrough"
	return -1
}

GetMonitorActiveWindow(){
	;; Get Monitor number at the center position of the Active window.
	WinGetPos x,y,width,height, A
	return GetMonitorAtPos(x+width/2, y+height/2)
}

MyOnExit(){
	for id, info in id2undoer {
		info.Undo()
	}
	id2undoer := Object()
	return 0
}

OnExit( "MyOnExit", 1 )

; Set up hot keys so that either alt-f11 or win-f11 will
; Toggle whether a program is in borderless windowed mode,

!F11::ToggleFakeFullscreen()
#F11::ToggleFakeFullscreen()

; And a hot key so that typing alt-win-f11 or win-alt-f11
; will cause this autohotkey script to exit.

!#F11::ExitApp