#SingleInstance Force
#Persistent
#NoEnv 
SetBatchLines -1 

pToken := Gdip_Startup()

GuiWidth := A_ScreenWidth
GuiHeight := A_ScreenHeight
Width := GuiWidth // 2
Height := GuiHeight

OnExit, Exit 

Gui, -Caption +E0x80000 +AlwaysOnTop +ToolWindow +OwnDialogs +HWNDhGui 
Gui, Show, NA

hbm := CreateDIBSection(GuiWidth, GuiHeight)
hdc := CreateCompatibleDC()
obm := SelectObject(hdc, hbm)
pGraphics := Gdip_GraphicsFromHDC(hdc)
Gdip_SetSmoothingMode(pGraphics, 4)
Return  

Esc:: ExitApp

f1::
	obj := StrSplit(Explorer_GetSelected(), "`n")  
	If (obj.Count() != 2)
		Return
		
	Gdip_GraphicsClear(pGraphics, 0xff000000) 
	Loop 2
	{
		pBitmap := Gdip_CreateBitmapFromFile(obj[A_Index])
		Gdip_GetImageDimensions(pBitmap, PicWidth, PicHeight) 
		StretchToFit(Width, Height, PicHeight / PicWidth, ChildX, ChildY, ChildWidth, ChildHeight)
		Gdip_DrawImage(pGraphics, pBitmap, ChildX + ((A_Index - 1) * Width), ChildY, ChildWidth, ChildHeight, 0, 0, PicWidth, PicHeight)
		Gdip_DisposeImage(pBitmap)
	}
	UpdateLayeredWindow(hGui, hdc, 0, 0, GuiWidth, GuiHeight)
	KeyWait, % A_ThisHotkey
	Gui, Show, NA w0 h0
	Return

Exit: 
	SelectObject(hdc, obm) 
	DeleteObject(hbm) 
	DeleteDC(hdc)
	Gdip_DeleteGraphics(pGraphics)
	Gdip_Shutdown(pToken)
	ExitApp

StretchToFit(ParentWidth, ParentHeight, ChildRatioHW, ByRef ChildX, ByRef ChildY, ByRef ChildWidth, ByRef ChildHeight) {
	If (ParentHeight / ParentWidth > ChildRatioHW)
		ChildWidth := ParentWidth, ChildHeight := ChildWidth * ChildRatioHW, ChildX := 0, ChildY := (ParentHeight - ChildHeight) / 2
	Else
		ChildHeight := ParentHeight, ChildWidth := ChildHeight / ChildRatioHW, ChildX := (ParentWidth - ChildWidth) / 2, ChildY := 0
} 

/*
	Library for getting info from a specific explorer window (if window handle not specified, the currently active
	window will be used).  Requires AHK_L or similar.  Works with the desktop.  Does not currently work with save
	dialogs and such.
	
	
	Explorer_GetSelected(hwnd="")   - paths of target window's selected items
	Explorer_GetAll(hwnd="")        - paths of all items in the target window's folder
	Explorer_GetPath(hwnd="")       - path of target window's folder
	
	example:
		F1::
			path := Explorer_GetPath()
			all := Explorer_GetAll()
			sel := Explorer_GetSelected()
			MsgBox % path
			MsgBox % all
			MsgBox % sel
		return
	
	Joshua A. Kinnison
	2011-04-27, 16:12
	http://www.autohotkey.com/board/topic/60985-get-paths-of-selected-items-in-an-explorer-window/
*/

Explorer_GetPath(hwnd="")
{
	if !(window := Explorer_GetWindow(hwnd))
		return ErrorLevel := "ERROR"
	if (window="desktop")
		return A_Desktop
	path := window.LocationURL
	path := RegExReplace(path, "ftp://.*@","ftp://")
	StringReplace, path, path, file:///
	StringReplace, path, path, /, \, All 
	
	; thanks to polyethene
	Loop
		If RegExMatch(path, "i)(?<=%)[\da-f]{1,2}", hex)
			StringReplace, path, path, `%%hex%, % Chr("0x" . hex), All
		Else Break
	return path
}
Explorer_GetAll(hwnd="")
{
	return Explorer_Get(hwnd)
}
Explorer_GetSelected(hwnd="")
{
	return Explorer_Get(hwnd,true)
}

Explorer_GetWindow(hwnd="")
{
	; thanks to jethrow for some pointers here
    WinGet, process, processName, % "ahk_id" hwnd := hwnd? hwnd:WinExist("A")
    WinGetClass class, ahk_id %hwnd%
	
	if (process!="explorer.exe")
		return
	if (class ~= "(Cabinet|Explore)WClass")
	{
		for window in ComObjCreate("Shell.Application").Windows
			if (window.hwnd==hwnd)
				return window
	}
	else if (class ~= "Progman|WorkerW") 
		return "desktop" ; desktop found
}
Explorer_Get(hwnd="",selection=false)
{
	if !(window := Explorer_GetWindow(hwnd))
		return ErrorLevel := "ERROR"
	if (window="desktop")
	{ 
		if selection
			ret := Explorer_GetSelectedDesktop() 
		else 
		{
			ControlGet, hwWindow, HWND,, SysListView321, ahk_class Progman
			if !hwWindow ; #D mode
				ControlGet, hwWindow, HWND,, SysListView321, A
			ControlGet, files, List, % ( selection ? "Selected":"") "Col1",,ahk_id %hwWindow%
			base := SubStr(A_Desktop,0,1)=="\" ? SubStr(A_Desktop,1,-1) : A_Desktop
			Loop, Parse, files, `n, `r
			{
				path := base "\" A_LoopField
				IfExist %path% ; ignore special icons like Computer (at least for now)
					ret .= path "`n"
			}
		}
	} 
	else
	{
		if selection
			collection := window.document.SelectedItems
		else
			collection := window.document.Folder.Items
		for item in collection
			ret .= item.path "`n"
	}
	return Trim(ret,"`n")
}
 
    ; http://forum.script-coding.com/viewtopic.php?pid=83582#p83582

Explorer_GetSelectedDesktop()
{
	shellWindows := ComObjCreate("{9BA05972-F6A8-11CF-A442-00A0C90A8F39}")
	
	desktop := shellWindows.Item(ComObj(19, 8))  
	if ptlb := ComObjQuery(desktop
		, "{4C96BE40-915C-11CF-99D3-00AA004AE837}"  ; SID_STopLevelBrowser
		, "{000214E2-0000-0000-C000-000000000046}") ; IID_IShellBrowser
	{ 
		if DllCall(NumGet(NumGet(ptlb+0)+15*A_PtrSize), "ptr", ptlb, "ptr*", psv:=0) = 0
		{ 
			VarSetCapacity(IID_IDispatch, 16)
			NumPut(0x46000000000000C0, NumPut(0x20400, IID_IDispatch, "int64"), "int64") 
			DllCall(NumGet(NumGet(psv+0)+15*A_PtrSize), "ptr", psv
				, "uint", 0, "ptr", &IID_IDispatch, "ptr*", pdisp:=0)
			
			Items := ComObjEnwrap(pdisp).SelectedItems()
			Loop, % Items.Count
				ret .= Items.Item(A_Index - 1).Path "`n" 
			ObjRelease(psv)
		}
		ObjRelease(ptlb)
	}
	return Trim(ret,"`n")
}