Gui, Add, Text, HwndMyTextHwnd, Here is some text that is

Question

Gui, Add, Text, HwndMyTextHwnd, Here is some text that is

given`na custom background color.
Gui +LastFound
Gui Show

SetWindowLong := A_PtrSize = 8 ? "SetWindowLongPtr" : "SetWindowLong"

GuiHwnd := WinExist("ahk_exe notepad.exe")
;GuiHwnd := WinExist()
MsgBox, GuiHwnd: %GuiHwnd%
WindowProcNew := RegisterCallback("WindowProc", "", 4, MyTextHwnd)
WindowProcOld := DllCall(SetWindowLong, Ptr, GuiHwnd, Int, -4, Ptr, WindowProcNew, Ptr)

return

WindowProc(hwnd, uMsg, wParam, lParam) {
global
Critical
ToolTip WindowProc: hwnd: %hwnd% uMsg: %uMsg% wParam: %wParam%
return DllCall("CallWindowProc", Ptr, WindowProcOld, Ptr, hwnd, UInt, uMsg, Ptr, wParam, Ptr, lParam)
}

GuiClose:
ExitApp