How can I detect focus lost in mintty under Cygwin?

Question

Does mintty under Cygwin in any way support the events of losing and gaining focus?

I'm looking for the equivalent of WM_KILLFOCUS from Windows or autocmd FocusLost * call ... from gvim, but under Cygwin within the mintty terminal.

Answer 1

Provided there was no actual answer after a few days, I'm providing my own, thanks to @Philippe's comment about GetForegroundWindow.

/* wait-focus-lost.cc */
#include <iostream>
#include <windows.h>

int main()
{
    const HWND initial_window = GetForegroundWindow();
    HWND current_window;
    while ((current_window = GetForegroundWindow()) == initial_window)
        Sleep(1);
    const auto title = new wchar_t[MAX_PATH*2];
    GetWindowTextW(current_window, title, MAX_PATH*2);
    std::wcout << title << std::endl;
}

^{Disclaimer: no error checking in above code}

This piece of code waits until the foreground window changes and prints out the title of the new foreground window to the mintty console.

I can now use this executable in a bash script to wait before executing another action that depends on focus being stolen.

---

Since my environment is Cygwin, I'm providing the Makefile in case someone comes along and tries to compile the above on their own:

CXX = x86_64-w64-mingw32-g++
CC = x86_64-w64-mingw32-gcc
LDFLAGS = -static
CXXFLAGS = -O2 -Wall -Wextra

all: wait-focus-lost.exe
wait-focus-lost.exe: wait-focus-lost

^{NB: Because of the .exe extension, the extra rule is needed under Cygwin to leverage both make implicit rules and dependency checking. Using just all: wait-focus-lost works for compilation, but breaks dependency checking.}