Alt+Tab with Grabbed Mouse

1#include <SDL.h>
2#include <iostream>
3
4void HandleWindowEvent(
5  SDL_WindowEvent& E, SDL_Window* Window) {
6  switch (E.event) {
7    case SDL_WINDOWEVENT_FOCUS_LOST:
8      // Window lost focus (e.g., through Alt+Tab)
9      SDL_SetWindowMouseGrab(Window, SDL_FALSE);
10      std::cout << "Released mouse grab "
11        "- lost focus\n";
12      break;
13
14    case SDL_WINDOWEVENT_FOCUS_GAINED:
15      // Window regained focus
16      SDL_SetWindowMouseGrab(Window, SDL_TRUE);
17      std::cout << "Restored mouse grab "
18        "- gained focus\n";
19      break;
20  }
21}
22
23int main(int argc, char** argv) {
24  SDL_Init(SDL_INIT_VIDEO);
25  SDL_Window* Window{SDL_CreateWindow(
26    "Mouse Grab Example",
27    100, 100, 800, 600,
28    SDL_WINDOW_SHOWN
29  )};
30
31  bool quit{false};
32  SDL_Event E;
33
34  // Initially grab the mouse
35  SDL_SetWindowMouseGrab(Window, SDL_TRUE);
36
37  while (!quit) {
38    while (SDL_PollEvent(&E)) {
39      if (E.type == SDL_QUIT) {
40        quit = true;
41      } else if (E.type == SDL_WINDOWEVENT) {
42        HandleWindowEvent(E.window, Window);
43      }
44    }
45  }
46
47  SDL_DestroyWindow(Window);
48  SDL_Quit();
49  return 0;
50}