SDL2 window sometimes fails to gain input focus on macOS at startup

[ffbh123456]

On macOS, an SDL2 window usually (75%+) gains input focus and receives mouse and keyboard input automatically at startup. However, occasionally it does not, and only receives events after being minimized and restored. In those cases, clicking the window cannot give it focus.

Platform: macOS[13.2], SDL2 [2.32.8]

SDL_Window* CreateWindow()
{
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTS)) {
        return nullptr;
    }

    SDL_Window* window = SDL_CreateWindow(
        "MyApp",
        SDL_WINDOWPOS_CENTERED,
        SDL_WINDOWPOS_CENTERED,
        960, 540,
        SDL_WINDOW_VULKAN | SDL_WINDOW_SHOWN | SDL_WINDOW_ALLOW_HIGHDPI
    );

    if (!window) {
        SDL_Quit();
        return nullptr;
    }

    SDL_RaiseWindow(window);
    SDL_SetWindowInputFocus(window);

    return window;
}

[slouken]

Are you seeing this with SDL3 as well?

[ffbh123456]

A few months ago, I tried SDL3 (3.2.18) but couldn’t get mouse or keyboard input to work, which is why I’m using SDL2 for now. At the time, I hadn’t tried the minimize-and-restore solution, so it might have been the same issue. Will try the latest SDL3 when I have time, though it probably won’t be very soon.

[goblinhack]

same issue on mac - SDL_WINDOW_ALWAYS_ON_TOP seemed to make it happen less often - but still does. Does that help your case a bit? (SDL2)

[icculus]

(Assigning to myself, but I'm not likely to get to this for SDL2 for awhile. If someone says this is happening in SDL3 also, though, it goes to the top of the queue.)

[goblinhack]

I noticed it happens when I move the mouse whilst starting the game. Possibly iTerm2 steals the focus while the game is starting.

[icculus]

This is possibly fixed by b2c3e6f, which should be in 2.32.10. If anyone can upgrade and verify, I'd appreciate it.

[goblinhack]

Alas, for me I'm on 2.32.10 already. I have a workaround, check if SDL_GetKeyboardFocus is null and if so, restart the program :) Not a great workaround I'll admit. I tried quitting the SDL video/destroying the window, but on the mac these things don't seen to do anything w.r.t closing the window immediately. I'll try SDL3 at some point too

[ffbh123456]

I just upgraded to SDL3. I started and stopped my application about 10 times, and I didn’t encounter this issue. I’ll comment if I manage to reproduce it again.

However, I do have two other issues in SDL3.
#14107
#14108

[ffbh123456]

same issue on mac - SDL_WINDOW_ALWAYS_ON_TOP seemed to make it happen less often - but still does. Does that help your case a bit? (SDL2)

After creating this issue, it occurs very rarely (less than 5%) in SDL2. I can’t remember whether it was caused by my code changes or by upgrading to the newest SDL2. Also, I did not use SDL_WINDOW_ALWAYS_ON_TOP.

[ffbh123456]

@icculus
This issue still exists in the latest SDL3. Although it doesn’t occur very often, it works correctly most of the time (over 95%).

[kevinw]

Also seeing this issue in latest SDL3.