commit d7a68c165d5139497523a67559c0e1f4df9efd50
Author:     Jonathan Dowland <jon+github@alcopop.org>
AuthorDate: Thu Apr 7 08:11:32 2016 +0100
Commit:     Jonathan Dowland <jon+github@alcopop.org>
CommitDate: Fri Apr 8 14:06:31 2016 +0100

    [sdl2-branch] toggle fullscreen with cmd+enter

    This morning's breakfast coding...

    Special-case listen for LGUI/RGUI + enter (which is Command on Mac;
    Windows key on Windows; Meta or whatever on Linux) and toggle
    fullscreen.

    On Mac, when you are fullscreen-via-maximize-button, if you push the mouse
    pointer to the top edge, the titlebar scrolls down and you could click to
    de-maximize. This does not happen if you are fullscreen-via-shortcut. I
    think this might be an SDL2 bug or quirk.
---
 src/i_video.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/i_video.c b/src/i_video.c
index c0fd78db..cc7c8331 100644
--- a/src/i_video.c
+++ b/src/i_video.c
@@ -318,6 +318,12 @@ static void HandleWindowEvent(SDL_WindowEvent *event)
     }
 }

+static void I_ToggleFullScreen(void)
+{
+    Uint32 flags = SDL_GetWindowFlags(screen) & SDL_WINDOW_FULLSCREEN_DESKTOP;
+    SDL_SetWindowFullscreen(screen, flags ^ SDL_WINDOW_FULLSCREEN_DESKTOP);
+}
+
 void I_GetEvent(void)
 {
     extern void I_HandleKeyboardEvent(SDL_Event *sdlevent);
@@ -331,6 +337,14 @@ void I_GetEvent(void)
         switch (sdlevent.type)
         {
             case SDL_KEYDOWN:
+                if (sdlevent.key.keysym.scancode == SDL_SCANCODE_RETURN &&
+                    sdlevent.key.keysym.mod & (KMOD_LGUI | KMOD_RGUI))
+                {
+                    I_ToggleFullScreen();
+                    break;
+                }
+                // deliberate fall-though
+
             case SDL_KEYUP:
 		I_HandleKeyboardEvent(&sdlevent);
                 break;