Add SDL_SetWindowAlwaysOnTop()

include/SDL_video.h

@@ -1010,6 +1010,21 @@ extern DECLSPEC void SDLCALL SDL_SetWindowBordered(SDL_Window * window,
 extern DECLSPEC void SDLCALL SDL_SetWindowResizable(SDL_Window * window,
                                                     SDL_bool resizable);
 
+/**
+ *  \brief Set the window to always be above the others.
+ *
+ *  This will add or remove the window's `SDL_WINDOW_ALWAYS_ON_TOP`
+ *  flag. This will bring the window to the front and keep the window above
+ *  the rest.
+ *
+ *  \param window The window of which to change the always on top state.
+ *  \param on_top  SDL_TRUE to set the window always on top, SDL_FALSE to disable.
+ *
+ *  \sa SDL_SetWindowAlwaysOnTop
+ */
+
+extern DECLSPEC void SDLCALL SDL_SetWindowAlwaysOnTop(SDL_Window * window,
+                                                      SDL_bool on_top);
 /**
  * Show a window.
  *

src/dynapi/SDL_dynapi_overrides.h

@@ -810,3 +810,4 @@
 #define SDL_AndroidShowToast SDL_AndroidShowToast_REAL
 #define SDL_GetAudioDeviceSpec SDL_GetAudioDeviceSpec_REAL
 #define SDL_TLSCleanup SDL_TLSCleanup_REAL
+#define SDL_SetWindowAlwaysOnTop SDL_SetWindowAlwaysOnTop_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -875,3 +875,4 @@ SDL_DYNAPI_PROC(int,SDL_AndroidShowToast,(const char *a, int b, int c, int d, in
 #endif
 SDL_DYNAPI_PROC(int,SDL_GetAudioDeviceSpec,(int a, int b, SDL_AudioSpec *c),(a,b,c),return)
 SDL_DYNAPI_PROC(void,SDL_TLSCleanup,(void),(),)
+SDL_DYNAPI_PROC(void,SDL_SetWindowAlwaysOnTop,(SDL_Window *a, SDL_bool b),(a,b),)

src/video/SDL_sysvideo.h

@@ -229,6 +229,7 @@ struct SDL_VideoDevice
     void (*RestoreWindow) (_THIS, SDL_Window * window);
     void (*SetWindowBordered) (_THIS, SDL_Window * window, SDL_bool bordered);
     void (*SetWindowResizable) (_THIS, SDL_Window * window, SDL_bool resizable);
+    void (*SetWindowAlwaysOnTop) (_THIS, SDL_Window * window, SDL_bool on_top);
     void (*SetWindowFullscreen) (_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen);
     int (*SetWindowGammaRamp) (_THIS, SDL_Window * window, const Uint16 * ramp);
     int (*GetWindowGammaRamp) (_THIS, SDL_Window * window, Uint16 * ramp);

src/video/SDL_video.c

@@ -2109,6 +2109,25 @@ SDL_SetWindowResizable(SDL_Window * window, SDL_bool resizable)
     }
 }
 
+void
+SDL_SetWindowAlwaysOnTop(SDL_Window * window, SDL_bool on_top)
+{
+    CHECK_WINDOW_MAGIC(window,);
+    if (!(window->flags & SDL_WINDOW_FULLSCREEN)) {
+        const int want = (on_top != SDL_FALSE);  /* normalize the flag. */
+        const int have = ((window->flags & SDL_WINDOW_ALWAYS_ON_TOP) != 0);
+        if ((want != have) && (_this->SetWindowAlwaysOnTop)) {
+            if (want) {
+                window->flags |= SDL_WINDOW_ALWAYS_ON_TOP;
+            } else {
+                window->flags &= ~SDL_WINDOW_ALWAYS_ON_TOP;
+            }
+            
+            _this->SetWindowAlwaysOnTop(_this, window, (SDL_bool) want);
+        }
+    }
+}
+
 void
 SDL_SetWindowSize(SDL_Window * window, int w, int h)
 {

src/video/cocoa/SDL_cocoavideo.m

@@ -92,6 +92,7 @@ Cocoa_CreateDevice(int devindex)
     device->RestoreWindow = Cocoa_RestoreWindow;
     device->SetWindowBordered = Cocoa_SetWindowBordered;
     device->SetWindowResizable = Cocoa_SetWindowResizable;
+    device->SetWindowAlwaysOnTop = Cocoa_SetWindowAlwaysOnTop;
     device->SetWindowFullscreen = Cocoa_SetWindowFullscreen;
     device->SetWindowGammaRamp = Cocoa_SetWindowGammaRamp;
     device->GetWindowGammaRamp = Cocoa_GetWindowGammaRamp;

src/video/cocoa/SDL_cocoawindow.h

@@ -142,6 +142,7 @@ extern void Cocoa_MinimizeWindow(_THIS, SDL_Window * window);
 extern void Cocoa_RestoreWindow(_THIS, SDL_Window * window);
 extern void Cocoa_SetWindowBordered(_THIS, SDL_Window * window, SDL_bool bordered);
 extern void Cocoa_SetWindowResizable(_THIS, SDL_Window * window, SDL_bool resizable);
+extern void Cocoa_SetWindowAlwaysOnTop(_THIS, SDL_Window * window, SDL_bool on_top);
 extern void Cocoa_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen);
 extern int Cocoa_SetWindowGammaRamp(_THIS, SDL_Window * window, const Uint16 * ramp);
 extern int Cocoa_GetWindowGammaRamp(_THIS, SDL_Window * window, Uint16 * ramp);

src/video/cocoa/SDL_cocoawindow.m

@@ -1819,6 +1819,18 @@ Cocoa_SetWindowResizable(_THIS, SDL_Window * window, SDL_bool resizable)
     }
 }}
 
+void
+Cocoa_SetWindowAlwaysOnTop(_THIS, SDL_Window * window, SDL_bool on_top)
+{ @autoreleasepool
+    {
+        NSWindow *nswindow = ((SDL_WindowData *) window->driverdata)->nswindow;
+        if (on_top) {
+            [nswindow setLevel:NSFloatingWindowLevel];
+        } else {
+            [nswindow setLevel:kCGNormalWindowLevel];
+        }
+    }}
+
 void
 Cocoa_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen)
 { @autoreleasepool

src/video/windows/SDL_windowsvideo.c

@@ -157,6 +157,7 @@ WIN_CreateDevice(int devindex)
     device->RestoreWindow = WIN_RestoreWindow;
     device->SetWindowBordered = WIN_SetWindowBordered;
     device->SetWindowResizable = WIN_SetWindowResizable;
+    device->SetWindowAlwaysOnTop = WIN_SetWindowAlwaysOnTop;
     device->SetWindowFullscreen = WIN_SetWindowFullscreen;
     device->SetWindowGammaRamp = WIN_SetWindowGammaRamp;
     device->GetWindowGammaRamp = WIN_GetWindowGammaRamp;

src/video/windows/SDL_windowswindow.c

@@ -631,6 +631,18 @@ WIN_SetWindowResizable(_THIS, SDL_Window * window, SDL_bool resizable)
     SetWindowLong(hwnd, GWL_STYLE, style);
 }
 
+void
+WIN_SetWindowAlwaysOnTop(_THIS, SDL_Window * window, SDL_bool on_top)
+{
+    SDL_WindowData *data = (SDL_WindowData *)window->driverdata;
+    HWND hwnd = data->hwnd;
+    if (on_top) {
+        SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);
+    } else {
+        SetWindowPos(hwnd, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);
+    }
+}
+
 void
 WIN_RestoreWindow(_THIS, SDL_Window * window)
 {

src/video/windows/SDL_windowswindow.h

@@ -73,6 +73,7 @@ extern void WIN_MinimizeWindow(_THIS, SDL_Window * window);
 extern void WIN_RestoreWindow(_THIS, SDL_Window * window);
 extern void WIN_SetWindowBordered(_THIS, SDL_Window * window, SDL_bool bordered);
 extern void WIN_SetWindowResizable(_THIS, SDL_Window * window, SDL_bool resizable);
+extern void WIN_SetWindowAlwaysOnTop(_THIS, SDL_Window * window, SDL_bool on_top);
 extern void WIN_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen);
 extern int WIN_SetWindowGammaRamp(_THIS, SDL_Window * window, const Uint16 * ramp);
 extern int WIN_GetWindowGammaRamp(_THIS, SDL_Window * window, Uint16 * ramp);