Update

Ensure SDL_FinishWindowCreation is still calle on Emscripten
Ensure drop paths are unique for each window
Use videodata instead of vdata
Remove unnecessary call to SDL_ShowWindow in testmouse

Author: Temdog007

src/video/SDL_video.c

@@ -2578,6 +2578,14 @@ bool SDL_RecreateWindow(SDL_Window *window, SDL_WindowFlags flags)
     bool need_vulkan_load = false;
     SDL_WindowFlags graphics_flags;
 
+#ifdef SDL_PLATFORM_EMSCRIPTEN
+    // Don't actually recreate the window in Emscripten because the SDL_WindowData's
+    // canvas_id and keyboard_element would be lost if destroyed
+    const bool recreate_window = false;
+#else
+    const bool recreate_window = true;
+#endif
+
     // ensure no more than one of these flags is set
     graphics_flags = flags & (SDL_WINDOW_OPENGL | SDL_WINDOW_METAL | SDL_WINDOW_VULKAN);
     if (graphics_flags & (graphics_flags - 1)) {
@@ -2646,13 +2654,9 @@ bool SDL_RecreateWindow(SDL_Window *window, SDL_WindowFlags flags)
         SDL_Vulkan_UnloadLibrary();
     }
 
-    // Don't actually recreate the window in Emscripten because the SDL_WindowData's
-    // canvas_id and keyboard_element would be lost if destroyed
-#ifndef SDL_PLATFORM_EMSCRIPTEN
-    if (_this->DestroyWindow && !(flags & SDL_WINDOW_EXTERNAL)) {
+    if (recreate_window && _this->DestroyWindow && !(flags & SDL_WINDOW_EXTERNAL)) {
         _this->DestroyWindow(_this, window);
     }
-#endif
 
     if (need_gl_load) {
         if (!SDL_GL_LoadLibrary(NULL)) {
@@ -2680,12 +2684,7 @@ bool SDL_RecreateWindow(SDL_Window *window, SDL_WindowFlags flags)
         window->w = window->windowed.w = window->floating.w;
         window->h = window->windowed.h = window->floating.h;
 
-#ifdef SDL_PLATFORM_EMSCRIPTEN
-        // Prevent -Wunused-but-set-variable
-        (void)loaded_opengl;
-        (void)loaded_vulkan;
-#else
-        if (!_this->CreateSDLWindow(_this, window, 0)) {
+        if (recreate_window && !_this->CreateSDLWindow(_this, window, 0)) {
             if (loaded_opengl) {
                 SDL_GL_UnloadLibrary();
                 window->flags &= ~SDL_WINDOW_OPENGL;
@@ -2696,7 +2695,6 @@ bool SDL_RecreateWindow(SDL_Window *window, SDL_WindowFlags flags)
             }
             return false;
         }
-#endif
     }
 
     if (flags & SDL_WINDOW_EXTERNAL) {
@@ -2727,9 +2725,7 @@ bool SDL_RecreateWindow(SDL_Window *window, SDL_WindowFlags flags)
         _this->SetWindowHitTest(window, true);
     }
 
-#ifndef SDL_PLATFORM_EMSCRIPTEN
     SDL_FinishWindowCreation(window, flags);
-#endif
 
     return true;
 }

src/video/emscripten/SDL_emscriptenevents.c

@@ -954,14 +954,18 @@ static void Emscripten_set_drag_event_callbacks(SDL_WindowData *data)
             target.addEventListener("dragover", window_data.eventHandlerDropDragover);
 
             window_data.drop_count = 0;
-            try
-            {
-                FS.mkdir("/tmp/filedrop")
-            }
-            catch(e)
-            {
-                // Throws if the directory already exists
+            function safeCreateDir(dir){
+                try
+                {
+                    FS.mkdir(dir)
+                }
+                catch(e)
+                {
+                    // Throws if the directory already exists
+                }
             }
+            safeCreateDir("/tmp/filedrop");
+            safeCreateDir(`/tmp/filedrop/${id}/`);
 
             window_data.eventHandlerDropDrop = function(event) {
                 event.preventDefault();
@@ -975,7 +979,7 @@ static void Emscripten_set_drag_event_callbacks(SDL_WindowData *data)
                         const file_reader = new FileReader();
                         file_reader.readAsArrayBuffer(file);
                         file_reader.onload = function(event) {
-                            const fs_dropdir = `/tmp/filedrop/${window_data.drop_count}`;
+                            const fs_dropdir = `/tmp/filedrop/${id}/${window_data.drop_count}`;
                             window_data.drop_count += 1;
 
                             const fs_filepath = `${fs_dropdir}/${file.name}`;
@@ -1032,7 +1036,7 @@ static void Emscripten_unset_drag_event_callbacks(SDL_WindowData *data)
                 }
             }
 
-            const path = "/tmp/filedrop";
+            const path = `/tmp/filedrop/${id}/`;
             function recursive_remove(dirpath) {
                 FS.readdir(dirpath).forEach((filename) => {
                     const p = `${dirpath}/${filename}`;

src/video/emscripten/SDL_emscriptenvideo.c

@@ -60,8 +60,8 @@ static int pending_swap_interval = -1;
 
 static void Emscripten_DeleteDevice(SDL_VideoDevice *device)
 {
-    SDL_VideoData *vdata = device->internal;
-    SDL_DestroyProperties(vdata->window_map);
+    SDL_VideoData *videodata = device->internal;
+    SDL_DestroyProperties(videodata->window_map);
     SDL_free(device);
 }
 
@@ -147,12 +147,12 @@ static SDL_VideoDevice *Emscripten_CreateDevice(void)
         return NULL;
     }
 
-    vdata = (SDL_VideoData *)SDL_calloc(1, sizeof(SDL_VideoData));
-    if (!vdata) {
+    videodata = (SDL_VideoData *)SDL_calloc(1, sizeof(SDL_VideoData));
+    if (!videodata) {
         return NULL;
     }
-    vdata->window_map = SDL_CreateProperties();
-    device->internal = vdata;
+    videodata->window_map = SDL_CreateProperties();
+    device->internal = videodata;
 
     /* Firefox sends blur event which would otherwise prevent full screen
      * when the user clicks to allow full screen.
@@ -468,7 +468,7 @@ EMSCRIPTEN_KEEPALIVE void requestFullscreenThroughSDL(SDL_Window *window)
 static bool Emscripten_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window, SDL_PropertiesID props)
 {
     SDL_WindowData *wdata;
-    SDL_VideoData *vdata;
+    SDL_VideoData *videodata;
     double scaled_w, scaled_h;
     double css_w, css_h;
     const char *selector;
@@ -485,6 +485,11 @@ static bool Emscripten_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window,
         selector = SDL_GetStringProperty(props, SDL_PROP_WINDOW_CREATE_EMSCRIPTEN_CANVAS_ID, "#canvas");
     }
 
+    if (!*selector || selector[0] != '#') {
+        SDL_SetError("Canvas ID must begin with a '#' character.");
+        return false;
+    }
+
     // If an element with this id already exists, it should be verified that it is to an HTML5CanvasElement
     canvas_exists = MAIN_THREAD_EM_ASM_INT({
         var id = UTF8ToString($0);
@@ -577,8 +582,8 @@ static bool Emscripten_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window,
     }
 
     // Ensure that there isn't another window that is using this canvas ID
-    vdata = _this->internal;
-    if (SDL_GetBooleanProperty(vdata->window_map, selector, false)) {
+    videodata = _this->internal;
+    if (SDL_GetBooleanProperty(videodata->window_map, selector, false)) {
         SDL_SetError("A window already exists that refers to canvas '%s'", selector);
         return false;
     }
@@ -645,10 +650,14 @@ static bool Emscripten_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window,
     SDL_SetStringProperty(window->props, SDL_PROP_WINDOW_EMSCRIPTEN_CANVAS_ID_STRING, wdata->canvas_id);
     SDL_SetStringProperty(window->props, SDL_PROP_WINDOW_EMSCRIPTEN_KEYBOARD_ELEMENT_STRING, wdata->keyboard_element);
 
-    if (!SDL_SetBooleanProperty(vdata->window_map, wdata->canvas_id, true)) {
+    if (!SDL_SetBooleanProperty(videodata->window_map, wdata->canvas_id, true)) {
         return false;
     }
 
+    if (window->flags & SDL_WINDOW_HIDDEN) {
+        Emscripten_HideWindow(_this, window);
+    }
+
     // Window has been successfully created
     return true;
 }
@@ -687,7 +696,7 @@ static void Emscripten_GetWindowSizeInPixels(SDL_VideoDevice *_this, SDL_Window
 static void Emscripten_DestroyWindow(SDL_VideoDevice *_this, SDL_Window *window)
 {
     SDL_WindowData *data;
-    SDL_VideoData *vdata;
+    SDL_VideoData *videodata;
 
     if (window->internal) {
         data = window->internal;
@@ -709,8 +718,8 @@ static void Emscripten_DestroyWindow(SDL_VideoDevice *_this, SDL_Window *window)
             }
         }, data->canvas_id);
 
-        vdata = _this->internal;
-        SDL_SetBooleanProperty(vdata->window_map, data->canvas_id, false);
+        videodata = _this->internal;
+        SDL_SetBooleanProperty(videodata->window_map, data->canvas_id, false);
         SDL_free(data->canvas_id);
 
         SDL_free(data->keyboard_element);

test/testmouse.c

@@ -332,9 +332,6 @@ int main(int argc, char *argv[])
         return 0;
     }
 
-    /* Window won't show on Emscripten without this */
-    SDL_ShowWindow(window);
-
     /* Main render loop */
 #ifdef SDL_PLATFORM_EMSCRIPTEN
     emscripten_set_main_loop_arg(loop, &loop_data, 0, 1);