Emscripten: Store canvas id in WindowData

Also replace all hardcoded uses of "#canvas" or NULL

src/video/emscripten/SDL_emscriptenevents.c

@@ -317,7 +317,7 @@ Emscripten_HandleMouseMove(int eventType, const EmscriptenMouseEvent *mouseEvent
 
     /* rescale (in case canvas is being scaled)*/
     double client_w, client_h, xscale, yscale;
-    emscripten_get_element_css_size(NULL, &client_w, &client_h);
+    emscripten_get_element_css_size(window_data->canvas_id, &client_w, &client_h);
     xscale = window_data->window->w / client_w;
     yscale = window_data->window->h / client_h;
 
@@ -374,7 +374,7 @@ Emscripten_HandleMouseButton(int eventType, const EmscriptenMouseEvent *mouseEve
     SDL_SendMouseButton(window_data->window, 0, sdl_button_state, sdl_button);
 
     /* Do not consume the event if the mouse is outside of the canvas. */
-    emscripten_get_element_css_size(NULL, &css_w, &css_h);
+    emscripten_get_element_css_size(window_data->canvas_id, &css_w, &css_h);
     if (mouseEvent->canvasX < 0 || mouseEvent->canvasX >= css_w ||
         mouseEvent->canvasY < 0 || mouseEvent->canvasY >= css_h) {
         return 0;
@@ -394,7 +394,7 @@ Emscripten_HandleMouseFocus(int eventType, const EmscriptenMouseEvent *mouseEven
     if (!isPointerLocked) {
         /* rescale (in case canvas is being scaled)*/
         double client_w, client_h;
-        emscripten_get_element_css_size(NULL, &client_w, &client_h);
+        emscripten_get_element_css_size(window_data->canvas_id, &client_w, &client_h);
 
         mx = mx * (window_data->window->w / client_w);
         my = my * (window_data->window->h / client_h);
@@ -440,7 +440,7 @@ Emscripten_HandleTouch(int eventType, const EmscriptenTouchEvent *touchEvent, vo
          return 0;
     }
 
-    emscripten_get_element_css_size(NULL, &client_w, &client_h);
+    emscripten_get_element_css_size(window_data->canvas_id, &client_w, &client_h);
 
     for (i = 0; i < touchEvent->numTouches; i++) {
         SDL_FingerID id;
@@ -587,14 +587,14 @@ Emscripten_HandleResize(int eventType, const EmscriptenUiEvent *uiEvent, void *u
             double h = window_data->window->h;
 
             if(window_data->external_size) {
-                emscripten_get_element_css_size(NULL, &w, &h);
+                emscripten_get_element_css_size(window_data->canvas_id, &w, &h);
             }
 
-            emscripten_set_canvas_element_size(NULL, w * window_data->pixel_ratio, h * window_data->pixel_ratio);
+            emscripten_set_canvas_element_size(window_data->canvas_id, w * window_data->pixel_ratio, h * window_data->pixel_ratio);
 
             /* set_canvas_size unsets this */
             if (!window_data->external_size && window_data->pixel_ratio != 1.0f) {
-                emscripten_set_element_css_size(NULL, w, h);
+                emscripten_set_element_css_size(window_data->canvas_id, w, h);
             }
 
             if (force) {
@@ -619,7 +619,7 @@ Emscripten_HandleCanvasResize(int eventType, const void *reserved, void *userDat
     if(window_data->fullscreen_resize)
     {
         double css_w, css_h;
-        emscripten_get_element_css_size(NULL, &css_w, &css_h);
+        emscripten_get_element_css_size(window_data->canvas_id, &css_w, &css_h);
         SDL_SendWindowEvent(window_data->window, SDL_WINDOWEVENT_RESIZED, css_w, css_h);
     }
 
@@ -640,23 +640,23 @@ Emscripten_RegisterEventHandlers(SDL_WindowData *data)
     const char *keyElement;
 
     /* There is only one window and that window is the canvas */
-    emscripten_set_mousemove_callback("#canvas", data, 0, Emscripten_HandleMouseMove);
+    emscripten_set_mousemove_callback(data->canvas_id, data, 0, Emscripten_HandleMouseMove);
 
-    emscripten_set_mousedown_callback("#canvas", data, 0, Emscripten_HandleMouseButton);
+    emscripten_set_mousedown_callback(data->canvas_id, data, 0, Emscripten_HandleMouseButton);
     emscripten_set_mouseup_callback("#document", data, 0, Emscripten_HandleMouseButton);
 
-    emscripten_set_mouseenter_callback("#canvas", data, 0, Emscripten_HandleMouseFocus);
-    emscripten_set_mouseleave_callback("#canvas", data, 0, Emscripten_HandleMouseFocus);
+    emscripten_set_mouseenter_callback(data->canvas_id, data, 0, Emscripten_HandleMouseFocus);
+    emscripten_set_mouseleave_callback(data->canvas_id, data, 0, Emscripten_HandleMouseFocus);
 
-    emscripten_set_wheel_callback("#canvas", data, 0, Emscripten_HandleWheel);
+    emscripten_set_wheel_callback(data->canvas_id, data, 0, Emscripten_HandleWheel);
 
     emscripten_set_focus_callback("#window", data, 0, Emscripten_HandleFocus);
     emscripten_set_blur_callback("#window", data, 0, Emscripten_HandleFocus);
 
-    emscripten_set_touchstart_callback("#canvas", data, 0, Emscripten_HandleTouch);
-    emscripten_set_touchend_callback("#canvas", data, 0, Emscripten_HandleTouch);
-    emscripten_set_touchmove_callback("#canvas", data, 0, Emscripten_HandleTouch);
-    emscripten_set_touchcancel_callback("#canvas", data, 0, Emscripten_HandleTouch);
+    emscripten_set_touchstart_callback(data->canvas_id, data, 0, Emscripten_HandleTouch);
+    emscripten_set_touchend_callback(data->canvas_id, data, 0, Emscripten_HandleTouch);
+    emscripten_set_touchmove_callback(data->canvas_id, data, 0, Emscripten_HandleTouch);
+    emscripten_set_touchcancel_callback(data->canvas_id, data, 0, Emscripten_HandleTouch);
 
     emscripten_set_pointerlockchange_callback("#document", data, 0, Emscripten_HandlePointerLockChange);
 
@@ -681,23 +681,23 @@ Emscripten_UnregisterEventHandlers(SDL_WindowData *data)
     const char *target;
 
     /* only works due to having one window */
-    emscripten_set_mousemove_callback("#canvas", NULL, 0, NULL);
+    emscripten_set_mousemove_callback(data->canvas_id, NULL, 0, NULL);
 
-    emscripten_set_mousedown_callback("#canvas", NULL, 0, NULL);
+    emscripten_set_mousedown_callback(data->canvas_id, NULL, 0, NULL);
     emscripten_set_mouseup_callback("#document", NULL, 0, NULL);
 
-    emscripten_set_mouseenter_callback("#canvas", NULL, 0, NULL);
-    emscripten_set_mouseleave_callback("#canvas", NULL, 0, NULL);
+    emscripten_set_mouseenter_callback(data->canvas_id, NULL, 0, NULL);
+    emscripten_set_mouseleave_callback(data->canvas_id, NULL, 0, NULL);
 
-    emscripten_set_wheel_callback("#canvas", NULL, 0, NULL);
+    emscripten_set_wheel_callback(data->canvas_id, NULL, 0, NULL);
 
     emscripten_set_focus_callback("#window", NULL, 0, NULL);
     emscripten_set_blur_callback("#window", NULL, 0, NULL);
 
-    emscripten_set_touchstart_callback("#canvas", NULL, 0, NULL);
-    emscripten_set_touchend_callback("#canvas", NULL, 0, NULL);
-    emscripten_set_touchmove_callback("#canvas", NULL, 0, NULL);
-    emscripten_set_touchcancel_callback("#canvas", NULL, 0, NULL);
+    emscripten_set_touchstart_callback(data->canvas_id, NULL, 0, NULL);
+    emscripten_set_touchend_callback(data->canvas_id, NULL, 0, NULL);
+    emscripten_set_touchmove_callback(data->canvas_id, NULL, 0, NULL);
+    emscripten_set_touchcancel_callback(data->canvas_id, NULL, 0, NULL);
 
     emscripten_set_pointerlockchange_callback("#document", NULL, 0, NULL);
 

src/video/emscripten/SDL_emscriptenvideo.c

@@ -196,6 +196,8 @@ Emscripten_CreateWindow(_THIS, SDL_Window * window)
         return SDL_OutOfMemory();
     }
 
+    wdata->canvas_id = SDL_strdup("#canvas");
+
     if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
         wdata->pixel_ratio = emscripten_get_device_pixel_ratio();
     } else {
@@ -206,8 +208,8 @@ Emscripten_CreateWindow(_THIS, SDL_Window * window)
     scaled_h = SDL_floor(window->h * wdata->pixel_ratio);
 
     /* set a fake size to check if there is any CSS sizing the canvas */
-    emscripten_set_canvas_element_size(NULL, 1, 1);
-    emscripten_get_element_css_size(NULL, &css_w, &css_h);
+    emscripten_set_canvas_element_size(wdata->canvas_id, 1, 1);
+    emscripten_get_element_css_size(wdata->canvas_id, &css_w, &css_h);
 
     wdata->external_size = SDL_floor(css_w) != 1 || SDL_floor(css_h) != 1;
 
@@ -218,14 +220,13 @@ Emscripten_CreateWindow(_THIS, SDL_Window * window)
 
         SDL_SendWindowEvent(window, SDL_WINDOWEVENT_RESIZED, css_w, css_h);
     }
-
-    emscripten_set_canvas_element_size(NULL, scaled_w, scaled_h);
+    emscripten_set_canvas_element_size(wdata->canvas_id, scaled_w, scaled_h);
 
     /* if the size is not being controlled by css, we need to scale down for hidpi */
     if (!wdata->external_size) {
         if (wdata->pixel_ratio != 1.0f) {
             /*scale canvas down*/
-            emscripten_set_element_css_size(NULL, window->w, window->h);
+            emscripten_set_element_css_size(wdata->canvas_id, window->w, window->h);
         }
     }
 
@@ -269,11 +270,11 @@ static void Emscripten_SetWindowSize(_THIS, SDL_Window * window)
         if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
             data->pixel_ratio = emscripten_get_device_pixel_ratio();
         }
-        emscripten_set_canvas_element_size(NULL, window->w * data->pixel_ratio, window->h * data->pixel_ratio);
+        emscripten_set_canvas_element_size(data->canvas_id, window->w * data->pixel_ratio, window->h * data->pixel_ratio);
 
         /*scale canvas down*/
         if (!data->external_size && data->pixel_ratio != 1.0f) {
-            emscripten_set_element_css_size(NULL, window->w, window->h);
+            emscripten_set_element_css_size(data->canvas_id, window->w, window->h);
         }
     }
 }
@@ -295,7 +296,8 @@ Emscripten_DestroyWindow(_THIS, SDL_Window * window)
 #endif
 
         /* We can't destroy the canvas, so resize it to zero instead */
-        emscripten_set_canvas_element_size(NULL, 0, 0);
+        emscripten_set_canvas_element_size(data->canvas_id, 0, 0);
+        SDL_free(data->canvas_id);
 
         SDL_free(window->driverdata);
         window->driverdata = NULL;
@@ -332,7 +334,7 @@ Emscripten_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * di
             data->requested_fullscreen_mode = window->flags & (SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN);
             data->fullscreen_resize = is_desktop_fullscreen;
 
-            res = emscripten_request_fullscreen_strategy(NULL, 1, &strategy);
+            res = emscripten_request_fullscreen_strategy(data->canvas_id, 1, &strategy);
             if(res != EMSCRIPTEN_RESULT_SUCCESS && res != EMSCRIPTEN_RESULT_DEFERRED) {
                 /* unset flags, fullscreen failed */
                 window->flags &= ~(SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN);

src/video/emscripten/SDL_emscriptenvideo.h

@@ -40,6 +40,8 @@ typedef struct SDL_WindowData
     SDL_Window *window;
     SDL_Surface *surface;
 
+    char *canvas_id;
+
     float pixel_ratio;
 
     SDL_bool external_size;