Platform: mouse click count is not available in Emscripten.

src/Magnum/Platform/Sdl2Application.cpp

@@ -374,15 +374,24 @@ void Sdl2Application::mainLoop() {
 
             case SDL_MOUSEBUTTONDOWN:
             case SDL_MOUSEBUTTONUP: {
-                MouseEvent e(static_cast<MouseEvent::Button>(event.button.button), {event.button.x, event.button.y}, event.button.clicks);
+                MouseEvent e(static_cast<MouseEvent::Button>(event.button.button), {event.button.x, event.button.y}
+                    #ifndef CORRADE_TARGET_EMSCRIPTEN
+                    , event.button.clicks
+                    #endif
+                    );
                 event.type == SDL_MOUSEBUTTONDOWN ? mousePressEvent(e) : mouseReleaseEvent(e);
             } break;
 
             case SDL_MOUSEWHEEL: {
-                MouseEvent e(event.wheel.y > 0 ? MouseEvent::Button::WheelUp : MouseEvent::Button::WheelDown, {event.wheel.x, event.wheel.y}, 0);
+                MouseEvent e(event.wheel.y > 0 ? MouseEvent::Button::WheelUp : MouseEvent::Button::WheelDown, {event.wheel.x, event.wheel.y}
+                    #ifndef CORRADE_TARGET_EMSCRIPTEN
+                    , 0
+                    #endif
+                );
                 mousePressEvent(e);
                 break;
             }
+
             case SDL_MOUSEMOTION: {
                 MouseMoveEvent e({event.motion.x, event.motion.y}, {event.motion.xrel, event.motion.yrel}, static_cast<MouseMoveEvent::Button>(event.motion.state));
                 mouseMoveEvent(e);

src/Magnum/Platform/Sdl2Application.h

@@ -1152,12 +1152,15 @@ class Sdl2Application::MouseEvent: public Sdl2Application::InputEvent {
          */
         constexpr Vector2i position() const { return _position; }
 
+        #ifndef CORRADE_TARGET_EMSCRIPTEN
         /**
          * @brief Click count
          *
          * Ignored for wheel events.
+         * @note Not available in @ref CORRADE_TARGET_EMSCRIPTEN "Emscripten".
          */
         constexpr Int clickCount() const { return _clickCount; }
+        #endif
 
         /**
          * @brief Modifiers
@@ -1167,11 +1170,21 @@ class Sdl2Application::MouseEvent: public Sdl2Application::InputEvent {
         Modifiers modifiers();
 
     private:
-        constexpr MouseEvent(Button button, const Vector2i& position, Int clickCount): _button{button}, _position{position}, _clickCount{clickCount}, _modifiersLoaded{false} {}
+        constexpr MouseEvent(Button button, const Vector2i& position
+            #ifndef CORRADE_TARGET_EMSCRIPTEN
+            , Int clickCount
+            #endif
+            ): _button{button}, _position{position},
+            #ifndef CORRADE_TARGET_EMSCRIPTEN
+            _clickCount{clickCount},
+            #endif
+            _modifiersLoaded{false} {}
 
         const Button _button;
         const Vector2i _position;
+        #ifndef CORRADE_TARGET_EMSCRIPTEN
         const Int _clickCount;
+        #endif
         bool _modifiersLoaded;
         Modifiers _modifiers;
 };