LibWeb: Support window.screen{X,Y,Left,Top}

Some sites query these properties for whatever reason, so let's support
them. (But let's always pretend the screen coordinates are (0, 0))

Userland/Libraries/LibWeb/Bindings/WindowObject.cpp

@@ -96,6 +96,11 @@ void WindowObject::initialize_global_object()
     define_native_function("scrollTo", scroll, 2, attr);
     define_native_function("scrollBy", scroll_by, 2, attr);
 
+    define_native_accessor("screenX", screen_x_getter, {}, attr);
+    define_native_accessor("screenY", screen_y_getter, {}, attr);
+    define_native_accessor("screenLeft", screen_left_getter, {}, attr);
+    define_native_accessor("screenTop", screen_top_getter, {}, attr);
+
     // Legacy
     define_native_accessor("event", event_getter, event_setter, JS::Attribute::Enumerable);
 
@@ -717,6 +722,38 @@ JS_DEFINE_NATIVE_FUNCTION(WindowObject::history_getter)
     return wrap(global_object, impl->associated_document().history());
 }
 
+JS_DEFINE_NATIVE_GETTER(WindowObject::screen_left_getter)
+{
+    auto* impl = impl_from(vm, global_object);
+    if (!impl)
+        return {};
+    return JS::Value(impl->screen_x());
+}
+
+JS_DEFINE_NATIVE_GETTER(WindowObject::screen_top_getter)
+{
+    auto* impl = impl_from(vm, global_object);
+    if (!impl)
+        return {};
+    return JS::Value(impl->screen_y());
+}
+
+JS_DEFINE_NATIVE_GETTER(WindowObject::screen_x_getter)
+{
+    auto* impl = impl_from(vm, global_object);
+    if (!impl)
+        return {};
+    return JS::Value(impl->screen_x());
+}
+
+JS_DEFINE_NATIVE_GETTER(WindowObject::screen_y_getter)
+{
+    auto* impl = impl_from(vm, global_object);
+    if (!impl)
+        return {};
+    return JS::Value(impl->screen_y());
+}
+
 #define __ENUMERATE(attribute, event_name)                                   \
     JS_DEFINE_NATIVE_FUNCTION(WindowObject::attribute##_getter)              \
     {                                                                        \

Userland/Libraries/LibWeb/Bindings/WindowObject.h

@@ -88,6 +88,11 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(scroll);
     JS_DECLARE_NATIVE_FUNCTION(scroll_by);
 
+    JS_DECLARE_NATIVE_GETTER(screen_x_getter);
+    JS_DECLARE_NATIVE_GETTER(screen_y_getter);
+    JS_DECLARE_NATIVE_GETTER(screen_left_getter);
+    JS_DECLARE_NATIVE_GETTER(screen_top_getter);
+
     JS_DECLARE_NATIVE_FUNCTION(alert);
     JS_DECLARE_NATIVE_FUNCTION(confirm);
     JS_DECLARE_NATIVE_FUNCTION(prompt);

Userland/Libraries/LibWeb/DOM/Window.cpp

@@ -315,4 +315,20 @@ float Window::device_pixel_ratio() const
     return 1.0f;
 }
 
+// https://drafts.csswg.org/cssom-view/#dom-window-screenx
+int Window::screen_x() const
+{
+    // The screenX and screenLeft attributes must return the x-coordinate, relative to the origin of the Web-exposed screen area,
+    // of the left of the client window as number of CSS pixels, or zero if there is no such thing.
+    return 0;
+}
+
+// https://drafts.csswg.org/cssom-view/#dom-window-screeny
+int Window::screen_y() const
+{
+    // The screenY and screenTop attributes must return the y-coordinate, relative to the origin of the screen of the Web-exposed screen area,
+    // of the top of the client window as number of CSS pixels, or zero if there is no such thing.
+    return 0;
+}
+
 }

Userland/Libraries/LibWeb/DOM/Window.h

@@ -89,6 +89,9 @@ public:
 
     float device_pixel_ratio() const;
 
+    int screen_x() const;
+    int screen_y() const;
+
 private:
     explicit Window(Document&);