diff --git a/crates/egui/src/context.rs b/crates/egui/src/context.rs index 92d3e236b330..4e44ddc1f100 100644 --- a/crates/egui/src/context.rs +++ b/crates/egui/src/context.rs @@ -1117,7 +1117,7 @@ impl Context { } /// Do all interaction for an existing widget, without (re-)registering it. - fn get_response(&self, widget_rect: WidgetRect) -> Response { + pub(crate) fn get_response(&self, widget_rect: WidgetRect) -> Response { let WidgetRect { id, layer_id, diff --git a/crates/egui/src/ui.rs b/crates/egui/src/ui.rs index 2f671edd041e..4be7ffe730d2 100644 --- a/crates/egui/src/ui.rs +++ b/crates/egui/src/ui.rs @@ -93,6 +93,9 @@ pub struct Ui { /// The sense for the ui background. /// It will be used for [Ui::interact_bg]. sense: Sense, + + /// Whether [`Ui::interact_bg`] should be called when the [`Ui`] is dropped. + should_interact_bg_on_drop: bool, } impl Ui { @@ -149,6 +152,7 @@ impl Ui { menu_state: None, stack: Arc::new(ui_stack), sense, + should_interact_bg_on_drop: true, }; // Register in the widget stack early, to ensure we are behind all widgets we contain: @@ -282,6 +286,7 @@ impl Ui { menu_state: self.menu_state.clone(), stack: Arc::new(ui_stack), sense, + should_interact_bg_on_drop: true, }; // Register in the widget stack early, to ensure we are behind all widgets we contain: @@ -989,11 +994,40 @@ impl Ui { self.interact(rect, id, sense) } + /// Read the [`Ui`]s background [`Response`]. + /// It's [`Sense`] will be based on the [`UiBuilder::sense`] used to create this [`Ui`]. + /// + /// The rectangle of the [`Response`] (and interactive area) will be [`Self::min_rect`] + /// of the last frame. + /// + /// On the first frame, when the [`Ui`] is created, this will return a [`Response`] with a + /// [`Rect`] of [`Rect::NOTHING`]. + pub fn read_response(&self) -> Response { + // This is the inverse of Context::read_response. We prefer a response + // based on last frame's widget rect since the one from this frame is Rect::NOTHING until + // Ui::interact_bg is called or the Ui is dropped. + self.ctx() + .viewport(|viewport| { + viewport + .prev_frame + .widgets + .get(self.id) + .or_else(|| viewport.this_frame.widgets.get(self.id)) + .copied() + }) + .map(|widget_rect| self.ctx().get_response(widget_rect)) + .expect( + "Since we always call Context::create_widget in Ui::new, this should never be None", + ) + } + /// Interact with the background of this [`Ui`], /// i.e. behind all the widgets. /// /// The rectangle of the [`Response`] (and interactive area) will be [`Self::min_rect`]. /// You can customize the [`Sense`] via [`UiBuilder::sense`]. + // This is marked as deprecated for public use but still makes sense to use internally. + #[deprecated = "Use Ui::read_response instead"] pub fn interact_bg(&self) -> Response { // We remove the id from used_ids to prevent a duplicate id warning from showing // when the ui was created with `UiBuilder::sense`. @@ -2178,7 +2212,9 @@ impl Ui { let mut child_ui = self.new_child(ui_builder); self.next_auto_id_salt = next_auto_id_salt; // HACK: we want `scope` to only increment this once, so that `ui.scope` is equivalent to `ui.allocate_space`. let ret = add_contents(&mut child_ui); - let response = self.allocate_rect(child_ui.min_rect(), Sense::hover()); + let response = child_ui.interact_bg(); + child_ui.should_interact_bg_on_drop = false; + self.allocate_rect(child_ui.min_rect(), Sense::hover()); InnerResponse::new(ret, response) } @@ -2717,34 +2753,6 @@ impl Ui { (InnerResponse { inner, response }, payload) } - - /// Create a child ui scope and pass its response to the closure. - /// You can use this to easily create interactive containers or custom buttons. - /// - /// This basically does three things: - /// 1. Read [`Ui`]s response via [`Context::read_response`]. - /// 2. Create a child ui scope and call the content fn - /// 3. Call [`Ui::interact_bg`] to set the right [`WidgetRect`] - pub fn interact_scope( - &mut self, - sense: Sense, - builder: UiBuilder, - content: impl FnOnce(&mut Self, Option) -> R, - ) -> InnerResponse { - let id_salt = builder.id_salt.unwrap_or(Id::new("interact_scope")); - let id = self.id.with(Id::new(id_salt)); - let response = self.ctx().read_response(id); - - self.scope_dyn( - builder.sense(sense).id_salt(id_salt), - Box::new(|ui| { - let inner = content(ui, response); - let response = ui.interact_bg(); - InnerResponse::new(inner, response) - }), - ) - .inner - } } /// # Menus @@ -2875,6 +2883,9 @@ impl Ui { #[cfg(debug_assertions)] impl Drop for Ui { fn drop(&mut self) { + if self.should_interact_bg_on_drop { + self.interact_bg(); + } register_rect(self, self.min_rect()); } }