Restore interact_bg behavior, rename Ui::should_interact_bg_on_drop a…

…nd improve docs

crates/egui/src/context.rs

@@ -1051,7 +1051,7 @@ impl Context {
     /// If the widget already exists, its state (sense, Rect, etc) will be updated.
     ///
     /// `allow_focus` should usually be true, unless you call this function multiple times with the
-    /// same widget, then `allow_focus` should only be true once (like in [`Ui::new`] (true) and [`Ui::interact_bg`] (false)).
+    /// same widget, then `allow_focus` should only be true once (like in [`Ui::new`] (true) and [`Ui::remember_min_rect`] (false)).
     #[allow(clippy::too_many_arguments)]
     pub(crate) fn create_widget(&self, w: WidgetRect, allow_focus: bool) -> Response {
         // Remember this widget

crates/egui/src/ui.rs

@@ -91,11 +91,12 @@ pub struct Ui {
     stack: Arc<UiStack>,
 
     /// 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,
+    /// Whether [`Ui::remember_min_rect`] should be called when the [`Ui`] is dropped.
+    /// This is an optimization, so we don't call [`Ui::remember_min_rect`] multiple times at the
+    /// end of a [`Ui::scope`].
+    min_rect_already_remembered: bool,
 }
 
 impl Ui {
@@ -152,7 +153,7 @@ impl Ui {
             menu_state: None,
             stack: Arc::new(ui_stack),
             sense,
-            should_interact_bg_on_drop: true,
+            min_rect_already_remembered: false,
         };
 
         // Register in the widget stack early, to ensure we are behind all widgets we contain:
@@ -286,7 +287,7 @@ impl Ui {
             menu_state: self.menu_state.clone(),
             stack: Arc::new(ui_stack),
             sense,
-            should_interact_bg_on_drop: true,
+            min_rect_already_remembered: false,
         };
 
         // Register in the widget stack early, to ensure we are behind all widgets we contain:
@@ -1021,14 +1022,10 @@ impl Ui {
             )
     }
 
-    /// 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 Uibuilder::sense with Ui::response instead"]
-    pub fn interact_bg(&self) -> Response {
+    /// Update the [`WidgetRect`] created in [`Ui::new`] or [`Ui::new_child`] with the current
+    /// [`Ui::min_rect`].
+    fn remember_min_rect(&mut self) -> Response {
+        self.min_rect_already_remembered = true;
         // We remove the id from used_ids to prevent a duplicate id warning from showing
         // when the ui was created with `UiBuilder::sense`.
         // This is a bit hacky, is there a better way?
@@ -1049,6 +1046,16 @@ impl Ui {
         )
     }
 
+    /// 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`].
+    #[deprecated = "Use UiBuilder::sense with Ui::response instead"]
+    pub fn interact_bg(&self, sense: Sense) -> Response {
+        // This will update the WidgetRect that was first created in `Ui::new`.
+        self.interact(self.min_rect(), self.id, sense)
+    }
+
     /// Is the pointer (mouse/touch) above this rectangle in this [`Ui`]?
     ///
     /// The `clip_rect` and layer of this [`Ui`] will be respected, so, for instance,
@@ -1066,7 +1073,7 @@ impl Ui {
     ///
     /// Note that this tests against the _current_ [`Ui::min_rect`].
     /// If you want to test against the final `min_rect`,
-    /// use [`Self::interact_bg`] instead.
+    /// use [`Self::response`] instead.
     pub fn ui_contains_pointer(&self) -> bool {
         self.rect_contains_pointer(self.min_rect())
     }
@@ -2212,9 +2219,7 @@ 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);
-        #[allow(deprecated)]
-        let response = child_ui.interact_bg();
-        child_ui.should_interact_bg_on_drop = false;
+        let response = child_ui.remember_min_rect();
         self.allocate_rect(child_ui.min_rect(), Sense::hover());
         InnerResponse::new(ret, response)
     }
@@ -2881,14 +2886,13 @@ impl Ui {
     }
 }
 
-#[cfg(debug_assertions)]
 impl Drop for Ui {
     fn drop(&mut self) {
-        if self.should_interact_bg_on_drop {
-            #[allow(deprecated)]
+        if !self.min_rect_already_remembered {
             // Register our final `min_rect`
-            self.interact_bg();
+            self.remember_min_rect();
         }
+        #[cfg(debug_assertions)]
         register_rect(self, self.min_rect());
     }
 }

crates/egui/src/ui_builder.rs

@@ -118,9 +118,12 @@ impl UiBuilder {
         self
     }
 
-    /// Set if you want sense clicks and/or drags.
+    /// Set if you want sense clicks and/or drags. Default is [`Sense::hover`].
+    /// The sense will be registered below the Senses of any widgets contained in this [`Ui`], so
+    /// if the user clicks a button contained within this [`Ui`], that button will receive the click
+    /// instead.
     ///
-    /// The response can be read with [`Ui::response`].
+    /// The response can be read early with [`Ui::response`].
     #[inline]
     pub fn sense(mut self, sense: Sense) -> Self {
         self.sense = Some(sense);