Hide tooltips when scrolling (#4784)

* Closes #4781

crates/egui/src/context.rs

@@ -1442,6 +1442,16 @@ impl Context {
         self.request_repaint_after_for(duration, self.viewport_id());
     }
 
+    /// Repaint after this many seconds.
+    ///
+    /// See [`Self::request_repaint_after`] for details.
+    #[track_caller]
+    pub fn request_repaint_after_secs(&self, seconds: f32) {
+        if let Ok(duration) = std::time::Duration::try_from_secs_f32(seconds) {
+            self.request_repaint_after(duration);
+        }
+    }
+
     /// Request repaint after at most the specified duration elapses.
     ///
     /// The backend can chose to repaint sooner, for instance if some other code called

crates/egui/src/input_state.rs

@@ -44,6 +44,12 @@ pub struct InputState {
     /// (We keep a separate [`TouchState`] for each encountered touch device.)
     touch_states: BTreeMap<TouchDeviceId, TouchState>,
 
+    // ----------------------------------------------
+    // Scrolling:
+    //
+    /// Time of the last scroll event.
+    last_scroll_time: f64,
+
     /// Used for smoothing the scroll delta.
     unprocessed_scroll_delta: Vec2,
 
@@ -87,6 +93,7 @@ pub struct InputState {
     /// * `zoom > 1`: pinch spread
     zoom_factor_delta: f32,
 
+    // ----------------------------------------------
     /// Position and size of the egui area.
     pub screen_rect: Rect,
 
@@ -161,11 +168,14 @@ impl Default for InputState {
             raw: Default::default(),
             pointer: Default::default(),
             touch_states: Default::default(),
+
+            last_scroll_time: f64::NEG_INFINITY,
             unprocessed_scroll_delta: Vec2::ZERO,
             unprocessed_scroll_delta_for_zoom: 0.0,
             raw_scroll_delta: Vec2::ZERO,
             smooth_scroll_delta: Vec2::ZERO,
             zoom_factor_delta: 1.0,
+
             screen_rect: Rect::from_min_size(Default::default(), vec2(10_000.0, 10_000.0)),
             pixels_per_point: 1.0,
             max_texture_side: 2048,
@@ -320,14 +330,24 @@ impl InputState {
             }
         }
 
+        let is_scrolling = raw_scroll_delta != Vec2::ZERO || smooth_scroll_delta != Vec2::ZERO;
+        let last_scroll_time = if is_scrolling {
+            time
+        } else {
+            self.last_scroll_time
+        };
+
         Self {
             pointer,
             touch_states: self.touch_states,
+
+            last_scroll_time,
             unprocessed_scroll_delta,
             unprocessed_scroll_delta_for_zoom,
             raw_scroll_delta,
             smooth_scroll_delta,
             zoom_factor_delta,
+
             screen_rect,
             pixels_per_point,
             max_texture_side: new.max_texture_side.unwrap_or(self.max_texture_side),
@@ -393,6 +413,12 @@ impl InputState {
         )
     }
 
+    /// How long has it been (in seconds) since the use last scrolled?
+    #[inline(always)]
+    pub fn time_since_last_scroll(&self) -> f32 {
+        (self.time - self.last_scroll_time) as f32
+    }
+
     /// The [`crate::Context`] will call this at the end of each frame to see if we need a repaint.
     ///
     /// Returns how long to wait for a repaint.
@@ -1218,6 +1244,7 @@ impl InputState {
             pointer,
             touch_states,
 
+            last_scroll_time,
             unprocessed_scroll_delta,
             unprocessed_scroll_delta_for_zoom,
             raw_scroll_delta,
@@ -1257,6 +1284,10 @@ impl InputState {
             });
         }
 
+        ui.label(format!(
+            "Time since last scroll: {:.1} s",
+            time - last_scroll_time
+        ));
         if cfg!(debug_assertions) {
             ui.label(format!(
                 "unprocessed_scroll_delta: {unprocessed_scroll_delta:?} points"
@@ -1270,6 +1301,7 @@ impl InputState {
             "smooth_scroll_delta: {smooth_scroll_delta:?} points"
         ));
         ui.label(format!("zoom_factor_delta: {zoom_factor_delta:4.2}x"));
+
         ui.label(format!("screen_rect: {screen_rect:?} points"));
         ui.label(format!(
             "{pixels_per_point} physical pixels for each logical point"

crates/egui/src/response.rs

@@ -611,6 +611,21 @@ impl Response {
             return false;
         }
 
+        let style = self.ctx.style();
+
+        let tooltip_delay = style.interaction.tooltip_delay;
+        let tooltip_grace_time = style.interaction.tooltip_grace_time;
+
+        let time_since_last_scroll = self.ctx.input(|i| i.time_since_last_scroll());
+
+        if time_since_last_scroll < tooltip_delay {
+            // See https://github.com/emilk/egui/issues/4781
+            // Note that this means we cannot have `ScrollArea`s in a tooltip.
+            self.ctx
+                .request_repaint_after_secs(tooltip_delay - time_since_last_scroll);
+            return false;
+        }
+
         let is_our_tooltip_open = self.is_tooltip_open();
 
         if is_our_tooltip_open {
@@ -680,9 +695,6 @@ impl Response {
             return false;
         }
 
-        let tooltip_delay = self.ctx.style().interaction.tooltip_delay;
-        let tooltip_grace_time = self.ctx.style().interaction.tooltip_grace_time;
-
         // There is a tooltip_delay before showing the first tooltip,
         // but once one tooltips is show, moving the mouse cursor to
         // another widget should show the tooltip for that widget right away.
@@ -692,23 +704,27 @@ impl Response {
             crate::popup::seconds_since_last_tooltip(&self.ctx) < tooltip_grace_time;
 
         if !tooltip_was_recently_shown && !is_our_tooltip_open {
-            if self.ctx.style().interaction.show_tooltips_only_when_still {
+            if style.interaction.show_tooltips_only_when_still {
                 // We only show the tooltip when the mouse pointer is still.
-                if !self.ctx.input(|i| i.pointer.is_still()) {
+                if !self
+                    .ctx
+                    .input(|i| i.pointer.is_still() && i.smooth_scroll_delta == Vec2::ZERO)
+                {
                     // wait for mouse to stop
                     self.ctx.request_repaint();
                     return false;
                 }
             }
 
-            let time_til_tooltip =
-                tooltip_delay - self.ctx.input(|i| i.pointer.time_since_last_movement());
+            let time_since_last_interaction = self.ctx.input(|i| {
+                i.time_since_last_scroll()
+                    .max(i.pointer.time_since_last_movement())
+            });
+            let time_til_tooltip = tooltip_delay - time_since_last_interaction;
 
             if 0.0 < time_til_tooltip {
                 // Wait until the mouse has been still for a while
-                if let Ok(duration) = std::time::Duration::try_from_secs_f32(time_til_tooltip) {
-                    self.ctx.request_repaint_after(duration);
-                }
+                self.ctx.request_repaint_after_secs(time_til_tooltip);
                 return false;
             }
         }

crates/egui/src/text_selection/visuals.rs

@@ -99,8 +99,7 @@ pub fn paint_text_cursor(
             total_duration - time_in_cycle
         };
 
-        ui.ctx()
-            .request_repaint_after(std::time::Duration::from_secs_f32(wake_in));
+        ui.ctx().request_repaint_after_secs(wake_in);
     } else {
         paint_cursor_end(painter, ui.visuals(), primary_cursor_rect);
     }

crates/egui_demo_lib/src/demo/tooltips.rs

@@ -19,7 +19,8 @@ impl crate::Demo for Tooltips {
         use crate::View as _;
         let window = egui::Window::new("Tooltips")
             .constrain(false) // So we can test how tooltips behave close to the screen edge
-            .resizable(false)
+            .resizable(true)
+            .default_size([450.0, 300.0])
             .scroll(false)
             .open(open);
         window.show(ctx, |ui| self.ui(ui));
@@ -34,6 +35,34 @@ impl crate::View for Tooltips {
             ui.add(crate::egui_github_link_file_line!());
         });
 
+        egui::SidePanel::right("scroll_test").show_inside(ui, |ui| {
+            ui.label(
+                "The scroll area below has many labels with interactive tooltips. \
+                 The purpose is to test that the tooltips close when you scroll.",
+            )
+            .on_hover_text("Try hovering a label below, then scroll!");
+            egui::ScrollArea::vertical()
+                .auto_shrink(false)
+                .show(ui, |ui| {
+                    for i in 0..1000 {
+                        ui.label(format!("This is line {i}")).on_hover_ui(|ui| {
+                            ui.style_mut().interaction.selectable_labels = true;
+                            ui.label(
+                            "This tooltip is interactive, because the text in it is selectable.",
+                        );
+                        });
+                    }
+                });
+        });
+
+        egui::CentralPanel::default().show_inside(ui, |ui| {
+            self.misc_tests(ui);
+        });
+    }
+}
+
+impl Tooltips {
+    fn misc_tests(&mut self, ui: &mut egui::Ui) {
         ui.label("All labels in this demo have tooltips.")
             .on_hover_text("Yes, even this one.");