Only show tooltips when mouse pointer is still

Revert to the old behavior by setting
`style.interaction.show_tooltips_only_when_still = false`.

CHANGELOG.md

@@ -21,6 +21,7 @@ NOTE: [`epaint`](crates/epaint/CHANGELOG.md), [`eframe`](crates/eframe/CHANGELOG
 
 ### Changed 🔧
 * Panels always have a separator line, but no stroke on other sides. Their spacing has also changed slightly ([#2261](https://github.com/emilk/egui/pull/2261)).
+* Tooltips are only shown when mouse pointer is still ([#2263](https://github.com/emilk/egui/pull/2263)).
 
 ### Fixed 🐛
 * ⚠️ BREAKING: Fix text being too small ([#2069](https://github.com/emilk/egui/pull/2069)).

crates/egui/src/containers/popup.rs

@@ -6,13 +6,13 @@ use crate::*;
 
 /// Same state for all tooltips.
 #[derive(Clone, Debug, Default)]
-pub(crate) struct MonoState {
+pub(crate) struct PopupState {
     last_id: Option<Id>,
     last_size: Vec<Vec2>,
 }
 
-impl MonoState {
-    fn load(ctx: &Context) -> Option<Self> {
+impl PopupState {
+    pub fn load(ctx: &Context) -> Option<Self> {
         ctx.data().get_temp(Id::null())
     }
 
@@ -45,6 +45,10 @@ impl MonoState {
         self.last_size.extend((0..index).map(|_| Vec2::ZERO));
         self.last_size.push(size);
     }
+
+    pub fn is_open(ctx: &Context, id: &Id) -> bool {
+        Self::load(ctx).map_or(false, |state| state.last_id == Some(*id))
+    }
 }
 
 // ----------------------------------------------------------------------------
@@ -181,7 +185,7 @@ fn show_tooltip_at_avoid_dyn<'c, R>(
         return None; // No good place for a tooltip :(
     };
 
-    let mut state = MonoState::load(ctx).unwrap_or_default();
+    let mut state = PopupState::load(ctx).unwrap_or_default();
     let expected_size = state.tooltip_size(id, count);
     let expected_size = expected_size.unwrap_or_else(|| vec2(64.0, 32.0));
 

crates/egui/src/response.rs

@@ -395,12 +395,18 @@ impl Response {
             return false;
         }
 
-        if self.ctx.style().interaction.show_tooltips_only_when_still
-            && !self.ctx.input().pointer.is_still()
-        {
-            // wait for mouse to stop
-            self.ctx.request_repaint();
-            return false;
+        if self.ctx.style().interaction.show_tooltips_only_when_still {
+            // We only show the tooltip when the mouse pointer is still,
+            // but once shown we keep showing it until the mouse leaves the parent.
+
+            use crate::containers::popup::PopupState;
+
+            let is_pointer_still = self.ctx.input().pointer.is_still();
+            if !is_pointer_still && !PopupState::is_open(&self.ctx, &self.id.with("__tooltip")) {
+                // wait for mouse to stop
+                self.ctx.request_repaint();
+                return false;
+            }
         }
 
         // We don't want tooltips of things while we are dragging them,

crates/egui/src/style.rs

@@ -668,7 +668,7 @@ impl Default for Interaction {
         Self {
             resize_grab_radius_side: 5.0,
             resize_grab_radius_corner: 10.0,
-            show_tooltips_only_when_still: false,
+            show_tooltips_only_when_still: true,
         }
     }
 }