From 2bb8a74010fc5d50c6b13ffd336ce5042f955554 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Fri, 31 May 2024 17:05:02 +0200
Subject: [PATCH] WIP: interact with contents of tooltips

---
 crates/egui/src/containers/popup.rs |  7 ++++++-
 crates/egui/src/layers.rs           |  2 +-
 crates/egui/src/response.rs         | 31 ++++++++++++++++++++++++++---
 3 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/crates/egui/src/containers/popup.rs b/crates/egui/src/containers/popup.rs
index 661de610712b..76f1c6dd27cb 100644
--- a/crates/egui/src/containers/popup.rs
+++ b/crates/egui/src/containers/popup.rs
@@ -135,7 +135,7 @@ fn show_tooltip_at_avoid_dyn<'c, R>(
         .pivot(pivot)
         .fixed_pos(anchor)
         .default_width(ctx.style().spacing.tooltip_width)
-        .interactable(false)
+        // .interactable(false)
         .show(ctx, |ui| {
             Frame::popup(&ctx.style()).show_dyn(ui, add_contents).inner
         });
@@ -234,6 +234,11 @@ pub fn was_tooltip_open_last_frame(ctx: &Context, widget_id: Id) -> bool {
     })
 }
 
+pub fn tooltip_area_state(ctx: &Context, widget_id: Id) -> Option<AreaState> {
+    let primary_tooltip_area_id = tooltip_id(widget_id, 0);
+    AreaState::load(ctx, primary_tooltip_area_id)
+}
+
 /// Helper for [`popup_above_or_below_widget`].
 pub fn popup_below_widget<R>(
     ui: &Ui,
diff --git a/crates/egui/src/layers.rs b/crates/egui/src/layers.rs
index b9b1fb5a5c38..5e5ad0838db8 100644
--- a/crates/egui/src/layers.rs
+++ b/crates/egui/src/layers.rs
@@ -49,7 +49,7 @@ impl Order {
             | Self::Middle
             | Self::Foreground
             | Self::Debug => true,
-            Self::Tooltip => false,
+            Self::Tooltip => true,
         }
     }
 
diff --git a/crates/egui/src/response.rs b/crates/egui/src/response.rs
index 8697a9743a50..7cceb4092ac8 100644
--- a/crates/egui/src/response.rs
+++ b/crates/egui/src/response.rs
@@ -2,8 +2,8 @@ use std::{any::Any, sync::Arc};
 
 use crate::{
     emath::{Align, Pos2, Rect, Vec2},
-    menu, ComboBox, Context, CursorIcon, Id, LayerId, PointerButton, Sense, Ui, WidgetRect,
-    WidgetText,
+    menu, tooltip_area_state, ComboBox, Context, CursorIcon, Id, LayerId, PointerButton, Sense, Ui,
+    WidgetRect, WidgetText,
 };
 
 // ----------------------------------------------------------------------------
@@ -570,6 +570,31 @@ impl Response {
             return true;
         }
 
+        let is_tooltip_open = self.is_tooltip_open();
+
+        if is_tooltip_open {
+            if let Some(area) = tooltip_area_state(&self.ctx, self.id) {
+                // We keep the tooltip open if hovered,
+                // or if the pointer is on its way to it,
+                // so that the user can interact with the tooltip
+                // (i.e. click links that are in it).
+
+                let rect = area.rect();
+                let pointer_in_area_or_on_the_way_there = self.ctx.input(|i| {
+                    if let Some(pos) = i.pointer.hover_pos() {
+                        rect.contains(pos)
+                            || rect.intersects_ray(pos, i.pointer.velocity().normalized())
+                    } else {
+                        false
+                    }
+                });
+
+                if pointer_in_area_or_on_the_way_there {
+                    return true;
+                }
+            }
+        }
+
         // Fast early-outs:
         if self.enabled {
             if !self.hovered || !self.ctx.input(|i| i.pointer.has_pointer()) {
@@ -605,7 +630,7 @@ impl Response {
         let tooltip_was_recently_shown = when_was_a_toolip_last_shown
             .map_or(false, |time| ((now - time) as f32) < tooltip_grace_time);
 
-        if !tooltip_was_recently_shown && !self.is_tooltip_open() {
+        if !tooltip_was_recently_shown && !is_tooltip_open {
             if self.ctx.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()) {