From 0b3ce29eb333ee6c611649836f4d21606778fc8c Mon Sep 17 00:00:00 2001
From: bflatastic <bombayapirat@gmail.com>
Date: Sat, 24 Oct 2026 14:14:37 +0700
Subject: [PATCH] Canvas: hover distances go when the pointer leaves the canvas

---
 crates/engine/src/measure_tests.rs | 18 ++++++++++++++++++
 crates/engine/src/tools.rs         | 10 ++++++++++
 crates/ui-egui/src/canvas.rs       |  4 ++--
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/crates/engine/src/measure_tests.rs b/crates/engine/src/measure_tests.rs
index 539386bd..9f793721 100644
--- a/crates/engine/src/measure_tests.rs
+++ b/crates/engine/src/measure_tests.rs
@@ -250,3 +250,21 @@ fn measure_distances_command() {
     assert!(s.execute("measure.distances", &json!({"ids": [f]})).is_err(), "top level: pass `to`");
     assert!(s.execute("measure.distances", &json!({"ids": [r], "to": 99999})).is_err());
 }
+
+#[test]
+fn leaving_the_canvas_clears_the_hover_measurement() {
+    let mut s = Session::new();
+    let a = rect(&mut s, 0.0, 0.0, 50.0, 50.0, None);
+    rect(&mut s, 100.0, 0.0, 50.0, 50.0, None);
+    ex(&mut s, "select.set", json!({"ids": [a]}));
+    assert!(!hover(&mut s, 125.0, 25.0, true, false, false).is_empty());
+    assert!(s.tool.overlay.measure_box.is_some());
+    s.pointer_left();
+    assert!(s.tool.overlay.guides.is_empty(), "{:?}", s.tool.overlay.guides);
+    assert_eq!(s.tool.overlay.measure_box, None);
+    // Dev Mode measures without Alt; leaving clears those too.
+    s.tool.dev_mode = true;
+    assert!(!hover(&mut s, 125.0, 25.0, false, false, false).is_empty());
+    s.pointer_left();
+    assert!(s.tool.overlay.guides.is_empty());
+}
diff --git a/crates/engine/src/tools.rs b/crates/engine/src/tools.rs
index 86feed4f..15a244f7 100644
--- a/crates/engine/src/tools.rs
+++ b/crates/engine/src/tools.rs
@@ -941,6 +941,16 @@ pub(crate) fn scale_factor(handle: Handle, q: Point, w0: f64, h0: f64, anchor: (
 }
 
 impl Session {
+    /// The pointer left the canvas: what hovering there showed goes (the distances Alt or Dev Mode
+    /// measured and the box measured to, a vector region's highlight), unless a gesture holds it.
+    pub fn pointer_left(&mut self) {
+        if !self.tool.busy() {
+            self.tool.overlay.guides.clear();
+            self.tool.overlay.measure_box = None;
+        }
+        self.vector_pointer_left();
+    }
+
     /// What a marquee starting at page point `p` selects inside: the top-level frame it starts in
     /// (its children), or the focus view's frame.
     pub(crate) fn marquee_within(&self, p: Point) -> Result<Option<NodeId>> {
diff --git a/crates/ui-egui/src/canvas.rs b/crates/ui-egui/src/canvas.rs
index 5ced1edc..8942bbac 100644
--- a/crates/ui-egui/src/canvas.rs
+++ b/crates/ui-egui/src/canvas.rs
@@ -542,7 +542,7 @@ fn input(app: &mut FigApp, ui: &mut Ui, resp: &egui::Response) -> bool {
         }
         // Leaving the canvas: nothing is hovered there any more.
         if !app.canvas.dragging && std::mem::take(&mut app.canvas.hovering) {
-            app.session.vector_pointer_left();
+            app.session.pointer_left();
         }
         // A pan whose button was released off the canvas is over.
         if !ctx.input(|i| i.pointer.button_down(egui::PointerButton::Middle) || i.pointer.primary_down()) {
@@ -640,7 +640,7 @@ fn input(app: &mut FigApp, ui: &mut Ui, resp: &egui::Response) -> bool {
     } else {
         // Something over the canvas took the pointer.
         if std::mem::take(&mut app.canvas.hovering) {
-            app.session.vector_pointer_left();
+            app.session.pointer_left();
         }
         None
     };