address review: same distance test in width profile lower bound; preview the whole drag when a symbolism tool deactivates

crates/doc/src/appearance/profile.rs

@@ -90,7 +90,8 @@ impl WidthProfile {
     /// discontinuous point (two points at `t`, within `1e-7`).
     pub fn around(&self, t: f64) -> ((f64, f64), (f64, f64)) {
         let p = &self.points;
-        let i = p.partition_point(|q| q.0 < t - 1e-7);
+        // The same distance test below, so a point exactly 1e-7 before `t` is never skipped by rounding.
+        let i = p.partition_point(|q| q.0 < t && (q.0 - t).abs() > 1e-7);
         if let Some(first) = p.get(i).filter(|q| (q.0 - t).abs() <= 1e-7) {
             let j = i + p[i..].partition_point(|q| q.0 - first.0 <= 1e-9) - 1;
             if j > i {
@@ -353,5 +354,8 @@ mod tests {
         // Many points at one position are one step, found without a pass over them all.
         let many = WidthProfile { points: (0..1000).map(|i| (0.5, i as f64, i as f64)).collect() };
         assert_eq!(many.around(0.5), ((0.0, 0.0), (999.0, 999.0)));
+        // 0.4999999 == 0.5 - 1e-7, yet its distance from 0.5 rounds above 1e-7: it is not part of the step.
+        let near = WidthProfile { points: vec![(0.4999999, 2.0, 2.0), (0.5, 1.0, 1.0), (0.5, 0.5, 0.25)] };
+        assert_eq!(near.around(0.5), ((1.0, 1.0), (0.5, 0.25)));
     }
 }

crates/tools/src/symbolism.rs

@@ -117,6 +117,19 @@ impl SymbolismTool {
     }
 }
 
+impl SymbolismTool {
+    /// Ends the drag: what is committed is the last preview, so the whole drag is shown first.
+    fn finish(&mut self, cx: &ToolContext) -> Vec<Action> {
+        self.active = false;
+        let stale = (self.previewed != self.points.len()).then(|| {
+            let (c, v) = self.command(cx);
+            Action::Preview(c, v)
+        });
+        self.points.clear();
+        stale.into_iter().chain([Action::Commit]).collect()
+    }
+}
+
 impl Tool for SymbolismTool {
     fn id(&self) -> &'static str {
         self.id
@@ -151,16 +164,7 @@ impl Tool for SymbolismTool {
                 let (c, v) = self.command(cx);
                 vec![Action::Preview(c, v)]
             }
-            PointerKind::Up if self.active => {
-                self.active = false;
-                // What is committed is the last preview: show the whole drag first.
-                let stale = (self.previewed != self.points.len()).then(|| {
-                    let (c, v) = self.command(cx);
-                    Action::Preview(c, v)
-                });
-                self.points.clear();
-                stale.into_iter().chain([Action::Commit]).collect()
-            }
+            PointerKind::Up if self.active => self.finish(cx),
             _ => vec![],
         }
     }
@@ -182,11 +186,9 @@ impl Tool for SymbolismTool {
         }
         vec![]
     }
-    fn deactivate(&mut self, _cx: &ToolContext) -> Vec<Action> {
+    fn deactivate(&mut self, cx: &ToolContext) -> Vec<Action> {
         if self.active {
-            self.active = false;
-            self.points.clear();
-            return vec![Action::Commit];
+            return self.finish(cx);
         }
         vec![]
     }
@@ -335,6 +337,23 @@ mod tests {
         assert_eq!(up.last(), Some(&Action::Commit));
     }
 
+    #[test]
+    fn switching_tools_mid_drag_previews_the_whole_drag_before_committing() {
+        let (d, _) = doc_with_rect();
+        let (s, p) = (Selection::default(), paint());
+        let cx = cx(&d, &s, &p);
+        let mut t = SymbolismTool::new("symbolShifter");
+        t.pointer(&cx, &PointerEvent::new(PointerKind::Down, 0.0, 0.0));
+        let n = 7 * crate::PREVIEW_ALL_UNTIL + 1; // not a point that previews
+        for i in 1..n {
+            t.pointer(&cx, &PointerEvent::new(PointerKind::Drag, 50.0 * i as f64, 0.0));
+        }
+        let a = t.deactivate(&cx);
+        assert!(matches!(a.first(), Some(Action::Preview(_, v)) if v["points"].as_array().unwrap().len() == n), "{a:?}");
+        assert_eq!(a.last(), Some(&Action::Commit));
+        assert!(!t.busy());
+    }
+
     #[test]
     fn adjust_tools_map_to_symbol_adjust() {
         let (d, _) = doc_with_rect();