midi: return old values from cursor traits

crates/midi/src/clip/clip_editor.rs

@@ -160,14 +160,14 @@ impl NoteRange for MidiEditor {
 
 impl NotePoint for MidiEditor {
     fn note_len (&self) -> usize { self.mode.note_len() }
-    fn set_note_len (&self, x: usize) { self.mode.set_note_len(x) }
+    fn set_note_len (&self, x: usize) -> usize { self.mode.set_note_len(x) }
     fn note_pos (&self) -> usize { self.mode.note_pos() }
-    fn set_note_pos (&self, x: usize) { self.mode.set_note_pos(x) }
+    fn set_note_pos (&self, x: usize) -> usize { self.mode.set_note_pos(x) }
 }
 
 impl TimePoint for MidiEditor {
     fn time_pos (&self) -> usize { self.mode.time_pos() }
-    fn set_time_pos (&self, x: usize) { self.mode.set_time_pos(x) }
+    fn set_time_pos (&self, x: usize) -> usize { self.mode.set_time_pos(x) }
 }
 
 impl MidiViewer for MidiEditor {

crates/midi/src/note/note_point.rs

@@ -7,7 +7,7 @@ pub struct MidiPointModel {
     /// Note coordinate of cursor
     pub note_pos: Arc<AtomicUsize>,
     /// Length of note that will be inserted, in pulses
-    pub note_len:   Arc<AtomicUsize>,
+    pub note_len: Arc<AtomicUsize>,
 }
 
 impl Default for MidiPointModel {
@@ -21,30 +21,52 @@ impl Default for MidiPointModel {
 }
 
 pub trait NotePoint {
-    fn note_len       (&self) -> usize;
-    fn set_note_len   (&self, x: usize);
-    fn note_pos     (&self) -> usize;
-    fn set_note_pos (&self, x: usize);
-    fn note_end (&self) -> usize { self.note_pos() + self.note_len() }
+    /// Get the current length of the note cursor.
+    fn note_len (&self) -> usize;
+    /// Set the length of the note cursor, returning the previous value.
+    fn set_note_len (&self, x: usize) -> usize;
+    /// Get the current pitch of the note cursor.
+    fn note_pos (&self) -> usize;
+    /// Set the current pitch fo the note cursor, returning the previous value.
+    fn set_note_pos (&self, x: usize) -> usize;
 }
 
 pub trait TimePoint {
-    fn time_pos     (&self) -> usize;
-    fn set_time_pos (&self, x: usize);
+    /// Get the current time position of the note cursor.
+    fn time_pos (&self) -> usize;
+    /// Set the current time position of the note cursor, returning the previous value.
+    fn set_time_pos (&self, x: usize) -> usize;
 }
 
-pub trait MidiPoint: NotePoint + TimePoint {}
+pub trait MidiPoint: NotePoint + TimePoint {
+    /// Get the current end of the note cursor.
+    fn note_end (&self) -> usize {
+        self.time_pos() + self.note_len()
+    }
+}
 
 impl<T: NotePoint + TimePoint> MidiPoint for T {}
 
 impl NotePoint for MidiPointModel {
-    fn note_len (&self) -> usize { self.note_len.load(Relaxed)}
-    fn set_note_len (&self, x: usize) { self.note_len.store(x, Relaxed) }
-    fn note_pos (&self) -> usize { self.note_pos.load(Relaxed).min(127) }
-    fn set_note_pos (&self, x: usize) { self.note_pos.store(x.min(127), Relaxed) }
+    fn note_len (&self) -> usize {
+        self.note_len.load(Relaxed)
+    }
+    fn set_note_len (&self, x: usize) -> usize {
+        self.note_len.swap(x, Relaxed)
+    }
+    fn note_pos (&self) -> usize {
+        self.note_pos.load(Relaxed).min(127)
+    }
+    fn set_note_pos (&self, x: usize) -> usize {
+        self.note_pos.swap(x.min(127), Relaxed)
+    }
 }
 
 impl TimePoint for MidiPointModel {
-    fn time_pos (&self) -> usize { self.time_pos.load(Relaxed) }
-    fn set_time_pos (&self, x: usize) { self.time_pos.store(x, Relaxed) }
+    fn time_pos (&self) -> usize {
+        self.time_pos.load(Relaxed)
+    }
+    fn set_time_pos (&self, x: usize) -> usize {
+        self.time_pos.swap(x, Relaxed)
+    }
 }

crates/midi/src/piano/piano_h.rs

@@ -242,14 +242,14 @@ impl NoteRange for PianoHorizontal {
 
 impl NotePoint for PianoHorizontal {
     fn note_len (&self) -> usize { self.point.note_len() }
-    fn set_note_len (&self, x: usize) { self.point.set_note_len(x) }
+    fn set_note_len (&self, x: usize) -> usize { self.point.set_note_len(x) }
     fn note_pos (&self) -> usize { self.point.note_pos() }
-    fn set_note_pos (&self, x: usize) { self.point.set_note_pos(x) }
+    fn set_note_pos (&self, x: usize) -> usize { self.point.set_note_pos(x) }
 }
 
 impl TimePoint for PianoHorizontal {
     fn time_pos (&self) -> usize { self.point.time_pos() }
-    fn set_time_pos (&self, x: usize) { self.point.set_time_pos(x) }
+    fn set_time_pos (&self, x: usize) -> usize { self.point.set_time_pos(x) }
 }
 
 impl MidiViewer for PianoHorizontal {