Combine source navigation and alias rename with canvas ownership guards

crates/oa-desktop/src/diagram.rs

@@ -47,6 +47,8 @@ pub struct DiagramCanvas<'a> {
     pub view_index: Option<&'a oa_core::view_options::ViewIndex>,
     pub diagram: Id,
     pub selected: Id,
+    /// Presentation-only navigation marker; never used by hit tests or edits.
+    pub navigation_focus: Option<Rectangle>,
     pub zoom: f32,
     pub pan: Vector,
     pub context: Context,
@@ -1323,6 +1325,14 @@ impl canvas::Program<Message> for DiagramCanvas<'_> {
                 f.fill(&Path::circle(center, 1.5), color);
             }
         }
+        if let Some(bounds) = self.navigation_focus {
+            f.stroke(
+                &Path::rectangle(bounds.position(), bounds.size()),
+                Stroke::default()
+                    .with_color(style::TEAL)
+                    .with_width(2.5 / self.zoom),
+            );
+        }
         if let Some(edge) = scene.routed.edges.get(&self.selected)
             && !edge.custom_suspended
         {
@@ -2038,6 +2048,7 @@ mod tests {
             allocation: None,
             diagram,
             selected: p.id,
+            navigation_focus: None,
             zoom: 1.,
             pan: Vector::ZERO,
         };
@@ -2113,6 +2124,7 @@ mod tests {
             allocation: None,
             diagram,
             selected: p.id,
+            navigation_focus: None,
             zoom: 0.6,
             pan: Vector::new(10., 20.),
         };
@@ -2229,6 +2241,7 @@ mod tests {
                 diagram,
                 context,
                 selected: p.id,
+                navigation_focus: None,
                 selected_bend: None,
                 zoom,
                 pan: Vector::new(20., 30.),
@@ -2399,6 +2412,7 @@ mod tests {
                 view_index: None,
                 diagram,
                 selected: edge,
+                navigation_focus: None,
                 zoom,
                 pan: Vector::new(150., 300.),
                 context: Context {
@@ -2475,6 +2489,7 @@ mod tests {
             view_index: None,
             diagram,
             selected: edge,
+            navigation_focus: None,
             zoom: 0.5,
             pan: Vector::new(150., 300.),
             context: Context {
@@ -2572,6 +2587,7 @@ mod tests {
             view_index: None,
             diagram,
             selected: edge,
+            navigation_focus: None,
             zoom: 1.,
             pan: Vector::new(150., 300.),
             context: Context {
@@ -2700,6 +2716,7 @@ mod tests {
                 view_index: None,
                 diagram,
                 selected: edge,
+                navigation_focus: None,
                 zoom: 0.7,
                 pan: Vector::new(350., 350.),
                 context: Context {
@@ -2754,6 +2771,7 @@ mod tests {
             view_index: None,
             diagram,
             selected: p.id,
+            navigation_focus: None,
             zoom: 1.,
             pan: Vector::new(100., 400.),
             context: Context {
@@ -2828,6 +2846,7 @@ mod tests {
             view_index: None,
             diagram,
             selected: edge,
+            navigation_focus: None,
             zoom: 1.,
             pan: Vector::new(100., 400.),
             context: Context {
@@ -2861,6 +2880,7 @@ mod tests {
             view_index: None,
             diagram,
             selected,
+            navigation_focus: None,
             zoom: 1.,
             pan: Vector::ZERO,
             context: Context {