Repair outgoing allocation drag boundary placement and feedback

crates/oa-desktop/src/allocation_drag.rs

@@ -210,7 +210,6 @@ impl SemanticPlan {
     pub fn project(&self) -> &Project {
         &self.candidate
     }
-    #[cfg(test)]
     pub fn index(&self) -> &ViewIndex {
         &self.index
     }
@@ -485,6 +484,57 @@ pub struct PresentationContext {
     pub target: Option<TargetPresentation>,
 }
 
+impl PresentationContext {
+    fn header_visible(self, header: Rect, outgoing: bool) -> bool {
+        if !outgoing {
+            return self.viewport.contains(header);
+        }
+        // Leaving a performer must not require fitting the entire work card
+        // inside the camera. Retain a 24px grab region so the result stays
+        // directly reachable; geometry/model admission is independent.
+        let width = (header.position.x + header.size.width)
+            .min(self.viewport.position.x + self.viewport.size.width)
+            - header.position.x.max(self.viewport.position.x);
+        let height = (header.position.y + header.size.height)
+            .min(self.viewport.position.y + self.viewport.size.height)
+            - header.position.y.max(self.viewport.position.y);
+        width * self.zoom >= 24. && height * self.zoom >= 24.
+    }
+}
+
+#[test]
+fn outgoing_header_retains_a_grab_region_without_requiring_full_camera_containment() {
+    let context = PresentationContext {
+        viewport: Rect {
+            position: Position { x: 0., y: 0. },
+            size: Size {
+                width: 800.,
+                height: 400.,
+            },
+        },
+        zoom: 0.75,
+        target: None,
+    };
+    let mut header = Rect {
+        position: Position { x: -100., y: 30. },
+        size: Size {
+            width: 224.,
+            height: 62.,
+        },
+    };
+    assert!(context.header_visible(header, true));
+    assert!(!context.header_visible(header, false));
+    header.position.x = -192.; // exactly 32 world pixels = 24 logical pixels
+    assert!(context.header_visible(header, true));
+    header.position.x -= 1.;
+    assert!(!context.header_visible(header, true));
+    header.position.x = 0.;
+    header.position.y = 368.;
+    assert!(context.header_visible(header, true));
+    header.position.y += 1.;
+    assert!(!context.header_visible(header, true));
+}
+
 #[derive(Debug)]
 pub struct PlacementPlan {
     pub diagram: Diagram,
@@ -496,8 +546,8 @@ pub struct PlacementPlan {
     commands: Vec<Command>,
 }
 
-/// `requested` is the original selected placement position plus pointer motion
-/// in the frozen transform (therefore preserving the press offset). Snap only
+/// `requested` preserves the frozen pointer offset unless the caller proposes
+/// bounded outward clearance for an outgoing drop. Snap only
 /// this root; apply the resulting identical delta to captured Q and its routes.
 /// No whole Project clone, validator or semantic ViewIndex rebuild occurs here.
 pub fn place(
@@ -577,7 +627,7 @@ pub fn place(
             height: selected.size.height.min(62.),
         },
     };
-    if !presentation.viewport.contains(header) {
+    if !presentation.header_visible(header, plan.destination == Destination::OutsidePerformers) {
         return Err(Refusal::LayoutRequired(
             "Make room or adjust the view, then drag again.".into(),
         ));