feat(edit): STRETCH crossing window selects objects implicitly (#338)

Bare STRETCH used to need a separate object-selection round before the
crossing window. Now the window itself picks the objects: with no prior
selection the command emits StretchWindow, the host gathers entities
whose world AABB touches the window (locked layers excluded) and
restarts at the base-point step. Over-selection is harmless since only
points inside the window move. The noun-verb flow (select first, then
STRETCH) is unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/app/command_driver.rs

@@ -1404,6 +1404,49 @@ impl OpenCADStudio {
                 self.restore_pre_cmd_tangent();
                 return self.on_quick_print_handles(handles);
             }
+            CmdResult::StretchWindow { win_min, win_max } => {
+                // Implicit STRETCH selection (#338): the crossing window drawn
+                // with no prior selection picks the objects itself. Entities
+                // whose world AABB touches the window are handed back to the
+                // command at the base-point step — over-selection is harmless,
+                // since only points INSIDE the window move anyway.
+                let mut handles: Vec<Handle> = Vec::new();
+                {
+                    let scene = &self.tabs[i].scene;
+                    let mut seen: rustc_hash::FxHashSet<Handle> = rustc_hash::FxHashSet::default();
+                    for w in scene.entity_wires().iter() {
+                        let Some(h) = crate::scene::Scene::handle_from_wire_name(&w.name) else {
+                            continue;
+                        };
+                        if !seen.insert(h) || scene.is_layer_locked(h) {
+                            continue;
+                        }
+                        let [ax, ay, bx, by] = w.aabb;
+                        if ax as f64 <= win_max.x
+                            && bx as f64 >= win_min.x
+                            && ay as f64 <= win_max.y
+                            && by as f64 >= win_min.y
+                        {
+                            handles.push(h);
+                        }
+                    }
+                }
+                if handles.is_empty() {
+                    self.command_line
+                        .push_output("STRETCH: nothing crosses the window.");
+                    self.tabs[i].active_cmd = None;
+                    self.tabs[i].snap_result = None;
+                    self.tabs[i].scene.clear_preview_wire();
+                    self.restore_pre_cmd_tangent();
+                } else {
+                    use crate::command::CadCommand;
+                    use crate::modules::draw::modify::stretch::StretchCommand;
+                    let wires = self.tabs[i].scene.wire_models_for(&handles);
+                    let cmd = StretchCommand::with_window(handles, wires, win_min, win_max);
+                    self.command_line.push_info(&CadCommand::prompt(&cmd));
+                    self.tabs[i].active_cmd = Some(Box::new(cmd));
+                }
+            }
             CmdResult::StretchEntities {
                 handles,
                 win_min,

src/app/commands/dim.rs

@@ -738,24 +738,26 @@ impl OpenCADStudio {
             }
 
             "STRETCH" => {
+                // With a prior selection the window only marks which points
+                // move. With none, the crossing window itself selects the
+                // objects — one round instead of a separate object-selection
+                // step (#338); the command emits StretchWindow for the host
+                // to resolve.
+                use crate::modules::draw::modify::stretch::StretchCommand;
                 let handles: Vec<_> = self.tabs[i]
                     .scene
                     .selected_entities()
                     .into_iter()
                     .map(|(h, _)| h)
                     .collect();
-                if handles.is_empty() {
-                    use crate::modules::draw::select::SelectObjectsCommand;
-                    let cmd = SelectObjectsCommand::new("STRETCH");
-                    self.command_line.push_info(&cmd.prompt());
-                    self.tabs[i].active_cmd = Some(Box::new(cmd));
+                let wires = if handles.is_empty() {
+                    Vec::new()
                 } else {
-                    use crate::modules::draw::modify::stretch::StretchCommand;
-                    let wires = self.tabs[i].scene.wire_models_for(&handles);
-                    let new_cmd = StretchCommand::new(handles, wires);
-                    self.command_line.push_info(&new_cmd.prompt());
-                    self.tabs[i].active_cmd = Some(Box::new(new_cmd));
-                }
+                    self.tabs[i].scene.wire_models_for(&handles)
+                };
+                let new_cmd = StretchCommand::new(handles, wires);
+                self.command_line.push_info(&new_cmd.prompt());
+                self.tabs[i].active_cmd = Some(Box::new(new_cmd));
             }
 
             "FILLET" => {

src/command.rs

@@ -908,6 +908,10 @@ pub enum CmdResult {
         scale: f32,
         angle: f32,
     },
+    /// Implicit STRETCH selection: the crossing window was drawn with no prior
+    /// selection, so the host resolves which entities it touches and restarts
+    /// the command at the base-point step with them. (#338)
+    StretchWindow { win_min: DVec3, win_max: DVec3 },
     /// Stretch entities: move only vertices/endpoints inside the crossing window.
     StretchEntities {
         handles: Vec<Handle>,

src/modules/draw/modify/stretch.rs

@@ -64,6 +64,22 @@ impl StretchCommand {
             step: Step::WindowCorner1,
         }
     }
+
+    /// Restart at the base-point step with the window already known — the
+    /// implicit-selection flow: the host resolved which entities the crossing
+    /// window touches and hands them in together with the window. (#338)
+    pub fn with_window(
+        handles: Vec<Handle>,
+        wire_models: Vec<WireModel>,
+        win_min: DVec3,
+        win_max: DVec3,
+    ) -> Self {
+        Self {
+            handles,
+            wire_models,
+            step: Step::Base { win_min, win_max },
+        }
+    }
 }
 
 impl CadCommand for StretchCommand {
@@ -73,10 +89,18 @@ impl CadCommand for StretchCommand {
 
     fn prompt(&self) -> String {
         match &self.step {
-            Step::WindowCorner1 => format!(
-                "STRETCH  Specify first corner of crossing window  [{} objects]:",
-                self.handles.len()
-            ),
+            Step::WindowCorner1 => {
+                if self.handles.is_empty() {
+                    // Implicit mode: the window both selects the objects and
+                    // marks which of their points move.
+                    "STRETCH  Specify first corner of crossing window:".into()
+                } else {
+                    format!(
+                        "STRETCH  Specify first corner of crossing window  [{} objects]:",
+                        self.handles.len()
+                    )
+                }
+            }
             Step::WindowCorner2(_) => "STRETCH  Specify opposite corner:".into(),
             Step::Base { .. } => "STRETCH  Specify base point:".into(),
             Step::Target { base, .. } => format!(
@@ -95,6 +119,12 @@ impl CadCommand for StretchCommand {
             Step::WindowCorner2(c1) => {
                 let win_min = c1.min(pt);
                 let win_max = c1.max(pt);
+                if self.handles.is_empty() {
+                    // Implicit mode: hand the window to the host, which
+                    // resolves the touched entities and restarts the command
+                    // at the base-point step via `with_window`. (#338)
+                    return CmdResult::StretchWindow { win_min, win_max };
+                }
                 self.step = Step::Base { win_min, win_max };
                 CmdResult::NeedPoint
             }