feat(iced): implement shape cycling for overlapping vector shapes

hcie-iced-app/crates/hcie-iced-gui/src/app.rs

@@ -346,6 +346,9 @@ pub struct IcedDocument {
     pub marching_ants_edges: Option<Arc<Vec<(u32, u32, u32, u32)>>>,
     /// Index of the currently selected vector shape (None = no selection).
     pub selected_vector_shape: Option<usize>,
+    /// Index into the list of shapes at the current click position for cycling
+    /// through overlapping vector shapes. Resets to 0 when clicking a new position.
+    pub vector_cycle_index: usize,
     /// Which vector edit handle is active (hovered or being dragged).
     pub vector_edit_handle: hcie_engine_api::VectorEditHandle,
 }
@@ -1017,6 +1020,7 @@ impl HcieIcedApp {
             selection_edge_cache: Default::default(),
             marching_ants_edges: None,
             selected_vector_shape: None,
+            vector_cycle_index: 0,
             vector_edit_handle: hcie_engine_api::VectorEditHandle::None,
         };
 
@@ -3075,6 +3079,7 @@ impl HcieIcedApp {
                     selection_edge_cache: Default::default(),
                     marching_ants_edges: None,
                     selected_vector_shape: None,
+                    vector_cycle_index: 0,
                     vector_edit_handle: hcie_engine_api::VectorEditHandle::None,
                 });
                 self.active_doc = self.documents.len() - 1;
@@ -3483,21 +3488,63 @@ impl HcieIcedApp {
                     }
                 }
 
-                // Hit-test vector shapes under cursor; select the topmost one.
+                // Find ALL shapes at the click position for cycling support.
-                if let Some(idx) = self.documents[self.active_doc].engine.find_vector_shape_at(x, y) {
+                // Collect indices of shapes whose bounding box contains (x, y),
-                    // Save snapshot before editing (for undo).
+                // iterating forward so index 0 is the bottom-most shape.
-                    let snapshot = self.documents[self.active_doc].engine.active_vector_shapes();
+                if let Some(shapes) = self.documents[self.active_doc].engine.active_vector_shapes() {
-                    self.vector_shapes_snapshot = snapshot;
+                    let hits: Vec<usize> = shapes.iter().enumerate()
-                    let doc = &mut self.documents[self.active_doc];
+                        .filter(|(_, s)| {
-                    doc.selected_vector_shape = Some(idx);
+                            let (l, t, r, b) = s.normalized_bounds();
-                    doc.vector_draw = None; // clear any preview
+                            x >= l && x <= r && y >= t && y <= b
-                    doc.vector_edit_handle = VEH::Move;
+                        })
-                    self.vector_drag_last = Some((x, y));
+                        .map(|(i, _)| i)
-                    crate::shape_sync::sync_tool_from_shape(self);
+                        .collect();
+
+                    if !hits.is_empty() {
+                        // Save snapshot before editing (for undo).
+                        let snapshot = self.documents[self.active_doc].engine.active_vector_shapes();
+                        self.vector_shapes_snapshot = snapshot;
+
+                        let doc = &mut self.documents[self.active_doc];
+                        let currently_selected = doc.selected_vector_shape;
+
+                        // If clicking on a position where a shape is already selected,
+                        // cycle through overlapping shapes.
+                        if let Some(cur_idx) = currently_selected {
+                            if hits.contains(&cur_idx) {
+                                // The current selection is among the hits — cycle to the next.
+                                let next_pos = (doc.vector_cycle_index + 1) % hits.len();
+                                doc.vector_cycle_index = next_pos;
+                                doc.selected_vector_shape = Some(hits[next_pos]);
+                            } else {
+                                // Clicked on a different region — select topmost and reset cycle.
+                                doc.vector_cycle_index = 0;
+                                doc.selected_vector_shape = Some(*hits.last().unwrap());
+                            }
+                        } else {
+                            // No shape was selected — pick the topmost (last in hits) and reset cycle.
+                            doc.vector_cycle_index = 0;
+                            doc.selected_vector_shape = Some(*hits.last().unwrap());
+                        }
+
+                        doc.vector_draw = None; // clear any preview
+                        doc.vector_edit_handle = VEH::Move;
+                        self.vector_drag_last = Some((x, y));
+                        crate::shape_sync::sync_tool_from_shape(self);
+                    } else {
+                        // No shape under cursor — deselect.
+                        let doc = &mut self.documents[self.active_doc];
+                        doc.selected_vector_shape = None;
+                        doc.vector_cycle_index = 0;
+                        doc.vector_edit_handle = VEH::None;
+                        self.vector_shapes_snapshot = None;
+                        self.vector_drag_last = None;
+                    }
                 } else {
-                    // No shape under cursor — deselect.
+                    // No vector shapes on this layer — deselect.
                     let doc = &mut self.documents[self.active_doc];
                     doc.selected_vector_shape = None;
+                    doc.vector_cycle_index = 0;
                     doc.vector_edit_handle = VEH::None;
                     self.vector_shapes_snapshot = None;
                     self.vector_drag_last = None;
@@ -3555,6 +3602,7 @@ impl HcieIcedApp {
                     let layer_id = self.documents[self.active_doc].engine.active_layer_id();
                     self.documents[self.active_doc].engine.delete_vector_shape(layer_id, idx);
                     self.documents[self.active_doc].selected_vector_shape = None;
+                    self.documents[self.active_doc].vector_cycle_index = 0;
                     self.vector_shapes_snapshot = None;
                     self.documents[self.active_doc].engine.mark_composite_dirty();
                     self.refresh_composite_if_needed();
@@ -3566,10 +3614,12 @@ impl HcieIcedApp {
             Message::VectorShapeSelect(idx) => {
                 self.documents[self.active_doc].selected_vector_shape = idx;
                 if idx.is_some() {
+                    self.documents[self.active_doc].vector_cycle_index = 0;
                     let snapshot = self.documents[self.active_doc].engine.active_vector_shapes();
                     self.vector_shapes_snapshot = snapshot;
                     crate::shape_sync::sync_tool_from_shape(self);
                 } else {
+                    self.documents[self.active_doc].vector_cycle_index = 0;
                     self.vector_shapes_snapshot = None;
                 }
             }
@@ -3578,6 +3628,7 @@ impl HcieIcedApp {
                 // Commit edits: clear snapshot and deselect.
                 let doc = &mut self.documents[self.active_doc];
                 doc.selected_vector_shape = None;
+                doc.vector_cycle_index = 0;
                 doc.vector_edit_handle = hcie_engine_api::VectorEditHandle::None;
                 self.vector_shapes_snapshot = None;
                 self.vector_drag_last = None;
@@ -3591,6 +3642,7 @@ impl HcieIcedApp {
                         *shapes = snapshot;
                     }
                     doc.selected_vector_shape = None;
+                    doc.vector_cycle_index = 0;
                     doc.vector_edit_handle = hcie_engine_api::VectorEditHandle::None;
                     self.vector_drag_last = None;
                     doc.engine.mark_composite_dirty();
@@ -4545,6 +4597,7 @@ impl HcieIcedApp {
                     selection_edge_cache: Default::default(),
                     marching_ants_edges: None,
                     selected_vector_shape: None,
+                    vector_cycle_index: 0,
                     vector_edit_handle: hcie_engine_api::VectorEditHandle::None,
                 });
             }