Improve Pen tool behavior to less aggressively delete single-point layers (#2605)

* add single-anchor-place

* clippy_changes

---------

Co-authored-by: Keavon Chambers <[email protected]>

Author: 0SlowPoke0

editor/src/messages/tool/tool_messages/pen_tool.rs

@@ -608,7 +608,9 @@ impl PenToolData {
 
 		// Get close path
 		let mut end = None;
-		let layer = self.current_layer?;
+		let selected_nodes = document.network_interface.selected_nodes();
+		let mut selected_layers = selected_nodes.selected_layers(document.metadata());
+		let layer = selected_layers.next().filter(|_| selected_layers.next().is_none()).or(self.current_layer)?;
 		let vector_data = document.network_interface.compute_modified_vector(layer)?;
 		let start = self.latest_point()?.id;
 		let transform = document.metadata().document_to_viewport * transform;
@@ -1029,7 +1031,9 @@ impl PenToolData {
 		let relative = if self.path_closed { None } else { self.latest_point().map(|point| point.pos) };
 		self.next_point = self.compute_snapped_angle(snap_data, transform, false, mouse, relative, true);
 
-		let layer = self.current_layer?;
+		let selected_nodes = document.network_interface.selected_nodes();
+		let mut selected_layers = selected_nodes.selected_layers(document.metadata());
+		let layer = selected_layers.next().filter(|_| selected_layers.next().is_none()).or(self.current_layer)?;
 		let vector_data = document.network_interface.compute_modified_vector(layer)?;
 		let transform = document.metadata().document_to_viewport * transform;
 		for point in vector_data.extendable_points(preferences.vector_meshes) {
@@ -1363,8 +1367,10 @@ impl Fsm for PenToolFsmState {
 			preferences,
 			..
 		} = tool_action_data;
+		let selected_nodes = document.network_interface.selected_nodes();
+		let mut selected_layers = selected_nodes.selected_layers(document.metadata());
+		let layer = selected_layers.next().filter(|_| selected_layers.next().is_none()).or(tool_data.current_layer);
 
-		let layer = tool_data.current_layer;
 		let mut transform = layer.map(|layer| document.metadata().transform_to_document(layer)).unwrap_or_default();
 
 		if !transform.inverse().is_finite() {
@@ -1666,7 +1672,13 @@ impl Fsm for PenToolFsmState {
 						.descendants(document.metadata())
 						.filter(|layer| !document.network_interface.is_artboard(&layer.to_node(), &[]));
 					if let Some((other_layer, _, _)) = should_extend(document, viewport, crate::consts::SNAP_POINT_TOLERANCE, layers, preferences) {
-						if let Some(current_layer) = tool_data.current_layer.filter(|layer| *layer != other_layer) {
+						let selected_nodes = document.network_interface.selected_nodes();
+						let mut selected_layers = selected_nodes.selected_layers(document.metadata());
+						if let Some(current_layer) = selected_layers
+							.next()
+							.filter(|current_layer| selected_layers.next().is_none() && *current_layer != other_layer)
+							.or(tool_data.current_layer.filter(|layer| *layer != other_layer))
+						{
 							merge_layers(document, current_layer, other_layer, responses);
 						}
 					}
@@ -1947,26 +1959,15 @@ impl Fsm for PenToolFsmState {
 				PenToolFsmState::Ready
 			}
 			(PenToolFsmState::PlacingAnchor, PenToolMessage::Confirm) => {
-				if let Some((vector_data, layer)) = layer.and_then(|layer| document.network_interface.compute_modified_vector(layer)).zip(layer) {
-					let single_point_in_layer = vector_data.point_domain.ids().len() == 1;
-
-					if single_point_in_layer {
-						responses.add(NodeGraphMessage::DeleteNodes {
-							node_ids: vec![layer.to_node()],
-							delete_children: true,
-						});
-						responses.add(NodeGraphMessage::RunDocumentGraph);
-					}
-				}
 				responses.add(DocumentMessage::EndTransaction);
 				tool_data.cleanup(responses);
 				tool_data.cleanup_target_selections(shape_editor, layer, document, responses);
 
 				PenToolFsmState::Ready
 			}
 			(PenToolFsmState::DraggingHandle(..), PenToolMessage::Abort) => {
+				responses.add(DocumentMessage::AbortTransaction);
 				if tool_data.handle_end.is_none() {
-					responses.add(DocumentMessage::AbortTransaction);
 					tool_data.cleanup(responses);
 					tool_data.cleanup_target_selections(shape_editor, layer, document, responses);
 
@@ -1977,7 +1978,7 @@ impl Fsm for PenToolFsmState {
 						.unwrap_or(PenToolFsmState::Ready)
 				}
 			}
-			(_, PenToolMessage::Abort) => {
+			(PenToolFsmState::PlacingAnchor, PenToolMessage::Abort) => {
 				let should_delete_layer = if let Some(vector_data) = layer.and_then(|layer| document.network_interface.compute_modified_vector(layer)) {
 					vector_data.point_domain.ids().len() == 1
 				} else {
@@ -1999,6 +2000,7 @@ impl Fsm for PenToolFsmState {
 
 				PenToolFsmState::Ready
 			}
+			(_, PenToolMessage::Abort) => PenToolFsmState::Ready,
 			(PenToolFsmState::DraggingHandle(..) | PenToolFsmState::PlacingAnchor, PenToolMessage::Undo) => {
 				if tool_data.point_index > 0 {
 					tool_data.point_index -= 1;