Make the Select tool re-select initially selected layers upon pressing Shift during box selection

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

@@ -281,6 +281,10 @@ struct SelectToolData {
 	selected_layers_changed: bool,
 	snap_candidates: Vec<SnapCandidatePoint>,
 	auto_panning: AutoPanning,
+	previously_selected_layers: Vec<LayerNodeIdentifier>,
+	previous_selected: bool,
+	restore_selection_debounce: bool,
+	shift_pressed_before_drag: bool,
 }
 
 impl SelectToolData {
@@ -557,6 +561,7 @@ impl Fsm for SelectToolFsmState {
 					.collect();
 				let intersection_list = document.click_list(input).collect::<Vec<_>>();
 				let intersection = document.find_deepest(&intersection_list);
+				tool_data.previously_selected_layers = selected.clone();
 
 				// If the user is dragging the bounding box bounds, go into ResizingBounds mode.
 				// If the user is dragging the rotate trigger, go into RotatingBounds mode.
@@ -656,10 +661,14 @@ impl Fsm for SelectToolFsmState {
 				// Dragging a selection box
 				else {
 					tool_data.layers_dragging = selected;
+					tool_data.previous_selected = true;
+					tool_data.shift_pressed_before_drag = true;
 
 					if !input.keyboard.key(extend_selection) {
 						responses.add(DocumentMessage::DeselectAllLayers);
 						tool_data.layers_dragging.clear();
+						tool_data.previous_selected = false;
+						tool_data.shift_pressed_before_drag = false
 					}
 
 					if let Some(intersection) = intersection {
@@ -672,14 +681,14 @@ impl Fsm for SelectToolFsmState {
 						}
 						tool_data.get_snap_candidates(document, input);
 
-						responses.add(DocumentMessage::StartTransaction);
-						SelectToolFsmState::Dragging
-					} else {
-						// Make a box selection, preserving previously selected layers
-						let selection = tool_data.nested_selection_behavior;
-						SelectToolFsmState::DrawingBox { selection }
-					}
-				};
+							responses.add(DocumentMessage::StartTransaction);
+							SelectToolFsmState::Dragging
+						} else {
+							// Make a box selection, preserving previously selected layers
+							let selection = tool_data.nested_selection_behavior;
+							SelectToolFsmState::DrawingBox { selection }
+						}
+					};
 				tool_data.non_duplicated_layers = None;
 
 				state
@@ -826,6 +835,43 @@ impl Fsm for SelectToolFsmState {
 			}
 			(SelectToolFsmState::DrawingBox { .. }, SelectToolMessage::PointerMove(modifier_keys)) => {
 				tool_data.drag_current = input.mouse.position;
+
+				let selection_set: HashSet<_> = tool_data.previously_selected_layers.iter().collect();
+
+				if input.keyboard.key(Key::Shift) && !tool_data.restore_selection_debounce {
+					log::info!("when shift is pressed:{:?}", tool_data.previous_selected);
+					tool_data.layers_dragging.extend(&tool_data.previously_selected_layers);
+					tool_data.previous_selected = false;
+					tool_data.restore_selection_debounce = true;
+				}
+
+				if !input.keyboard.key(Key::Shift) && tool_data.restore_selection_debounce {
+					if tool_data.previous_selected {
+						tool_data.layers_dragging.extend(&tool_data.previously_selected_layers);
+					} else {
+						tool_data.layers_dragging.retain(|layer| !selection_set.contains(layer));
+					}
+					if tool_data.shift_pressed_before_drag {
+						tool_data.layers_dragging.extend(&tool_data.previously_selected_layers);
+						tool_data.shift_pressed_before_drag = false;
+					}
+					tool_data.restore_selection_debounce = false;
+				}
+
+				let selected_nodes: Vec<_> = tool_data
+					.layers_dragging
+					.iter()
+					.filter_map(|layer| {
+						if *layer != LayerNodeIdentifier::ROOT_PARENT {
+							Some(layer.to_node())
+						} else {
+							log::error!("ROOT_PARENT found in tool_data.layers_dragging during selection set");
+							None
+						}
+					})
+					.collect();
+
+				responses.add(NodeGraphMessage::SelectedNodesSet { nodes: selected_nodes });
 				responses.add(OverlaysMessage::Draw);
 
 				// AutoPanning