Add draggable upstream nodes feature (#1812)

* drag upstream nodes, fix node deselection

* Ignore bottom layer inputs

* Fix amplified movement

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

editor/src/messages/portfolio/document/node_graph/node_graph_message.rs

@@ -67,6 +67,7 @@ pub enum NodeGraphMessage {
 	MoveSelectedNodes {
 		displacement_x: i32,
 		displacement_y: i32,
+		move_upstream: bool,
 	},
 	PasteNodes {
 		serialized_nodes: String,

editor/src/messages/portfolio/document/node_graph/node_graph_message_handler.rs

@@ -62,6 +62,9 @@ pub struct NodeGraphMessageHandler {
 	pub node_metadata: HashMap<NodeId, NodeMetadata>,
 	/// Cache for the bounding box around all nodes in node graph space.
 	pub bounding_box_subpath: Option<Subpath<PointId>>,
+	/// Index of selected node to be deselected on pointer up when shift clicking an already selected node
+	pub deselect_on_pointer_up: Option<usize>,
+	/// Adds the auto panning functionality to the node graph when dragging a node or selection box to the edge of the viewport.
 	auto_panning: AutoPanning,
 }
 
@@ -473,7 +476,11 @@ impl<'a> MessageHandler<NodeGraphMessage, NodeGraphHandlerData<'a>> for NodeGrap
 				responses.add(NodeGraphMessage::RunDocumentGraph);
 				responses.add(NodeGraphMessage::SendGraph);
 			}
-			NodeGraphMessage::MoveSelectedNodes { displacement_x, displacement_y } => {
+			NodeGraphMessage::MoveSelectedNodes {
+				displacement_x,
+				displacement_y,
+				move_upstream,
+			} => {
 				let network_path = if selected_nodes.selected_nodes_ref().iter().any(|node_id| document_network.nodes.contains_key(node_id)) {
 					Vec::new()
 				} else {
@@ -484,7 +491,20 @@ impl<'a> MessageHandler<NodeGraphMessage, NodeGraphHandlerData<'a>> for NodeGrap
 					warn!("No network");
 					return;
 				};
-				for node_id in selected_nodes.selected_nodes(network).cloned().collect::<Vec<_>>() {
+				let mut nodes_to_move = selected_nodes.selected_nodes(network).cloned().collect::<HashSet<_>>();
+				if move_upstream {
+					for selected_node_id in selected_nodes.selected_nodes(network) {
+						let Some(selected_node) = network.nodes.get(selected_node_id) else {
+							log::error!("Could not get selected node from network");
+							continue;
+						};
+						// Only drag nodes that are children of the selected layer
+						if let Some(NodeInput::Node { node_id, .. }) = selected_node.inputs.get(1) {
+							nodes_to_move.extend(network.upstream_flow_back_from_nodes(vec![*node_id], FlowType::UpstreamFlow).map(|(_, node_id)| node_id))
+						};
+					}
+				}
+				for node_id in nodes_to_move {
 					if document_network.nested_network(&network_path).unwrap().exports_metadata.0 == node_id {
 						let network = document_network.nested_network_mut(&network_path).unwrap();
 						network.exports_metadata.1 += IVec2::new(displacement_x, displacement_y);
@@ -761,12 +781,11 @@ impl<'a> MessageHandler<NodeGraphMessage, NodeGraphHandlerData<'a>> for NodeGrap
 						modified_selected = true;
 
 						let index = updated_selected.iter().enumerate().find_map(|(i, node_id)| if *node_id == clicked_id { Some(i) } else { None });
-						// Remove from selection if already selected
+						// Remove from selection (on PointerUp) if already selected
-						if let Some(index) = index {
+						self.deselect_on_pointer_up = index;
-							updated_selected.remove(index);
+
-						}
 						// Add to selection if not already selected. Necessary in order to drag multiple nodes
-						else {
+						if index.is_none() {
 							updated_selected.push(clicked_id);
 						};
 					}
@@ -807,7 +826,6 @@ impl<'a> MessageHandler<NodeGraphMessage, NodeGraphHandlerData<'a>> for NodeGrap
 				}
 				self.box_selection_start = Some(UVec2::new(viewport_location.x.round().abs() as u32, viewport_location.y.round().abs() as u32));
 			}
-			// TODO: Alt+drag should move all upstream nodes as well
 			NodeGraphMessage::PointerMove { shift } => {
 				let Some(network) = document_network.nested_network(&self.network) else {
 					return;
@@ -899,6 +917,7 @@ impl<'a> MessageHandler<NodeGraphMessage, NodeGraphHandlerData<'a>> for NodeGrap
 						responses.add(NodeGraphMessage::MoveSelectedNodes {
 							displacement_x: graph_delta.x - drag_start.round_x,
 							displacement_y: graph_delta.y - drag_start.round_y,
+							move_upstream: ipp.keyboard.get(shift as usize),
 						});
 						drag_start.round_x = graph_delta.x;
 						drag_start.round_y = graph_delta.y;
@@ -943,6 +962,13 @@ impl<'a> MessageHandler<NodeGraphMessage, NodeGraphHandlerData<'a>> for NodeGrap
 					warn!("No network");
 					return;
 				};
+				if let Some(node_to_deselect) = self.deselect_on_pointer_up {
+					let mut new_selected_nodes = selected_nodes.selected_nodes_ref().clone();
+					new_selected_nodes.remove(node_to_deselect);
+					responses.add(NodeGraphMessage::SelectedNodesSet { nodes: new_selected_nodes });
+					self.deselect_on_pointer_up = None;
+				}
+
 				// Disconnect if the wire was previously connected to an input
 				let viewport_location = ipp.mouse.position;
 				let point = node_graph_to_viewport.inverse().transform_point2(viewport_location);
@@ -2792,6 +2818,7 @@ impl Default for NodeGraphMessageHandler {
 			context_menu: None,
 			node_metadata: HashMap::new(),
 			bounding_box_subpath: None,
+			deselect_on_pointer_up: None,
 			auto_panning: Default::default(),
 		}
 	}