Generalize layers as merge nodes to enable adjustment layers (#1712)

* WIP, backward traversal issues

* Fix some tool issues

* Remove debugging

* Change some indices

* WIP: new artboard node

* WIP: add artboard node

* WIP: Artboard node and create_artboard

* WIP: Artboard node implementation complete

* WIP: Artboards input for output node

* Complete Artboard node

* Generalize LayerNodeIdentifier,  monitor_nodes support for Artboard node, adjust ResizeArtboard/ClearArtboards, move alias validation to Rust

* Fix misaligned artboard click targets

* Generalize/clarify create_layer and insert_between

* non-negative dimensions for resize_artboard

* Show artboards in layer panel

* Generalize create_layer for layer output node

* Generalize delete_layer/delete_artboard to NodeGraphMessage::DeleteNodes. Fixed upstream flow Iter

* remove old primary_input function

* Vertical node visuals, remove is_layer function, rename Layer node to Merge node, toggle display as layer

exposed_value_count type fix

Vertical node visuals, remove is_layer function, rename Layer node to Merge node, toggle display as layer

* Fix demo artwork

* Layer display context menu

* Automatically select artboard, fix warnings

* Improvements to context menu and layer invariant enforcement

* Remove display_as_layer and update load_structure

* Improve load_structure to show more layers, improve FlowIter, improve layer naming, layer rearrangement validation.

* Clean up demo artwork using generalized layers

* Improve design of Layers panel and graph nodes

* MoveSelectedLayersTo rewrite to support generalized layer nodes

* Include artboards in deepest_common_ancestor, fix resize_artboard/delete_artboard, sync artboard tool to layer panel

* MoveSelectedLayersTo adjustments

* Sync non layer node visibility with metadata

* Include non layer nodes when moving/creating layer

* Fix group layers and get_post_node_with_index

* Include non layer nodes in UngroupSelectedLayers

* GroupSelected for all selected nodes, UnGroupSelected position adjustments

* Add grouping for layers in different folders

* Fix hidden layers

* Prevent node from connecting to itself, fix undo automatic node insertion,

* Fix undo CreateEmptyFolder, fix grouping nested layer nodes

* Formatting

* Remove test and check if node is layer from network

* Fix undo group layers

* Check off roadmap

* MoveUpstreamSiblingsToChild adjustments

* Replace tabs with spaces, remove mut from argument

* Final code review pass

---------

Co-authored-by: 0hypercube <0hypercube@gmail.com>
Co-authored-by: Keavon Chambers <keavon@keavon.com>

frontend/wasm/src/editor_api.rs

@@ -523,8 +523,8 @@ impl EditorHandle {
 	#[wasm_bindgen(js_name = moveLayerInTree)]
 	pub fn move_layer_in_tree(&self, insert_parent_id: Option<u64>, insert_index: Option<usize>) {
 		let insert_parent_id = insert_parent_id.map(NodeId);
-
 		let parent = insert_parent_id.map(LayerNodeIdentifier::new_unchecked).unwrap_or_default();
+
 		let message = DocumentMessage::MoveSelectedLayersTo {
 			parent,
 			insert_index: insert_index.map(|x| x as isize).unwrap_or(-1),
@@ -568,6 +568,30 @@ impl EditorHandle {
 		self.dispatch(message);
 	}
 
+	/// Inserts node in-between two other nodes
+	#[wasm_bindgen(js_name = insertNodeBetween)]
+	pub fn insert_node_between(
+		&self,
+		post_node_id: u64,
+		post_node_input_index: usize,
+		insert_node_output_index: usize,
+		insert_node_id: u64,
+		insert_node_input_index: usize,
+		pre_node_output_index: usize,
+		pre_node_id: u64,
+	) {
+		let message = NodeGraphMessage::InsertNodeBetween {
+			post_node_id: NodeId(post_node_id),
+			post_node_input_index,
+			insert_node_output_index,
+			insert_node_id: NodeId(insert_node_id),
+			insert_node_input_index,
+			pre_node_output_index,
+			pre_node_id: NodeId(pre_node_id),
+		};
+		self.dispatch(message);
+	}
+
 	/// Shifts the node and its children to stop nodes going on top of each other
 	#[wasm_bindgen(js_name = shiftNode)]
 	pub fn shift_node(&self, node_id: u64) {
@@ -686,6 +710,14 @@ impl EditorHandle {
 		self.dispatch(message);
 	}
 
+	/// Toggle display type for a layer
+	#[wasm_bindgen(js_name = setToNodeOrLayer)]
+	pub fn set_to_node_or_layer(&self, id: u64, is_layer: bool) {
+		let node_id = NodeId(id);
+		let message = NodeGraphMessage::SetToNodeOrLayer { node_id, is_layer };
+		self.dispatch(message);
+	}
+
 	#[wasm_bindgen(js_name = injectImaginatePollServerStatus)]
 	pub fn inject_imaginate_poll_server_status(&self) {
 		self.dispatch(PortfolioMessage::ImaginatePollServerStatus);