Drag to rearrange layers in the layer panel (#434)

* Add insert line

* Implement dragging

* Improve CSS and variable naming consistency

* Resolved folder crash, added Undo/Redo support

* Removed marker TODO leftover

* JS cleanup

* WIP preserving expanded state (via LayerData) when copy/pasting and moving layers in layer panel

* Finish making folders copy/paste preserving expanded state, but not recursively yet

* Add cut, copy, and paste to the Edit menu (#440)

* Add cut

* Hook up edit dropdown

* Use copy message

Co-authored-by: Keavon Chambers <keavon@keavon.com>
Co-authored-by: otdavies <oliver@psyfer.io>

frontend/wasm/src/api.rs

@@ -390,6 +390,12 @@ impl JsEditorHandle {
 		self.dispatch(message);
 	}
 
+	/// Move a layer to be next to the specified neighbor
+	pub fn move_layer_in_tree(&self, layer: Vec<LayerId>, insert_above: bool, neighbor: Vec<LayerId>) {
+		let message = DocumentMessage::MoveLayerInTree { layer, insert_above, neighbor };
+		self.dispatch(message);
+	}
+
 	/// Set the blend mode for the selected layers
 	pub fn set_blend_mode_for_selected_layers(&self, blend_mode_svg_style_name: String) -> Result<(), JsValue> {
 		let blend_mode = translate_blend_mode(blend_mode_svg_style_name.as_str());

frontend/wasm/src/lib.rs

@@ -31,6 +31,5 @@ fn panic_hook(info: &panic::PanicInfo) {
 	let panic_info = info.to_string();
 	let title = "The editor crashed — sorry about that".to_string();
 	let description = "An internal error occurred. Reload the editor to continue. Please report this by filing an issue on GitHub.".to_string();
-
 	EDITOR_HAS_CRASHED.with(|crash_status| crash_status.borrow_mut().replace(FrontendMessage::DisplayPanic { panic_info, title, description }));
 }