Implement anchor and handle point rendering with the Path Tool (#353)

* Implement Path Tool

* Draw a red rectangle where the first point on the shape is

* Correctly render anchors, handles, and connecting lines

* Fix drain() which can panic

* Refactor frontend messages to work as return values not callbacks

* Reduce the number of unnecessary frontend updates

* Fix stack overflow by using a loop

* Group Document Render calls and put them at the end

* Speed hacks for dirtification

* Add performance

* Bunch folder changed updates

* Add triggers to redraw overlays to movement_handler

* Polish the pixel-perfect rendering of vector manipulators

* Restore scrollbars that were disabled

* Cleanup

* WIP Add shape outline rendering

* Fix compiling

* Add outlines to selected shapes

* Fix outlines rendering over handles and anchors

* Fix dirtification

* Add a comment

* Address code review feedback

* Formatting

* Small tweaks

Co-authored-by: Oliver Davies <oliver@psyfer.io>
Co-authored-by: Dennis Kobert <dennis@kobert.dev>

editor/src/lib.rs

@@ -26,9 +26,6 @@ pub use graphene::LayerId;
 #[doc(inline)]
 pub use graphene::document::Document as SvgDocument;
 
-#[doc(inline)]
-pub use frontend::Callback;
-
 use communication::dispatcher::Dispatcher;
 // TODO: serialize with serde to save the current editor state
 pub struct Editor {
@@ -38,14 +35,16 @@ pub struct Editor {
 use message_prelude::*;
 
 impl Editor {
-	pub fn new(callback: Callback) -> Self {
-		Self {
-			dispatcher: Dispatcher::new(callback),
-		}
+	pub fn new() -> Self {
+		Self { dispatcher: Dispatcher::new() }
 	}
 
-	pub fn handle_message<T: Into<Message>>(&mut self, message: T) -> Result<(), EditorError> {
-		self.dispatcher.handle_message(message)
+	pub fn handle_message<T: Into<Message>>(&mut self, message: T) -> Result<Vec<FrontendMessage>, EditorError> {
+		self.dispatcher.handle_message(message).map(|_| {
+			let mut responses = Vec::new();
+			std::mem::swap(&mut responses, &mut self.dispatcher.responses);
+			responses
+		})
 	}
 }