Implement svg layer structure (#59)

* Add folder struct

* Add file system like structure to interface with svgs

* Add primitive undo functionality

* Restructure layer system

core/editor/src/dispatcher/events.rs

@@ -113,6 +113,7 @@ pub enum Key {
 	KeyE,
 	KeyV,
 	KeyX,
+	KeyZ,
 	Key0,
 	Key1,
 	Key2,

core/editor/src/dispatcher/mod.rs

@@ -85,28 +85,28 @@ impl Dispatcher {
 
 		let (responses, operations) = editor_state.tool_state.active_tool()?.handle_input(event, &editor_state.document);
 
-		self.dispatch_operations(&mut editor_state.document, &operations);
+		self.dispatch_operations(&mut editor_state.document, operations);
 		// TODO - Dispatch Responses
 
 		Ok(())
 	}
 
-	fn dispatch_operations(&self, document: &mut Document, operations: &[Operation]) {
+	fn dispatch_operations<I: IntoIterator<Item = Operation>>(&self, document: &mut Document, operations: I) {
 		for operation in operations {
-			self.dispatch_operation(document, operation);
+			if let Err(error) = self.dispatch_operation(document, operation) {
+				log::error!("{}", error);
+			}
 		}
 	}
 
-	fn dispatch_operation(&self, document: &mut Document, operation: &Operation) {
-		document.handle_operation(operation, |svg: String| {
-			self.dispatch_response(Response::UpdateCanvas { document: svg });
-		});
+	fn dispatch_operation(&self, document: &mut Document, operation: Operation) -> Result<(), EditorError> {
+		document.handle_operation(operation, |svg: String| self.dispatch_response(Response::UpdateCanvas { document: svg }))?;
+		Ok(())
 	}
 
-	pub fn dispatch_responses(&self, responses: &[Response]) {
+	pub fn dispatch_responses<I: IntoIterator<Item = Response>>(&self, responses: I) {
 		for response in responses {
-			// TODO - Remove clone when Response is Copy
-			self.dispatch_response(response.clone());
+			self.dispatch_response(response);
 		}
 	}
 

core/editor/src/error.rs

@@ -1,5 +1,6 @@
 use crate::events::Event;
 use crate::Color;
+use document_core::DocumentError;
 use thiserror::Error;
 
 /// The error type used by the Graphite editor.
@@ -15,6 +16,8 @@ pub enum EditorError {
 	Color(String),
 	#[error("The requested tool does not exist")]
 	UnknownTool,
+	#[error("The operation caused a document error {0:?}")]
+	Document(String),
 }
 
 macro_rules! derive_from {
@@ -31,3 +34,4 @@ derive_from!(&str, Misc);
 derive_from!(String, Misc);
 derive_from!(Color, Color);
 derive_from!(Event, InvalidEvent);
+derive_from!(DocumentError, Document);

core/editor/src/tools/ellipse.rs

@@ -1,5 +1,5 @@
 use crate::events::{Event, Response};
-use crate::events::{MouseKeys, ViewportPosition};
+use crate::events::{Key, MouseKeys, ViewportPosition};
 use crate::tools::{Fsm, Tool};
 use crate::Document;
 use document_core::Operation;
@@ -45,12 +45,20 @@ impl Fsm for EllipseToolFsmState {
 				data.drag_start = mouse_state.position;
 				EllipseToolFsmState::LmbDown
 			}
+			(EllipseToolFsmState::Ready, Event::KeyDown(Key::KeyZ)) => {
+				if let Some(id) = document.root.list_layers().last() {
+					operations.push(Operation::DeleteLayer { path: vec![*id] })
+				}
+				EllipseToolFsmState::Ready
+			}
 
 			// TODO - Check for left mouse button
 			(EllipseToolFsmState::LmbDown, Event::MouseUp(mouse_state)) => {
 				let r = data.drag_start.distance(&mouse_state.position);
 				log::info!("draw ellipse with radius: {:.2}", r);
 				operations.push(Operation::AddCircle {
+					path: vec![],
+					insert_index: -1,
 					cx: data.drag_start.x as f64,
 					cy: data.drag_start.y as f64,
 					r: data.drag_start.distance(&mouse_state.position),

core/editor/src/tools/rectangle.rs

@@ -1,5 +1,5 @@
 use crate::events::{Event, Response};
-use crate::events::{MouseKeys, ViewportPosition};
+use crate::events::{Key, MouseKeys, ViewportPosition};
 use crate::tools::{Fsm, Tool};
 use crate::Document;
 use document_core::Operation;
@@ -45,6 +45,12 @@ impl Fsm for RectangleToolFsmState {
 				data.drag_start = mouse_state.position;
 				RectangleToolFsmState::LmbDown
 			}
+			(RectangleToolFsmState::Ready, Event::KeyDown(Key::KeyZ)) => {
+				if let Some(id) = document.root.list_layers().last() {
+					operations.push(Operation::DeleteLayer { path: vec![*id] })
+				}
+				RectangleToolFsmState::Ready
+			}
 
 			// TODO - Check for left mouse button
 			(RectangleToolFsmState::LmbDown, Event::MouseUp(mouse_state)) => {
@@ -53,6 +59,8 @@ impl Fsm for RectangleToolFsmState {
 				let start = data.drag_start;
 				let end = mouse_state.position;
 				operations.push(Operation::AddRect {
+					path: vec![],
+					insert_index: -1,
 					x0: start.x as f64,
 					y0: start.y as f64,
 					x1: end.x as f64,