Add alignment overlays

editor/src/tool/snapping.rs

@@ -1,24 +1,71 @@
-use glam::DVec2;
+use std::f64::consts::PI;
-use graphene::LayerId;
 
-use crate::consts::SNAP_TOLERANCE;
+use glam::{DAffine2, DVec2};
+use graphene::{
+	layers::style::{self, Stroke},
+	LayerId, Operation,
+};
+
+use crate::{
+	consts::{COLOR_ACCENT, SNAP_TOLERANCE},
+	message_prelude::*,
+};
 
 use super::DocumentMessageHandler;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Default)]
 pub struct SnapHandler {
 	snap_targets: Option<(Vec<f64>, Vec<f64>)>,
-}
+	overlay_paths: Vec<Vec<LayerId>>,
-impl Default for SnapHandler {
-	fn default() -> Self {
-		Self { snap_targets: None }
-	}
 }
 
 impl SnapHandler {
+	fn add_overlays(&mut self, responses: &mut VecDeque<Message>, viewport_bounds: DVec2) {
+		fn add_overlay_line(responses: &mut VecDeque<Message>, transform: DAffine2) -> Vec<LayerId> {
+			let layer_path = vec![generate_uuid()];
+
+			let operation = Operation::AddOverlayLine {
+				path: layer_path.clone(),
+				transform: transform.to_cols_array(),
+				style: style::PathStyle::new(Some(Stroke::new(COLOR_ACCENT, 1.0)), None),
+			};
+			responses.push_back(DocumentMessage::Overlay(operation.into()).into());
+
+			layer_path
+		}
+
+		if let Some((x_targets, y_targets)) = &self.snap_targets {
+			for x_target in x_targets {
+				self.overlay_paths.push(add_overlay_line(
+					responses,
+					DAffine2::from_scale_angle_translation(DVec2::new(viewport_bounds.y, 1.), PI / 2., DVec2::new(x_target.round(), 0.)),
+				));
+			}
+			for y_target in y_targets {
+				self.overlay_paths.push(add_overlay_line(
+					responses,
+					DAffine2::from_scale_angle_translation(DVec2::new(viewport_bounds.x, 1.), 0., DVec2::new(0., y_target.round())),
+				));
+			}
+		}
+	}
+
+	fn remove_overlays(&mut self, responses: &mut VecDeque<Message>) {
+		while let Some(layer) = self.overlay_paths.pop() {
+			responses.push_back(DocumentMessage::Overlay(Operation::DeleteLayer { path: layer }.into()).into());
+		}
+	}
+
 	/// Gets a list of snap targets for the X and Y axes in Viewport coords for the target layers (usually all layers or all non-selected layers.)
 	/// This should be called at the start of a drag.
-	pub fn start_snap(&mut self, document_message_handler: &DocumentMessageHandler, target_layers: Vec<Vec<LayerId>>, ignore_layers: &[Vec<LayerId>]) {
+	pub fn start_snap(
+		&mut self,
+		responses: &mut VecDeque<Message>,
+		viewport_bounds: DVec2,
+		document_message_handler: &DocumentMessageHandler,
+		target_layers: Vec<Vec<LayerId>>,
+		ignore_layers: &[Vec<LayerId>],
+	) {
 		if document_message_handler.snapping_enabled {
 			// Could be made into sorted Vec or a HashSet for more performant lookups.
 			self.snap_targets = Some(
@@ -30,6 +77,7 @@ impl SnapHandler {
 					.map(|vec| vec.into())
 					.unzip(),
 			);
+			self.add_overlays(responses, viewport_bounds);
 		}
 	}
 
@@ -104,7 +152,8 @@ impl SnapHandler {
 		}
 	}
 
-	pub fn cleanup(&mut self) {
+	pub fn cleanup(&mut self, responses: &mut VecDeque<Message>) {
+		self.remove_overlays(responses);
 		self.snap_targets = None;
 	}
 }

editor/src/tool/tools/ellipse.rs

@@ -81,7 +81,7 @@ impl Fsm for EllipseToolFsmState {
 		if let ToolMessage::Ellipse(event) = event {
 			match (self, event) {
 				(Ready, DragStart) => {
-					shape_data.start(document, input.mouse.position);
+					shape_data.start(responses, input.viewport_bounds.size(), document, input.mouse.position);
 					responses.push_back(DocumentMessage::StartTransaction.into());
 					shape_data.path = Some(vec![generate_uuid()]);
 					responses.push_back(DocumentMessage::DeselectAllLayers.into());
@@ -112,12 +112,12 @@ impl Fsm for EllipseToolFsmState {
 						false => responses.push_back(DocumentMessage::CommitTransaction.into()),
 					}
 
-					shape_data.cleanup();
+					shape_data.cleanup(responses);
 					Ready
 				}
 				(Drawing, Abort) => {
 					responses.push_back(DocumentMessage::AbortTransaction.into());
-					shape_data.cleanup();
+					shape_data.cleanup(responses);
 
 					Ready
 				}

editor/src/tool/tools/line.rs

@@ -86,7 +86,7 @@ impl Fsm for LineToolFsmState {
 		if let ToolMessage::Line(event) = event {
 			match (self, event) {
 				(Ready, DragStart) => {
-					data.snap_handler.start_snap(document, document.all_layers_sorted(), &[]);
+					data.snap_handler.start_snap(responses, input.viewport_bounds.size(), document, document.all_layers_sorted(), &[]);
 					data.drag_start = data.snap_handler.snap_position(document, input.mouse.position);
 
 					responses.push_back(DocumentMessage::StartTransaction.into());
@@ -120,7 +120,7 @@ impl Fsm for LineToolFsmState {
 				}
 				(Drawing, DragStop) => {
 					data.drag_current = data.snap_handler.snap_position(document, input.mouse.position);
-					data.snap_handler.cleanup();
+					data.snap_handler.cleanup(responses);
 
 					// TODO: introduce comparison threshold when operating with canvas coordinates (https://github.com/GraphiteEditor/Graphite/issues/100)
 					match data.drag_start == input.mouse.position {
@@ -133,7 +133,7 @@ impl Fsm for LineToolFsmState {
 					Ready
 				}
 				(Drawing, Abort) => {
-					data.snap_handler.cleanup();
+					data.snap_handler.cleanup(responses);
 					responses.push_back(DocumentMessage::AbortTransaction.into());
 					data.path = None;
 					Ready

editor/src/tool/tools/pen.rs

@@ -94,7 +94,7 @@ impl Fsm for PenToolFsmState {
 					data.path = Some(vec![generate_uuid()]);
 					data.layer_exists = false;
 
-					data.snap_handler.start_snap(document, document.all_layers_sorted(), &[]);
+					data.snap_handler.start_snap(responses, input.viewport_bounds.size(), document, document.all_layers_sorted(), &[]);
 					let snapped_position = data.snap_handler.snap_position(document, input.mouse.position);
 
 					let pos = transform.inverse() * DAffine2::from_translation(snapped_position);
@@ -148,7 +148,7 @@ impl Fsm for PenToolFsmState {
 
 					data.path = None;
 					data.points.clear();
-					data.snap_handler.cleanup();
+					data.snap_handler.cleanup(responses);
 
 					Ready
 				}

editor/src/tool/tools/rectangle.rs

@@ -82,7 +82,7 @@ impl Fsm for RectangleToolFsmState {
 		if let ToolMessage::Rectangle(event) = event {
 			match (self, event) {
 				(Ready, DragStart) => {
-					shape_data.start(document, input.mouse.position);
+					shape_data.start(responses, input.viewport_bounds.size(), document, input.mouse.position);
 					responses.push_back(DocumentMessage::StartTransaction.into());
 					shape_data.path = Some(vec![generate_uuid()]);
 					responses.push_back(DocumentMessage::DeselectAllLayers.into());
@@ -113,13 +113,13 @@ impl Fsm for RectangleToolFsmState {
 						false => responses.push_back(DocumentMessage::CommitTransaction.into()),
 					}
 
-					shape_data.cleanup();
+					shape_data.cleanup(responses);
 
 					Ready
 				}
 				(Drawing, Abort) => {
 					responses.push_back(DocumentMessage::AbortTransaction.into());
-					shape_data.cleanup();
+					shape_data.cleanup(responses);
 
 					Ready
 				}

editor/src/tool/tools/resize.rs

@@ -14,9 +14,9 @@ pub struct Resize {
 }
 impl Resize {
 	/// Starts a resize, assigning the snap targets and snapping the starting position.
-	pub fn start(&mut self, document: &DocumentMessageHandler, mouse_position: DVec2) {
+	pub fn start(&mut self, responses: &mut VecDeque<Message>, viewport_bounds: DVec2, document: &DocumentMessageHandler, mouse_position: DVec2) {
 		let layers = document.all_layers_sorted();
-		self.snap_handler.start_snap(document, layers, &[]);
+		self.snap_handler.start_snap(responses, viewport_bounds, document, layers, &[]);
 		self.drag_start = self.snap_handler.snap_position(document, mouse_position);
 	}
 
@@ -47,8 +47,8 @@ impl Resize {
 		}
 	}
 
-	pub fn cleanup(&mut self) {
+	pub fn cleanup(&mut self, responses: &mut VecDeque<Message>) {
-		self.snap_handler.cleanup();
+		self.snap_handler.cleanup(responses);
 		self.path = None;
 	}
 }

editor/src/tool/tools/select.rs

@@ -200,7 +200,8 @@ impl Fsm for SelectToolFsmState {
 					} else {
 						Vec::new()
 					};
-					data.snap_handler.start_snap(document, document.non_selected_layers_sorted(), &ignore_layers);
+					data.snap_handler
+						.start_snap(responses, input.viewport_bounds.size(), document, document.non_selected_layers_sorted(), &ignore_layers);
 					state
 				}
 				(Dragging, MouseMove { snap_angle }) => {
@@ -255,7 +256,7 @@ impl Fsm for SelectToolFsmState {
 						true => DocumentMessage::Undo,
 						false => DocumentMessage::CommitTransaction,
 					};
-					data.snap_handler.cleanup();
+					data.snap_handler.cleanup(responses);
 					responses.push_front(response.into());
 					Ready
 				}

editor/src/tool/tools/shape.rs

@@ -83,7 +83,7 @@ impl Fsm for ShapeToolFsmState {
 		if let ToolMessage::Shape(event) = event {
 			match (self, event) {
 				(Ready, DragStart) => {
-					shape_data.start(document, input.mouse.position);
+					shape_data.start(responses, input.viewport_bounds.size(), document, input.mouse.position);
 					responses.push_back(DocumentMessage::StartTransaction.into());
 					shape_data.path = Some(vec![generate_uuid()]);
 					responses.push_back(DocumentMessage::DeselectAllLayers.into());
@@ -121,12 +121,12 @@ impl Fsm for ShapeToolFsmState {
 						false => responses.push_back(DocumentMessage::CommitTransaction.into()),
 					}
 
-					shape_data.cleanup();
+					shape_data.cleanup(responses);
 					Ready
 				}
 				(Drawing, Abort) => {
 					responses.push_back(DocumentMessage::AbortTransaction.into());
-					shape_data.cleanup();
+					shape_data.cleanup(responses);
 
 					Ready
 				}