Add snapping to ends of the gradient line

editor/src/messages/portfolio/document/utility_types/misc.rs

@@ -307,6 +307,19 @@ pub enum PathSnapSource {
 	IntersectionPoint,
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum GradientSnapSource {
+	Endpoint,
+}
+
+impl fmt::Display for GradientSnapSource {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		match self {
+			GradientSnapSource::Endpoint => write!(f, "Gradient: Endpoint"),
+		}
+	}
+}
+
 impl fmt::Display for PathSnapSource {
 	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 		match self {
@@ -347,6 +360,7 @@ pub enum SnapSource {
 	Artboard(ArtboardSnapSource),
 	Path(PathSnapSource),
 	Alignment(AlignmentSnapSource),
+	Gradient(GradientSnapSource),
 }
 
 impl SnapSource {
@@ -377,6 +391,7 @@ impl fmt::Display for SnapSource {
 			SnapSource::Artboard(artboard_snap_source) => write!(f, "{artboard_snap_source}"),
 			SnapSource::Path(path_snap_source) => write!(f, "{path_snap_source}"),
 			SnapSource::Alignment(alignment_snap_source) => write!(f, "{alignment_snap_source}"),
+			SnapSource::Gradient(gradient_snap_source) => write!(f, "{gradient_snap_source}"),
 		}
 	}
 }

editor/src/messages/tool/common_functionality/snapping.rs

@@ -259,6 +259,11 @@ impl SnapManager {
 		let snapped = self.free_snap(snap_data, &point, SnapTypeConfiguration::default());
 		self.update_indicator(snapped);
 	}
+	pub fn gradient_preview_draw(&mut self, snap_data: &SnapData, mouse: DVec2) {
+		let point = SnapCandidatePoint::gradient_handle(snap_data.document.metadata().document_to_viewport.inverse().transform_point2(mouse));
+		let snapped = self.free_snap(snap_data, &point, SnapTypeConfiguration::default());
+		self.update_indicator(snapped);
+	}
 
 	pub fn indicator_pos(&self) -> Option<DVec2> {
 		self.indicator.as_ref().map(|point| point.snapped_point_document)

editor/src/messages/tool/common_functionality/snapping/layer_snapper.rs

@@ -453,6 +453,10 @@ impl SnapCandidatePoint {
 		Self::new_source(document_point, SnapSource::Path(PathSnapSource::AnchorPointWithFreeHandles))
 	}
 
+	pub fn gradient_handle(document_point: DVec2) -> Self {
+		Self::new_source(document_point, SnapSource::Gradient(GradientSnapSource::Endpoint))
+	}
+
 	pub fn handle_neighbors(document_point: DVec2, neighbors: impl Into<Vec<DVec2>>) -> Self {
 		let mut point = Self::new_source(document_point, SnapSource::Path(PathSnapSource::AnchorPointWithFreeHandles));
 		point.neighbors = neighbors.into();

editor/src/messages/tool/tool_messages/gradient_tool.rs

@@ -4,7 +4,7 @@ use crate::messages::portfolio::document::overlays::utility_types::OverlayContex
 use crate::messages::portfolio::document::utility_types::document_metadata::LayerNodeIdentifier;
 use crate::messages::tool::common_functionality::auto_panning::AutoPanning;
 use crate::messages::tool::common_functionality::graph_modification_utils::{NodeGraphLayer, get_gradient};
-use crate::messages::tool::common_functionality::snapping::SnapManager;
+use crate::messages::tool::common_functionality::snapping::{SnapCandidatePoint, SnapData, SnapManager, SnapTypeConfiguration};
 use graphene_std::vector::style::{Fill, Gradient, GradientType};
 
 #[derive(Default, ExtractField)]
@@ -378,6 +378,9 @@ impl Fsm for GradientToolFsmState {
 					}
 				}
 
+				let snap_data = SnapData::new(document, input, viewport);
+				tool_data.snap_manager.draw_overlays(snap_data, &mut overlay_context);
+
 				self
 			}
 			(GradientToolFsmState::Ready { .. }, GradientToolMessage::SelectionChanged) => {
@@ -591,7 +594,15 @@ impl Fsm for GradientToolFsmState {
 			}
 			(GradientToolFsmState::Drawing, GradientToolMessage::PointerMove { constrain_axis }) => {
 				if let Some(selected_gradient) = &mut tool_data.selected_gradient {
-					let mouse = input.mouse.position; // tool_data.snap_manager.snap_position(responses, document, input.mouse.position);
+					let mut mouse = input.mouse.position;
+					let snap_data = SnapData::new(document, input, viewport);
+					let point = SnapCandidatePoint::gradient_handle(document.metadata().document_to_viewport.inverse().transform_point2(mouse));
+					let snapped = tool_data.snap_manager.free_snap(&snap_data, &point, SnapTypeConfiguration::default());
+					if snapped.is_snapped() {
+						mouse = document.metadata().document_to_viewport.transform_point2(snapped.snapped_point_document);
+					}
+					tool_data.snap_manager.update_indicator(snapped);
+
 					selected_gradient.update_gradient(
 						mouse,
 						responses,
@@ -661,6 +672,9 @@ impl Fsm for GradientToolFsmState {
 					}
 				}
 
+				let snap_data = SnapData::new(document, input, viewport);
+				tool_data.snap_manager.gradient_preview_draw(&snap_data, mouse);
+
 				responses.add(OverlaysMessage::Draw);
 				GradientToolFsmState::Ready { hover_insertion }
 			}