Part of #641: Image Trace: Advanced as a section that stays open, and View modes

- The Image Trace panel's Advanced options sit under a full-width collapsible
  header (widgets::section_toggle, also used by New Document's Advanced
  Options); whether it is open is kept with the UI preferences.
- View: Tracing Result, Tracing Result with Outlines, Outlines, Outlines with
  Source Image and Source Image, in the panel, the Control bar and the
  Properties panel. The view is saved in the Image Trace object's settings
  (`trace.view`), kept when it is traced again, set with the new
  `imageTrace.setView` command (or `view` on imageTrace.make) and drawn by the
  canvas only (RenderOptions::trace_views): exports, printing and Expand keep
  the tracing result.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/doc/src/lib.rs

@@ -40,6 +40,7 @@ pub mod slices;
 pub mod style_libs;
 pub mod swatches;
 pub mod text;
+pub mod trace;
 
 use std::collections::BTreeMap;
 use std::sync::Arc;
@@ -89,6 +90,7 @@ pub use text::{
     ParaDirection, ParaStyle, PathAlign, PathEffect, ScriptMetrics, TabAlign, TabStop, TextKind, TextObject, TextRun, TextStyleDef, TextWrap,
     VerticalAlign, WrapShape,
 };
+pub use trace::TraceView;
 pub use vectorcraft_color as color;
 pub use vectorcraft_geom as geom;
 

crates/doc/src/node.rs

@@ -463,7 +463,8 @@ pub struct Node {
     /// Opacity mask (Transparency panel). Its art lives here, outside the layer tree.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub mask: Option<Box<OpacityMask>>,
-    /// Image Trace object: `{preset, params}` it was traced with (the Image Trace panel shows them).
+    /// Image Trace object: `{preset, params, view?}` it was traced with (the Image Trace panel shows
+    /// them; `view` is its [`crate::TraceView`] id, absent for the tracing result).
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub trace: Option<Box<serde_json::Value>>,
     /// Object → Text Wrap: area type below this object (in the same layer) flows around it.

crates/doc/src/trace.rs

@@ -0,0 +1,92 @@
+//! Image Trace objects' View: how a live trace draws on screen.
+//!
+//! An Image Trace object is a group whose `trace` holds `{preset, params, view}` (see
+//! `imageTrace.make`). The view is a viewing aid only: exports, printing and Expand always use the
+//! tracing result, whatever it is set to.
+
+use crate::node::Node;
+
+/// Image Trace › View.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub enum TraceView {
+    /// The traced shapes as they are filled.
+    #[default]
+    Result,
+    /// The traced shapes, with their outlines over them.
+    ResultWithOutlines,
+    /// Only the traced shapes' outlines.
+    Outlines,
+    /// The source image, with the traced shapes' outlines over it.
+    OutlinesWithSource,
+    /// Only the source image.
+    Source,
+}
+
+impl TraceView {
+    /// Panel order.
+    pub const ALL: [Self; 5] = [Self::Result, Self::ResultWithOutlines, Self::Outlines, Self::OutlinesWithSource, Self::Source];
+
+    /// The id used in command params and in the saved `trace` object.
+    pub fn id(self) -> &'static str {
+        match self {
+            Self::Result => "tracingResult",
+            Self::ResultWithOutlines => "tracingResultWithOutlines",
+            Self::Outlines => "outlines",
+            Self::OutlinesWithSource => "outlinesWithSourceImage",
+            Self::Source => "sourceImage",
+        }
+    }
+
+    /// The view an id names (any case).
+    pub fn from_id(id: &str) -> Option<Self> {
+        Self::ALL.into_iter().find(|v| v.id().eq_ignore_ascii_case(id))
+    }
+
+    /// The view an Image Trace object's `trace` settings ask for (the tracing result when they
+    /// name none, or an unknown one).
+    pub fn of(trace: &serde_json::Value) -> Self {
+        trace.get("view").and_then(serde_json::Value::as_str).and_then(Self::from_id).unwrap_or_default()
+    }
+
+    /// Whether the source image shows.
+    pub fn shows_source(self) -> bool {
+        matches!(self, Self::OutlinesWithSource | Self::Source)
+    }
+
+    /// Whether the traced shapes show filled.
+    pub fn shows_result(self) -> bool {
+        matches!(self, Self::Result | Self::ResultWithOutlines)
+    }
+
+    /// Whether the traced shapes' outlines show.
+    pub fn shows_outlines(self) -> bool {
+        matches!(self, Self::ResultWithOutlines | Self::Outlines | Self::OutlinesWithSource)
+    }
+}
+
+impl Node {
+    /// The View of an Image Trace object (the tracing result for anything else, or an unknown id).
+    pub fn trace_view(&self) -> TraceView {
+        self.trace.as_deref().map(TraceView::of).unwrap_or_default()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ids_round_trip_and_unknown_views_show_the_result() {
+        for v in TraceView::ALL {
+            assert_eq!(TraceView::from_id(v.id()), Some(v));
+            assert_eq!(TraceView::from_id(&v.id().to_ascii_uppercase()), Some(v));
+            assert!(v.shows_result() || v.shows_outlines() || v.shows_source(), "{v:?} shows something");
+        }
+        let mut g = Node::group(crate::NodeId(1), vec![]);
+        assert_eq!(g.trace_view(), TraceView::Result);
+        g.trace = Some(Box::new(serde_json::json!({"view": "outlines"})));
+        assert_eq!(g.trace_view(), TraceView::Outlines);
+        g.trace = Some(Box::new(serde_json::json!({"view": "sepia"})));
+        assert_eq!(g.trace_view(), TraceView::Result);
+    }
+}