M3.44: graphic styles keep opacity and blend, capture groups and type, add on Alt-click

Styles now store the object's opacity, blend mode, isolate and knockout and apply them.
New Graphic Style from a group without its own paint captures its topmost object's
appearance, and from type its characters' fill and stroke. Names are made unique.
graphicStyle.apply takes ids and add (Alt-click in the panel adds the style on top of the
existing appearance). graphicStyle.list reports every style. Applying links objects to a
stable style id (Node.graphic_style), which the management commands build on.

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

crates/doc/src/lib.rs

@@ -254,11 +254,49 @@ impl Default for GridPrefs {
     }
 }
 
-/// A named graphic style (Graphic Styles panel).
+/// A named graphic style (Graphic Styles panel): an appearance plus the object's transparency.
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
 pub struct GraphicStyle {
     pub name: String,
     pub appearance: Appearance,
+    /// Stable id linked objects refer to ([`Node::graphic_style`]); 0 until first needed (styles
+    /// from older files get one when an object is first linked to them).
+    #[serde(default, skip_serializing_if = "skip::is_default")]
+    pub id: u32,
+    #[serde(default = "one", skip_serializing_if = "skip::is_one")]
+    pub opacity: f32,
+    #[serde(default, skip_serializing_if = "skip::is_default")]
+    pub blend: vectorcraft_color::BlendMode,
+    #[serde(default, skip_serializing_if = "skip::is_default")]
+    pub isolate: bool,
+    #[serde(default, skip_serializing_if = "skip::is_default")]
+    pub knockout: bool,
+}
+
+fn one() -> f32 {
+    1.0
+}
+
+/// The name of the style new documents list first (Sort by Name keeps it first).
+pub const DEFAULT_GRAPHIC_STYLE: &str = "Default Graphic Style";
+
+impl GraphicStyle {
+    /// A style with `appearance` and default transparency (no id yet).
+    pub fn new(name: impl Into<String>, appearance: Appearance) -> Self {
+        Self { name: name.into(), appearance, id: 0, opacity: 1.0, blend: Default::default(), isolate: false, knockout: false }
+    }
+    /// A style capturing `n`'s transparency and `appearance`.
+    pub fn of(name: impl Into<String>, appearance: Appearance, n: &Node) -> Self {
+        Self { opacity: n.opacity, blend: n.blend, isolate: n.isolate, knockout: n.knockout, ..Self::new(name, appearance) }
+    }
+    /// Give `n` this style's transparency.
+    pub fn apply_transparency(&self, n: &mut Node) {
+        (n.opacity, n.blend, n.isolate, n.knockout) = (self.opacity, self.blend, self.isolate, self.knockout);
+    }
+    /// Does `n` have this style's transparency?
+    pub fn transparency_matches(&self, n: &Node) -> bool {
+        (n.opacity, n.blend, n.isolate, n.knockout) == (self.opacity, self.blend, self.isolate, self.knockout)
+    }
 }
 
 /// A symbol definition.
@@ -633,20 +671,51 @@ impl Document {
     }
 }
 
+/// Graphic styles.
+impl Document {
+    /// Index of the graphic style named `name`.
+    pub fn graphic_style_index(&self, name: &str) -> Option<usize> {
+        self.graphic_styles.iter().position(|g| g.name == name)
+    }
+    /// The graphic style named `name`.
+    pub fn graphic_style(&self, name: &str) -> Option<&GraphicStyle> {
+        self.graphic_styles.iter().find(|g| g.name == name)
+    }
+    /// The graphic style with id `id` (0 never matches).
+    pub fn graphic_style_by_id(&self, id: u32) -> Option<&GraphicStyle> {
+        self.graphic_styles.iter().find(|g| g.id != 0 && g.id == id)
+    }
+    /// An id no graphic style has.
+    pub fn next_graphic_style_id(&self) -> u32 {
+        self.graphic_styles.iter().map(|g| g.id).max().unwrap_or(0) + 1
+    }
+    /// The id of graphic style `index`, assigning one if it has none yet.
+    pub fn graphic_style_id(&mut self, index: usize) -> u32 {
+        if self.graphic_styles[index].id == 0 {
+            self.graphic_styles[index].id = self.next_graphic_style_id();
+        }
+        self.graphic_styles[index].id
+    }
+    /// The default name of a new graphic style: the first free "Graphic Style N", N counting on
+    /// from the number of styles.
+    pub fn new_graphic_style_name(&self) -> String {
+        (self.graphic_styles.len() + 1..).map(|i| format!("Graphic Style {i}")).find(|n| self.graphic_style(n).is_none()).unwrap_or_default()
+    }
+}
+
 fn default_graphic_styles() -> Vec<GraphicStyle> {
     use vectorcraft_color::{Color, Paint};
-    vec![
-        GraphicStyle { name: "Default Graphic Style".into(), appearance: Appearance::default_art() },
-        GraphicStyle { name: "Black Outline".into(), appearance: Appearance::basic(Paint::None, Paint::solid(Color::BLACK), 1.0) },
-        GraphicStyle {
-            name: "Heavy Ink".into(),
-            appearance: Appearance::basic(Paint::solid(Color::from_hex("#1b1464").unwrap()), Paint::solid(Color::BLACK), 4.0),
-        },
-        GraphicStyle {
-            name: "Sunshine".into(),
-            appearance: Appearance::basic(Paint::solid(Color::from_hex("#fbb03b").unwrap()), Paint::solid(Color::from_hex("#f15a24").unwrap()), 2.0),
-        },
+    let solid = |hex| Paint::solid(Color::from_hex(hex).unwrap());
+    [
+        GraphicStyle::new(DEFAULT_GRAPHIC_STYLE, Appearance::default_art()),
+        GraphicStyle::new("Black Outline", Appearance::basic(Paint::None, Paint::solid(Color::BLACK), 1.0)),
+        GraphicStyle::new("Heavy Ink", Appearance::basic(solid("#1b1464"), Paint::solid(Color::BLACK), 4.0)),
+        GraphicStyle::new("Sunshine", Appearance::basic(solid("#fbb03b"), solid("#f15a24"), 2.0)),
     ]
+    .into_iter()
+    .zip(1..)
+    .map(|(g, id)| GraphicStyle { id, ..g })
+    .collect()
 }
 
 #[cfg(test)]

crates/doc/src/node.rs

@@ -270,6 +270,10 @@ pub struct Node {
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub graph: Option<Box<crate::graph::GraphSpec>>,
     pub kind: NodeKind,
+    /// The [`crate::GraphicStyle::id`] last applied to this object. It stays linked while it keeps
+    /// that style's look: editing its appearance or transparency breaks the link.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub graphic_style: Option<u32>,
 }
 
 /// Opacity mask: the luminance of the mask art sets the object's opacity (white = opaque).
@@ -314,6 +318,7 @@ impl Node {
             wrap: None,
             graph: None,
             kind,
+            graphic_style: None,
         }
     }
     pub fn path(id: NodeId, path: PathData, appearance: Appearance) -> Self {