Select: select.color picks objects by fill and stroke colour, no object needed

Scripts had to know an object id before they could select art by colour
(select.same.* and select.magicWand start from one). select.color
{fill?, stroke?} takes colours as paint.setFill does and selects the
objects whose fill and stroke read as them in #rrggbb, as
document.inspect reports colours, with Select > Same's selection rules.

The label is translated in each of the 23 catalogs, which
complete_languages_translate_every_menu_string requires.

crates/engine/src/cmd/select.rs

@@ -89,6 +89,15 @@ pub fn specs() -> Vec<CommandSpec> {
             has_doc,
             anchors_many
         ),
+        cmd!(
+            "select.color",
+            "Select by Color",
+            [],
+            None,
+            "{fill?: colour, stroke?: colour (as paint.setFill's color; at least one)} select the objects whose fill (and stroke) reads as that colour in #rrggbb, as document.inspect reports colours, whatever its swatch or tint; with both, the objects that match both. No object needs to be selected first; Select > Reselect repeats it → {count}",
+            has_doc,
+            select_color
+        ),
         cmd!(
             "select.same.fillColor",
             "Fill Color",
@@ -528,6 +537,22 @@ fn stroke_weight(n: &Node) -> f64 {
     if paint.is_none() { 0.0 } else { width }
 }
 
+/// Select by Color: the objects whose fill and stroke read as the colours given, compared as the
+/// `#rrggbb` `document.inspect` reports, so a script can pick art by colour without an object id.
+fn select_color(s: &mut Session, p: &Value) -> Result<Value> {
+    const C: &str = "select.color";
+    let hex = |key: &str| match p.get(key).filter(|v| !v.is_null()) {
+        None => Ok(None),
+        Some(v) => color_value(v).map(|c| Some(c.to_hex())).ok_or_else(|| bad(C, format!("`{key}`: not a colour: {v}"))),
+    };
+    let (fill, stroke) = (hex("fill")?, hex("stroke")?);
+    if fill.is_none() && stroke.is_none() {
+        return Err(bad(C, "give `fill`, `stroke` or both"));
+    }
+    let reads_as = |paint: Paint, hex: Option<&str>| hex.is_none_or(|h| paint.color().is_some_and(|c| c.to_hex() == h));
+    select_where(s, C, p, |_, n| !n.is_container() && reads_as(fill_of(n), fill.as_deref()) && reads_as(stroke_of(n).0, stroke.as_deref()))
+}
+
 fn same(s: &mut Session, cmd: &str, eq: impl Fn(&Node, &Node) -> bool) -> Result<Value> {
     let st = s.doc()?;
     let refn = st.selection.objects.first().and_then(|id| st.doc.node(*id)).cloned().ok_or_else(|| bad(cmd, "nothing selected"))?;

crates/engine/src/tests_menucmds.rs

@@ -1026,6 +1026,38 @@ fn select_same_paint_reads_type_characters() {
     assert_eq!(same(&mut s, t1, "select.same.fillAndStroke"), vec![t1, r]);
 }
 
+/// Select by Color needs no object to start from: it matches fills and strokes as
+/// `document.inspect` reports them, `#rrggbb`.
+#[test]
+fn select_color_matches_fill_and_stroke_without_a_selection() {
+    let mut s = session();
+    let [a, b, c] = [0.0, 20.0, 40.0].map(|x| rect(&mut s, x, 0.0, 10.0, 10.0));
+    let t = text(&mut s, "a");
+    fill(&mut s, a, "#000000");
+    fill(&mut s, t, "#000000");
+    // A grey as a PDF stores it reads as #fefefe.
+    s.execute("paint.setFill", &json!({"ids": [b.0], "color": [0.996, 0.996, 0.996]})).unwrap();
+    fill(&mut s, c, "#ff0000");
+    s.execute("paint.setStroke", &json!({"ids": [a.0, c.0], "color": "#0000ff"})).unwrap();
+    s.execute("select.none", &json!({})).unwrap();
+    let pick = |s: &mut Session, p: Value| {
+        s.execute("select.color", &p).unwrap();
+        let mut v = selected(s);
+        v.sort();
+        v
+    };
+    assert_eq!(pick(&mut s, json!({"fill": "#000000"})), vec![a, t]);
+    assert_eq!(pick(&mut s, json!({"fill": "#fefefe"})), vec![b]);
+    assert_eq!(pick(&mut s, json!({"stroke": "#0000ff"})), vec![a, c]);
+    assert_eq!(pick(&mut s, json!({"fill": "#000000", "stroke": "#0000ff"})), vec![a]);
+    // Select > Reselect repeats it.
+    s.execute("select.none", &json!({})).unwrap();
+    s.execute("select.reselect", &json!({})).unwrap();
+    assert_eq!(selected(&s), vec![a]);
+    assert!(s.execute("select.color", &json!({})).is_err());
+    assert!(s.execute("select.color", &json!({"fill": "not a colour"})).is_err());
+}
+
 #[test]
 fn select_direction_handles_selects_all_anchors() {
     let mut s = session();