FIELD: Field dialog, FIELD command and the ATTDEF field buttons

A Field dialog with the fields the application evaluates and the
reference format choices, FIELD placing a field as multi-line text, the
attribute definition dialogs' field buttons, field attachment on commit,
system variable / file size / regional date providers for field
evaluation, and the codec patch with the field authoring API.

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

src/modules/annotate/field_cmd.rs

@@ -0,0 +1,190 @@
+// FIELD — places the field chosen in the Field dialog as a multi-line text,
+// and the object pick behind the dialog's "Select object" button.
+
+use codec::entities::mtext::AttachmentPoint;
+use codec::entities::MText;
+use codec::types::{Handle, Vector3};
+use codec::EntityType;
+use glam::DVec3;
+
+use crate::command::{CadCommand, CmdResult, InputKind, WorkingPlane};
+
+/// A field to attach to the entity a command commits: the field code and the
+/// objects it refers to.
+pub type TextField = (String, Vec<Handle>);
+
+#[derive(Clone, Copy, PartialEq)]
+enum Step {
+    Point,
+    Height,
+    Justify,
+}
+
+/// `Specify start point or [Height/Justify]:` → an MTEXT holding the field.
+pub struct FieldPlaceCommand {
+    step: Step,
+    value: String,
+    field: TextField,
+    style: String,
+    height: f64,
+    attachment: AttachmentPoint,
+    plane: WorkingPlane,
+}
+
+impl FieldPlaceCommand {
+    pub fn new(value: String, field: TextField, style: String, height: f64) -> Self {
+        Self {
+            step: Step::Point,
+            value,
+            field,
+            style,
+            height,
+            attachment: AttachmentPoint::TopLeft,
+            plane: WorkingPlane::default(),
+        }
+    }
+}
+
+fn short(v: f64) -> String {
+    let t = format!("{v:.4}");
+    t.trim_end_matches('0').trim_end_matches('.').to_string()
+}
+
+impl CadCommand for FieldPlaceCommand {
+    fn name(&self) -> &'static str {
+        "FIELD"
+    }
+
+    fn set_working_plane(&mut self, plane: WorkingPlane) {
+        self.plane = plane;
+    }
+
+    fn prompt(&self) -> String {
+        match self.step {
+            Step::Point => "Specify start point or [Height/Justify]:".into(),
+            Step::Height => format!("Specify height <{}>:", short(self.height)),
+            Step::Justify => "Enter justification [TL/TC/TR/ML/MC/MR/BL/BC/BR] <TL>:".into(),
+        }
+    }
+
+    fn input_kind(&self) -> InputKind {
+        match self.step {
+            Step::Justify => InputKind::SingleToken,
+            _ => InputKind::Point,
+        }
+    }
+
+    fn point_step_accepts_keywords(&self) -> bool {
+        self.step == Step::Point
+    }
+
+    fn on_text_input(&mut self, text: &str) -> Option<CmdResult> {
+        let word = text.trim().trim_start_matches('_').to_ascii_uppercase();
+        match self.step {
+            Step::Point => match word.as_str() {
+                "H" | "HEIGHT" => self.step = Step::Height,
+                "J" | "JUSTIFY" => self.step = Step::Justify,
+                "" => return Some(CmdResult::ReportError("Point or option keyword required.".into())),
+                _ => return Some(CmdResult::ReportError("Point or option keyword required.".into())),
+            },
+            Step::Height => {
+                if word.is_empty() {
+                    self.step = Step::Point;
+                    return Some(CmdResult::NeedPoint);
+                }
+                match word.parse::<f64>() {
+                    Ok(v) if v > 0.0 => {
+                        self.height = v;
+                        self.step = Step::Point;
+                    }
+                    Ok(_) => return Some(CmdResult::ReportError("Value must be positive and nonzero.".into())),
+                    Err(_) => return Some(CmdResult::ReportError("Requires numeric distance or two points.".into())),
+                }
+            }
+            Step::Justify => {
+                self.attachment = match word.as_str() {
+                    "" | "TL" => AttachmentPoint::TopLeft,
+                    "TC" => AttachmentPoint::TopCenter,
+                    "TR" => AttachmentPoint::TopRight,
+                    "ML" => AttachmentPoint::MiddleLeft,
+                    "MC" => AttachmentPoint::MiddleCenter,
+                    "MR" => AttachmentPoint::MiddleRight,
+                    "BL" => AttachmentPoint::BottomLeft,
+                    "BC" => AttachmentPoint::BottomCenter,
+                    "BR" => AttachmentPoint::BottomRight,
+                    _ => return Some(CmdResult::ReportError("Invalid option keyword.".into())),
+                };
+                self.step = Step::Point;
+            }
+        }
+        Some(CmdResult::NeedPoint)
+    }
+
+    fn on_point(&mut self, pt: DVec3) -> CmdResult {
+        if self.step == Step::Height {
+            return CmdResult::NeedPoint;
+        }
+        let p = self.plane.to_local(pt);
+        let mut mtext = MText::new();
+        mtext.value = self.value.clone();
+        mtext.insertion_point = Vector3::new(p.x, p.y, p.z);
+        mtext.height = self.height;
+        mtext.style = self.style.clone();
+        mtext.attachment_point = self.attachment;
+        CmdResult::CommitAndExit(self.plane.place_entity(EntityType::MText(mtext)))
+    }
+
+    fn on_enter(&mut self) -> CmdResult {
+        match self.step {
+            Step::Point => CmdResult::ReportError("Point or option keyword required.".into()),
+            _ => self.on_text_input("").unwrap_or(CmdResult::NeedPoint),
+        }
+    }
+
+    fn text_field(&self) -> Option<TextField> {
+        Some(self.field.clone())
+    }
+}
+
+/// The Field dialog's "Select object": one object is picked and handed back
+/// (`_FIELD_OBJECT <handle>`); Esc returns without one.
+pub struct FieldObjectPickCommand;
+
+impl CadCommand for FieldObjectPickCommand {
+    fn name(&self) -> &'static str {
+        "FIELD"
+    }
+
+    fn prompt(&self) -> String {
+        "Select object:".into()
+    }
+
+    fn needs_entity_pick(&self) -> bool {
+        true
+    }
+
+    fn entity_pick_highlights_hover(&self) -> bool {
+        true
+    }
+
+    fn on_entity_pick(&mut self, handle: Handle, _pt: DVec3) -> CmdResult {
+        if handle.is_null() {
+            return CmdResult::NeedPoint;
+        }
+        CmdResult::Dispatch(format!("_FIELD_OBJECT {:X}", handle.value()))
+    }
+
+    fn on_point(&mut self, _pt: DVec3) -> CmdResult {
+        CmdResult::NeedPoint
+    }
+
+    fn on_enter(&mut self) -> CmdResult {
+        CmdResult::Dispatch("_FIELD_OBJECT".into())
+    }
+
+    fn on_escape(&mut self) -> CmdResult {
+        CmdResult::Dispatch("_FIELD_OBJECT".into())
+    }
+}
+
+inventory::submit!(crate::command::CommandRegistration { names: &["FIELD"] });

src/modules/annotate/mod.rs

@@ -7,6 +7,7 @@ pub mod angular_dim;
 pub mod data_extract;
 pub mod data_link;
 pub mod ddedit;
+pub mod field_cmd;
 pub mod diameter_dim;
 pub mod dim_baseline;
 pub mod dim_continue;