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/app/commands/attdef.rs

@@ -54,6 +54,7 @@ impl OpenCADStudio {
                 if let Some(state) = self.attdef_dialog.as_mut() {
                     if let Some(value) = value {
                         state.default = value;
+                        state.field = None;
                     }
                     self.active_modal = Some(crate::app::ModalKind::AttDef);
                 }
@@ -134,6 +135,7 @@ impl OpenCADStudio {
             align_below: false,
             can_align_below: session.last.is_some(),
             error: None,
+            field: None,
         });
         drop(session);
         self.tabs[i].active_cmd = None;
@@ -154,6 +156,8 @@ impl OpenCADStudio {
             default: a.default_value.clone(),
             constant: a.flags.constant,
             error: None,
+            field: None,
+            field_changed: false,
         });
         self.active_modal = Some(crate::app::ModalKind::AttDefEdit);
     }
@@ -164,7 +168,15 @@ impl OpenCADStudio {
             match m {
                 AttdefDialogMsg::EditTag(v) => edit.tag = v,
                 AttdefDialogMsg::EditPrompt(v) => edit.prompt = v,
-                AttdefDialogMsg::EditDefault(v) => edit.default = v,
+                AttdefDialogMsg::EditDefault(v) => {
+                    edit.default = v;
+                    edit.field = None;
+                    edit.field_changed = true;
+                }
+                AttdefDialogMsg::EditInsertField => {
+                    self.active_modal = None;
+                    self.open_field_dialog(crate::ui::window::field_dialog::FieldTarget::AttdefEdit);
+                }
                 AttdefDialogMsg::Help => self.command_line.push_info(
                     crate::t!("Changes the tag, prompt and default value of an attribute definition.")
                         .as_ref(),
@@ -189,7 +201,15 @@ impl OpenCADStudio {
             AttdefDialogMsg::Annotative(v) => state.annotative = v,
             AttdefDialogMsg::Tag(v) => state.tag = v,
             AttdefDialogMsg::Prompt(v) => state.prompt = v,
-            AttdefDialogMsg::Default(v) => state.default = v,
+            AttdefDialogMsg::Default(v) => {
+                state.default = v;
+                state.field = None;
+            }
+            AttdefDialogMsg::InsertField => {
+                self.active_modal = None;
+                self.open_field_dialog(crate::ui::window::field_dialog::FieldTarget::AttdefDefault);
+                return Task::none();
+            }
             AttdefDialogMsg::Justify(c) => state.justify = c.0,
             AttdefDialogMsg::Style(v) => state.style = v,
             AttdefDialogMsg::Height(v) => state.height = v,
@@ -279,6 +299,7 @@ impl OpenCADStudio {
             oblique_angle: defaults.oblique_angle,
             boundary_width: width,
             line_spacing: 1.0,
+            field: state.field.clone(),
         };
         self.attdef_dialog = None;
         self.close_active_modal();
@@ -336,7 +357,7 @@ impl OpenCADStudio {
             self.tabs[i].scene.document.get_entity(state.handle),
             Some(codec::EntityType::AttributeDefinition(a))
                 if a.tag != attdef::normalize_tag(&state.tag) || a.prompt != state.prompt || a.default_value != state.default
-        );
+        ) || state.field_changed;
         if changed && !self.reject_locked_edit(i, state.handle) {
             self.push_undo_snapshot(i, "DDEDIT");
             if let Some(codec::EntityType::AttributeDefinition(a)) =
@@ -348,6 +369,14 @@ impl OpenCADStudio {
                 }
                 a.default_value = state.default.clone();
             }
+            if state.field_changed {
+                crate::entities::field::set_text_field(
+                    &mut self.tabs[i].scene.document,
+                    state.handle,
+                    state.field.clone(),
+                    &state.default,
+                );
+            }
             self.tabs[i]
                 .scene
                 .bump_entities(&[(state.handle, crate::scene::ChangeKind::Modified)]);

src/app/commands/field.rs

@@ -0,0 +1,206 @@
+//! FIELD and the Field dialog behind the ƒ buttons of the attribute
+//! definition dialogs.
+
+use crate::app::{Message, OpenCADStudio};
+use crate::command::CadCommand;
+use crate::modules::annotate::field_cmd::{FieldObjectPickCommand, FieldPlaceCommand};
+use crate::ui::window::field_dialog::{
+    fields_of, object_properties, FieldDialogMsg, FieldDialogState, FieldTarget, DATE_FORMATS,
+    NAMED_TYPES,
+};
+use iced::Task;
+
+impl OpenCADStudio {
+    pub(super) fn dispatch_field(&mut self, cmd: &str, i: usize) -> Option<Task<Message>> {
+        match cmd {
+            "FIELD" => {
+                self.open_field_dialog(FieldTarget::NewText);
+                Some(Task::none())
+            }
+            cmd if cmd == "_FIELD_OBJECT" || cmd.starts_with("_FIELD_OBJECT ") => {
+                let handle = cmd
+                    .split_whitespace()
+                    .nth(1)
+                    .and_then(|h| u64::from_str_radix(h, 16).ok())
+                    .map(codec::Handle::new);
+                if let Some(state) = self.field_dialog.as_mut() {
+                    if let Some(entity) = handle.and_then(|h| self.tabs[i].scene.document.get_entity(h)) {
+                        let props = object_properties(entity);
+                        state.object = Some((entity.common().handle, crate::t!(crate::entities::names::ui_name(entity)).into_owned()));
+                        state.object_prop = props.first().copied();
+                        state.object_props = props;
+                    }
+                    self.active_modal = Some(crate::app::ModalKind::Field);
+                    self.refresh_field_preview();
+                }
+                Some(Task::none())
+            }
+            _ => None,
+        }
+    }
+
+    /// Open the Field dialog for `target`.
+    pub(in crate::app) fn open_field_dialog(&mut self, target: FieldTarget) {
+        let mut state = FieldDialogState::new(target);
+        state.examples = DATE_FORMATS
+            .iter()
+            .map(|f| self.field_value(&format!("\\AcVar Date \\f \"{f}\""), &[]))
+            .collect();
+        self.field_dialog = Some(state);
+        self.fill_named_objects();
+        self.refresh_field_preview();
+        self.active_modal = Some(crate::app::ModalKind::Field);
+    }
+
+    fn field_value(&self, code: &str, objects: &[codec::Handle]) -> String {
+        crate::entities::field::evaluate(&self.tabs[self.active_tab].scene.document, code, objects, None)
+            .unwrap_or_else(|| "----".to_string())
+    }
+
+    fn refresh_field_preview(&mut self) {
+        let Some(state) = self.field_dialog.as_ref() else {
+            return;
+        };
+        let (code, objects) = state.code();
+        let preview = if state.complete() { self.field_value(&code, &objects) } else { String::new() };
+        if let Some(state) = self.field_dialog.as_mut() {
+            state.preview = preview;
+        }
+    }
+
+    /// The names of the chosen named-object type, sorted.
+    fn fill_named_objects(&mut self) {
+        let Some(state) = self.field_dialog.as_mut() else {
+            return;
+        };
+        let document = &self.tabs[self.active_tab].scene.document;
+        let mut names: Vec<(String, codec::Handle)> = match NAMED_TYPES[state.named_type] {
+            "Block" => document
+                .block_records
+                .iter()
+                .filter(|b| !b.name.starts_with('*'))
+                .map(|b| (b.name.clone(), b.handle))
+                .collect(),
+            "Dimstyle" => document.dim_styles.iter().map(|s| (s.name.clone(), s.handle)).collect(),
+            "Layer" => document.layers.iter().map(|l| (l.name.clone(), l.handle)).collect(),
+            "Linetype" => document.line_types.iter().map(|l| (l.name.clone(), l.handle)).collect(),
+            "Textstyle" => document
+                .text_styles
+                .iter()
+                .filter(|s| !s.name.is_empty())
+                .map(|s| (s.name.clone(), s.handle))
+                .collect(),
+            "View" => document.views.iter().map(|v| (v.name.clone(), v.handle)).collect(),
+            _ => Vec::new(),
+        };
+        names.sort_by_key(|(n, _)| n.to_lowercase());
+        state.named_names = names;
+        state.named = None;
+    }
+
+    pub(in crate::app) fn on_field_dialog(&mut self, m: FieldDialogMsg) -> Task<Message> {
+        let i = self.active_tab;
+        let Some(state) = self.field_dialog.as_mut() else {
+            return Task::none();
+        };
+        match m {
+            FieldDialogMsg::Category(c) => {
+                state.category = c;
+                let names = fields_of(c);
+                if !names.contains(&state.name) {
+                    state.name = names.first().copied().unwrap_or("Date");
+                }
+            }
+            FieldDialogMsg::Name(n) => {
+                state.name = n;
+                state.text_case = 0;
+            }
+            FieldDialogMsg::DateFormat(f) => state.date_format = f,
+            FieldDialogMsg::DateExample(k) => {
+                if let Some(f) = DATE_FORMATS.get(k) {
+                    state.date_format = f.to_string();
+                }
+            }
+            FieldDialogMsg::TextCase(k) => state.text_case = k,
+            FieldDialogMsg::FileParts(b) => state.file_parts = b,
+            FieldDialogMsg::FileExtension(v) => state.file_extension = v,
+            FieldDialogMsg::SizeUnit(k) => state.size_unit = k,
+            FieldDialogMsg::SysVar(v) => state.sysvar = v,
+            FieldDialogMsg::Diesel(v) => state.diesel = v,
+            FieldDialogMsg::NamedType(k) => {
+                state.named_type = k;
+                self.fill_named_objects();
+            }
+            FieldDialogMsg::Named(k) => state.named = Some(k),
+            FieldDialogMsg::ObjectProp(p) => state.object_prop = Some(p),
+            FieldDialogMsg::SelectObject => {
+                // The dialog waits while one object is picked.
+                self.active_modal = None;
+                let command = FieldObjectPickCommand;
+                self.command_line.push_info(&command.prompt());
+                self.tabs[i].active_cmd = Some(Box::new(command));
+                return Task::none();
+            }
+            FieldDialogMsg::Help => self.command_line.push_info(
+                crate::t!("Inserts a field: text that updates from the drawing, the date or another source.").as_ref(),
+            ),
+            FieldDialogMsg::Ok => return self.field_dialog_ok(i),
+        }
+        self.refresh_field_preview();
+        Task::none()
+    }
+
+    fn field_dialog_ok(&mut self, i: usize) -> Task<Message> {
+        let Some(state) = self.field_dialog.take() else {
+            return Task::none();
+        };
+        let (code, objects) = state.code();
+        let value = state.preview.clone();
+        let field = Some((code, objects));
+        match state.target {
+            FieldTarget::NewText => {
+                self.close_active_modal();
+                let defaults =
+                    crate::scene::creation_style::current_text_defaults(&self.tabs[i].scene.document);
+                let command = FieldPlaceCommand::new(
+                    value,
+                    field.expect("set above"),
+                    defaults.style_name,
+                    defaults.height,
+                );
+                self.reset_command_start_state(i);
+                self.command_line.push_info(&command.prompt());
+                self.tabs[i].active_cmd = Some(Box::new(command));
+                self.push_ucs_to_cmd(i);
+                return self.focus_cmd_input();
+            }
+            FieldTarget::AttdefDefault => {
+                if let Some(dialog) = self.attdef_dialog.as_mut() {
+                    dialog.default = value;
+                    dialog.field = field;
+                }
+                self.active_modal = Some(crate::app::ModalKind::AttDef);
+            }
+            FieldTarget::AttdefEdit => {
+                if let Some(edit) = self.attdef_edit.as_mut() {
+                    edit.default = value;
+                    edit.field = field;
+                    edit.field_changed = true;
+                }
+                self.active_modal = Some(crate::app::ModalKind::AttDefEdit);
+            }
+        }
+        Task::none()
+    }
+
+    /// The dialogs a Field dialog was opened from come back when it closes.
+    pub(in crate::app) fn close_field_dialog(&mut self) {
+        let target = self.field_dialog.take().map(|s| s.target);
+        self.close_active_modal();
+        self.active_modal = match target {
+            Some(FieldTarget::AttdefDefault) if self.attdef_dialog.is_some() => Some(crate::app::ModalKind::AttDef),
+            Some(FieldTarget::AttdefEdit) if self.attdef_edit.is_some() => Some(crate::app::ModalKind::AttDefEdit),
+            _ => None,
+        };
+    }
+}

src/app/commands/mod.rs

@@ -5,6 +5,7 @@ use iced::Task;
 use std::path::PathBuf;
 
 mod attdef;
+mod field;
 mod blocks;
 mod xref_attach;
 mod dim;
@@ -282,6 +283,9 @@ impl OpenCADStudio {
         if let Some(t) = self.dispatch_attdef(cmd, i) {
             return Some(t);
         }
+        if let Some(t) = self.dispatch_field(cmd, i) {
+            return Some(t);
+        }
         if let Some(t) = self.dispatch_draw(cmd, i) {
             return Some(t);
         }