feat(view): implement LIMITS command

Closes #478

src/modules/view/limits.rs

@@ -0,0 +1,98 @@
+use glam::{DVec2, DVec3};
+
+use crate::command::{CadCommand, CmdOption, CmdResult};
+
+enum LimitsStep {
+    FirstCorner,
+    OppositeCorner(DVec2),
+}
+
+/// Interactive front-end for LIMITS. The command itself only gathers input;
+/// the dispatched form mutates the active drawing/layout in one central place.
+pub struct LimitsCommand {
+    step: LimitsStep,
+    current_min: DVec2,
+    current_max: DVec2,
+}
+
+impl LimitsCommand {
+    pub fn new(current_min: DVec2, current_max: DVec2) -> Self {
+        Self {
+            step: LimitsStep::FirstCorner,
+            current_min,
+            current_max,
+        }
+    }
+
+    fn point_text(point: DVec2) -> String {
+        format!("{:.17} {:.17}", point.x, point.y)
+    }
+}
+
+impl CadCommand for LimitsCommand {
+    fn name(&self) -> &'static str {
+        "LIMITS"
+    }
+
+    fn prompt(&self) -> String {
+        match self.step {
+            LimitsStep::FirstCorner => format!(
+                "LIMITS  Specify first corner or [On / Off] <{:.4},{:.4}>:",
+                self.current_min.x, self.current_min.y
+            ),
+            LimitsStep::OppositeCorner(_) => format!(
+                "LIMITS  Specify opposite corner <{:.4},{:.4}>:",
+                self.current_max.x, self.current_max.y
+            ),
+        }
+    }
+
+    fn options(&self) -> Vec<CmdOption> {
+        match self.step {
+            LimitsStep::FirstCorner => vec![CmdOption::new("On", "ON"), CmdOption::new("Off", "OFF")],
+            LimitsStep::OppositeCorner(_) => Vec::new(),
+        }
+    }
+
+    fn on_text_input(&mut self, text: &str) -> Option<CmdResult> {
+        if !matches!(self.step, LimitsStep::FirstCorner) {
+            return None;
+        }
+        match text.trim().to_ascii_uppercase().as_str() {
+            "ON" => Some(CmdResult::Dispatch("LIMITS ON".to_string())),
+            "OFF" => Some(CmdResult::Dispatch("LIMITS OFF".to_string())),
+            _ => None,
+        }
+    }
+
+    fn on_point(&mut self, point: DVec3) -> CmdResult {
+        let point = point.truncate();
+        match self.step {
+            LimitsStep::FirstCorner => {
+                self.step = LimitsStep::OppositeCorner(point);
+                CmdResult::NeedPoint
+            }
+            LimitsStep::OppositeCorner(first) => CmdResult::Dispatch(format!(
+                "LIMITS SET {} {}",
+                Self::point_text(first),
+                Self::point_text(point)
+            )),
+        }
+    }
+
+    fn on_enter(&mut self) -> CmdResult {
+        match self.step {
+            LimitsStep::FirstCorner => {
+                self.step = LimitsStep::OppositeCorner(self.current_min);
+                CmdResult::NeedPoint
+            }
+            LimitsStep::OppositeCorner(first) => CmdResult::Dispatch(format!(
+                "LIMITS SET {} {}",
+                Self::point_text(first),
+                Self::point_text(self.current_max)
+            )),
+        }
+    }
+}
+
+inventory::submit!(crate::command::CommandRegistration { names: &["LIMITS"] });

src/modules/view/mod.rs

@@ -4,6 +4,7 @@ mod cascade;
 mod file_tabs;
 mod hidden;
 mod layout_tabs;
+pub mod limits;
 mod orbit;
 mod ortho;
 mod pan;