feat: preview and commit Saved Scenario spacing gestures

crates/oa-desktop/src/behavior/scenario.rs

@@ -5,10 +5,8 @@ use super::*;
 use iced::widget::{Column, column, text_input};
 use std::{cell::RefCell, collections::BTreeSet};
 mod camera;
-// Pure spacing experiment; no production gesture or command dispatch is wired.
 pub(crate) mod focus;
-#[cfg(test)]
-mod spacing;
+pub(crate) mod spacing;
 use super::scenario_layout::{
     Representation,
     presentation::{self, ScenarioPresentation},
@@ -109,6 +107,7 @@ impl std::fmt::Display for CanvasTool {
 }
 #[derive(Debug, Clone)]
 pub enum CanvasEvent {
+    Spacing(spacing::Event),
     Scrolled(Context, ScrollArea, iced::Vector),
     Restored(Context, Id, ScrollArea, iced::Vector),
     Viewport(Context, Size),
@@ -149,6 +148,7 @@ pub enum ScrollArea {
 impl CanvasEvent {
     pub fn context(&self) -> Context {
         match self {
+            Self::Spacing(event) => event.stamp().context,
             Self::Scrolled(context, _, _)
             | Self::Restored(context, ..)
             | Self::Viewport(context, _)
@@ -217,6 +217,7 @@ pub enum ValueSection {
 const VALUE_PAGE_SIZE: usize = 24;
 #[derive(Default)]
 pub struct State {
+    spacing: Option<spacing::controller::Session>,
     draft: Option<Draft>,
     form_session: Id,
     form_mount: Id,
@@ -373,6 +374,7 @@ impl State {
             self.canvas_tool = Some((owner, CanvasTool::Select));
         }
         if changed || self.presentation.visit.is_nil() {
+            self.spacing = None;
             self.presentation.visit = Id::new_v4();
             self.restore = None;
             return true;
@@ -381,10 +383,12 @@ impl State {
     }
     /// Suspend captured events while preserving this destination's camera state.
     pub(crate) fn leave(&mut self) {
+        self.spacing = None;
         self.presentation.visit = Id::nil();
         self.restore = None;
     }
     pub(crate) fn forget_view(&mut self) {
+        self.spacing = None;
         self.presentation.identity = None;
         self.presentation.representation = None;
         self.presentation.visit = Id::nil();