Copy and Paste in the timeline's feature menu (#1131)

The feature menu of the bottom timeline and the side history gets Copy (the selection, or the right-clicked feature) and Paste (at the marker). Ctrl+click in the bottom timeline toggles a feature in the selection (#1034).

crates/ui-egui/src/timeline_left.rs

@@ -5,7 +5,7 @@ use serde_json::json;
 use solidcraft_engine::doc::FeatureKind;
 
 use crate::theme::Tokens;
-use crate::timeline::{delete_feature, delete_features, icon_of, transport_glyph};
+use crate::timeline::{clipboard_buttons, delete_feature, delete_features, icon_of, selected_feature_ids, transport_glyph};
 use crate::{SolveApp, icons};
 
 const FOLDER_INDENT: f32 = 14.0;
@@ -209,18 +209,6 @@ fn group_for(groups: &[solidcraft_engine::doc::TimelineGroup], feature: u64) ->
     groups.iter().find(|group| group.features.contains(&feature)).map(|group| group.id)
 }
 
-fn selected_feature_ids(app: &SolveApp) -> Vec<u64> {
-    app.session
-        .doc
-        .features
-        .iter()
-        .filter(|feature| {
-            app.session.selection.iter().any(|selection| matches!(selection, solidcraft_engine::Sel::Feature { id } if *id == feature.id))
-        })
-        .map(|feature| feature.id)
-        .collect()
-}
-
 fn selected_drag_items(app: &SolveApp, origin_x: f32, source_group: Option<u64>) -> DragItems {
     DragItems { features: selected_feature_ids(app), groups: app.tree.picked_timeline_groups.clone(), origin_x, source_group }
 }
@@ -797,6 +785,8 @@ fn vertical_features(app: &mut SolveApp, ui: &mut egui::Ui) {
                 ui.close();
             }
             ui.separator();
+            clipboard_buttons(app, ui, *id);
+            ui.separator();
             selection_actions(app, ui, &groups);
             ui.separator();
             if ui.button("Delete").clicked() {