Add workspaces_for_output helper function

src/main.rs

@@ -167,6 +167,16 @@ impl App {
         self.workspaces.iter_mut().find(|i| &i.handle == handle)
     }
 
+    // TODO iterate in order based on `coordinates`
+    fn workspaces_for_output<'a>(
+        &'a self,
+        output: &'a wl_output::WlOutput,
+    ) -> impl Iterator<Item = &Workspace> + 'a {
+        self.workspaces
+            .iter()
+            .filter(|w| w.outputs.contains(output))
+    }
+
     fn toplevel_for_handle_mut(
         &mut self,
         handle: &ZcosmicToplevelHandleV1,

src/view/mod.rs

@@ -57,9 +57,7 @@ pub(crate) fn layer_surface<'a>(
     }
     let layout = app.conf.workspace_config.workspace_layout;
     let sidebar = workspaces_sidebar(
-        app.workspaces
+        app.workspaces_for_output(&surface.output),
-            .iter()
-            .filter(|i| i.outputs.contains(&surface.output)),
         &surface.output,
         layout,
         drop_target,
@@ -80,9 +78,8 @@ pub(crate) fn layer_surface<'a>(
     );
     // TODO multiple active workspaces? Not currently supported by cosmic.
     let first_active_workspace = app
-        .workspaces
+        .workspaces_for_output(&surface.output)
-        .iter()
+        .find(|w| w.is_active);
-        .find(|i| i.outputs.contains(&surface.output) && i.is_active);
     let toplevels = if let Some(workspace) = first_active_workspace {
         toplevel_dnd_destination(
             DropTarget::OutputToplevels(workspace.handle.clone(), surface.output.clone()),