Update state management

1 files changed, 32 insertions, 0 deletions

diff --git a/lib/stitch.ml b/lib/stitch.ml
new file mode 100644
index 0000000..e49ed9c
--- /dev/null
+++ b/lib/stitch.ml
@@ -0,0 +1,32 @@
+module Grep = Grep
+module Common = Common
+module Todos = Todos
+module Headlines = Headlines
+
+let start (tag : string) () =
+  (* This is a rather funky state management that isn't maybe entirely functional.
+     What we do is store a function for each view that restores it's state.
+
+     This allows us to remember the state of the view and restore it as we travel between different views.
+
+     It does create a rather funky, cyclical state though.
+  *)
+  let term = Common.Term.create () in
+  let restore_headline_state = ref (fun () -> ()) in
+  let restore_todo_state = ref (fun () -> ()) in
+  let goto_headline_from_todo new_todo_state =
+    restore_todo_state := new_todo_state;
+    !restore_headline_state ()
+  in
+  (restore_todo_state
+   := fun () ->
+        let todo = Todos.init ~goto_headlines:goto_headline_from_todo in
+        Todos.render term todo);
+  let headline =
+    Headlines.init
+      ~goto_todos_view:(fun new_state ->
+        restore_headline_state := new_state;
+        !restore_todo_state ())
+      ~regexp:tag
+  in
+  Headlines.render term headline