Update state management

5 files changed, 69 insertions, 68 deletions

diff --git a/lib/headlines.ml b/lib/headlines.ml
index 4565f5f..7d410d7 100644
--- a/lib/headlines.ml
+++ b/lib/headlines.ml
@@ -4,18 +4,33 @@ open Notty
 module Input_screen = Input_screen
 module Stitched_article = Stitched_article
 module Help_screen = Help_screen
-module Todos = Todos
 
 type state =
   { pos : int * int
   ; scroll : int
   ; content : (string * string) array
   ; content_pretty : string array
-  ; todo_state : Todos.state option
+  ; goto_todos_view : (unit -> unit) -> unit
   }
 
+let init ~goto_todos_view ~regexp =
+  let tag = if String.equal regexp "" then None else Some regexp in
+  let content =
+    match tag with
+    | None -> Grep.get_headlines () |> Grep.parse_headlines
+    | Some tag -> Grep.get_tagged_headlines tag () |> Grep.parse_headlines
+  in
+  if Array.length content == 0
+  then (
+    print_endline "Regexp not found";
+    exit 0)
+  else (
+    let content_pretty = content |> Grep.pretty_format in
+    { pos = 0, 0; scroll = 0; content; content_pretty; goto_todos_view })
+
+
 (* TODO: Add page title *)
-let rec render t ({ pos; scroll; content; content_pretty; todo_state } as state) =
+let rec render t ({ pos; scroll; content; content_pretty; goto_todos_view } as state) =
   let x, y = pos in
   let img =
     let dot = I.string A.(st bold) ">" |> I.pad ~l:0 ~t:(y - scroll)
@@ -51,26 +66,7 @@ let rec render t ({ pos; scroll; content; content_pretty; todo_state } as state)
   | `Mouse ((`Press _ | `Drag), (_, y), _) ->
     render t { state with pos = 0, min y content_length }
   | `Key (`ASCII '?', []) -> Help_screen.render t { go_back = (fun () -> render t state) }
-  | `Key (`ASCII '2', []) ->
-    (match todo_state with
-     | Some todo_state ->
-       Todos.render
-         t
-         { todo_state with
-           goto_headlines =
-             (fun new_state -> render t { state with todo_state = Some new_state })
-         }
-     | None ->
-       let todo_content = Grep.get_todos () |> Grep.parse_todo_string in
-       let todo_pretty = Grep.pretty_format_todo todo_content in
-       let todo_state =
-         Todos.init
-           ~goto_headlines:(fun new_state ->
-             render t { state with todo_state = Some new_state })
-           ~content:(todo_content |> Array.of_list)
-           ~content_pretty:(todo_pretty |> Array.of_list)
-       in
-       Todos.render t todo_state)
+  | `Key (`ASCII '2', []) -> goto_todos_view (fun () -> render t state)
   | `Key (`ASCII 's', []) ->
     let content =
       Array.map
@@ -89,7 +85,7 @@ let rec render t ({ pos; scroll; content; content_pretty; todo_state } as state)
       ; content_pretty = full_content_pretty
       ; scroll = 0
       ; go_back = (fun () -> render t state)
-      ; todo_state
+      ; goto_todos_view
       }
   | `Key (`ASCII 'r', []) ->
     let (input_state : Input_screen.state) =
@@ -145,21 +141,3 @@ let rec render t ({ pos; scroll; content; content_pretty; todo_state } as state)
     in
     run_editor ()
   | _ -> render t state
-
-
-let start (tag : string) () =
-  let tag = if String.equal tag "" then None else Some tag in
-  let content =
-    match tag with
-    | None -> Grep.get_headlines () |> Grep.parse_headlines
-    | Some tag -> Grep.get_tagged_headlines tag () |> Grep.parse_headlines
-  in
-  if Array.length content == 0
-  then (
-    print_endline "No entry for tag";
-    exit 0)
-  else (
-    let content_pretty = content |> Grep.pretty_format in
-    render
-      (Common.Term.create ())
-      { pos = 0, 0; scroll = 0; content; content_pretty; todo_state = None })
diff --git a/lib/shared_state.ml b/lib/shared_state.ml
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/lib/shared_state.ml
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
diff --git a/lib/stitched_article.ml b/lib/stitched_article.ml
index c71ca14..66a108e 100644
--- a/lib/stitched_article.ml
+++ b/lib/stitched_article.ml
@@ -10,11 +10,14 @@ type state =
   ; content : (string * int * string * int) array
   ; go_back : unit -> unit
   ; content_pretty : Grep.display_type array
-  ; todo_state : Todos.state option
+  ; goto_todos_view : (unit -> unit) -> unit
   }
 
 (* TODO: Use grep -l to filter notes by regexp and rerender those files*)
-let rec render t ({ pos; scroll; content_pretty; go_back; content; todo_state } as state) =
+let rec render
+  t
+  ({ pos; scroll; content_pretty; go_back; content; goto_todos_view } as state)
+  =
   let size_x, size_y = Common.Term.size t in
   let x, y = pos in
   let img =
@@ -50,26 +53,7 @@ let rec render t ({ pos; scroll; content_pretty; go_back; content; todo_state }
   | `Key (`ASCII 'j', []) | `Key (`ASCII 'N', [ `Ctrl ]) -> scroll_down ()
   | `Key (`ASCII 'k', []) | `Key (`ASCII 'P', [ `Ctrl ]) -> scroll_up ()
   | `Key (`ASCII '?', []) -> Help_screen.render t { go_back = (fun () -> render t state) }
-  | `Key (`ASCII '2', []) ->
-    (match todo_state with
-     | Some todo_state ->
-       Todos.render
-         t
-         { todo_state with
-           goto_headlines =
-             (fun new_state -> render t { state with todo_state = Some new_state })
-         }
-     | None ->
-       let todo_content = Grep.get_todos () |> Grep.parse_todo_string in
-       let todo_pretty = Grep.pretty_format_todo todo_content in
-       let todo_state =
-         Todos.init
-           ~goto_headlines:(fun new_state ->
-             render t { state with todo_state = Some new_state })
-           ~content:(todo_content |> Array.of_list)
-           ~content_pretty:(todo_pretty |> Array.of_list)
-       in
-       Todos.render t todo_state)
+  | `Key (`ASCII '2', []) -> goto_todos_view (fun () -> render t state)
   | `Key (`ASCII 'e', []) | `Key (`Enter, []) ->
     (* Editor might be set with extra args, in that case we need to separate these *)
     let[@warning "-8"] (editor :: args) =
diff --git a/lib/todos.ml b/lib/todos.ml
index 4e52cd4..d2af47f 100644
--- a/lib/todos.ml
+++ b/lib/todos.ml
@@ -8,11 +8,18 @@ type state =
   ; scroll : int
   ; content : (string * string) array
   ; content_pretty : string array
-  ; goto_headlines : state -> unit
+  ; goto_headlines : (unit -> unit) -> unit
   }
 
-let init ~goto_headlines ~content ~content_pretty =
-  { pos = 0, 0; scroll = 0; content; content_pretty; goto_headlines }
+let init ~goto_headlines =
+  let content = Grep.get_todos () |> Grep.parse_todo_string in
+  let content_pretty = Grep.pretty_format_todo content in
+  { pos = 0, 0
+  ; scroll = 0
+  ; content = content |> Array.of_list
+  ; content_pretty = content_pretty |> Array.of_list
+  ; goto_headlines
+  }
 
 
 let load_todos () =
@@ -75,7 +82,7 @@ let rec render t ({ pos; scroll; content; content_pretty; goto_headlines } as st
       }
     in
     Input_screen.render t input_state
-  | `Key (`ASCII '1', []) -> goto_headlines state
+  | `Key (`ASCII '1', []) -> goto_headlines (fun () -> render t state)
   | `Key (`ASCII 'j', []) | `Key (`ASCII 'N', [ `Ctrl ]) -> scroll_down ()
   | `Key (`ASCII 'k', []) | `Key (`ASCII 'P', [ `Ctrl ]) -> scroll_up ()
   | `Key (`ASCII 't', []) ->