Enable manual path entry in new profile assistant

GTK file chooser allows selecting either files or directories but not
both. File choosers in the new profile assistant are configured for
selecting directories, with the expectation that this covers the vast
majority of usages. This patch adds text entry fields for users who wish
to manually enter the paths. As a side effect, this enables specifying a
single file as a sync root.

src/uigtk3.ml

@@ -1407,10 +1407,19 @@ let createProfile parent =
 
   (* Directory selection *)
   let directorySelection = GPack.vbox ~border_width:12 ~spacing:6 () in
+  let dirhb = GPack.hbox ~packing:(directorySelection#pack ~expand:false) () in
   adjustSize
     (GMisc.label ~xalign:0. ~line_wrap:true ~justify:`LEFT
        ~text:"Please select the two directories that you want to synchronize."
-       ~packing:(directorySelection#pack ~expand:false) ());
+       ~packing:(dirhb#pack ~expand:false) ());
+  let manualEntryB =
+    GButton.toggle_button ~label:"I want to enter the paths manually"
+      ~packing:(dirhb#pack ~expand:false ~from:`END) () in
+  (* Not sure what's going on here, but when setting the focus on an element,
+     it's actually the next element that gets the focus by default. We want
+     the focus to be on the first directory selector. Setting the focus on the
+     button here achieves exactly that... *)
+  ignore (manualEntryB#misc#connect#map ~callback:manualEntryB#misc#grab_focus);
   let secondDirLabel1 =
     GMisc.label ~xalign:0. ~line_wrap:true ~justify:`LEFT
       ~text:"The second directory is relative to your home \
@@ -1434,11 +1443,25 @@ let createProfile parent =
     al#set_left_padding 12;
     GPack.table ~rows:2 ~columns:2 ~col_spacings:12 ~row_spacings:6
       ~packing:(al#add) () in
-(*XXX Should focus on this button when becomes visible... *)
+
+  let noneToEmpty o = match o with None -> "" | Some s -> s in
+  let connectButtonAndEntry btn entry =
+    ignore (btn#connect#selection_changed ~callback:(fun () ->
+      if not entry#is_focus then entry#set_text (noneToEmpty btn#filename)));
+    ignore (entry#connect#changed ~callback:(fun () ->
+      if entry#is_focus then ignore (btn#set_filename entry#text)))
+  in
+
+  let firstDirHbox =
+    GPack.hbox ~homogeneous:true ~packing:(tbl#attach ~left:1 ~top:0 ~expand:`X) () in
+  let firstFileEntry = GEdit.entry ~packing:(firstDirHbox#pack ~expand:false) () in
   let firstDirButton =
     GFile.chooser_button ~action:`SELECT_FOLDER ~title:"First Directory"
-       ~packing:(tbl#attach ~left:1 ~top:0 ~expand:`X) ()
+       ~packing:firstDirHbox#add ()
   in
+  connectButtonAndEntry firstDirButton firstFileEntry;
+  GtkReact.show firstFileEntry (GtkReact.toggle_button manualEntryB);
+
   isLocal >| (fun b -> firstDirButton#set_title
                          (if b then "First Directory" else "Local Directory"));
   GtkReact.label_underlined
@@ -1447,11 +1470,18 @@ let createProfile parent =
        ~packing:(tbl#attach ~left:0 ~top:0 ~expand:`NONE) ())
     (isLocal >> fun b ->
        if b then "_First directory:" else "_Local directory:");
-  let noneToEmpty o = match o with None -> "" | Some s -> s in
   let firstDir = GtkReact.file_chooser firstDirButton >> noneToEmpty in
+
+  let secondDirHbox =
+    GPack.hbox ~homogeneous:true ~packing:(tbl#attach ~left:1 ~top:1 ~expand:`X) () in
+  let secondFileEntry = GEdit.entry ~packing:(secondDirHbox#pack ~expand:false) () in
   let secondDirButton =
     GFile.chooser_button ~action:`SELECT_FOLDER ~title:"Second Directory"
-       ~packing:(tbl#attach ~left:1 ~top:1 ~expand:`X) () in
+       ~packing:secondDirHbox#add () in
+  connectButtonAndEntry secondDirButton secondFileEntry;
+  GtkReact.show secondFileEntry
+    (React.lift2 (&&) isLocal (GtkReact.toggle_button manualEntryB));
+
   let secondDirLabel =
     GMisc.label ~xalign:0.
       ~text:"Se_cond directory:"
@@ -1478,8 +1508,7 @@ let createProfile parent =
   let dirExplanationLabel =
     GMisc.label ~xalign:0. ~line_wrap:true ~justify:`LEFT
       ~text:"Note: To synchronize a single file with another file, you \
-             currently have to create the profile manually or specify the \
-             files on the command line."
+             have to enter the paths manually."
       ~packing:(directorySelection#pack ~expand:false) ()
   in
   dirExplanationLabel#set_max_width_chars 80;