feat(layout/#592): layout tabs - part 1 (#2013)

* add layouts to model

* add layout command

* previous/next layout commands

* refactor: move views to View module

* add layout tab bar

* wire up tabnew/tabedit (incomplete)

* configuration settings

* hide layout tabs in zen mode

* RemoveLastBlocked -> RemoveLastWasBlocked

* fix off by one bug

* fix "missing default value" warnings

* labeled ~index on Tabs.render

* fix closing behaviour

src/Components/Tabs.re

@@ -49,7 +49,7 @@ let schedulePostRender = f => postRenderQueue := [f, ...postRenderQueue^];
 let component = React.Expert.component("Tabs");
 let make =
     (
-      ~children as render: 'a => element,
+      ~children as render: (~isSelected: bool, ~index: int, 'a) => element,
       ~items: list('a),
       ~selectedIndex: option(int),
       ~style,
@@ -117,7 +117,12 @@ let make =
         ref={r => setOuterRef(_ => Some(r))}
         style=outerStyle>
         <View onDimensionsChanged=postRender style=innerStyle>
-          {List.map(render, items) |> React.listToElement}
+          {List.mapi(
+             index =>
+               render(~isSelected=Some(index) == selectedIndex, ~index),
+             items,
+           )
+           |> React.listToElement}
         </View>
       </View>,
       hooks,

src/Feature/Layout/Configuration.re

@@ -0,0 +1,59 @@
+open Oni_Core;
+open Config.Schema;
+
+module Codec: {
+  let showLayoutTabs: Config.Schema.codec([ | `always | `smart | `off]);
+  let layoutTabPosition: Config.Schema.codec([ | `top | `bottom]);
+} = {
+  let showLayoutTabs =
+    custom(
+      ~decode=
+        Json.Decode.(
+          string
+          |> map(
+               fun
+               | "always" => `always
+               | "smart" => `smart
+               | "off" => `off
+               | _ => `smart,
+             )
+        ),
+      ~encode=
+        Json.Encode.(
+          fun
+          | `always => string("always")
+          | `smart => string("smart")
+          | `off => string("off")
+        ),
+    );
+
+  let layoutTabPosition =
+    custom(
+      ~decode=
+        Json.Decode.(
+          string
+          |> map(
+               fun
+               | "top" => `top
+               | "bottom" => `bottom
+               | _ => `bottom,
+             )
+        ),
+      ~encode=
+        Json.Encode.(
+          fun
+          | `top => string("top")
+          | `bottom => string("bottom")
+        ),
+    );
+};
+
+let showLayoutTabs =
+  setting("oni.layout.showLayoutTabs", Codec.showLayoutTabs, ~default=`smart);
+
+let layoutTabPosition =
+  setting(
+    "oni.layout.layoutTabPosition",
+    Codec.layoutTabPosition,
+    ~default=`bottom,
+  );