On browser and file_browser screens, focus the first item when appearing

lua/browser.lua

@@ -118,6 +118,7 @@ return screen:new {
     end
 
     widgets.InfiniteList(self.root, self.iterator, {
+      focus_first_item = true,
       get_icon = get_icon_func,
       callback = function(item)
         return function()

lua/file_browser.lua

@@ -59,6 +59,7 @@ return screen:new {
     end
 
     widgets.InfiniteList(self.root, self.iterator, {
+      focus_first_item = true,
       callback = function(item)
         return function()
           local is_dir = item:is_directory()

lua/widgets.lua

@@ -306,10 +306,11 @@ function widgets.InfiniteList(parent, iterator, opts)
     fwd_iterator:prev()
   end
 
-  local function add_item(item, index)
+  local function add_item(item, index, item_opts)
     if not item then
       return
     end
+    item_opts = item_opts or {}
     local this_item = index
     local add_to_top = false
     if this_item < first_index then
@@ -325,6 +326,9 @@ function widgets.InfiniteList(parent, iterator, opts)
     if add_to_top then
       btn:move_to_index(0)
     end
+    if item_opts.focus then
+      btn:focus()
+    end
     -- opts.callback should take an item and return a function matching the arg of onClicked
     if opts.callback then
       btn:onClicked(opts.callback(item))
@@ -361,7 +365,7 @@ function widgets.InfiniteList(parent, iterator, opts)
     if not val then
       break
     end
-    add_item(val, idx)
+    add_item(val, idx, { focus = (opts.focus_first_item and idx == 0) })
   end
 
   return infinite_list