properly handle empty text entry fields (including transformations)

common/SoundPlayer.lua

@@ -5,13 +5,13 @@ local Util  = require('opus.util')
 local peripheral = _G.peripheral
 
 if not peripheral.find('speaker') then
-  error('No speaker attached')
+	error('No speaker attached')
 end
 
 local rawSounds = Util.readLines('packages/games/etc/sounds.txt') or error('Unable to read sounds file')
 local sounds = { }
 for _, s in pairs(rawSounds) do
-  table.insert(sounds, { name = s })
+	table.insert(sounds, { name = s })
 end
 
 UI:configure('SoundPlayer', ...)
@@ -25,21 +25,21 @@ local page = UI.Page {
 		x = 10, y = 2, ex = -3,
 		limit = 32,
 	},
-  grid = UI.ScrollingGrid {
+	grid = UI.ScrollingGrid {
 		y = 4,
-    columns = {
-      { heading = 'Name', key = 'name' },
-    },
-    values = sounds,
-  },
+		columns = {
+			{ heading = 'Name', key = 'name' },
+		},
+		values = sounds,
+	},
 }
 
 function page:eventHandler(event)
-  if event.type == 'grid_select' then
-    Sound.play(event.selected.name)
+	if event.type == 'grid_select' then
+		Sound.play(event.selected.name)
 
 	elseif event.type == 'text_change' then
-		if #event.text == 0 then
+		if not event.text then
 			self.grid.values = sounds
 		else
 			self.grid.values = { }
@@ -51,12 +51,12 @@ function page:eventHandler(event)
 		end
 		self.grid:update()
 		self.grid:setIndex(1)
-    self.grid:draw()
+		self.grid:draw()
 
-  else
-    return UI.Page.eventHandler(self, event)
-  end
-  return true
+	else
+		return UI.Page.eventHandler(self, event)
+	end
+	return true
 end
 
 UI:setPage(page)