Override unusable methods in Text element

gfx/text.lua

@@ -1,9 +1,41 @@
 local Element = require("element")
 local Text = Element:new{ text = "" }
 
+function Text:new(o)
+  o.width = nil
+  o.height = nil
+
+  return Element.new(self, o)
+end
+
+function Text:setText(text)
+  self:setDirty()
+  self.text = text
+end
+
 function Text:draw()
   Element.draw(self)
   self.render.window.write(self.text)
 end
 
+function Text:getHeight()
+  return 1
+end
+
+function Text:getWidth()
+  return #self.text
+end
+
+function Text:setWidth()
+  error("Dimensions are derived from content")
+end
+
+function Text:setHeight()
+  error("Dimensions are derived from content")
+end
+
+function Text:resize()
+  error("Dimensions are derived from content")
+end
+
 return Text