diff --git a/gfx/container.lua b/gfx/container.lua
index 14be45a..44dc18e 100644
--- a/gfx/container.lua
+++ b/gfx/container.lua
@@ -4,6 +4,40 @@ local Element = require("gfx.element")
 
 local Container = Prop.attach(Element:new(), Children)
 
+function Container:getHeight()
+  if self:isStrict() then
+    return Element.getHeight(self)
+  end
+  local max = 0
+  for _,child in self:_iterateChildren() do
+    max = math.max(max, child:getY() + child:getHeight())
+  end
+  return max
+end
+
+function Container:getWidth()
+  if self:isStrict() then
+    return Element.getWidth(self)
+  end
+  local max = 0
+  for _,child in self:_iterateChildren() do
+    max = math.max(max, child:getX() + child:getWidth())
+  end
+  return max
+end
+
+function Container:isStrict()
+  return self.strict == true
+end
+
+function Container:setStrict(strict)
+  local needReload = (not not self.strict) ~= strict
+  self.strict = strict
+  if needReload then
+    self:_reload()
+  end
+end
+
 function Container:_reload()
   Element._reload(self)