ExtJS Floating Panel - relative positioning

Question

How do i get a floating Component to position itself relative to its parent Container and maintain its relative position to the Container when the Container is moved?

e.g. when the Container is scrolled up or down

At the moment the floating Component seems to position itself relative to the Viewport (even though i've set 'fixed:false').

Framework: ExtJS 5.1

Answer 1

Just in case someone searching for an answer nowadays - in ExtJS 6.2 Ext.Widget.relative property were added, which does exactly what the question asks for.

For older versions of the framework, you can look at the implementation.