Flutter atvaizdinimas apima tris medžius — Widget medį (konfigūracija), Element medį (instantuoti, valdomi widget'ai) ir RenderObject medį (išdėstymas ir piešimas). Supratimas apie šią grandinę paaiškina, kaip Flutter efektyviai paverčia widget'us pikseliais.
Trys medžiai
WIDGET tree → immutable CONFIGURATION (what you write: the description of the UI)
→ cheap to create/recreate; rebuilt often (build() returns new widgets)
ELEMENT tree → the INSTANTIATED widgets; manages lifecycle and LINKS widgets to render
objects; PERSISTS across rebuilds (this is the key to efficiency)
RENDEROBJECT tree → does the actual LAYOUT, PAINTING, and hit-testing (the heavy objects)
→ expensive; REUSED and updated (not recreated) across rebuilds
