Last updated at 6:20 pm UTC on 4 October 2020
The World or world in Morphic is the rectangular area which fills the whole screen.
World starting with an uppercase W is a global variable (replaced, see below) which keeps the instance of the topmost PasteUpMorph of the currently active MorphicProject.
World starting with a lower case w is the instance variable of the project. Both variables point to the same object.
- All other morphs are submorphs (or submorphs of submorphs) of the world Morph.
- Every Morph answers the message #world which returns this topmost instance of PasteUpMorph.
- All Morphs you see on a screen belong to one big composition hierarchy with the global variable World pointing to the topmost Morph, which is a PasteUpMorph.
- The World PasteUpMorph instance refers to a WorldState object
World PasteUpMorph object (data structure)
In December 2017 references to the global variable World have been replaced with
Project current world
This applies to the version which was later released as Squeak 5.2.
Remove global variable World
It is better to start using the global ActiveWorld rather than the global 'World'.
The reason is given here.