question: public void insertUpdate ( DocumentEvent changes , Shape a , ViewFactory f ) { updateChildren ( changes , a ) ; Rectangle alloc = ( ( a != null ) && isAllocationValid ( ) ) ? getInsideAllocation ( a ) : null ; int pos = changes . getOffset ( ) ; View v = getViewAtPosition ( pos , alloc ) ; if ( v != null ) v . insertUpdate ( changes , alloc , f ) ; }
target:  Gives notification that something was inserted into the document in a location that this view is responsible for. This is implemented to simply update the children.