MiG InfoCom MiG Calendar AShape Developer Manual - Manual (Page 17)

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InteractionBroker
It is the interpreter of
Command s. Since Command s are very
generic something is needed to interpret what that Command
wants to do, if that is not contained in the Command itself.
Command
The
Command is a concrete class and contains a generic
(again) description of something to do. It consists of the
command string, a property/value pair that may be use to
explain it further, and a target.
CommandSet
A collection of link
Command s. Is an interface and is
implemented by DefaultCommand . It is used to chain
multiple commands together for one interaction. You can use
CompositeCommand for this.
Expression
An
Expression is something that can be evaluated to true
or false . The only thing you have for sure is a
PropertyProvider that you can use to get values for
certain properties. Expression is an interface and the
concrete implementations provides some context to which
properties is interesting and how they should be evaluated.
For instance the LogicalExpression denotes a comparison
algorithm where you provide a property name and a value
that is should relate to with anyone of it's ten operators (e.g.
equals, is_null and in_collection). The actual object to
compare the give value to is gotten from the mandatory
PropertyProvider .
Since the PropertyProvider can be different for every
evaluation this makes for a great way to describe expressions
like: “If the object that the mouse is over right now is named
background”. Currently
ActivityInteractor and
MouseKeyInteractor implement the PropertyProvider
interface and will thus pass them self as the
PropertyProvider to the Expression' s evaluate
method. This means they can return property values for
things like a list of named areas the mouse was over when it
was pressed
(
MouseKeyInteractor.PROP_MOUSE_PRESSED_LIST ).
Static Overrides
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