coin_scxml3
State chart xml classes - this set of classes is a basic implementation of state chart xml.
Usage
Classes
class ScXML
base class
for
event
targets
for
inter-system
event
communication
class
ScXMLStateMachine
base class
for
element
reader
objects
class
ScXMLScxmlElt
base class
for
evaluator
data
objects
in
the
SCXML
data
module
class
ScXMLConstantDataObj
base class
for
immediate
data
values
class
ScXMLReferenceDataObj
Detailed Description
This set of classes is a basic implementation of State Chart XML.
It is not complete, nor is it necessary conformant to those parts it implements.
Currently Coin uses SCXML for managing 3D viewer user interaction (the non-model-interaction part) - the examiner navigation mode in layman terms.
The Draft Specification for SCXML is at http://www.w3.org/TR/scxml/.
See also
Navigation Classes
Since
Coin 3.0
State Chart XML
The ScXML part of Coin is a basic, non-conformant, partial implementation of State Chart XML, based on the W3C Working Draft 16 May 2008 of SCXML http://www.w3.org/TR/2008/WD-scxml-20080516/. The latest version should be at http://www.w3.org/TR/scxml/. Read that document for a basic understanding how SCXML documents should be constructed.
Coin uses SCXML for setting up its navigation systems, to be able to remove hardcoded logic for user navigation and externalize it into XML files. This makes it easy for users to customize the navigation system for their own purposes.
Unsupported Items:
- •
-
The <parallel> element is not supported as intended with parallel states. Coin will just treat it as an ordinary <state> element for now. Parallel states is not high up on the priority list, so expect this to be handled after a lot of other functionality is in place.
- •
-
The <datamodel>-related part of the specification is not fully supported.
- •
-
The 'target' attribute in the <transition> element can only identify a single state currently, not multiple as you would have to when having support for <parallel> elements (which we don't have).
- •
-
The virtual state elements like <history> and <anchor> are just implemented as dummy states for now and do not do anything in relation to what they should actually do.
For learning more about how ScXML is implemented and used in Coin, take a look at $COINDIR/scxml/navigation/examiner.xml (or in the Coin source directory, data/scxml/navigation/examiner.xml) for an example of how an SCXML system for camera navigation looks, and look at the source files in src/navigation/ for the C++ counterparts to the same SCXML navigation system.
Since
Coin 3.0