StateTreeBuilder class

Provides a build method that constructs a state tree.

StateTreeBuilder is primary means to supply a state tree to a TreeStateMachine. The typical usage is to use a high-level builder API to define a state tree. This API provides a StateTreeBuildProvider implementation that can construct a RootNodeInfo that reifies the definition of the tree. A StateTreeBuilder can then be constructed with this implementation, which in turn can be used to construct a TreeStateMachine.

// Hypothetical class providing high-level API for defining a state tree
class MyTreeBuilder implements StateTreeBuildProvider {
  // APIs for definining states...

  RootNodeBuildInfo createRootNodeBuildInfo() {
    // Create a RootNodeBuildInfo based on API calls
    // to this builder....
  }
}

var myBuilder = MyTreeBuilder();
// Call myBuilder methods to define a state tree....

// The state tree builder will call myBuilder.createRootNodeBuildInfo()
var treeBuilder = StateTreeBuilder(myBuilder);

// The state machine will call treeBuilder.build()
var stateMachine = TreeStateMachine(treeBuilder);

If _createBuildContext is provided, it will be called each time build is called, and the resulting build context will be used during tree construction. This is typically not needed, but may be useful in advanced scenarios requiring access to the state tree as it is built.