AbstractNode class

An abstract node in a tree.

AbstractNode has as notion of depth, attachment, and parent, but does not have a model for children.

When a subclass is changing the parent of a child, it should call either parent.adoptChild(child) or parent.dropChild(child) as appropriate. Subclasses can expose an API for manipulating the tree if desired (e.g. a setter for a child property, or an add() method to manipulate a list).

The current parent node is exposed by the parent property.

The current attachment state is exposed by attached. The root of any tree that is to be considered attached should be manually attached by calling attach. Other than that, the attach and detach methods should not be called directly; attachment is managed automatically by the aforementioned adoptChild and dropChild methods.

Subclasses that have children must override attach and detach as described in the documentation for those methods.

Nodes always have a depth greater than their ancestors'. There's no guarantee regarding depth between siblings. The depth of a node is used to ensure that nodes are processed in depth order. The depth of a child can be more than one greater than the depth of the parent, because the depth values are never decreased: all that matters is that it's greater than the parent. Consider a tree with a root node A, a child B, and a grandchild C. Initially, A will have depth 0, B depth 1, and C depth 2. If C is moved to be a child of A, sibling of B, then the numbers won't change. C's depth will still be 2. The depth is automatically maintained by the adoptChild and dropChild methods.





attached bool
Whether this node is in a tree whose root is attached to something. [...]
depth int
The depth of this node in the tree. [...]
owner Object
The owner for this node (null if unattached). [...]
parent AbstractNode
The parent of this node in the tree.
hashCode int
The hash code for this object. [...]
read-only, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited


adoptChild(covariant AbstractNode child) → void
Mark the given node as being a child of this node. [...]
@mustCallSuper, @protected
attach(covariant Object owner) → void
Mark this node as attached to the given owner. [...]
detach() → void
Mark this node as detached. [...]
dropChild(covariant AbstractNode child) → void
Disconnect the given node from this node. [...]
@mustCallSuper, @protected
redepthChild(AbstractNode child) → void
Adjust the depth of the given child to be greater than this node's own depth. [...]
redepthChildren() → void
Adjust the depth of this node's children, if any. [...]
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
toString() String
Returns a string representation of this object.


operator ==(dynamic other) bool
The equality operator. [...]