org.apache.sis.util.collection

Interface TreeTable.Node

All Known Implementing Classes:

DefaultTreeTable.Node

Enclosing interface:

TreeTable

public static interface TreeTable.Node

A node in a tree combined with a row in a table. A TreeTable.Node can be seen as a tree node associated to a single user object (like ordinary trees), augmented with the capability to describe some aspects of the user object in pre-defined columns. The list of allowed columns is given by the TreeTable.getColumns() method.

The following table summarizes the tree-related and table-related methods:

Tree-table methods

Tree-related methods	Table-related methods
getParent() getChildren() newChild()	getValue(TableColumn) setValue(TableColumn, Object) isEditable(TableColumn)

In addition, each Node can be associated to an arbitrary object by the getUserObject() method. This object is not used directly by the tree tables.

Since:

0.3

Defined in the sis-utility module

Method Summary

Methods

Modifier and Type	Method and Description
Collection<TreeTable.Node>	getChildren() Returns the children of this node.
TreeTable.Node	getParent() Returns the parent node, or null if this node is the root of the tree.
Object	getUserObject() Returns the user object associated to this node.
<V> V	getValue(TableColumn<V> column) Returns the value in the given column, or null if none.
boolean	isEditable(TableColumn<?> column) Determines whether the value in the specified column is editable.
boolean	isLeaf() Returns true if this node can not have any children.
TreeTable.Node	newChild() Creates a new child with the same columns than the other children, and adds it to the children collection.
<V> void	setValue(TableColumn<V> column, V value) Sets the value for the given column (optional operation).

Method Detail

getParent

TreeTable.Node getParent()

Returns the parent node, or null if this node is the root of the tree.

There is intentionally no setParent(Node) method, as children and parent managements are highly implementation-dependant. If the children collection is modifiable, then implementations are encouraged to update automatically the parent when a child is added to or removed from that collection.

Returns:

The parent, or null if none.

isLeaf

boolean isLeaf()

Returns true if this node can not have any children. The children collection of a leaf node can only be empty, and adding new child is an unsupported operation.

This value is provided as a tip for graphical user interfaces, in order to determine if a node is expandable (even if empty). TreeTableFormat does not use this value.

Returns:

true if this node can not have any children.

getChildren

Collection<TreeTable.Node> getChildren()

Returns the children of this node. The returned collection may or may not be modifiable, at implementation choice. If the collection is modifiable, then it shall be live, i.e. any modification to the returned collection are reflected immediately in the tree. This allows addition or removal of child nodes as below:

TreeTable.Node newNode = new ...; // Create a new node here.
parent.getChildren().add(newNode);

The collection is often a List, but not necessarily. For some implementations like the metadata tree table view, compliance to the List contract is impractical or inefficient.

Returns:

The children, or an empty collection if none.

newChild

TreeTable.Node newChild()
                        throws UnsupportedOperationException

Creates a new child with the same columns than the other children, and adds it to the children collection. The new child is typically added at the end of the collection, but this is not mandatory: implementations can add the child at whatever position they see fit.

Returns:

The new child.

Throws:

UnsupportedOperationException - If this node can not add new children.

getValue

<V> V getValue(TableColumn<V> column)

Returns the value in the given column, or null if none.

Type Parameters:

V - The base type of values in the given column.

Parameters:

column - Identifier of the column from which to get the value.

Returns:

The value in the given column, or null if none.

See Also:

TreeTable.getColumns()

setValue

<V> void setValue(TableColumn<V> column,
                V value)
              throws IllegalArgumentException,
                     UnsupportedOperationException

Sets the value for the given column (optional operation). The isEditable(TableColumn) method can be invoked before this setter method for determining if the given column is modifiable.

Type Parameters:

V - The base type of values in the given column.

Parameters:

column - Identifier of the column into which to set the value.

value - The value to set.

Throws:

IllegalArgumentException - If the given column is not a legal column for this node.

UnsupportedOperationException - If values in the given column can not be modified.

See Also:

TreeTable.getColumns(), isEditable(TableColumn)

isEditable

boolean isEditable(TableColumn<?> column)

Determines whether the value in the specified column is editable. If the given column is not a legal column for this Node instance, then this method returns false.

Parameters:

column - The column to query.

Returns:

true if the given column is a legal column for this Node implementation and the corresponding value is editable, or false otherwise.

getUserObject

Object getUserObject()

Returns the user object associated to this node. The user object is for information purpose only and does not appear in the rendered tree. It is typically a Java object whose content is splitted into the various table columns.

Example: If a CityLocation class is defined as a (city name, latitude, longitude) tuple, then a TreeTable.Node could be defined to have 3 columns for the above 3 tuple components, and the user object could be the original CityLocation instance.

Returns:

Any object stored at this node by the user, or null if none.