Package com.vaadin.client.flow

Class StateTree

java.lang.Object

com.vaadin.client.flow.StateTree

public class StateTree
extends Object

A client-side representation of a server-side state tree.

Since:

1.0

Author:

Vaadin Ltd

Constructor Summary

Constructors

Constructor	Description
StateTree(Registry registry)	Creates a new instance connected to the given registry.

Method Summary

Modifier and Type	Method	Description
StateNode	getNode(int id)	Finds the node with the given id.
Registry	getRegistry()	Gets the Registry that this state tree belongs to.
StateNode	getRootNode()	Gets the root node of this tree.
StateNode	getStateNodeForDomNode(DomNode domNode)	Returns the state node in the tree for the given dom node or null if none found.
boolean	isActive(StateNode node)	Checks whether the node is active.
boolean	isResync()	Check if tree is resynchronizing after a prepareForResync()
boolean	isUpdateInProgress()	Returns whether this tree is currently being updated by TreeChangeProcessor.processChanges(StateTree, JsonArray).
boolean	isVisible(StateNode node)	Returns the visibility state of the node.
void	prepareForResync()	Unregisters all nodes except root from this tree, and clears the root's features.
void	registerNode(StateNode node)	Registers a node with this tree.
void	sendEventToServer(StateNode node, String eventType, elemental.json.JsonObject eventData)	Sends an event to the server.
void	sendExistingElementAttachToServer(StateNode parent, int requestedId, int assignedId, String tagName, int index)	Sends a data for attach existing element server side callback.
void	sendExistingElementWithIdAttachToServer(StateNode parent, int requestedId, int assignedId, String id)	Sends a data for attach existing element with id server side callback.
void	sendNodePropertySyncToServer(MapProperty property)	Sends a map property sync to the server.
void	sendTemplateEventToServer(StateNode node, String methodName, JsArray<?> argsArray, int promiseId)	Sends a request to call server side method with methodName using argsArray as argument values.
void	setResync(boolean resync)	Set the resynchronization state for the StateTree.
void	setUpdateInProgress(boolean updateInProgress)	Mark this tree as being updated.
void	unregisterNode(StateNode node)	Unregisters a node from this tree.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StateTree

public StateTree(Registry registry)

Creates a new instance connected to the given registry.

Parameters:

registry - the global registry

Method Detail

setUpdateInProgress

public void setUpdateInProgress(boolean updateInProgress)

Mark this tree as being updated.

Parameters:

updateInProgress - true if the tree is being updated, false if not

See Also:

isUpdateInProgress()

isUpdateInProgress

public boolean isUpdateInProgress()

Returns whether this tree is currently being updated by TreeChangeProcessor.processChanges(StateTree, JsonArray).

Returns:

true if being updated, false if not

registerNode

public final void registerNode(StateNode node)

Registers a node with this tree.

Parameters:

node - the node to register

unregisterNode

public void unregisterNode(StateNode node)

Unregisters a node from this tree. Once the node has been unregistered, it can't be registered again.

Parameters:

node - the node to unregister

prepareForResync

public void prepareForResync()

Unregisters all nodes except root from this tree, and clears the root's features. Use to reset the tree in preparation for rebuilding it in in a resynchronization response.

isResync

public boolean isResync()

Check if tree is resynchronizing after a prepareForResync()

Returns:

true if resync called

setResync

public void setResync(boolean resync)

Set the resynchronization state for the StateTree.

Parameters:

resync - resynchronization state to set

getStateNodeForDomNode

public StateNode getStateNodeForDomNode(DomNode domNode)

Returns the state node in the tree for the given dom node or null if none found.

Comparison is done with Node.isSameNode() method which is same as === comparison.

Parameters:

domNode - the dom node to find state node for

Returns:

the state node or null

getNode

public StateNode getNode(int id)

Finds the node with the given id.

Parameters:

id - the id

Returns:

the node with the given id, or null if no such node is registered.

getRootNode

public StateNode getRootNode()

Gets the root node of this tree.

Returns:

the root node

sendEventToServer

public void sendEventToServer(StateNode node,
                              String eventType,
                              elemental.json.JsonObject eventData)

Sends an event to the server.

Parameters:

node - the node that listened to the event

eventType - the type of event

eventData - extra data associated with the event

sendNodePropertySyncToServer

public void sendNodePropertySyncToServer(MapProperty property)

Sends a map property sync to the server.

Parameters:

property - the property that should have its value synced to the server, not null

sendTemplateEventToServer

public void sendTemplateEventToServer(StateNode node,
                                      String methodName,
                                      JsArray<?> argsArray,
                                      int promiseId)

Sends a request to call server side method with methodName using argsArray as argument values.

In cases when the state tree has been changed and we receive a delayed or deferred template event the event is just ignored.

Parameters:

node - the node referring to the server side instance containing the method

methodName - the method name

argsArray - the arguments array for the method

promiseId - the promise id to use for getting the result back, or -1 if no result is expected

sendExistingElementAttachToServer

public void sendExistingElementAttachToServer(StateNode parent,
                                              int requestedId,
                                              int assignedId,
                                              String tagName,
                                              int index)

Sends a data for attach existing element server side callback.

Parameters:

parent - parent of the node to attach

requestedId - originally requested id of a server side node

assignedId - identifier which should be used on the server side for the element (instead of requestedId)

tagName - the requested tagName

index - the index of the element on the server side

sendExistingElementWithIdAttachToServer

public void sendExistingElementWithIdAttachToServer(StateNode parent,
                                                    int requestedId,
                                                    int assignedId,
                                                    String id)

Sends a data for attach existing element with id server side callback.

Parameters:

parent - parent of the node to attach

requestedId - originally requested id of a server side node

assignedId - identifier which should be used on the server side for the element (instead of requestedId)

id - id of requested element

getRegistry

public Registry getRegistry()

Gets the Registry that this state tree belongs to.

Returns:

the registry of this tree, not null

isVisible

public boolean isVisible(StateNode node)

Returns the visibility state of the node.

Parameters:

node - the node whose visibility is tested

Returns:

true is the node is visible, false otherwise

isActive

public boolean isActive(StateNode node)

Checks whether the node is active.

The node is active if it's visible and all its ancestors are visible.

Parameters:

node - the node whose activity is tested

Returns:

true is the node is active, false otherwise