com.vaadin.flow.component.internal.

java.lang.Object
- com.vaadin.flow.component.internal.UIInternals

All Implemented Interfaces:

Serializable
```
public class UIInternals
extends Object
implements Serializable
```
Holds UI-specific methods and data which are intended for internal use by the framework.
For internal use only. May be renamed or removed in a future release.

Since:

1.0

Author:

Vaadin Ltd

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`UIInternals.JavaScriptInvocation`	A `Page.executeJs(String, Serializable...)` invocation that has not yet been sent to the client.

Constructor Summary

Constructors
Constructor	Description
`UIInternals(UI ui)`	Creates a new instance for the given UI.
`UIInternals(UI ui, UIInternalUpdater internalsHandler)`	Creates a new instance for the given UI.

Method Summary

All Methods
Modifier and Type	Method	Description
`Registration`	`addAfterNavigationListener(AfterNavigationListener listener)`	Add a listener that will be informed when new components have been attached and all navigation tasks have resolved.
`Registration`	`addBeforeEnterListener(BeforeEnterListener listener)`	Add a listener that will be informed when a new set of components are going to be attached.
`Registration`	`addBeforeLeaveListener(BeforeLeaveListener listener)`	Add a listener that will be informed when old components are detached.
`void`	`addComponentDependencies(Class<? extends Component> componentClass)`	Adds the dependencies defined using `StyleSheet` or `JavaScript` on the given Component class.
`Registration`	`addHeartbeatListener(HeartbeatListener listener)`
`void`	`addJavaScriptInvocation(PendingJavaScriptInvocation invocation)`	Adds a JavaScript invocation to be sent to the client.
`boolean`	`cancelPendingTitleUpdate()`	Cancels any pending page title update set via `setTitle(String)`.
`void`	`clearLastHandledNavigation()`	Clear latest handled navigation location.
`List<PendingJavaScriptInvocation>`	`dumpPendingJavaScriptInvocations()`	Gets all the pending JavaScript invocations and clears the queue.
`Component`	`getActiveDragSourceComponent()`	Gets the drag source of an active HTML5 drag event.
`Component`	`getActiveModalComponent()`	Get the active modal component if modal components set.
`List<HasElement>`	`getActiveRouterTargetsChain()`	Gets the currently active router target and parent layouts.
`Location`	`getActiveViewLocation()`	Gets the location of the currently shown view.
`String`	`getAppId()`	Gets the application id tied with this UI.
`String`	`getAppShellTitle()`	Gets the stored app shell title.
`ConstantPool`	`getConstantPool()`	Gets the constant pool that is used for keeping track of constants shared with the client for this UI.
`String`	`getContextRootRelativePath()`	Gets the relative path from the UI (servlet) path to the context root.
`BeforeLeaveEvent.ContinueNavigationAction`	`getContinueNavigationAction()`	Get stored `BeforeLeaveEvent.ContinueNavigationAction` if any.
`DependencyList`	`getDependencyList()`	Returns the helper which handles loading of dependencies (css, js).
`ExtendedClientDetails`	`getExtendedClientDetails()`	The extended client details, if obtained, are cached in this field.
`Location`	`getLastHandledLocation()`	Get the latest handled location or empty optional if no active navigation.
`long`	`getLastHeartbeatTimestamp()`	Returns the timestamp of the last received heartbeat for the related UI.
`int`	`getLastProcessedClientToServerId()`	Gets the last processed server message id.
`byte[]`	`getLastProcessedMessageHash()`	Gets the hash of the last processed message from the client.
`<E> List<E>`	`getListeners(Class<E> handler)`	Get all registered listeners for given navigation handler type.
`PushConnection`	`getPushConnection()`	Returns the internal push connection object used by the related UI.
`Router`	`getRouter()`	Gets the router used for navigating in this UI, if the router was active when this UI was initialized.
`int`	`getServerSyncId()`	Gets the server sync id.
`VaadinSession`	`getSession()`	Gets the VaadinSession to which the related UI is attached.
`StateTree`	`getStateTree()`	Gets the state tree of the related UI.
`String`	`getTitle()`	Gets the page title recorded with `Page.setTitle(String)`.
`UI`	`getUI()`	Gets the UI that this instance belongs to.
`boolean`	`hasLastHandledLocation()`	Check if we have already started navigation to some location on this roundtrip.
`boolean`	`hasModalComponent()`	Check if we have a modal component defined for the UI.
`void`	`incrementServerId()`	Increments the server sync id.
`boolean`	`isDirty()`	Checks if there are changes waiting to be sent to the client side.
`void`	`moveElementsFrom(UI otherUI)`	Move all the children of the other UI to this current UI.
`void`	`setActiveDragSourceComponent(Component activeDragSourceComponent)`	Sets the drag source of an active HTML5 drag event.
`void`	`setAppId(String appId)`	Sets the application id tied with this UI.
`void`	`setAppShellTitle(String appShellTitle)`	Records the text content of the title tag in the application shell.
`void`	`setChildModal(Component child)`	Makes an existing child component modal.
`void`	`setChildModeless(Component child)`	Sets the given child modeless.
`void`	`setContextRoot(String contextRootRelativePath)`	Sets the relative path from the UI (servlet) path to the context root.
`void`	`setContinueNavigationAction(BeforeLeaveEvent.ContinueNavigationAction continueNavigationAction)`	Set a `BeforeLeaveEvent.ContinueNavigationAction` or null to clear existing action.
`void`	`setExtendedClientDetails(ExtendedClientDetails details)`	Updates the extended client details.
`void`	`setLastHandledNavigation(Location location)`	Set the latest navigation location for active navigation.
`void`	`setLastHeartbeatTimestamp(long lastHeartbeat)`	Sets the last heartbeat request timestamp for the related UI.
`void`	`setLastProcessedClientToServerId(int lastProcessedClientToServerId, byte[] lastProcessedMessageHash)`	Sets the last processed server message id.
`void`	`setPushConnection(PushConnection pushConnection)`	Sets the internal push connection object used by the related UI.
`void`	`setSession(VaadinSession session)`	Sets the session to which the related UI is assigned.
`void`	`setTitle(String title)`	Records the page title set with `Page.setTitle(String)`.
`void`	`showRouteTarget(Location viewLocation, Component target, List<RouterLayout> layouts)`	Shows a route target in the related UI.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - UIInternals
```
public UIInternals(UI ui)
```
    Creates a new instance for the given UI.
    
    Parameters:
    
    ui - the UI to use
  - UIInternals
```
public UIInternals(UI ui,
                   UIInternalUpdater internalsHandler)
```
    Creates a new instance for the given UI.
    
    Parameters:
    
    ui - the UI to use
    
    internalsHandler - an implementation of UIInternalUpdater
- Method Detail
  - getStateTree
```
public StateTree getStateTree()
```
    Gets the state tree of the related UI.
    
    Returns:
    
    the state tree
  - getLastProcessedClientToServerId
```
public int getLastProcessedClientToServerId()
```
    Gets the last processed server message id.
    Used internally for communication tracking.
    
    Returns:
    
    lastProcessedServerMessageId the id of the last processed server message
  - getLastProcessedMessageHash
```
public byte[] getLastProcessedMessageHash()
```
    Gets the hash of the last processed message from the client.
    The hash is set through setLastProcessedClientToServerId(int, byte[]).
    Used internally for communication tracking.
    
    Returns:
    
    the hash as a byte array, or null if no hash has been set
  - setLastProcessedClientToServerId
```
public void setLastProcessedClientToServerId(int lastProcessedClientToServerId,
                                             byte[] lastProcessedMessageHash)
```
    Sets the last processed server message id.
    Used internally for communication tracking.
    
    Parameters:
    
    lastProcessedClientToServerId - the id of the last processed server message
    
    lastProcessedMessageHash - the hash of the message
  - getServerSyncId
```
public int getServerSyncId()
```
    Gets the server sync id.
    The sync id is incremented by one whenever a new response is written. This id is then sent over to the client. The client then adds the most recent sync id to each communication packet it sends back to the server. This way, the server knows at what state the client is when the packet is sent. If the state has changed on the server side since that, the server can try to adjust the way it handles the actions from the client side.
    The sync id value -1 is ignored to facilitate testing with pre-recorded requests.
    
    Returns:
    
    the server sync id
  - incrementServerId
```
public void incrementServerId()
```
    Increments the server sync id.
    This should only be called by whoever sends a message to the client, after the message has been sent.
  - getLastHeartbeatTimestamp
```
public long getLastHeartbeatTimestamp()
```
    Returns the timestamp of the last received heartbeat for the related UI.
    This method is not intended to be overridden. If it is overridden, care should be taken since this method might be called in situations where UI.getCurrent() does not return the UI.
    
    Returns:
    
    The time the last heartbeat request occurred, in milliseconds since the epoch.
    
    See Also:
    
    VaadinService.closeInactiveUIs(VaadinSession)
  - setLastHeartbeatTimestamp
```
public void setLastHeartbeatTimestamp(long lastHeartbeat)
```
    Sets the last heartbeat request timestamp for the related UI. Called by the framework whenever the application receives a valid heartbeat request for the UI.
    This method is not intended to be overridden. If it is overridden, care should be taken since this method might be called in situations where UI.getCurrent() does not return the UI.
    
    Parameters:
    
    lastHeartbeat - The time the last heartbeat request occurred, in milliseconds since the epoch.
  - setSession
```
public void setSession(VaadinSession session)
```
    Sets the session to which the related UI is assigned.
    This method is for internal use by the framework. To explicitly close a UI, see UI.close().
    
    Parameters:
    
    session - the session to set
    
    Throws:
    
    IllegalStateException - if the session has already been set
    
    See Also:
    
    getSession()
  - getPushConnection
```
public PushConnection getPushConnection()
```
    Returns the internal push connection object used by the related UI. This method should only be called by the framework.
    This method is not intended to be overridden. If it is overridden, care should be taken since this method might be called in situations where UI.getCurrent() does not return the UI.
    
    Returns:
    
    the push connection used by the UI, or null if push is not available.
  - setPushConnection
```
public void setPushConnection(PushConnection pushConnection)
```
    Sets the internal push connection object used by the related UI. This method should only be called by the framework.
    The pushConnection argument must be non-null if and only if getPushConfiguration().getPushMode().isEnabled().
    
    Parameters:
    
    pushConnection - the push connection to use for the UI
  - addBeforeEnterListener
```
public Registration addBeforeEnterListener(BeforeEnterListener listener)
```
    Add a listener that will be informed when a new set of components are going to be attached.
    
    Parameters:
    
    listener - the before enter listener
    
    Returns:
    
    handler to remove the event listener
  - addBeforeLeaveListener
```
public Registration addBeforeLeaveListener(BeforeLeaveListener listener)
```
    Add a listener that will be informed when old components are detached.
    
    Parameters:
    
    listener - the before leave listener
    
    Returns:
    
    handler to remove the event listener
  - addAfterNavigationListener
```
public Registration addAfterNavigationListener(AfterNavigationListener listener)
```
    Add a listener that will be informed when new components have been attached and all navigation tasks have resolved.
    
    Parameters:
    
    listener - the after navigation listener
    
    Returns:
    
    handler to remove the event listener
  - addHeartbeatListener
```
public Registration addHeartbeatListener(HeartbeatListener listener)
```
  - getListeners
```
public <E> List<E> getListeners(Class<E> handler)
```
    Get all registered listeners for given navigation handler type.
    
    Type Parameters:
    
    E - the handler type
    
    Parameters:
    
    handler - handler to get listeners for
    
    Returns:
    
    unmodifiable list of registered listeners for navigation handler
  - addJavaScriptInvocation
```
public void addJavaScriptInvocation(PendingJavaScriptInvocation invocation)
```
    Adds a JavaScript invocation to be sent to the client.
    
    Parameters:
    
    invocation - the invocation to add
  - dumpPendingJavaScriptInvocations
```
public List<PendingJavaScriptInvocation> dumpPendingJavaScriptInvocations()
```
    Gets all the pending JavaScript invocations and clears the queue.
    
    Returns:
    
    a list of pending JavaScript invocations
  - setTitle
```
public void setTitle(String title)
```
    Records the page title set with Page.setTitle(String).
    You should not set the page title for the browser with this method, use Page.setTitle(String) instead.
    
    Parameters:
    
    title - the title to set
  - setAppShellTitle
```
public void setAppShellTitle(String appShellTitle)
```
    Records the text content of the title tag in the application shell.
    NOTE Intended for internal use, you should not call this method.
    
    Parameters:
    
    appShellTitle - the appShellTitle to set
  - getTitle
```
public String getTitle()
```
    Gets the page title recorded with Page.setTitle(String).
    NOTE this might not be up to date with the actual title set since it is not updated from the browser and the update might have been canceled before it has been sent to the browser with cancelPendingTitleUpdate().
    
    Returns:
    
    the page title
  - getAppShellTitle
```
public String getAppShellTitle()
```
    Gets the stored app shell title.
    NOTE Intended for internal use, you should not call this method.
    
    Returns:
    
    the app shell title
  - cancelPendingTitleUpdate
```
public boolean cancelPendingTitleUpdate()
```
    Cancels any pending page title update set via setTitle(String).
    
    Returns:
    
    true if pending title update was cancelled, false if not
  - showRouteTarget
```
public void showRouteTarget(Location viewLocation,
                            Component target,
                            List<RouterLayout> layouts)
```
    Shows a route target in the related UI. This method is intended for framework use only. Use UI.navigate(String) to change the route target that is shown in a UI.
    
    Parameters:
    
    viewLocation - the location of the route target relative to the servlet serving the UI, not null
    
    target - the component to show, not null
    
    layouts - the parent layouts
  - moveElementsFrom
```
public void moveElementsFrom(UI otherUI)
```
    Move all the children of the other UI to this current UI.
    
    Parameters:
    
    otherUI - the other UI to transfer content from.
  - getActiveRouterTargetsChain
```
public List<HasElement> getActiveRouterTargetsChain()
```
    Gets the currently active router target and parent layouts.
    
    Returns:
    
    a list of active router target and parent layout instances, starting from the innermost part
  - getActiveViewLocation
```
public Location getActiveViewLocation()
```
    Gets the location of the currently shown view. The location is relative the servlet mapping used for serving the related UI.
    
    Returns:
    
    the view location, not null
  - getSession
```
public VaadinSession getSession()
```
    Gets the VaadinSession to which the related UI is attached.
    The method will return null if the UI is not currently attached to a VaadinSession.
    
    Returns:
    
    the VaadinSession to which the related UI is attached
  - getDependencyList
```
public DependencyList getDependencyList()
```
    Returns the helper which handles loading of dependencies (css, js).
    
    Returns:
    
    the dependency list helper
  - addComponentDependencies
```
public void addComponentDependencies(Class<? extends Component> componentClass)
```
    Adds the dependencies defined using StyleSheet or JavaScript on the given Component class.
    
    Parameters:
    
    componentClass - the component class to read annotations from
  - getConstantPool
```
public ConstantPool getConstantPool()
```
    Gets the constant pool that is used for keeping track of constants shared with the client for this UI.
    
    Returns:
    
    the constant pool to use, not null
  - getLastHandledLocation
```
public Location getLastHandledLocation()
```
    Get the latest handled location or empty optional if no active navigation.
    
    Returns:
    
    location if navigated during active navigation or null
  - setLastHandledNavigation
```
public void setLastHandledNavigation(Location location)
```
    Set the latest navigation location for active navigation.
    
    Parameters:
    
    location - last location navigated to
  - hasLastHandledLocation
```
public boolean hasLastHandledLocation()
```
    Check if we have already started navigation to some location on this roundtrip.
    
    Returns:
    
    true if the last navigation location != null
  - clearLastHandledNavigation
```
public void clearLastHandledNavigation()
```
    Clear latest handled navigation location.
  - getContinueNavigationAction
```
public BeforeLeaveEvent.ContinueNavigationAction getContinueNavigationAction()
```
    Get stored BeforeLeaveEvent.ContinueNavigationAction if any.
    
    Returns:
    
    continue navigation action object
  - setContinueNavigationAction
```
public void setContinueNavigationAction(BeforeLeaveEvent.ContinueNavigationAction continueNavigationAction)
```
    Set a BeforeLeaveEvent.ContinueNavigationAction or null to clear existing action.
    
    Parameters:
    
    continueNavigationAction - continue navigation action to store or null
  - setAppId
```
public void setAppId(String appId)
```
    Sets the application id tied with this UI. Different applications in the same page have different unique ids.
    
    Parameters:
    
    appId - the id of the application tied with this UI
  - getAppId
```
public String getAppId()
```
    Gets the application id tied with this UI. Different applications in the same page have different unique ids.
    
    Returns:
    
    the id of the application tied with this UI
  - getRouter
```
public Router getRouter()
```
    Gets the router used for navigating in this UI, if the router was active when this UI was initialized.
    
    Returns:
    
    the router used for this UI, or null if there is no router or the UI doesn't support navigation.
  - isDirty
```
public boolean isDirty()
```
    Checks if there are changes waiting to be sent to the client side.
    
    Returns:
    
    true if there are pending changes, false otherwise
  - setContextRoot
```
public void setContextRoot(String contextRootRelativePath)
```
    Sets the relative path from the UI (servlet) path to the context root.
    
    Parameters:
    
    contextRootRelativePath - the relative path from servlet to context root
  - getContextRootRelativePath
```
public String getContextRootRelativePath()
```
    Gets the relative path from the UI (servlet) path to the context root.
    
    Returns:
    
    the relative path from servlet to context root
  - setActiveDragSourceComponent
```
public void setActiveDragSourceComponent(Component activeDragSourceComponent)
```
    Sets the drag source of an active HTML5 drag event.
    
    Parameters:
    
    activeDragSourceComponent - the drag source component
    
    Since:
    
    2.0
  - getActiveDragSourceComponent
```
public Component getActiveDragSourceComponent()
```
    Gets the drag source of an active HTML5 drag event.
    
    Returns:
    
    Extension of the drag source component if the drag event is active and originated from this UI, null otherwise.
    
    Since:
    
    2.0
  - getUI
```
public UI getUI()
```
    Gets the UI that this instance belongs to.
    
    Returns:
    
    the UI instance.
  - getExtendedClientDetails
```
public ExtendedClientDetails getExtendedClientDetails()
```
    The extended client details, if obtained, are cached in this field.
    
    Returns:
    
    the extended client details, or null if not yet received.
  - setExtendedClientDetails
```
public void setExtendedClientDetails(ExtendedClientDetails details)
```
    Updates the extended client details.
    
    Parameters:
    
    details - the updated extended client details.
  - hasModalComponent
```
public boolean hasModalComponent()
```
    Check if we have a modal component defined for the UI.
    
    Returns:
    
    true if modal component is defined
  - getActiveModalComponent
```
public Component getActiveModalComponent()
```
    Get the active modal component if modal components set.
    
    Returns:
    
    the current active modal component
  - setChildModal
```
public void setChildModal(Component child)
```
    Makes an existing child component modal. This will make the UI and the other components inside it inert - they will not react to any user interaction until the modal component is removed.
    In case there was an existing modal component in the UI already, that is made inert until the given new component is removed. The UI is no longer inert after all modal components have been removed from it. Inert state is updated automatically when a component is removed from the UI, no need to call anything. Moving an inert component will remove inert status.
    
    Parameters:
    
    child - the child component to toggle modal
  - setChildModeless
```
public void setChildModeless(Component child)
```
    Sets the given child modeless. The inert state of the UI and other child components is updated. This method is called automatically when a modal child component is removed from the UI.
    
    Parameters:
    
    child - the child component to make modeless

com.vaadin.flow.component.internal.

Class UIInternals

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

UIInternals

UIInternals

Method Detail

getStateTree

getLastProcessedClientToServerId

getLastProcessedMessageHash

setLastProcessedClientToServerId

getServerSyncId

incrementServerId

getLastHeartbeatTimestamp

setLastHeartbeatTimestamp

setSession

getPushConnection

setPushConnection

addBeforeEnterListener

addBeforeLeaveListener

addAfterNavigationListener

addHeartbeatListener

getListeners

addJavaScriptInvocation

dumpPendingJavaScriptInvocations

setTitle

setAppShellTitle

getTitle

getAppShellTitle

cancelPendingTitleUpdate

showRouteTarget

moveElementsFrom

getActiveRouterTargetsChain

getActiveViewLocation

getSession

getDependencyList

addComponentDependencies

getConstantPool

getLastHandledLocation

setLastHandledNavigation

hasLastHandledLocation

clearLastHandledNavigation

getContinueNavigationAction

setContinueNavigationAction

setAppId

getAppId

getRouter

isDirty

setContextRoot

getContextRootRelativePath

setActiveDragSourceComponent

getActiveDragSourceComponent

getUI

getExtendedClientDetails

setExtendedClientDetails

hasModalComponent

getActiveModalComponent

setChildModal

setChildModeless