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Class UI

    • Field Detail

      • actionManager

        protected ActionManager actionManager

        Keeps track of the Actions added to this component, and manages the painting and handling as well.

    • Constructor Detail

      • UI

        public UI()

        Creates a new empty UI without a caption. The content of the UI must be set by calling setContent(Component) before using the UI.

      • UI

        public UI​(Component content)

        Creates a new UI with the given component (often a layout) as its content.

        Parameters:

        content - the component to use as this UIs content.

        See Also:

        setContent(Component)

    • Method Detail

      • getState

        protected UIState getState()

        Description copied from class: AbstractComponent

        Returns the shared state bean with information to be sent from the server to the client. Subclasses should override this method and set any relevant fields of the state returned by super.getState().

        Overrides:

        getState in class AbstractSingleComponentContainer

        Returns:

        updated component shared state

      • getSession

        public VaadinSession getSession()

        Gets the application object to which the component is attached.

        The method will return null if the component is not currently attached to an application.

        Getting a null value is often a problem in constructors of regular components and in the initializers of custom composite components. A standard workaround is to use VaadinSession.getCurrent() to retrieve the application instance that the current request relates to. Another way is to move the problematic initialization to attach(), as described in the documentation of the method.

        Overrides:

        getSession in class AbstractClientConnector

        Returns:

        the parent application of the component or null.

        See Also:

        attach()

      • paintContent

        public void paintContent​(PaintTarget target)
                  throws PaintException

        Description copied from interface: LegacyComponent

        Paints the Paintable into a UIDL stream. This method creates the UIDL sequence describing it and outputs it to the given UIDL stream.

        It is called when the contents of the component should be painted in response to the component first being shown or having been altered so that its visual representation is changed.

        Specified by:

        paintContent in interface LegacyComponent

        Parameters:

        target - the target UIDL stream where the component should paint itself to.

        Throws:

        PaintException - if the paint operation failed.

      • changeVariables

        public void changeVariables​(Object source,
                            Map<String,​Object> variables)

        Description copied from interface: VariableOwner

        Called when one or more variables handled by the implementing class are changed.

        Specified by:

        changeVariables in interface VariableOwner

        Parameters:

        source - the Source of the variable change. This is the origin of the event. For example in Web Adapter this is the request.

        variables - the Mapping from variable names to new variable values.

      • setSession

        public void setSession​(VaadinSession session)

        Sets the session to which this UI is assigned.

        This method is for internal use by the framework. To explicitly close a UI, see close().

        Parameters:

        session - the session to set

        Throws:

        IllegalStateException - if the session has already been set

        See Also:

        getSession()

      • getUIId

        public int getUIId()

        Gets the id of the UI, used to identify this UI within its application when processing requests. The UI id should be present in every request to the server that originates from this UI. VaadinService.findUI(VaadinRequest) uses this id to find the route to which the request belongs.

        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 getCurrent() does not return this UI.

        Returns:

        the id of this UI

      • removeWindow

        public boolean removeWindow​(Window window)

        Remove the given subwindow from this UI. Since Vaadin 6.5, Window.CloseListeners are called also when explicitly removing a window by calling this method. Since Vaadin 6.5, returns a boolean indicating if the window was removed or not.

        Parameters:

        window - Window to be removed.

        Returns:

        true if the subwindow was removed, false otherwise

      • getWindows

        public Collection<Window> getWindows()

        Gets all the windows added to this UI.

        Returns:

        an unmodifiable collection of windows

      • setDisconnectPushOnRefresh

        protected void setDisconnectPushOnRefresh​(boolean disconnectPushOnRefresh)

        Normally when UI is refreshed when PreserveOnRefresh is used, UI checks if Push connection is active and disconnects it in order to avoid race condition. With some application containers like Payara this can have side effects. With this method it is possible turn off this feature. See framework issue #12577.

        Parameters:

        disconnectPushOnRefresh - boolean value.

      • setFocusedComponent

        public void setFocusedComponent​(Component.Focusable focusable)

        This method is used by Component.Focusable objects to request focus to themselves. Focus renders must be handled at window level (instead of Component.Focusable) due we want the last focused component to be focused in client too. Not the one that is rendered last (the case we'd get if implemented in Focusable only). To focus component from Vaadin application, use Focusable.focus(). See Component.Focusable.

        Parameters:

        focusable - to be focused on next paint

      • scrollIntoView

        public void scrollIntoView​(Component component)
                    throws IllegalArgumentException

        Scrolls any component between the component and UI to a suitable position so the component is visible to the user. The given component must belong to this UI.

        Parameters:

        component - the component to be scrolled into view

        Throws:

        IllegalArgumentException - if component does not belong to this UI

      • doInit

        public void doInit​(VaadinRequest request,
                   int uiId,
                   String embedId)

        Internal initialization method, should not be overridden. This method is not declared as final because that would break compatibility with e.g. CDI.

        Parameters:

        request - the initialization request

        uiId - the id of the new ui

        embedId - the embed id of this UI, or null if no id is known

        See Also:

        getUIId(), getEmbedId()

      • getUiRootPath

        public String getUiRootPath()

        Gets the part of path (from browser's URL) that points to this UI. Basically the same as the value from Page.getLocation(), but without possible view identifiers or path parameters.

        Returns:

        the part of path (from browser's URL) that points to this UI, without possible view identifiers or path parameters

        Since:

        8.2

      • getUiPathInfo

        public String getUiPathInfo()

        Gets the path info part of the request that is used to detect the UI. This is defined during UI init by certain UIProviders that map different UIs to different URIs, like Vaadin Spring. This information is used by the Navigator when the UI is annotated with PushStateNavigation.

        For example if the UI is accessed through http://example.com/MyUI/mainview/parameter=1 the path info would be /MyUI.

        Returns:

        the path info part of the request; null if no request from client has been processed

        Since:

        8.2

      • init

        protected abstract void init​(VaadinRequest request)

        Initializes this UI. This method is intended to be overridden by subclasses to build the view and configure non-component functionality. Performing the initialization in a constructor is not suggested as the state of the UI is not properly set up when the constructor is invoked.

        The VaadinRequest can be used to get information about the request that caused this UI to be created.

        Parameters:

        request - the Vaadin request that caused this UI to be created

      • doRefresh

        public void doRefresh​(VaadinRequest request)

        Internal reinitialization method, should not be overridden.

        Parameters:

        request - the request that caused this UI to be reloaded

        Since:

        7.2

      • refresh

        protected void refresh​(VaadinRequest request)

        Reinitializes this UI after a browser refresh if the UI is set to be preserved on refresh, typically using the PreserveOnRefresh annotation. This method is intended to be overridden by subclasses if needed; the default implementation is empty.

        The VaadinRequest can be used to get information about the request that caused this UI to be reloaded.

        Parameters:

        request - the request that caused this UI to be reloaded

        Since:

        7.2

      • setCurrent

        public static void setCurrent​(UI ui)

        Sets the thread local for the current UI. This method is used by the framework to set the current application whenever a new request is processed and it is cleared when the request has been processed.

        The application developer can also use this method to define the current UI outside the normal request handling, e.g. when initiating custom background threads.

        The UI is stored using a weak reference to avoid leaking memory in case it is not explicitly cleared.

        Parameters:

        ui - the UI to register as the current UI

        See Also:

        getCurrent(), ThreadLocal

      • getCurrent

        public static UI getCurrent()

        Gets the currently used UI. The current UI is automatically defined when processing requests to the server. In other cases, (e.g. from background threads), the current UI is not automatically defined.

        The UI is stored using a weak reference to avoid leaking memory in case it is not explicitly cleared.

        Returns:

        the current UI instance if available, otherwise null

        See Also:

        setCurrent(UI)

      • setScrollTop

        public void setScrollTop​(int scrollTop)

        Set top offset to which the UI should scroll to.

        Parameters:

        scrollTop -

      • getScrollTop

        public int getScrollTop()

      • setScrollLeft

        public void setScrollLeft​(int scrollLeft)

        Set left offset to which the UI should scroll to.

        Parameters:

        scrollLeft -

      • getScrollLeft

        public int getScrollLeft()

      • removeActionHandler

        public void removeActionHandler​(Action.Handler actionHandler)

        Description copied from interface: Action.Container

        Removes a previously registered action handler for the contents of this container.

        Specified by:

        removeActionHandler in interface Action.Container

        Parameters:

        actionHandler - the handler to be removed.

      • setResizeLazy

        public void setResizeLazy​(boolean resizeLazy)

        Should resize operations be lazy, i.e. should there be a delay before layout sizes are recalculated and resize events are sent to the server. Speeds up resize operations in slow UIs with the penalty of slightly decreased usability.

        Default value: false

        When there are active window resize listeners, lazy resize mode should be used to avoid a large number of events during resize.

        Parameters:

        resizeLazy - true to use a delay before recalculating sizes, false to calculate immediately.

      • isResizeLazy

        public boolean isResizeLazy()

        Checks whether lazy resize is enabled.

        Returns:

        true if lazy resize is enabled, false if lazy resize is not enabled

      • addClickListener

        public Registration addClickListener​(MouseEvents.ClickListener listener)

        Add a click listener to the UI. The listener is called whenever the user clicks inside the UI. Also when the click targets a component inside the UI, provided the targeted component does not prevent the click event from propagating.

        Parameters:

        listener - The listener to add, not null

        Returns:

        a registration object for removing the listener

        Since:

        8.0

        See Also:

        Registration

      • isConnectorEnabled

        public boolean isConnectorEnabled()

        Description copied from interface: ClientConnector

        Checks if the communicator is enabled. An enabled communicator is allowed to receive messages from its counter-part.

        Specified by:

        isConnectorEnabled in interface ClientConnector

        Overrides:

        isConnectorEnabled in class AbstractComponent

        Returns:

        true if the connector can receive messages, false otherwise

      • getPage

        public Page getPage()

      • getNavigator

        public Navigator getNavigator()

        Returns the navigator attached to this UI or null if there is no navigator.

        Returns:

      • setNavigator

        public void setNavigator​(Navigator navigator)

        For internal use only.

        Parameters:

        navigator -

      • setCaption

        @Deprecated
public void setCaption​(String caption)
        Deprecated.
        As of 7.0, use Page.setTitle(String)

        Setting the caption of a UI is not supported. To set the title of the HTML page, use Page.setTitle

        Specified by:

        setCaption in interface Component

        Overrides:

        setCaption in class AbstractComponent

        Parameters:

        caption - the new caption for the component. If the caption is null, no caption is shown and it does not normally take any space

      • showNotification

        @Deprecated
public void showNotification​(String caption)
        Deprecated.
        As of 7.0, use Notification.show instead but be aware that Notification.show does not allow HTML.

        Shows a notification message on the middle of the UI. The message automatically disappears ("humanized message"). Care should be taken to to avoid XSS vulnerabilities as the caption is rendered as html.

        Parameters:

        caption - The message

        See Also:

        showNotification(Notification), Notification

      • showNotification

        @Deprecated
public void showNotification​(String caption,
                             Notification.Type type)
        Deprecated.
        As of 7.0, use Notification.show instead but be aware that Notification.show does not allow HTML.

        Shows a notification message the UI. The position and behavior of the message depends on the type, which is one of the basic types defined in Notification, for instance Notification.TYPE_WARNING_MESSAGE. Care should be taken to to avoid XSS vulnerabilities as the caption is rendered as html.

        Parameters:

        caption - The message

        type - The message type

        See Also:

        showNotification(Notification), Notification

      • showNotification

        @Deprecated
public void showNotification​(String caption,
                             String description)
        Deprecated.
        As of 7.0, use new Notification(...).show(Page) instead but be aware that HTML by default not allowed.

        Shows a notification consisting of a bigger caption and a smaller description on the middle of the UI. The message automatically disappears ("humanized message"). Care should be taken to to avoid XSS vulnerabilities as the caption and description are rendered as html.

        Parameters:

        caption - The caption of the message

        description - The message description

        See Also:

        showNotification(Notification), Notification

      • showNotification

        @Deprecated
public void showNotification​(String caption,
                             String description,
                             Notification.Type type)
        Deprecated.
        As of 7.0, use new Notification(...).show(Page) instead but be aware that HTML by default not allowed.

        Shows a notification consisting of a bigger caption and a smaller description. The position and behavior of the message depends on the type, which is one of the basic types defined in Notification , for instance Notification.TYPE_WARNING_MESSAGE. Care should be taken to to avoid XSS vulnerabilities as the caption and description are rendered as html.

        Parameters:

        caption - The caption of the message

        description - The message description

        type - The message type

        See Also:

        showNotification(Notification), Notification

      • showNotification

        @Deprecated
public void showNotification​(String caption,
                             String description,
                             Notification.Type type,
                             boolean htmlContentAllowed)
        Deprecated.
        As of 7.0, use new Notification(...).show(Page).

        Shows a notification consisting of a bigger caption and a smaller description. The position and behavior of the message depends on the type, which is one of the basic types defined in Notification , for instance Notification.TYPE_WARNING_MESSAGE. Care should be taken to avoid XSS vulnerabilities if html content is allowed.

        Parameters:

        caption - The message caption

        description - The message description

        type - The type of message

        htmlContentAllowed - Whether html in the caption and description should be displayed as html or as plain text

        See Also:

        showNotification(Notification), Notification

      • getLastHeartbeatTimestamp

        public long getLastHeartbeatTimestamp()

        Returns the timestamp of the last received heartbeat for this 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 getCurrent() does not return this 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 this UI. Called by the framework whenever the application receives a valid heartbeat request for this 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 getCurrent() does not return this UI.

        Parameters:

        lastHeartbeat - The time the last heartbeat request occurred, in milliseconds since the epoch.

      • getTheme

        public String getTheme()

        Gets the theme currently in use by this UI.

        Returns:

        the theme name

      • setTheme

        public void setTheme​(String theme)

        Sets the theme currently in use by this UI

        Calling this method will remove the old theme (CSS file) from the application and add the new theme.

        Note that this method is NOT SAFE to call in a portal environment or other environment where there are multiple UIs on the same page. The old CSS file will be removed even if there are other UIs on the page which are still using it.

        Parameters:

        theme - The new theme name

        Since:

        7.3

      • close

        public void close()

        Marks this UI to be detached from the session at the end of the current request, or the next request if there is no current request (if called from a background thread, for instance.)

        The UI is detached after the response is sent, so in the current request it can still update the client side normally. However, after the response any new requests from the client side to this UI will cause an error, so usually the client should be asked, for instance, to reload the page (serving a fresh UI instance), to close the page, or to navigate somewhere else.

        Note that this method is strictly for users to explicitly signal the framework that the UI should be detached. Overriding it is not a reliable way to catch UIs that are to be detached. Instead, UI.detach() should be overridden or a ClientConnector.DetachListener used.

      • isClosing

        public boolean isClosing()

        Returns whether this UI is marked as closed and is to be detached.

        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 getCurrent() does not return this UI.

        Returns:

        whether this UI is closing.

        See Also:

        close()

      • detach

        public void detach()

        Called before the UI is removed from the session. A UI instance is detached exactly once, either:

        • after it is explicitly closed.
        • when its session is closed or expires
        • after three missed heartbeat requests.

        Note that when a UI is detached, any changes made in the detach methods of any children or ClientConnector.DetachListeners that would be communicated to the client are silently ignored.

        Specified by:

        detach in interface ClientConnector

        Overrides:

        detach in class AbstractComponent

      • setContent

        public void setContent​(Component content)

        Description copied from class: AbstractSingleComponentContainer

        Sets the content of this container. The content is a component that serves as the outermost item of the visual contents. The content must always be set, either with a constructor parameter or by calling this method. Previous versions of Vaadin used a VerticalLayout with margins enabled as the default content but that is no longer the case.

        Specified by:

        setContent in interface SingleComponentContainer

        Overrides:

        setContent in class AbstractSingleComponentContainer

        Parameters:

        content - a component (typically a layout) to use as content

      • setTabIndex

        public void setTabIndex​(int tabIndex)

        Description copied from interface: Component.Focusable

        Sets the tabulator index of the Focusable component. The tab index property is used to specify the order in which the fields are focused when the user presses the Tab key. Components with a defined tab index are focused sequentially first, and then the components with no tab index. 

         Form loginBox = new Form();
 loginBox.setCaption("Login");
 layout.addComponent(loginBox);

 // Create the first field which will be focused
 TextField username = new TextField("User name");
 loginBox.addField("username", username);

 // Set focus to the user name
 username.focus();

 TextField password = new TextField("Password");
 loginBox.addField("password", password);

 Button login = new Button("Login");
 loginBox.getFooter().addComponent(login);

 // An additional component which natural focus order would
 // be after the button.
 CheckBox remember = new CheckBox("Remember me");
 loginBox.getFooter().addComponent(remember);

 username.setTabIndex(1);
 password.setTabIndex(2);
 remember.setTabIndex(3); // Different than natural place
 login.setTabIndex(4);

        After all focusable user interface components are done, the browser can begin again from the component with the smallest tab index, or it can take the focus out of the page, for example, to the location bar.

        If the tab index is not set (is set to zero), the default tab order is used. The order is somewhat browser-dependent, but generally follows the HTML structure of the page.

        A negative value means that the component is completely removed from the tabulation order and can not be reached by pressing the Tab key at all.

        Specified by:

        setTabIndex in interface Component.Focusable

        Parameters:

        tabIndex - the tab order of this component. Indexes usually start from 1. Zero means that default tab order should be used. A negative value means that the field should not be included in the tabbing sequence.

        See Also:

        Component.Focusable.getTabIndex()

      • accessSynchronously

        public void accessSynchronously​(Runnable runnable)
                         throws UIDetachedException

        Locks the session of this UI and runs the provided Runnable right away.

        It is generally recommended to use access(Runnable) instead of this method for accessing a session from a different thread as access(Runnable) can be used while holding the lock of another session. To avoid causing deadlocks, this methods throws an exception if it is detected than another session is also locked by the current thread.

        This method behaves differently than access(Runnable) in some situations:

        Parameters:

        runnable - the runnable which accesses the UI

        Throws:

        UIDetachedException - if the UI is not attached to a session (and locking can therefore not be done)

        IllegalStateException - if the current thread holds the lock for another session

        Since:

        7.1

        See Also:

        access(Runnable), VaadinSession.accessSynchronously(Runnable)

      • access

        public Future<Void> access​(Runnable runnable)

        Provides exclusive access to this UI from outside a request handling thread.

        The given runnable is executed while holding the session lock to ensure exclusive access to this UI. If the session is not locked, the lock will be acquired and the runnable is run right away. If the session is currently locked, the runnable will be run before that lock is released.

        RPC handlers for components inside this UI do not need to use this method as the session is automatically locked by the framework during RPC handling.

        Please note that the runnable might be invoked on a different thread or later on the current thread, which means that custom thread locals might not have the expected values when the command is executed. getCurrent(), VaadinSession.getCurrent() and VaadinService.getCurrent() are set according to this UI before executing the command. Other standard CurrentInstance values such as VaadinService.getCurrentRequest() and VaadinService.getCurrentResponse() will not be defined.

        The returned future can be used to check for task completion and to cancel the task.

        Parameters:

        runnable - the runnable which accesses the UI

        Returns:

        a future that can be used to check for task completion and to cancel the task

        Throws:

        UIDetachedException - if the UI is not attached to a session (and locking can therefore not be done)

        Since:

        7.1

        See Also:

        getCurrent(), accessSynchronously(Runnable), VaadinSession.access(Runnable), VaadinSession.lock()

      • getTooltipConfiguration

        public TooltipConfiguration getTooltipConfiguration()

        Retrieves the object used for configuring tooltips.

        Returns:

        The instance used for tooltip configuration

      • getNotificationConfiguration

        public NotificationConfiguration getNotificationConfiguration()

        Retrieves the object used for configuring notifications.

        Returns:

        The instance used for notification configuration

      • getLoadingIndicatorConfiguration

        public LoadingIndicatorConfiguration getLoadingIndicatorConfiguration()

        Retrieves the object used for configuring the loading indicator.

        Returns:

        The instance used for configuring the loading indicator

      • push

        public void push()

        Pushes the pending changes and client RPC invocations of this UI to the client-side.

        If push is enabled, but the push connection is not currently open, the push will be done when the connection is established.

        As with all UI methods, the session must be locked when calling this method. It is also recommended that getCurrent() is set up to return this UI since writing the response may invoke logic in any attached component or extension. The recommended way of fulfilling these conditions is to use access(Runnable).

        Throws:

        IllegalStateException - if push is disabled.

        UIDetachedException - if this UI is not attached to a session.

        Since:

        7.1

        See Also:

        getPushConfiguration()

      • getPushConnection

        public PushConnection getPushConnection()

        Returns the internal push connection object used by this 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 getCurrent() does not return this UI.

        Returns:

        the push connection used by this UI, or null if push is not available.

      • setPushConnection

        public void setPushConnection​(PushConnection pushConnection)

        Sets the internal push connection object used by this 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 this UI

      • setPollInterval

        public void setPollInterval​(int intervalInMillis)

        Sets the interval with which the UI should poll the server to see if there are any changes. Polling is disabled by default.

        Note that it is possible to enable push and polling at the same time but it should not be done to avoid excessive server traffic.

        Add-on developers should note that this method is only meant for the application developer. An add-on should not set the poll interval directly, rather instruct the user to set it.

        Parameters:

        intervalInMillis - The interval (in ms) with which the UI should poll the server or -1 to disable polling

      • getPollInterval

        public int getPollInterval()

        Returns the interval with which the UI polls the server.

        Returns:

        The interval (in ms) with which the UI polls the server or -1 if polling is disabled

      • getPushConfiguration

        public PushConfiguration getPushConfiguration()

        Retrieves the object used for configuring the push channel.

        Returns:

        The instance used for push configuration

        Since:

        7.1

      • getReconnectDialogConfiguration

        public ReconnectDialogConfiguration getReconnectDialogConfiguration()

        Retrieves the object used for configuring the reconnect dialog.

        Returns:

        The instance used for reconnect dialog configuration

        Since:

        7.6

      • getOverlayContainerLabel

        public String getOverlayContainerLabel()

        Get the label that is added to the container element, where tooltip, notification and dialogs are added to.

        Returns:

        the label of the container

      • setOverlayContainerLabel

        public void setOverlayContainerLabel​(String overlayContainerLabel)

        Sets the label that is added to the container element, where tooltip, notifications and dialogs are added to.

        This is helpful for users of assistive devices, as this element is reachable for them.

        Parameters:

        overlayContainerLabel - label to use for the container

      • getLocaleService

        public LocaleService getLocaleService()

        Returns the locale service which handles transmission of Locale data to the client.

        Returns:

        The LocaleService for this UI

        Since:

        7.1

      • getEmbedId

        public String getEmbedId()

        Gets a string the uniquely distinguishes this UI instance based on where it is embedded. The embed identifier is based on the window.name DOM attribute of the browser window where the UI is displayed and the id of the div element where the UI is embedded.

        Returns:

        the embed id for this UI, or null if no id known

        Since:

        7.2

      • 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

        Since:

        7.6

      • setLastProcessedClientToServerId

        public void setLastProcessedClientToServerId​(int lastProcessedClientToServerId)

        Sets the last processed server message id. Used internally for communication tracking.

        Parameters:

        lastProcessedClientToServerId - the id of the last processed server message

        Since:

        7.6

      • setActiveDragSource

        public void setActiveDragSource​(DragSourceExtension<? extends AbstractComponent> extension)

        Sets the drag source of an active HTML5 drag event.

        Parameters:

        extension - Extension of the drag source component.

        Since:

        8.1

        See Also:

        DragSourceExtension

      • getActiveDragSource

        public DragSourceExtension<? extends AbstractComponent> getActiveDragSource()

        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:

        8.1

        See Also:

        DragSourceExtension

      • setMobileHtml5DndEnabled

        public void setMobileHtml5DndEnabled​(boolean enabled)

        Enable or disable HTML5 DnD for mobile devices.

        Usually you should enable the support in the init(VaadinRequest) method. By default, it is disabled. This operation is NOOP when the user is not on a mobile device.

        Changing this will effect all DragSourceExtension and DropTargetExtension (and subclasses) that have not yet been attached to the UI on the client side.

        NOTE: When disabling this after it has been enabled, it will not affect DragSourceExtension and DropTargetExtension (and subclasses) that have been previously added. Those extensions should be explicitly removed to make sure user cannot perform DnD operations anymore.

        Parameters:

        enabled - true if enabled, false if not

        Since:

        8.1

      • isUsingThoroughSizeCheck

        public boolean isUsingThoroughSizeCheck()

        Returns whether LayoutManager uses thorough size check that evaluates the presence of the element and uses calculated size, or defaults to a slightly faster check that can result in incorrect size information if the check is triggered while a transform animation is ongoing. This can happen e.g. when a PopupView is opened.

        By default, the thorough size check is enabled.

        Returns:

        true if thorough size check enabled, false if not

        Since:

        8.13

      • setUsingThoroughSizeCheck

        public void setUsingThoroughSizeCheck​(boolean thoroughSizeCheck)

        Set whether LayoutManager should use thorough size check that evaluates the presence of the element and uses calculated size, or default to a slightly faster check that can result in incorrect size information if the check is triggered while a transform animation is ongoing. This can happen e.g. when a PopupView is opened.

        By default, the thorough size check is enabled.

        Parameters:

        thoroughSizeCheck - true if thorough size check enabled, false if not

        Since:

        8.13

      • runAfterRoundTrip

        public UI.DelayedCallbackRegistration runAfterRoundTrip​(UI.DelayedCallback callback)

        Executes the given callback function after a single client round-trip. If this UI gets detached before he callback gets processed, execution is cancelled.

        Parameters:

        callback - the callback to trigger after the round-trip

        Returns:

        registration object that can be used to cancel the callback

        Since:

        8.18

      • runAfterRoundTrip

        public UI.DelayedCallbackRegistration runAfterRoundTrip​(UI.DelayedCallback callback,
                                                        int numberOfRoundTripsToWait)

        Executes the given callback function after the given number of client round-trips. If this UI gets detached before he callback gets processed, execution is cancelled.

        Note: it is not recommended to use a large number as a way of simulating a delay.

        Parameters:

        callback - the callback to trigger after the configured round-trips

        numberOfRoundTripsToWait - how many round-trips should be waited for before triggering the callback

        Returns:

        registration object that can be used to cancel the callback

        Since:

        8.18

      • runAfterRoundTrip

        public UI.DelayedCallbackRegistration runAfterRoundTrip​(UI.DelayedCallback callback,
                                                        UI.DelayedCallback cancelCallback)

        Executes the given callback function after a single client round-trip, or the cancel callback if the execution is cancelled through UI.DelayedCallbackRegistration.cancel(). The framework cancels the execution if this UI gets detached before he callback gets processed, but the method can also be called by implementing application's code.

        Parameters:

        callback - the callback to trigger after the round-trip

        cancelCallback - the callback to trigger if the execution gets cancelled

        Returns:

        registration object that can be used to cancel the callback

        Since:

        8.18

      • runAfterRoundTrip

        public UI.DelayedCallbackRegistration runAfterRoundTrip​(UI.DelayedCallback callback,
                                                        UI.DelayedCallback cancelCallback,
                                                        int numberOfRoundTripsToWait)

        Executes the given callback function after the given number of client round-trips, or the cancel callback if the execution is cancelled through UI.DelayedCallbackRegistration.cancel(). The framework cancels the execution if this UI gets detached before he callback gets processed, but the method can also be called by implementing application's code.

        Note: it is not recommended to use a large number or round-trips as a way of simulating a delay.

        Parameters:

        callback - the callback to trigger after the configured round-trips

        cancelCallback - the callback to trigger if the execution gets cancelled

        numberOfRoundTripsToWait - how many round-trips should be waited for before triggering the callback

        Returns:

        registration object that can be used to cancel the callback

        Since:

        8.18