Package org.vaadin.miki.shared.text

Class TextSelectionDelegate<C extends com.vaadin.flow.component.Component & CanSelectText & CanReceiveSelectionEventsFromClient>

java.lang.Object

org.vaadin.miki.shared.text.TextSelectionDelegate<C>

All Implemented Interfaces:

Serializable, TextSelectionNotifier<C>, CanReceiveSelectionEventsFromClient, CanSelectText

Direct Known Subclasses:

TextModificationDelegate

public class TextSelectionDelegate<C extends com.vaadin.flow.component.Component & CanSelectText & CanReceiveSelectionEventsFromClient>
extends Object
implements Serializable, CanSelectText, CanReceiveSelectionEventsFromClient, TextSelectionNotifier<C>

A class that handles common behaviour related to text selection. This is mostly for internal use. There are a lot of steps that need to be taken care of to integrate this with any component. Please check project's wiki. The methods onAttach onDetach must be overwritten in the delegating class and delegated here. The source component must implement CanSelectText and CanReceiveSelectionEventsFromClient and delegate them to this object. The client-side component must mix in text-selection-mixin.js or otherwise react to needed JS method calls. Finally, the delegating class must implement methods: @ClientCallable void selectionChanged(int, int, String) and @ClientCallable void reinitialiseEventListening(). The first method should call this object's fireTextSelectionEvent(boolean, int, int, String) and the second method should just be delegated to this object.

Since:

2020-06-01

Author:

miki

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static String	SELECTED_TEXT_ATTRIBUTE_NAME	Defines the name of the HTML attribute that contains the selected text.

Constructor Summary

Constructors

Constructor	Description
TextSelectionDelegate(C source, com.vaadin.flow.component.ComponentEventBus eventBus, com.vaadin.flow.function.SerializableSupplier<String> stringValueSupplier)	Creates the delegate for a given component.

Method Summary

Modifier and Type	Method	Description
com.vaadin.flow.shared.Registration	addTextSelectionListener(TextSelectionListener<C> listener)	Adds the listener.
void	clearSelectionOnValueChange()	Handles selection change on value change if there are no client notifications.
void	fireTextSelectionEvent(boolean fromClient, int start, int end, String text)	Fires text selection event.
protected C	getSource()	Gets the source component.
protected com.vaadin.flow.dom.Element	getSourceElement()	Gets the element for the source component.
void	informClientAboutSendingEvents(boolean value)	Sends information to the client side about whether or not it should forward text selection change events.
boolean	isReceivingSelectionEventsFromClient()	Check if client will inform server on selection change.
void	onAttach(com.vaadin.flow.component.AttachEvent event, Consumer<com.vaadin.flow.component.AttachEvent> originalMethod)	Informs client about sending events and calls the original method.
void	onDetach(com.vaadin.flow.component.DetachEvent event, Consumer<com.vaadin.flow.component.DetachEvent> originalMethod)	Informs client to not send events (if needed) and calls the original method.
void	reinitialiseListeners()	This method should be called in response to @ClientCallable void reinitialiseListeners() on the owning object.
void	select(int from, int to)	Selects text starting from index from (inclusive) and ending at index to (exclusive).
void	selectAll()	Selects entire text in the component.
void	selectNone()	Removes the current selection and selects no text.
void	setReceivingSelectionEventsFromClient(boolean receivingSelectionEventsFromClient)	Configures sending events by the client-side component.

Methods inherited from class java.lang.Object

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

Field Detail

SELECTED_TEXT_ATTRIBUTE_NAME

public static final String SELECTED_TEXT_ATTRIBUTE_NAME

Defines the name of the HTML attribute that contains the selected text.

See Also:

Constant Field Values

Constructor Detail

TextSelectionDelegate

public TextSelectionDelegate(C source,
                             com.vaadin.flow.component.ComponentEventBus eventBus,
                             com.vaadin.flow.function.SerializableSupplier<String> stringValueSupplier)

Creates the delegate for a given component.

Parameters:

source - Source of all events, data, etc.

eventBus - Event bus to use for firing events. Typically, source.getEventBus().

stringValueSupplier - Method to obtain current value of the component as a String.

Method Detail

getSource

protected final C getSource()

Gets the source component.

Returns:

Source component.

getSourceElement

protected final com.vaadin.flow.dom.Element getSourceElement()

Gets the element for the source component.

Returns:

The element.

informClientAboutSendingEvents

public void informClientAboutSendingEvents(boolean value)

Sends information to the client side about whether or not it should forward text selection change events.

Parameters:

value - When true, client-side will notify server about changes in text selection.

fireTextSelectionEvent

public void fireTextSelectionEvent(boolean fromClient,
                                   int start,
                                   int end,
                                   String text)

Fires text selection event.

Parameters:

fromClient - Whether or not the event originates from the client.

start - Selection start.

end - Selection end.

text - Selection text.

selectAll

public void selectAll()

Description copied from interface: CanSelectText

Selects entire text in the component.

Specified by:

selectAll in interface CanSelectText

selectNone

public void selectNone()

Description copied from interface: CanSelectText

Removes the current selection and selects no text.

Specified by:

selectNone in interface CanSelectText

select

public void select(int from,
                   int to)

Description copied from interface: CanSelectText

Selects text starting from index from (inclusive) and ending at index to (exclusive).

Specified by:

select in interface CanSelectText

Parameters:

from - Starting index (inclusive).

to - Ending index (exclusive).

clearSelectionOnValueChange

public void clearSelectionOnValueChange()

Handles selection change on value change if there are no client notifications. Does nothing if the component is receiving client-side notifications.

onAttach

public void onAttach(com.vaadin.flow.component.AttachEvent event,
                     Consumer<com.vaadin.flow.component.AttachEvent> originalMethod)

Informs client about sending events and calls the original method.

Parameters:

event - Event.

originalMethod - Method to call. Must not be null.

onDetach

public void onDetach(com.vaadin.flow.component.DetachEvent event,
                     Consumer<com.vaadin.flow.component.DetachEvent> originalMethod)

Informs client to not send events (if needed) and calls the original method.

Parameters:

event - Event.

originalMethod - Method to call. Must not be null.

addTextSelectionListener

public com.vaadin.flow.shared.Registration addTextSelectionListener(TextSelectionListener<C> listener)

Description copied from interface: TextSelectionNotifier

Adds the listener.

Specified by:

addTextSelectionListener in interface TextSelectionNotifier<C extends com.vaadin.flow.component.Component & CanSelectText & CanReceiveSelectionEventsFromClient>

Parameters:

listener - A listener to add.

Returns:

A Registration that can be used to stop listening to the event.

isReceivingSelectionEventsFromClient

public boolean isReceivingSelectionEventsFromClient()

Description copied from interface: CanReceiveSelectionEventsFromClient

Check if client will inform server on selection change. Note: this feature is by default turned off.

Specified by:

isReceivingSelectionEventsFromClient in interface CanReceiveSelectionEventsFromClient

Returns:

When true, each selection change in the client-side component will result in this component broadcasting a TextSelectionEvent.

setReceivingSelectionEventsFromClient

public void setReceivingSelectionEventsFromClient(boolean receivingSelectionEventsFromClient)

Description copied from interface: CanReceiveSelectionEventsFromClient

Configures sending events by the client-side component. Note: this feature is by default turned off.

Specified by:

setReceivingSelectionEventsFromClient in interface CanReceiveSelectionEventsFromClient

Parameters:

receivingSelectionEventsFromClient - When false, selecting text in client-side component will not send an event to server-side component. When true, it will.

reinitialiseListeners

public void reinitialiseListeners()

This method should be called in response to @ClientCallable void reinitialiseListeners() on the owning object.