java.lang.Object
- com.vaadin.flow.data.binder.ReadOnlyHasValue<V>

Type Parameters:: V - the value type

All Implemented Interfaces:: HasValue<HasValue.ValueChangeEvent<V>,V>, Serializable

public class ReadOnlyHasValue<V>
extends Object
implements HasValue<HasValue.ValueChangeEvent<V>,V>, Serializable

Generic HasValue to use any type of component with Vaadin data binding.

Example:

 Label label = new Label();
 ReadOnlyHasValue<String> hasValue = new ReadOnlyHasValue<>(label::setText);
 binder.forField(hasValue).bind(SomeBean::getName, null);

Since:: 1.0
See Also:: Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from interface com.vaadin.flow.component.HasValue
  HasValue.ValueChangeEvent<V>, HasValue.ValueChangeListener<E extends HasValue.ValueChangeEvent<?>>

Constructor Summary

Constructors
Constructor	Description
`ReadOnlyHasValue(SerializableConsumer<V> valueProcessor)`	Creates new `ReadOnlyHasValue` with `null` as an empty value.
`ReadOnlyHasValue(SerializableConsumer<V> valueProcessor, V emptyValue)`	Creates new `ReadOnlyHasValue`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Registration`	`addValueChangeListener(HasValue.ValueChangeListener<? super HasValue.ValueChangeEvent<V>> listener)`	Adds a value change listener.
`V`	`getEmptyValue()`	Returns the value that represents an empty value.
`V`	`getValue()`	Returns the current value of this object.
`boolean`	`isReadOnly()`	Returns whether this `HasValue` is in read-only mode or not.
`boolean`	`isRequiredIndicatorVisible()`	Checks whether the required indicator is visible.
`void`	`setReadOnly(boolean readOnly)`	Sets the read-only mode of this `HasValue` to given mode.
`void`	`setRequiredIndicatorVisible(boolean requiredIndicatorVisible)`	Sets the required indicator visible or not.
`void`	`setValue(V value)`	Sets the value of this object.

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

Methods inherited from interface com.vaadin.flow.component.HasValue
clear, getOptionalValue, isEmpty

- Constructor Detail
  - ReadOnlyHasValue
```
public ReadOnlyHasValue(SerializableConsumer<V> valueProcessor,
                        V emptyValue)
```
    Creates new ReadOnlyHasValue
    
    Parameters:
    
    valueProcessor - the value valueProcessor, e.g. a setter for displaying the value in a component
    
    emptyValue - the value to be used as empty, null by default
  - ReadOnlyHasValue
```
public ReadOnlyHasValue(SerializableConsumer<V> valueProcessor)
```
    Creates new ReadOnlyHasValue with null as an empty value.
    
    Parameters:
    
    valueProcessor - the value valueProcessor, e.g. a setter for displaying the value in a component
- Method Detail
  - setValue
```
public void setValue(V value)
```
    Description copied from interface: HasValue
    
    Sets the value of this object. If the new value is not equal to getValue(), fires a value change event. May throw IllegalArgumentException if the value is not acceptable.
    Implementation note: the implementing class should document whether null values are accepted or not, and override HasValue.getEmptyValue() if the empty value is not null.
    
    Specified by:
    
    setValue in interface HasValue<HasValue.ValueChangeEvent<V>,V>
    
    Parameters:
    
    value - the new value
  - getValue
```
public V getValue()
```
    Description copied from interface: HasValue
    
    Returns the current value of this object.
    Implementation note: the implementing class should document whether null values may be returned or not, and override HasValue.getEmptyValue() if the empty value is not null.
    
    Specified by:
    
    getValue in interface HasValue<HasValue.ValueChangeEvent<V>,V>
    
    Returns:
    
    the current value
  - addValueChangeListener
```
public Registration addValueChangeListener(HasValue.ValueChangeListener<? super HasValue.ValueChangeEvent<V>> listener)
```
    Description copied from interface: HasValue
    
    Adds a value change listener. The listener is called when the value of this HasValue is changed either by the user or programmatically.
    
    Specified by:
    
    addValueChangeListener in interface HasValue<HasValue.ValueChangeEvent<V>,V>
    
    Parameters:
    
    listener - the value change listener, not null
    
    Returns:
    
    a registration for the listener
  - isRequiredIndicatorVisible
```
public boolean isRequiredIndicatorVisible()
```
    Description copied from interface: HasValue
    
    Checks whether the required indicator is visible.
    
    Specified by:
    
    isRequiredIndicatorVisible in interface HasValue<HasValue.ValueChangeEvent<V>,V>
    
    Returns:
    
    true if visible, false if not
  - setRequiredIndicatorVisible
```
public void setRequiredIndicatorVisible(boolean requiredIndicatorVisible)
```
    Description copied from interface: HasValue
    
    Sets the required indicator visible or not.
    If set visible, it is visually indicated in the user interface.
    The method is intended to be used with Binder which does server-side validation. In case HTML element has its own (client-side) validation it should be disabled when setRequiredIndicatorVisible(true) is called and re-enabled back on setRequiredIndicatorVisible(false). It's responsibility of each component implementation to follow the contract so that the method call doesn't do anything else than show/hide the "required" indication. Usually components provide their own setRequired method which should be called in case the client-side validation is required.
    
    Specified by:
    
    setRequiredIndicatorVisible in interface HasValue<HasValue.ValueChangeEvent<V>,V>
    
    Parameters:
    
    requiredIndicatorVisible - true to make the required indicator visible, false if not
  - setReadOnly
```
public void setReadOnly(boolean readOnly)
```
    Description copied from interface: HasValue
    
    Sets the read-only mode of this HasValue to given mode. The user can't change the value when in read-only mode.
    A HasValue with a visual component in read-only mode typically looks visually different to signal to the user that the value cannot be edited.
    
    Specified by:
    
    setReadOnly in interface HasValue<HasValue.ValueChangeEvent<V>,V>
    
    Parameters:
    
    readOnly - a boolean value specifying whether the component is put read-only mode or not
  - isReadOnly
```
public boolean isReadOnly()
```
    Description copied from interface: HasValue
    
    Returns whether this HasValue is in read-only mode or not.
    
    Specified by:
    
    isReadOnly in interface HasValue<HasValue.ValueChangeEvent<V>,V>
    
    Returns:
    
    false if the user can modify the value, true if not.
  - getEmptyValue
```
public V getEmptyValue()
```
    Description copied from interface: HasValue
    
    Returns the value that represents an empty value.
    By default HasValue is expected to support null as empty values. Specific implementations might not support this.
    
    Specified by:
    
    getEmptyValue in interface HasValue<HasValue.ValueChangeEvent<V>,V>
    
    Returns:
    
    empty value

Class ReadOnlyHasValue<V>

Nested Class Summary

Nested classes/interfaces inherited from interface com.vaadin.flow.component.HasValue

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface com.vaadin.flow.component.HasValue

Constructor Detail

ReadOnlyHasValue

ReadOnlyHasValue

Method Detail

setValue

getValue

addValueChangeListener

isRequiredIndicatorVisible

setRequiredIndicatorVisible

setReadOnly

isReadOnly

getEmptyValue