Package com.vaadin.flow.component.textfield

Class AbstractNumberField<C extends AbstractNumberField<C,T>,T extends Number>

java.lang.Object
com.vaadin.flow.component.Component
com.vaadin.flow.component.AbstractField<C,T>
com.vaadin.flow.component.AbstractSinglePropertyField<TComponent,TValue>
com.vaadin.flow.component.textfield.TextFieldBase<C,T>
com.vaadin.flow.component.textfield.AbstractNumberField<C,T>
All Implemented Interfaces:
AttachNotifier, BlurNotifier<C>, CompositionNotifier, DetachNotifier, Focusable<C>, FocusNotifier<C>, HasElement, HasEnabled, HasHelper, HasLabel, HasSize, HasStyle, HasValidation, HasValue<AbstractField.ComponentValueChangeEvent<C,T>,T>, HasValueAndElement<AbstractField.ComponentValueChangeEvent<C,T>,T>, InputNotifier, KeyNotifier, HasClearButton, HasClientValidation, HasPrefix, HasSuffix, HasTooltip, HasValidationProperties, HasAutocapitalize, HasAutocomplete, HasAutocorrect, HasPrefixAndSuffix, HasValidator<T>, HasValueChangeMode, Serializable
Direct Known Subclasses:
IntegerField, NumberField
public abstract class AbstractNumberField<C extends AbstractNumberField<C,T>,T extends Number> extends TextFieldBase<C,T>
Abstract base class for components based on vaadin-number-field element and its subclasses.
Author:
Vaadin Ltd.
See Also:

  • Constructor Details

    • AbstractNumberField

      public AbstractNumberField(SerializableFunction<String,T> parser, SerializableFunction<T,String> formatter, double absoluteMin, double absoluteMax)
      Sets up the common logic for number fields.
      Parameters:
      parser - function to parse the client-side value string into server-side value
      formatter - function to format the server-side value into client-side value string
      absoluteMin - the smallest possible value of the number type of the field, will be used as the default min value at server-side
      absoluteMax - the largest possible value of the number type of the field, will be used as the default max value at server-side

  • Method Details

    • setStepButtonsVisible

      public void setStepButtonsVisible(boolean stepButtonsVisible)
      Sets the visibility of the buttons for increasing/decreasing the value accordingly to the default or specified step.
      Parameters:
      stepButtonsVisible - true if control buttons should be visible; false if those should be hidden
      See Also:

    • isStepButtonsVisible

      public boolean isStepButtonsVisible()
      Gets whether the buttons for increasing/decreasing the value are visible.
      Returns:
      true if buttons are visible, false otherwise
      See Also:

    • getEmptyValue

      public T getEmptyValue()
      Returns the value that represents an empty value.
      Specified by:
      getEmptyValue in interface HasValue<C extends AbstractNumberField<C,T>,T extends Number>
      Overrides:
      getEmptyValue in class AbstractField<C extends AbstractNumberField<C,T>,T extends Number>
      Returns:
      empty value

    • setValue

      public void setValue(T value)
      Sets the value of this number field. If the new value is not equal to getValue(), fires a value change event.
      Specified by:
      setValue in interface HasValue<C extends AbstractNumberField<C,T>,T extends Number>
      Overrides:
      setValue in class AbstractField<C extends AbstractNumberField<C,T>,T extends Number>
      Parameters:
      value - the new value

    • getValue

      public T getValue()
      Returns the current value of the number field. By default, the empty number field will return null .
      Specified by:
      getValue in interface HasValue<C extends AbstractNumberField<C,T>,T extends Number>
      Overrides:
      getValue in class AbstractField<C extends AbstractNumberField<C,T>,T extends Number>
      Returns:
      the current value.

    • setMin

      protected void setMin(double min)
      Sets the minimum value of the field.
      Parameters:
      min - the double value to set

    • getMinDouble

      protected double getMinDouble()
      The minimum value of the field.

    • setMax

      protected void setMax(double max)
      Sets the maximum value of the field.
      Parameters:
      max - the double value to set

    • getMaxDouble

      protected double getMaxDouble()
      The maximum value of the field.

    • setStep

      protected void setStep(double step)
      Sets the allowed number intervals of the field.
      Parameters:
      step - the double value to set

    • getStepDouble

      protected double getStepDouble()
      The allowed number intervals of the field.

    • getDefaultValidator

      public Validator<T> getDefaultValidator()
      Description copied from interface: HasValidator
      Returns a validator that checks the state of the Value. This should be overridden for components with internal value conversion or validation, e.g. when the user is providing a string that has to be parsed into a date. An invalid input from user will be exposed to a Binder and can be seen as a validation failure.
      Returns:
      state validator

    • addValidationStatusChangeListener

      public Registration addValidationStatusChangeListener(ValidationStatusChangeListener<T> listener)
      Description copied from interface: HasValidator
      Enables the implementing components to notify changes in their validation status to the observers.

      Note: This method can be overridden by the implementing classes e.g. components, to enable the associated Binder.Binding instance subscribing for their validation change events and revalidate itself.

      This method primarily designed for notifying the Binding about the validation status changes of a bound component at the client-side. WebComponents such as <vaadin-date-picker> or any other component that accept a formatted text as input should be able to communicate their invalid status to their server-side instance, and a bound server-side component instance must notify its binding about this validation status change as well. When the binding instance revalidates, a chain of validators and convertors get executed one of which is the default validator provided by HasValidator.getDefaultValidator(). Thus, In order for the binding to be able to show/clear errors for its associated bound field, it is important that implementing components take that validation status into account while implementing any validator and converter including HasValidator.getDefaultValidator(). Here is an example: 

       @Tag("date-picker-demo")
 public class DatePickerDemo implements HasValidator<LocalDate> {

     // Each web component has a way to communicate its validation status
     // to its server-side component instance. The following clientSideValid
     // state is introduced here just for the sake of simplicity of this code
     // snippet:
     boolean clientSideValid = true;

     /**
      * Note how clientSideValid engaged in the definition
      * of this method. It is important to reflect this status either
      * in the returning validation result of this method or any other
      * validation that is associated with this component.
      */
     @Override
     public Validator getDefaultValidator() {
          return (value, valueContext) -> clientSideValid ? ValidationResult.ok()
                 : ValidationResult.error("Invalid date format");
     }

     private final Collection<ValidationStatusChangeListener<LocalDate>>
         validationStatusListeners = new ArrayList<>();

     /**
      * This enables the binding to subscribe for the validation status
      * change events that are fired by this component and revalidate
      * itself respectively.
      */
     @Override
     public Registration addValidationStatusChangeListener(
             ValidationStatusChangeListener<LocalDate> listener) {
         validationStatusListeners.add(listener);
         return () -> validationStatusListeners.remove(listener);
     }

     private void fireValidationStatusChangeEvent(
             boolean newValidationStatus) {
         if (this.clientSideValid != newValidationStatus) {
             this.clientSideValid = newValidationStatus;
             var event = new ValidationStatusChangeEvent<>(this,
                     newValidationStatus);
             validationStatusListeners.forEach(
                     listener -> listener.validationStatusChanged(event));
         }
     }
 }
      Returns:
      Registration of the added listener.
      See Also:

    • validate

      protected void validate()
      Performs server-side validation of the current value. This is needed because it is possible to circumvent the client-side validation constraints using browser development tools.

    • 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.

      Parameters:
      requiredIndicatorVisible - true to make the required indicator visible, false if not

    • onAttach

      protected void onAttach(AttachEvent attachEvent)
      Description copied from class: Component
      Called when the component is attached to a UI.

      The default implementation does nothing.

      This method is invoked before the AttachEvent is fired for the component.

      Overrides:
      onAttach in class Component
      Parameters:
      attachEvent - the attach event