Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.vaadin.v7.ui; import com.vaadin.ui.Component; import com.vaadin.ui.Component.Focusable; import com.vaadin.v7.data.BufferedValidatable; import com.vaadin.v7.data.Property; /** * Field interface is implemented by all classes (field components) that have a * value that the user can change through the user interface. * * Field components are built upon the framework defined in the Field interface * and the {@link AbstractField} base class. * * The Field interface inherits the {@link Component} superinterface and also * the {@link Property} interface to have a value for the field. * * @author Vaadin Ltd. * * @param <T> * the type of values in the field, which might not be the same type * as that of the data source if converters are used * * @deprecated This interface is, apart from the rename, identical to the Vaadin * 7 {@code com.vaadin.ui.Field}. It is provided for compatibility * and migration purposes. As of 8.0, new field components should * extend {@link AbstractField} instead. */ @Deprecated public interface Field<T> extends Focusable, BufferedValidatable, Property<T>, Property.ValueChangeNotifier, Property.ValueChangeListener, Property.Editor { /** * Is this field required. * * Required fields must filled by the user. * * @return <code>true</code> if the field is required,otherwise * <code>false</code>. * @since 3.1 */ public boolean isRequired(); /** * Sets the field required. Required fields must filled by the user. * * @param required * Is the field required. * @since 3.1 */ public void setRequired(boolean required); /** * Sets the error message to be displayed if a required field is empty. * * @param requiredMessage * Error message. * @since 5.2.6 */ public void setRequiredError(String requiredMessage); /** * Gets the error message that is to be displayed if a required field is * empty. * * @return Error message. * @since 5.2.6 */ public String getRequiredError(); /** * An <code>Event</code> object specifying the Field whose value has been * changed. * * @author Vaadin Ltd. * @since 3.0 * * @deprecated As of 8.0, replaced by {@link ValueChangeEvent}. */ @Deprecated @SuppressWarnings("serial") public static class ValueChangeEvent extends Component.Event implements Property.ValueChangeEvent { /** * Constructs a new event object with the specified source field object. * * @param source * the field that caused the event. */ public ValueChangeEvent(Field source) { super(source); } /** * Gets the Property which triggered the event. * * @return the Source Property of the event. */ @Override public Property getProperty() { return (Property) getSource(); } } /** * Is the field empty? * * In general, "empty" state is same as null. As an exception, TextField * also treats empty string as "empty". * * @since 7.4 * @return true if the field is empty, false otherwise */ public boolean isEmpty(); /** * Clears the value of the field. * <p> * The field value is typically reset to the initial value of the field. * Calling {@link #isEmpty()} on a cleared field must always returns true. * * @since 7.4 */ public void clear(); }