Java tutorial
/* * #%L * Diana UI Core * %% * Copyright (C) 2014 Diana UI * %% * 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. * #L% */ package com.dianaui.universal.core.client.ui; import com.dianaui.universal.core.client.ui.constants.Styles; import com.google.gwt.dom.client.*; import com.google.gwt.event.logical.shared.ValueChangeEvent; import com.google.gwt.i18n.client.HasDirection.Direction; import com.google.gwt.i18n.shared.DirectionEstimator; import com.google.gwt.safehtml.shared.SafeHtml; import com.google.gwt.uibinder.client.UiConstructor; import com.google.gwt.user.client.DOM; import com.google.gwt.user.client.Event; /** * A mutually-exclusive selection radio button widget. Fires * {@link com.google.gwt.event.dom.client.ClickEvent ClickEvents} when the radio * button is clicked, and {@link ValueChangeEvent ValueChangeEvents} when the * button becomes checked. Note, however, that browser limitations prevent * ValueChangeEvents from being sent when the radio button is cleared as a side * effect of another in the group being clicked. * <p> * <h3>Built-in Bidi Text Support</h3> * This widget is capable of automatically adjusting its direction according to * its content. This feature is controlled by {@link #setDirectionEstimator} or * passing a DirectionEstimator parameter to the constructor, and is off by * default. * </p> * * @author Sven Jacobs */ public class Radio extends CheckBox { private Boolean oldValue; /** * Creates a new radio associated with a particular group, and initialized * with the given HTML label. All radio buttons associated with the same * group name belong to a mutually-exclusive set. * <p/> * Radio buttons are grouped by their name attribute, so changing their name * using the setName() method will also change their associated group. * * @param name the group name with which to associate the radio button * @param label this radio button's html label */ public Radio(String name, SafeHtml label) { this(name, label.asString(), true); } /** * @param name the group name with which to associate the radio button * @param label this radio button's html label * @param dir the text's direction. Note that {@code DEFAULT} means * direction should be inherited from the widget's parent * element. * @see #RadioButton(String, SafeHtml) */ public Radio(String name, SafeHtml label, Direction dir) { this(name); setHTML(label, dir); } /** * @param name the group name with which to associate the radio button * @param label this radio button's html label * @param directionEstimator A DirectionEstimator object used for automatic direction * adjustment. For convenience, * {@link #DEFAULT_DIRECTION_ESTIMATOR} can be used. * @see #RadioButton(String, SafeHtml) */ public Radio(String name, SafeHtml label, DirectionEstimator directionEstimator) { this(name); setDirectionEstimator(directionEstimator); setHTML(label.asString()); } /** * Creates a new radio associated with a particular group, and initialized * with the given HTML label. All radio buttons associated with the same * group name belong to a mutually-exclusive set. * <p/> * Radio buttons are grouped by their name attribute, so changing their name * using the setName() method will also change their associated group. * * @param name the group name with which to associate the radio button * @param label this radio button's label */ public Radio(String name, String label) { this(name); setText(label); } /** * @param name the group name with which to associate the radio button * @param label this radio button's label * @param dir the text's direction. Note that {@code DEFAULT} means * direction should be inherited from the widget's parent * element. * @see #RadioButton(String, SafeHtml) */ public Radio(String name, String label, Direction dir) { this(name); setText(label, dir); } /** * @param name the group name with which to associate the radio button * @param label this radio button's label * @param directionEstimator A DirectionEstimator object used for automatic direction * adjustment. For convenience, * {@link #DEFAULT_DIRECTION_ESTIMATOR} can be used. * @see #RadioButton(String, SafeHtml) */ public Radio(String name, String label, DirectionEstimator directionEstimator) { this(name); setDirectionEstimator(directionEstimator); setText(label); } /** * Creates a new radio button associated with a particular group, and * initialized with the given label (optionally treated as HTML). All radio * buttons associated with the same group name belong to a * mutually-exclusive set. * <p/> * Radio buttons are grouped by their name attribute, so changing their name * using the setName() method will also change their associated group. * * @param name name the group with which to associate the radio button * @param label this radio button's label * @param asHTML <code>true</code> to treat the specified label as HTML */ public Radio(String name, String label, boolean asHTML) { this(name); if (asHTML) { setHTML(label); } else { setText(label); } } /** * Creates a new radio associated with a particular group name. All radio * buttons associated with the same group name belong to a * mutually-exclusive set. * <p/> * Radio buttons are grouped by their name attribute, so changing their name * using the setName() method will also change their associated group. * * @param name the group name with which to associate the radio button */ @UiConstructor public Radio(String name) { super(DOM.createDiv(), Document.get().createRadioInputElement(name)); setStyleName(Styles.RADIO); LabelElement label = Document.get().createLabelElement(); label.appendChild(inputElem); label.appendChild(labelElem); getElement().appendChild(label); } protected Radio(Element elem, InputElement inputElement) { super(elem, inputElement); } /** * Overridden to send ValueChangeEvents only when appropriate. */ @Override public void onBrowserEvent(Event event) { switch (DOM.eventGetType(event)) { case Event.ONMOUSEUP: case Event.ONBLUR: case Event.ONKEYDOWN: // Note the old value for onValueChange purposes (in ONCLICK case) oldValue = getValue(); break; case Event.ONCLICK: EventTarget target = event.getEventTarget(); if (Element.is(target) && labelElem.isOrHasChild(Element.as(target))) { // They clicked the label. Note our pre-click value, and // short circuit event routing so that other click handlers // don't hear about it oldValue = getValue(); return; } // It's not the label. Let our handlers hear about the // click... super.onBrowserEvent(event); // ...and now maybe tell them about the change ValueChangeEvent.fireIfNotEqual(Radio.this, oldValue, getValue()); return; } super.onBrowserEvent(event); } /** * Change the group name of this radio button. * <p/> * Radio buttons are grouped by their name attribute, so changing their name * using the setName() method will also change their associated group. * <p/> * If changing this group name results in a new radio group with multiple * radio buttons selected, this radio button will remain selected and the * other radio buttons will be unselected. * * @param name name the group with which to associate the radio button */ @Override public void setName(String name) { super.setName(name); } @Override public void sinkEvents(int eventBitsToAdd) { // Like CheckBox, we want to hear about inputElem. We // also want to know what's going on with the label, to // make sure onBrowserEvent is able to record value changes // initiated by label events if (isOrWasAttached()) { Event.sinkEvents(inputElem, eventBitsToAdd | Event.getEventsSunk(inputElem)); if (labelElem != null) Event.sinkEvents(labelElem, eventBitsToAdd | Event.getEventsSunk(labelElem)); } else { super.sinkEvents(eventBitsToAdd); } } /** * No-op. CheckBox's click handler is no good for radio button, so don't use * it. Our event handling is all done in {@link #onBrowserEvent} */ @Override protected void ensureDomEventHandlers() { } }