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.ui.renderers; import java.lang.reflect.Method; import com.vaadin.event.ConnectorEventListener; import com.vaadin.event.MouseEvents.ClickEvent; import com.vaadin.shared.MouseEventDetails; import com.vaadin.shared.Registration; import com.vaadin.shared.ui.grid.renderers.ClickableRendererState; import com.vaadin.shared.ui.grid.renderers.RendererClickRpc; import com.vaadin.ui.Grid; import com.vaadin.ui.Grid.Column; import com.vaadin.util.ReflectTools; /** * An abstract superclass for {@link Renderer}s that render clickable items. * Click listeners can be added to a renderer to be notified when any of the * rendered items is clicked. * * @param <T> * the type of the parent {@link Grid} * @param <V> * the type presented by the renderer * * @since 7.4 * @author Vaadin Ltd */ public abstract class ClickableRenderer<T, V> extends AbstractRenderer<T, V> { /** * An interface for listening to {@link RendererClickEvent renderer click * events}. * * @see ButtonRenderer#addClickListener(RendererClickListener) */ @FunctionalInterface public interface RendererClickListener<T> extends ConnectorEventListener { static final Method CLICK_METHOD = ReflectTools.findMethod(RendererClickListener.class, "click", RendererClickEvent.class); /** * Called when a rendered button is clicked. * * @param event * the event representing the click */ void click(RendererClickEvent<T> event); } /** * An event fired when a clickable widget rendered by a ClickableRenderer is * clicked. * * @param <T> * the item type associated with this click event */ public static class RendererClickEvent<T> extends ClickEvent { private final T item; private final Column<T, ?> column; protected RendererClickEvent(Grid<T> source, T item, Column<T, ?> column, MouseEventDetails mouseEventDetails) { super(source, mouseEventDetails); this.item = item; this.column = column; } /** * Returns the item of the row where the click event originated. * * @return the item of the clicked row * @since 8.0 */ public T getItem() { return item; } /** * Returns the {@link Column} where the click event originated. * * @return the column of the click event */ public Column<T, ?> getColumn() { return column; } } /** * Creates a new clickable renderer with the given presentation type. No * null representation will be used. * * @param presentationType * the data type that this renderer displays, not * <code>null</code> */ protected ClickableRenderer(Class<V> presentationType) { this(presentationType, null); } /** * Creates a new clickable renderer with the given presentation type and * null representation. * * @param presentationType * the data type that this renderer displays, not * <code>null</code> * @param nullRepresentation * a string that will be sent to the client instead of a regular * value in case the actual cell value is <code>null</code>. May * be <code>null</code>. */ protected ClickableRenderer(Class<V> presentationType, String nullRepresentation) { super(presentationType, nullRepresentation); registerRpc((RendererClickRpc) (String rowKey, String columnId, MouseEventDetails mouseDetails) -> { Grid<T> grid = getParentGrid(); T item = grid.getDataCommunicator().getKeyMapper().get(rowKey); Column<T, V> column = getParent(); fireEvent(new RendererClickEvent<>(grid, item, column, mouseDetails)); }); } /** * Adds a click listener to this button renderer. The listener is invoked * every time one of the buttons rendered by this renderer is clicked. * * @param listener * the click listener to be added, not null * @since 8.0 */ public Registration addClickListener(RendererClickListener<T> listener) { return addListener(RendererClickEvent.class, listener, RendererClickListener.CLICK_METHOD); } /** * Removes the given click listener from this renderer. * * @param listener * the click listener to be removed */ @Deprecated public void removeClickListener(RendererClickListener<T> listener) { removeListener(RendererClickEvent.class, listener); } @Override protected ClickableRendererState getState() { return (ClickableRendererState) super.getState(); } @Override protected ClickableRendererState getState(boolean markAsDirty) { return (ClickableRendererState) super.getState(markAsDirty); } }