Java tutorial
/* * Copyright 2000-2014 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.client.ui; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import com.google.gwt.core.client.Scheduler; import com.google.gwt.event.dom.client.BlurHandler; import com.google.gwt.event.dom.client.KeyDownEvent; import com.google.gwt.event.dom.client.KeyDownHandler; import com.google.gwt.event.dom.client.KeyPressEvent; import com.google.gwt.event.dom.client.KeyPressHandler; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.user.client.Command; import com.google.gwt.user.client.Timer; import com.google.gwt.user.client.ui.Composite; import com.google.gwt.user.client.ui.FlowPanel; import com.google.gwt.user.client.ui.Focusable; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.RichTextArea; import com.google.gwt.user.client.ui.Widget; import com.vaadin.client.ApplicationConnection; import com.vaadin.client.BrowserInfo; import com.vaadin.client.ConnectorMap; import com.vaadin.client.ui.ShortcutActionHandler.ShortcutActionHandlerOwner; import com.vaadin.client.ui.richtextarea.VRichTextToolbar; /** * This class implements a basic client side rich text editor component. * * @author Vaadin Ltd. * */ public class VRichTextArea extends Composite implements Field, KeyPressHandler, KeyDownHandler, Focusable { /** * The input node CSS classname. */ public static final String CLASSNAME = "v-richtextarea"; /** For internal use only. May be removed or replaced in the future. */ public String id; /** For internal use only. May be removed or replaced in the future. */ public ApplicationConnection client; /** For internal use only. May be removed or replaced in the future. */ public boolean immediate = false; /** For internal use only. May be removed or replaced in the future. */ public RichTextArea rta; /** For internal use only. May be removed or replaced in the future. */ public VRichTextToolbar formatter; /** For internal use only. May be removed or replaced in the future. */ public HTML html = new HTML(); private final FlowPanel fp = new FlowPanel(); private boolean enabled = true; /** For internal use only. May be removed or replaced in the future. */ public int maxLength = -1; private int toolbarNaturalWidth = 500; /** For internal use only. May be removed or replaced in the future. */ public HandlerRegistration keyPressHandler; private ShortcutActionHandlerOwner hasShortcutActionHandler; private boolean readOnly = false; private final Map<BlurHandler, HandlerRegistration> blurHandlers = new HashMap<BlurHandler, HandlerRegistration>(); public VRichTextArea() { createRTAComponents(); fp.add(formatter); fp.add(rta); initWidget(fp); setStyleName(CLASSNAME); TouchScrollDelegate.enableTouchScrolling(html, html.getElement()); } private void createRTAComponents() { rta = new RichTextArea(); rta.setWidth("100%"); rta.addKeyDownHandler(this); formatter = new VRichTextToolbar(rta); // Add blur handlers for (Entry<BlurHandler, HandlerRegistration> handler : blurHandlers.entrySet()) { // Remove old registration handler.getValue().removeHandler(); // Add blur handlers addBlurHandler(handler.getKey()); } } public void setEnabled(boolean enabled) { if (this.enabled != enabled) { // rta.setEnabled(enabled); swapEditableArea(); this.enabled = enabled; } } /** * Swaps html to rta and visa versa. */ private void swapEditableArea() { String value = getValue(); if (html.isAttached()) { fp.remove(html); if (BrowserInfo.get().isWebkit()) { fp.remove(formatter); createRTAComponents(); // recreate new RTA to bypass #5379 fp.add(formatter); } fp.add(rta); } else { fp.remove(rta); fp.add(html); } setValue(value); } /** For internal use only. May be removed or replaced in the future. */ public void selectAll() { /* * There is a timing issue if trying to select all immediately on first * render. Simple deferred command is not enough. Using Timer with * moderated timeout. If this appears to fail on many (most likely slow) * environments, consider increasing the timeout. * * FF seems to require the most time to stabilize its RTA. On Vaadin * tiergarden test machines, 200ms was not enough always (about 50% * success rate) - 300 ms was 100% successful. This however was not * enough on a sluggish old non-virtualized XP test machine. A bullet * proof solution would be nice, GWT 2.1 might however solve these. At * least setFocus has a workaround for this kind of issue. */ new Timer() { @Override public void run() { rta.getFormatter().selectAll(); } }.schedule(320); } public void setReadOnly(boolean b) { if (isReadOnly() != b) { swapEditableArea(); readOnly = b; } // reset visibility in case enabled state changed and the formatter was // recreated formatter.setVisible(!readOnly); } private boolean isReadOnly() { return readOnly; } @Override public void setHeight(String height) { super.setHeight(height); if (height == null || height.equals("")) { rta.setHeight(""); } } @Override public void setWidth(String width) { if (width.equals("")) { /* * IE cannot calculate the width of the 100% iframe correctly if * there is no width specified for the parent. In this case we would * use the toolbar but IE cannot calculate the width of that one * correctly either in all cases. So we end up using a default width * for a RichTextArea with no width definition in all browsers (for * compatibility). */ super.setWidth(toolbarNaturalWidth + "px"); } else { super.setWidth(width); } } @Override public void onKeyPress(KeyPressEvent event) { if (maxLength >= 0) { Scheduler.get().scheduleDeferred(new Command() { @Override public void execute() { if (rta.getHTML().length() > maxLength) { rta.setHTML(rta.getHTML().substring(0, maxLength)); } } }); } } @Override public void onKeyDown(KeyDownEvent event) { // delegate to closest shortcut action handler // throw event from the iframe forward to the shortcuthandler ShortcutActionHandler shortcutHandler = getShortcutHandlerOwner().getShortcutActionHandler(); if (shortcutHandler != null) { shortcutHandler.handleKeyboardEvent(com.google.gwt.user.client.Event.as(event.getNativeEvent()), ConnectorMap.get(client).getConnector(this)); } } private ShortcutActionHandlerOwner getShortcutHandlerOwner() { if (hasShortcutActionHandler == null) { Widget parent = getParent(); while (parent != null) { if (parent instanceof ShortcutActionHandlerOwner) { break; } parent = parent.getParent(); } hasShortcutActionHandler = (ShortcutActionHandlerOwner) parent; } return hasShortcutActionHandler; } @Override public int getTabIndex() { return rta.getTabIndex(); } @Override public void setAccessKey(char key) { rta.setAccessKey(key); } @Override public void setFocus(boolean focused) { /* * Similar issue as with selectAll. Focusing must happen before possible * selectall, so keep the timeout here lower. */ new Timer() { @Override public void run() { rta.setFocus(true); } }.schedule(300); } @Override public void setTabIndex(int index) { rta.setTabIndex(index); } /** * Set the value of the text area * * @param value * The text value. Can be html. */ public void setValue(String value) { if (rta.isAttached()) { rta.setHTML(value); } else { html.setHTML(value); } } /** * Get the value the text area */ public String getValue() { if (rta.isAttached()) { return rta.getHTML(); } else { return html.getHTML(); } } /** * Browsers differ in what they return as the content of a visually empty * rich text area. This method is used to normalize these to an empty * string. See #8004. * * @return cleaned html string */ public String getSanitizedValue() { BrowserInfo browser = BrowserInfo.get(); String result = getValue(); if (browser.isFirefox()) { if ("<br>".equals(result)) { result = ""; } } else if (browser.isWebkit() || browser.isEdge()) { if ("<br>".equals(result) || "<div><br></div>".equals(result)) { result = ""; } } else if (browser.isIE()) { if ("<P> </P>".equals(result)) { result = ""; } } else if (browser.isOpera()) { if ("<br>".equals(result) || "<p><br></p>".equals(result)) { result = ""; } } return result; } /** * Adds a blur handler to the component. * * @param blurHandler * the blur handler to add */ public void addBlurHandler(BlurHandler blurHandler) { blurHandlers.put(blurHandler, rta.addBlurHandler(blurHandler)); } /** * Removes a blur handler. * * @param blurHandler * the handler to remove */ public void removeBlurHandler(BlurHandler blurHandler) { HandlerRegistration registration = blurHandlers.remove(blurHandler); if (registration != null) { registration.removeHandler(); } } }