Java tutorial
/* * Copyright 2007 Google Inc. * * 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.google.gwt.user.client.ui; import com.google.gwt.core.client.GWT; import com.google.gwt.event.logical.shared.HasInitializeHandlers; import com.google.gwt.event.logical.shared.InitializeEvent; import com.google.gwt.event.logical.shared.InitializeHandler; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.safehtml.client.HasSafeHtml; import com.google.gwt.safehtml.shared.SafeHtml; import com.google.gwt.user.client.ui.impl.RichTextAreaImpl; /** * A rich text editor that allows complex styling and formatting. * * Because some browsers do not support rich text editing, and others support * only a limited subset of functionality, there are two formatter interfaces, * accessed via {@link #getBasicFormatter()} and {@link #getExtendedFormatter()} * . A browser that does not support rich text editing at all will return * <code>null</code> for both of these, while one that supports only the basic * functionality will return <code>null</code> for the latter. * * <p> * <img class='gallery' src='doc-files/RichTextArea.png'/> * </p> * * <h3>CSS Style Rules</h3> * <dl> * <dt>.gwt-RichTextArea</dt> * <dd>Applied to the rich text element.</dd> * </dl> */ public class RichTextArea extends FocusWidget implements HasHTML, HasInitializeHandlers, HasSafeHtml { /** * <p> * This interface is used to access basic formatting options, when available. * If the implementation supports basic formatting, then * {@link RichTextArea#getBasicFormatter()} will return an instance of this * class. * </p> * <p> * The formatter will format the user selected text in the * {@link RichTextArea}. As a result, it will only work reliably if the * {@link RichTextArea} is attached, visible to on the page, and has been * focused at least once. If you just want to initialize the content of the * {@link RichTextArea}, use {@link RichTextArea#setHTML(String)} instead. * </p> * * @deprecated use {@link RichTextArea.Formatter} instead */ @Deprecated public interface BasicFormatter { /** * Gets the background color. * * @return the background color */ String getBackColor(); /** * Gets the foreground color. * * @return the foreground color */ String getForeColor(); /** * Is the current region bold? * * @return true if the current region is bold */ boolean isBold(); /** * Is the current region italic? * * @return true if the current region is italic */ boolean isItalic(); /** * Is the current region subscript? * * @return true if the current region is subscript */ boolean isSubscript(); /** * Is the current region superscript? * * @return true if the current region is superscript */ boolean isSuperscript(); /** * Is the current region underlined? * * @return true if the current region is underlined */ boolean isUnderlined(); /** * Selects all the text. */ void selectAll(); /** * Sets the background color. * * @param color the new background color */ void setBackColor(String color); /** * Sets the font name. * * @param name the new font name */ void setFontName(String name); /** * Sets the font size. * * @param fontSize the new font size */ void setFontSize(FontSize fontSize); /** * Sets the foreground color. * * @param color the new foreground color */ void setForeColor(String color); /** * Sets the justification. * * @param justification the new justification */ void setJustification(Justification justification); /** * Toggles bold. */ void toggleBold(); /** * Toggles italic. */ void toggleItalic(); /** * Toggles subscript. */ void toggleSubscript(); /** * Toggles superscript. */ void toggleSuperscript(); /** * Toggles underline. */ void toggleUnderline(); } /** * <p> * This interface is used to access full formatting options, when available. * If the implementation supports full formatting, then * {@link RichTextArea#getExtendedFormatter()} will return an instance of this * class. * </p> * <p> * The formatter will format the user selected text in the * {@link RichTextArea}. As a result, it will only work reliably if the * {@link RichTextArea} is attached, visible to on the page, and has been * focused at least once. If you just want to initialize the content of the * {@link RichTextArea}, use {@link RichTextArea#setHTML(String)} instead. * </p> * * @deprecated use {@link RichTextArea.Formatter} instead */ @Deprecated public interface ExtendedFormatter extends BasicFormatter { /** * Creates a link to the supplied URL. * * @param url the URL to be linked to */ void createLink(String url); /** * Inserts a horizontal rule. */ void insertHorizontalRule(); /** * Inserts an image element. * * @param url the url of the image to be inserted */ void insertImage(String url); /** * Starts an numbered list. Indentation will create nested items. */ void insertOrderedList(); /** * Starts an bulleted list. Indentation will create nested items. */ void insertUnorderedList(); /** * Is the current region strikethrough? * * @return true if the current region is strikethrough */ boolean isStrikethrough(); /** * Left indent. */ void leftIndent(); /** * Removes all formatting on the selected text. */ void removeFormat(); /** * Removes any link from the selected text. */ void removeLink(); /** * Right indent. */ void rightIndent(); /** * Toggles strikethrough. */ void toggleStrikethrough(); } /** * Font size enumeration. Represents the seven basic HTML font sizes, as * defined in CSS. */ public static class FontSize { /** * Represents a Large font. */ public static final FontSize LARGE = new FontSize(5); /** * Represents a Medium font. */ public static final FontSize MEDIUM = new FontSize(4); /** * Represents a Small font. */ public static final FontSize SMALL = new FontSize(3); /** * Represents an X-Large font. */ public static final FontSize X_LARGE = new FontSize(6); /** * Represents an X-Small font. */ public static final FontSize X_SMALL = new FontSize(2); /** * Represents an XX-Large font. */ public static final FontSize XX_LARGE = new FontSize(7); /** * Represents an XX-Small font. */ public static final FontSize XX_SMALL = new FontSize(1); private int number; private FontSize(int number) { this.number = number; } /** * Gets the HTML font number associated with this font size. * * @return an integer from 1 to 7 inclusive */ public int getNumber() { return number; } @Override public String toString() { return Integer.toString(number); } } /** * <p> * This interface is used to access full formatting options, when available. * If the implementation supports full formatting, then * {@link RichTextArea#getFormatter()} will return an instance of this class. * </p> * <p> * The formatter will format the user selected text in the * {@link RichTextArea}. As a result, it will only work reliably if the * {@link RichTextArea} is attached, visible to on the page, and has been * focused at least once. If you just want to initialize the content of the * {@link RichTextArea}, use {@link RichTextArea#setHTML(String)} instead. * </p> */ public interface Formatter extends ExtendedFormatter { /** * Creates a link to the supplied URL. * * @param url the URL to be linked to */ void createLink(String url); /** * Gets the background color. * * @return the background color */ String getBackColor(); /** * Gets the foreground color. * * @return the foreground color */ String getForeColor(); /** * Inserts a horizontal rule. */ void insertHorizontalRule(); /** * Inserts generic html. * * @param html the HTML to insert */ void insertHTML(String html); /** * Inserts an image element. * * @param url the url of the image to be inserted */ void insertImage(String url); /** * Starts an numbered list. Indentation will create nested items. */ void insertOrderedList(); /** * Starts an bulleted list. Indentation will create nested items. */ void insertUnorderedList(); /** * Is the current region bold? * * @return true if the current region is bold */ boolean isBold(); /** * Is the current region italic? * * @return true if the current region is italic */ boolean isItalic(); /** * Is the current region strikethrough? * * @return true if the current region is strikethrough */ boolean isStrikethrough(); /** * Is the current region subscript? * * @return true if the current region is subscript */ boolean isSubscript(); /** * Is the current region superscript? * * @return true if the current region is superscript */ boolean isSuperscript(); /** * Is the current region underlined? * * @return true if the current region is underlined */ boolean isUnderlined(); /** * Left indent. */ void leftIndent(); /** * Redo an action that was just undone. */ void redo(); /** * Removes all formatting on the selected text. */ void removeFormat(); /** * Removes any link from the selected text. */ void removeLink(); /** * Right indent. */ void rightIndent(); /** * Selects all the text. */ void selectAll(); /** * Sets the background color. * * @param color the new background color */ void setBackColor(String color); /** * Sets the font name. * * @param name the new font name */ void setFontName(String name); /** * Sets the font size. * * @param fontSize the new font size */ void setFontSize(FontSize fontSize); /** * Sets the foreground color. * * @param color the new foreground color */ void setForeColor(String color); /** * Sets the justification. * * @param justification the new justification */ void setJustification(Justification justification); /** * Toggles bold. */ void toggleBold(); /** * Toggles italic. */ void toggleItalic(); /** * Toggles strikethrough. */ void toggleStrikethrough(); /** * Toggles subscript. */ void toggleSubscript(); /** * Toggles superscript. */ void toggleSuperscript(); /** * Toggles underline. */ void toggleUnderline(); /** * Undo the last action. */ void undo(); } /** * Justification enumeration. The three values are <code>left</code>, * <code>right</code>, <code>center</code>. */ public static class Justification { /** * Center justification. */ public static final Justification CENTER = new Justification("Center"); /** * Full justification. */ public static final Justification FULL = new Justification("Full"); /** * Left justification. */ public static final Justification LEFT = new Justification("Left"); /** * Right justification. */ public static final Justification RIGHT = new Justification("Right"); private String tag; private Justification(String tag) { this.tag = tag; } @Override public String toString() { return "Justify " + tag; } } private RichTextAreaImpl impl = GWT.create(RichTextAreaImpl.class); /** * Creates a new, blank {@link RichTextArea} object with no stylesheet. */ public RichTextArea() { setElement(impl.getElement()); setStyleName("gwt-RichTextArea"); impl.setOwner(this); } public HandlerRegistration addInitializeHandler(InitializeHandler handler) { return addHandler(handler, InitializeEvent.getType()); } /** * Gets the basic rich text formatting interface. Note that formatting can * only be done when the {@link RichTextArea} is attached, visible on the * page, and has been focused by the user. * * @return <code>null</code> if basic formatting is not supported * @deprecated use {@link #getFormatter()} instead */ @Deprecated public BasicFormatter getBasicFormatter() { return getFormatter(); } /** * Gets the full rich text formatting interface. Note that formatting can only * be done when the {@link RichTextArea} is attached, visible on the page, and * has been focused by the user. * * @return <code>null</code> if full formatting is not supported * @deprecated use {@link #getFormatter()} instead */ @Deprecated public ExtendedFormatter getExtendedFormatter() { return getFormatter(); } /** * Gets the rich text formatting interface. Note that formatting can only be * done when the {@link RichTextArea} is attached, visible on the page, and * has been focused by the user. * * @return <code>null</code> if full formatting is not supported */ public Formatter getFormatter() { if (impl instanceof Formatter) { return (Formatter) impl; } return null; } public String getHTML() { return impl.getHTML(); } public String getText() { return impl.getText(); } @Override public boolean isEnabled() { return impl.isEnabled(); } @Override public void setEnabled(boolean enabled) { impl.setEnabled(enabled); } @Override public void setFocus(boolean focused) { // There are different problems on each browser when you try to focus an // unattached rich text iframe, so just cut it off early. if (isAttached()) { impl.setFocus(focused); } } public void setHTML(String html) { impl.setHTML(html); } public void setHTML(SafeHtml html) { setHTML(html.asString()); } public void setText(String text) { impl.setText(text); } @Override protected void onAttach() { super.onAttach(); impl.initElement(); } @Override protected void onDetach() { super.onDetach(); impl.uninitElement(); } }