粘贴到JTextPane时如何保留源文本样式?

Question

使用Java Swing，我正在使用RTFEditorKit((创建一个简单的.rtf文件编辑器应用程序。我正在使用JTextPane。我为粗体、斜体、下划线文本添加了代码。

我的问题场景： 我有两行文字，第一行文字充满了粗体样式，第二行文字充满了斜体风格。 将一些文本从第一行(粗体(复制到第二行时，将粗体文本粘贴到第二行后，它将以斜体样式显示。

预期场景：粘贴后应为粗体样式，应保留样式。 如何在Java Swing中实现这一点？谁能帮忙？谢谢。

Answer 1

这是我多年前在论坛上找到的一些旧代码。

它复制带有文本的各个属性。

不知道它是否适用于RTFEditorKit：

/*
crwood:
http://forum.java.sun.com/thread.jspa?threadID=5137992&tstart=0
*/
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.event.*;
import java.io.IOException;
import java.text.*;
import java.util.*;
import java.util.List;
import javax.swing.*;
import javax.swing.text.*;
public class StyleTransfer {
private JPanel getContent() {
JTextPane left = new JTextPane();
initialize(left);
left.setDragEnabled(true);
left.setTransferHandler(new StyleTransferHandler());
JTextPane right = new JTextPane();
right.setDragEnabled(true);
right.setTransferHandler(new StyleTransferHandler());
JPanel panel = new JPanel(new GridLayout(0,1));
panel.add(new JScrollPane(left));
panel.add(new JScrollPane(right));
panel.add( new JScrollPane( new JTextArea() ) );
return panel;
}
private void initialize(JTextPane textPane) {
String text = "This component models paragraphs that are composed of " +
"runs of character level attributes. Each paragraph may have a " +
"logical style attached to it which contains the default attributes " +
"to use if not overridden by attributes set on the paragraph or " +
"character run. Components and images may be embedded in the flow " +
"of text."; // 0 - 319
StyledDocument doc = textPane.getStyledDocument();
createStyles(doc);
setContent(doc, text);
styleContent(doc);
}
private void createStyles(StyledDocument doc) {
Style baseStyle = doc.addStyle("base", null);
StyleConstants.setFontFamily(baseStyle, "Lucida Sans Unicode");
StyleConstants.setFontSize(baseStyle, 18);
StyleConstants.setLeftIndent(baseStyle, 10f);
Style style = doc.addStyle("bold", baseStyle);
StyleConstants.setBold(style, true);
style = doc.addStyle("italic", baseStyle);
StyleConstants.setItalic(style, true);
style = doc.addStyle("blue", baseStyle);
StyleConstants.setForeground(style, Color.blue);
style = doc.addStyle("underline", baseStyle);
StyleConstants.setUnderline(style, true);
style = doc.addStyle("green", baseStyle);
StyleConstants.setForeground(style, Color.green.darker());
StyleConstants.setUnderline(style, true);
style = doc.addStyle("highlight", baseStyle);
StyleConstants.setForeground(style, Color.yellow);
StyleConstants.setBackground(style, Color.black);
}
private void setContent(StyledDocument doc, String text) {
try {
doc.insertString(0, text, doc.getStyle("base"));
} catch(BadLocationException e) {
System.out.println(e);
}
}
private void styleContent(StyledDocument doc) {
String[] names = {
"underline", "highlight", "blue", "italic",
"green", "green", "bold", "bold"
};
int[] starts  = { 22, 62, 116, 164, 233, 246, 261, 276 };
int[] lengths = { 10, 26,  13,  18,   9,   9,  10,   6 };
Style style = doc.getStyle("base");
doc.setLogicalStyle(0, style);
for(int j = 0; j < names.length; j++) {
style = doc.getStyle(names[j]);
doc.setCharacterAttributes(starts[j], lengths[j], style, false);
}
}
public JMenuBar getMenuBar () {
JMenuItem menuItem = null;
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("Edit");
menu.setMnemonic(KeyEvent.VK_E);
menuItem = new JMenuItem(new DefaultEditorKit.CutAction());
menuItem.setText("Cut");
menuItem.setMnemonic(KeyEvent.VK_T);
menu.add(menuItem);
menuItem = new JMenuItem(new DefaultEditorKit.CopyAction());
menuItem.setText("Copy");
menuItem.setMnemonic(KeyEvent.VK_C);
menu.add(menuItem);
menuItem = new JMenuItem(new DefaultEditorKit.PasteAction());
menuItem.setText("Paste");
menuItem.setMnemonic(KeyEvent.VK_P);
menu.add(menuItem);
menuBar.add(menu);
return menuBar;
}
public static void main(String[] args) {
System.setProperty("swing.aatext", "true");
StyleTransfer test = new StyleTransfer();
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setJMenuBar(test.getMenuBar());
f.getContentPane().add(test.getContent());
f.setSize(500,500);
f.setLocation(100,50);
f.setVisible(true);
}
}
class StyleTransferHandler extends TransferHandler {
String mimeType = DataFlavor.javaJVMLocalObjectMimeType +
";class=StyledString";
DataFlavor styledStringFlavor;
public StyleTransferHandler() {
try {
styledStringFlavor = new DataFlavor(mimeType);
} catch(ClassNotFoundException e) {
System.out.println("Unable to create styledStringFlavor");
}
}
public boolean canImport(JComponent comp, DataFlavor[] transferFlavors) {
for(int j = 0; j < transferFlavors.length; j++) {
if(styledStringFlavor.equals(transferFlavors[j]))
return true;
}
return false;
}
protected Transferable createTransferable(JComponent c) {
JTextPane textPane = (JTextPane)c;
int start = textPane.getSelectionStart();
int end = textPane.getSelectionEnd();
StyledString ss = new StyledString("");
if(start != -1 && start != end) {
String text = textPane.getSelectedText();
ss = new StyledString(text);
StyledDocument doc = textPane.getStyledDocument();
extractAttributes(doc, start, end, ss);
}
System.out.println(ss);
return new StyledStringTransferable(ss);
}
private void extractAttributes(StyledDocument doc, int selectionStart,
int selectionEnd, StyledString styledStr) {
int pos = selectionStart;
styledStr.logicalStyle = doc.getLogicalStyle(pos);
while(pos < selectionEnd) {
Element element = doc.getCharacterElement(pos);
AttributeSet attrs = element.getAttributes();
int endOffset = element.getEndOffset();
int end = (endOffset < selectionEnd) ? endOffset : selectionEnd;
styledStr.addAttributes(attrs, pos, end);
pos = end;
}
}
/**
* MOVE is not supported in superclass implementation
* and exportDone is implemented to do nothing - see api.
*/
public void exportAsDrag(JComponent comp, InputEvent e, int action) {
super.exportAsDrag(comp, e, action);
Clipboard clip = comp.getToolkit().getSystemClipboard();
exportDone(comp, clip, action);
}
/**
* MOVE is not supported in superclass implementation
* and exportDone is implemented to do nothing - see api.
*/
public void exportToClipboard(JComponent comp, Clipboard clip, int action) {
super.exportToClipboard(comp, clip, action);
exportDone(comp, clip, action);
}
public void exportDone(JComponent comp, Clipboard clip, int action) {
JTextPane textPane = (JTextPane)comp;
if(action == MOVE) {
int offset = textPane.getSelectionStart();
int length = textPane.getSelectionEnd() - offset;
StyledDocument doc = textPane.getStyledDocument();
try {
doc.remove(offset, length);
} catch(BadLocationException e) {
System.out.println(e);
}
}
}
public int getSourceActions(JComponent c) {
return COPY_OR_MOVE;
}
public boolean importData(JComponent comp, Transferable t) {
if(canImport(comp, t.getTransferDataFlavors())) {
StyledString styledStr = null;
try {
styledStr = (StyledString)t.getTransferData(styledStringFlavor);
List attrs = styledStr.attrs;
List locs = styledStr.locs;
JTextPane textPane = (JTextPane)comp;
int pos = textPane.getCaretPosition();
StyledDocument doc = textPane.getStyledDocument();
Style logicalStyle = styledStr.logicalStyle;
// Insert the text.
try {
doc.insertString(pos, styledStr.text, logicalStyle);
} catch(BadLocationException e) {
System.out.println(e);
}
// Appy the style runs to the inserted text.
for(int j = 0; j < attrs.size(); j++) {
AttributeSet as = (AttributeSet)attrs.get(j);
Location loc = (Location)locs.get(j);
doc.setCharacterAttributes(pos, loc.length, as, false);
pos += loc.length;
}
return true;
} catch(UnsupportedFlavorException ufe) {
System.out.println("importData UnsupportedFlavor: " +
ufe.getMessage());
} catch(IOException ioe) {
System.out.println("importData IO Error: " + ioe.getMessage());
}
}
return false;
}
class StyledStringTransferable implements Transferable {
private StyledString styledString;
StyledStringTransferable(StyledString ss) {
styledString = ss;
}
public Object getTransferData(DataFlavor flavor)
throws UnsupportedFlavorException {
if(!isDataFlavorSupported(flavor))
throw new UnsupportedFlavorException(flavor);
return styledString;
}
public DataFlavor[] getTransferDataFlavors() {
return new DataFlavor[] { styledStringFlavor };
}
public boolean isDataFlavorSupported(DataFlavor flavor) {
return styledStringFlavor.equals(flavor);
}
public String toString() {
return "StyledStringTransferable: " + styledString;
}
}
}
class StyledString {
String text;
List attrs;
List locs;
Style logicalStyle;
public StyledString(String text) {
this.text = text;
attrs = new ArrayList();
locs  = new ArrayList();
}
public void addAttributes(AttributeSet atts, int start, int end) {
attrs.add(atts);
locs.add(new Location(start, end));
}
public String toString() {
StringBuffer sb = new StringBuffer("StyledString[");
for(int j = 0; j < attrs.size(); j++) {
sb.append("Attributes[");
Enumeration e = ((AttributeSet)attrs.get(j)).getAttributeNames();
while(e.hasMoreElements()) {
Object key = e.nextElement();
Object value = ((AttributeSet)attrs.get(j)).getAttribute(key);
sb.append("key:" + key + ",value:" + value + ";");
}
sb.append("]");
sb.append(" for " + locs.get(j));
if(j < attrs.size()-1)
sb.append("n");
}
System.out.println(sb);
return sb.toString();
}
}
class Location {
int start;
int length;
public Location(int start, int end) {
this.start = start;
length = end - start;
}
public String toString() {
return "Location[start:" + start + ",length:" + length + "]";
}
}