JEditorPane

Also ser JTextArea and JTextPane

Borland Description

A text component to edit various kinds of content. This component uses implementations of the EditorKit to accomplish its behavior. It effectively morphs into the proper kind of text editor for the kind of content it is given. The content type that editor is bound to at any given time is determined by the EditorKit currently installed. If the content is set to a new URL, its type is used to determine the EditorKit that should be used to load the content.

By default, the following types of content are known:

text/plain

Plain text, which is the default the type given isn't recognized. The kit used in this case is an extension of DefaultEditorKit that produces a wrapped plain text view. text/html

HTML text .

The kit used in this case is the class javax.swing.text.html.HTMLEditorKit which provides html 3.2 support.

text/rtf

RTF text. The kit used in this case is the class javax.swing.text.rtf.RTFEditorKit which provides a limited support of the Rich Text Format.

There are several ways to load content into this component.

1. The setText method can be used to initialize the component from a string. In this case the current EditorKit will be used, and the content type will be expected to be of this type.
2. The read method can be used to initialize the component from a Reader. Note that if the content type is html, relative references (e.g. for things like images) can't be resolved unless the < base > tag is used or the Base property on HTMLDocument is set. In this case the current EditorKit will be used, and the content type will be expected to be of this type.
3. The setPage method can be used to initialize the component from a URL. In this case, the content type will be determined from the URL, and the registered EditorKit for that content type will be set.

For the keyboard keys used by this component in the standard Look and Feel (L&F)&F) renditions, see the JEditorPane key assignments.

Some kinds of content may provide hyperlink support by generating hyperlink events. The html EditorKit will generate hyperlink events if the JEditorPane is not editable (i.e. JEditorPane.setEditable(false); has been called). If html frames are embedded in the document, the typical response would be to change a portion of the current document. The following code fragment is a possible hyperlink listener implementation, that treats html frame events specially, and simply displays any other activated hyperlinks.

class  Hyperactive implements  HyperlinkListener {
	public void  hyperlinkUpdate(HyperlinkEvent e) {
		if  (e.getEventType() == HyperlinkEvent.EventType.ACTIVATED) {
			JEditorPane pane = (JEditorPane) e.getSource();
			if  (e instanceof HTMLFrameHyperlinkEvent) {
			HTMLFrameHyperlinkEvent  evt = (HTMLFrameHyperlinkEvent)e;
			HTMLDocument doc = (HTMLDocument)pane.getDocument();
			doc.processHTMLFrameHyperlinkEvent(evt);
		}
		else  {
			try  {
				pane.setPage(e.getURL());
			} 
			catch  (Throwable t) {
				t.printStackTrace();
			}
		}
	}
    }
}
 

Culturally dependent information in some documents is handled through a mechanism called character encoding. Character encoding is an unambiguous mapping of the members of a character set (letters, ideographs, digits, symbols, or control functions) to specific numeric code values. It represents the way the file is stored. Example character encodings are ISO-8859-1, ISO-8859-5, Shift-jis, Euc-jp, and UTF-8. When the file is passed to an user agent (JEditorPane) it is converted to the document character set (ISO-10646 aka Unicode).

There are multiple ways to get a character set mapping to happen with JEditorPane.

1. One way is to specify the character set as a parameter of the MIME type. This will be established by a call to the setContentType method. If the content is loaded by the setPage method the content type will have been set according to the specification of the URL. It the file is loaded directly, the content type would be expected to have been set prior to loading.
2. Another way the character set can be specified is in the document itself. This requires reading the document prior to determining the character set that is desired. To handle this, it is expected that the EditorKit.read operation throw a ChangedCharSetException which will be caught. The read is then restarted with a new Reader that uses the character set specified in the ChangedCharSetException (which is an IOException).

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. A future release of Swing will provide support for long term persistence.