com.fathzer.soft.ajlib.swing.widget.HTMLPane Maven / Gradle / Ivy

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package com.fathzer.soft.ajlib.swing.widget;

import java.io.IOException;
import java.io.StringReader;
import java.net.URISyntaxException;
import java.net.URL;

import javax.swing.JScrollPane;
import javax.swing.JTextPane;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.event.HyperlinkEvent;
import javax.swing.event.HyperlinkListener;

import com.fathzer.soft.ajlib.swing.Browser;
import com.fathzer.soft.ajlib.swing.framework.Application;

/** A HTML component.
 * @author Jean-Marc Astesana
 * 
License: LGPL v3
 */
@SuppressWarnings("serial")
public class HTMLPane extends JScrollPane {
	public static final String CONTENT_CHANGED_PROPERTY = "CHANGED";  //$NON-NLS-1$
	private static final String HTML_START_TAG = ""; //$NON-NLS-1$
	private static final String HTML_END_TAG = ""; //$NON-NLS-1$
	private JTextPane textPane;
	private String contentType;
	private DocumentListener docListener;

	/** Constructor.
	 */
	public HTMLPane () {
		super();
		this.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
		this.contentType = null;
		getTextPane().getDocument().addDocumentListener(getDocumentListener());
		this.setViewportView(getTextPane());
	}
	
	public HTMLPane (URL url) throws IOException {
		this();
		setContent(url);
	}

	public HTMLPane (String text) {
		this();
		setContent(text);
	}

	/** Sets the panel content.
	 * 
If this panel content type is not set, the content type is determined by the content of the text.
	 * If it starts with "<html>" and ends with "</html>", the panel assumes the content type is "text/html".
	 * 
If not, the content type is assumed to "text/plain".
	 * 
If the content type is set, this content type is used. It allows you to display an html code source,
	 * by invoking this.setContentType("text/plain") before calling this method.  
	 * @param text The text to be set.
	 * @see #setContentType(String)
	 */
	public void setContent (String text) {
		String type;
		if (this.contentType==null) {
			String trimmed = text.trim();
			boolean html = trimmed.length()>=HTML_START_TAG.length()+HTML_END_TAG.length();
			if (html) {
				html = HTML_START_TAG.equalsIgnoreCase(trimmed.substring(0, HTML_START_TAG.length()));
			}
			if (html) {
				html = HTML_END_TAG.equalsIgnoreCase(trimmed.substring(trimmed.length() - HTML_END_TAG.length()));
			}
			type = html?"text/html":"text/plain"; //$NON-NLS-1$ //$NON-NLS-2$
		} else {
			type = this.contentType;
		}
		getTextPane().setContentType(type);
		// We should not use textPane.setText because it scrolls the textPane to the end of the text
		try {
			getTextPane().read(new StringReader(text), type);
			getTextPane().getDocument().addDocumentListener(getDocumentListener());
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
	}
	
	public void setContent (URL url) throws IOException {
		if (url != null) {
			getTextPane().setPage(url);
			textPane.getDocument().addDocumentListener(getDocumentListener());
		}
	}
	
	/** Gets the internal text pane.
	 * @return A JTextPane
	 */
	public JTextPane getTextPane() {
		if (this.textPane==null) {
			textPane = new JTextPane();
			textPane.setEditable(false);
			textPane.addHyperlinkListener(new HyperlinkListener() {
				@Override
				public void hyperlinkUpdate(HyperlinkEvent e) {
					if (e.getEventType()==HyperlinkEvent.EventType.ACTIVATED) {
						URL url = e.getURL();
						if (url==null) {
							throw new IllegalArgumentException(e.getDescription()+" leads to a null url");
						}
						try {
							Browser.show(url.toURI(), HTMLPane.this, Application.getString("Generic.error", getLocale())); //$NON-NLS-1$
						} catch (URISyntaxException ex) {
							throw new RuntimeException(ex);
						}
					}
				}
			});
			textPane.getDocument().addDocumentListener(getDocumentListener());
		}
		return this.textPane;
	}
	
	private DocumentListener getDocumentListener() {
		if (docListener==null) {
			docListener = new DocumentListener() {
				@Override
				public void removeUpdate(DocumentEvent e) {
					firePropertyChange(CONTENT_CHANGED_PROPERTY, null, null);
				}
				@Override
				public void insertUpdate(DocumentEvent e) {
					firePropertyChange(CONTENT_CHANGED_PROPERTY, null, null);
				}
				@Override
				public void changedUpdate(DocumentEvent e) {
					firePropertyChange(CONTENT_CHANGED_PROPERTY, null, null);
				}
			};
		}
		return docListener;
	}

	/** Sets the content type.
	 * 
Please note that this method as no effect on the current content. It should only have an effect on future calls to setContent.
	 * @param contentType A content type or null for the content type to be automatically set when calling set content.
	 * @see #setContent(String)
	 */
	public void setContentType(String contentType) {
		this.contentType = contentType;
		if (contentType!=null) {
			getTextPane().setContentType(contentType);
		}
	}
}