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The Java Developers Almanac 1.4Order this book from Amazon. |
e1006. Highlighting Words in a JTextComponentThis example demonstrates how to highlight a range of characters in a text component using highlights. The example uses a text component's highlighter to create and manage the highlights. Since one of the highlights in the highlighter is the selection, we must be careful when removing highlights not to remove the selection.The way in which we identify our highlights is to create the highlight using a private painter. So when removing highlights from the highlighter, we remove only the ones whose painter is an instance of the private painter. If many different highlight styles are required, it is
necessary to use styles with a JTextArea textComp = new JTextArea(); // Highlight the occurrences of the word "public" highlight(textComp, "public"); // Creates highlights around all occurrences of pattern in textComp public void highlight(JTextComponent textComp, String pattern) { // First remove all old highlights removeHighlights(textComp); try { Highlighter hilite = textComp.getHighlighter(); Document doc = textComp.getDocument(); String text = doc.getText(0, doc.getLength()); int pos = 0; // Search for pattern while ((pos = text.indexOf(pattern, pos)) >= 0) { // Create highlighter using private painter and apply around pattern hilite.addHighlight(pos, pos+pattern.length(), myHighlightPainter); pos += pattern.length(); } } catch (BadLocationException e) { } } // Removes only our private highlights public void removeHighlights(JTextComponent textComp) { Highlighter hilite = textComp.getHighlighter(); Highlighter.Highlight[] hilites = hilite.getHighlights(); for (int i=0; i<hilites.length; i++) { if (hilites[i].getPainter() instanceof MyHighlightPainter) { hilite.removeHighlight(hilites[i]); } } } // An instance of the private subclass of the default highlight painter Highlighter.HighlightPainter myHighlightPainter = new MyHighlightPainter(Color.red); // A private subclass of the default highlight painter class MyHighlightPainter extends DefaultHighlighter.DefaultHighlightPainter { public MyHighlightPainter(Color color) { super(color); } }
e1008. Sharing Styles Between JTextPanes e1009. Listing the Styles Associated with a JTextPane e1010. Listing the Attributes in a Style e1011. Using a Popup to Apply Styles to a JTextPane e1012. Retaining the Logical Style When Setting a New Paragraph Style e1013. Automatically Updating Styled Text When a Style Is Updated e1014. Determining If a Style Attribute Applies to a Character or the Paragraph
© 2002 Addison-Wesley. |