我希望能够在我的JTextPane中每一行交替使用灰色和白色作为背景。我尝试通过重载paintComponent()方法并根据组件高度和字体大小手动绘制背景来实现,但是我没有成功。
请问有什么提示吗?
请问有什么提示吗?
public static void main(String[] args) {
JTextPane t = new JTextPane();
t.setSelectionColor(new Color(1.0f, 1.0f, 1.0f, 0.0f));
Highlighter hilite = new MyHighlighter();
t.setHighlighter(hilite);
t.setText("Line1\nLine2\nLine3\nLine4\nLine5\n");
DefaultHighlightPainter whitePainter = new DefaultHighlighter.DefaultHighlightPainter(Color.WHITE);
DefaultHighlightPainter grayPainter = new DefaultHighlighter.DefaultHighlightPainter(Color.GRAY);
try {
Document doc = t.getDocument();
String text = doc.getText(0, doc.getLength());
int start = 0;
int end = 0 ;
boolean even = true;
//look for newline char, and then toggle between white and gray painters.
while ((end = text.indexOf('\n', start)) >= 0) {
even = !even;
DefaultHighlightPainter painter = even ? grayPainter : whitePainter;
hilite.addHighlight(start, end+1, painter);
start = end+1;
}
} catch (BadLocationException e) {
e.printStackTrace();
}
JPanel p = new JPanel(new BorderLayout());
p.add(t, BorderLayout.CENTER);
JFrame f = new JFrame();
f.add(p);
f.setSize(100, 100);
f.setVisible(true);
}
这里是VonC的MyHighlighter
:
class MyHighlighter extends DefaultHighlighter
{
private JTextComponent component;
/**
* @see javax.swing.text.DefaultHighlighter#install(javax.swing.text.JTextComponent)
*/
@Override
public final void install(final JTextComponent c)
{
super.install(c);
this.component = c;
}
/**
* @see javax.swing.text.DefaultHighlighter#deinstall(javax.swing.text.JTextComponent)
*/
@Override
public final void deinstall(final JTextComponent c)
{
super.deinstall(c);
this.component = null;
}
/**
* Same algo, except width is not modified with the insets.
*
* @see javax.swing.text.DefaultHighlighter#paint(java.awt.Graphics)
*/
@Override
public final void paint(final Graphics g)
{
final Highlighter.Highlight[] highlights = getHighlights();
final int len = highlights.length;
for (int i = 0; i < len; i++)
{
Highlighter.Highlight info = highlights[i];
if (info.getClass().getName().indexOf("LayeredHighlightInfo") > -1)
{
// Avoid allocing unless we need it.
final Rectangle a = this.component.getBounds();
final Insets insets = this.component.getInsets();
a.x = insets.left;
a.y = insets.top;
// a.width -= insets.left + insets.right + 100;
a.height -= insets.top + insets.bottom;
for (; i < len; i++)
{
info = highlights[i];
if (info.getClass().getName().indexOf(
"LayeredHighlightInfo") > -1)
{
final Highlighter.HighlightPainter p = info
.getPainter();
p.paint(g, info.getStartOffset(), info
.getEndOffset(), a, this.component);
}
}
}
}
}
}
这里是一个可能解决方案的示例。
简单解释一下,JTextPane是一个样式文档编辑器,因此允许更改StyledDocument,也就是包含样式信息(例如给定行的背景颜色)的文档。
JTextField someField = new JTextField();
someField.setBackground(Color.GREY );
JTextPane pane = new JTextPane();
pane.setContentType("text/html");
String text = /*some html table or set of divs for formatting */
pane.setText(text);
myJFrame.add(pane);
当您构建文本字符串时,可以使用CSS设置交替颜色,或直接将其硬编码到创建的文档中。这将帮助您避免覆盖重绘方法。
在不允许用户编辑框(即将setEditable设置为false)的情况下,这将起作用良好。如果您希望每次用户按Enter键时都重新绘制该行,则必须调整解决方案。