我正在开发一个创建文本编辑器（基本上是记事本）的项目，Swing我遇到了行号问题。我必须说我对 java 还很陌生，但我正在尽我所能来改变它！
JEditorPane您在处理我正在使用的行号的类下面。但每次它向行号添加另一个数字时，我都会得到一个重复的分隔线，用于约 10 行文本。我怎样才能防止这种情况发生。
另外，我怎样才能添加一个“长线标记”，'m'从左边开始画出大约 100 个字符的另一条线。
这是课程：
/**
* Part of the source code got from here:
* developer.com/java/other/article.php/3318421/Add-Line-Numbering-in-the-JEditorPane.htm
*
* About the Author Stanislav Lapitsky is an offshore software developer and
* consultant with more than 7 years of programming experience. His area of
* knowledge includes java based technologies and RDBMS.
*
*/
package MainGUI;
/**
*
* @author mrbigheart
*/
import java.awt.*;
import javax.swing.*;
import javax.swing.text.*;
public class LineNumbers {
// private default constructor
private LineNumbers() {
}
// private constructor
private LineNumbers(JEditorPane edit) {
edit.setEditorKit(new NumberedEditorKit());
}
// static factory
public static LineNumbers valueOf(JEditorPane edit) {
return new LineNumbers(edit);
}
}
class NumberedEditorKit extends StyledEditorKit {
@Override
public ViewFactory getViewFactory() {
return new NumberedViewFactory();
}
}
class NumberedViewFactory implements ViewFactory {
@Override
public View create(Element elem) {
String kind = elem.getName();
if (kind != null) {
switch (kind) {
case AbstractDocument.ContentElementName:
return new LabelView(elem);
case AbstractDocument.ParagraphElementName:
// return new ParagraphView(elem);
return new NumberedParagraphView(elem);
case AbstractDocument.SectionElementName:
return new BoxView(elem, View.Y_AXIS);
case StyleConstants.ComponentElementName:
return new ComponentView(elem);
case StyleConstants.IconElementName:
return new IconView(elem);
}
}
// default to text display
return new LabelView(elem);
}
}
final class NumberedParagraphView extends ParagraphView {
public static short NUMBERS_WIDTH = 30;
public NumberedParagraphView(Element e) {
super(e);
short top = 7;
short left = 0;
short bottom = 0;
short right = 0;
this.setInsets(top, left, bottom, right);
}
// indent for the JEditorPane
@Override
protected void setInsets(short top, short left, short bottom,
short right) {
super.setInsets(top, (short) (left + NUMBERS_WIDTH + 5),
bottom, right);
}
@Override
public void paintChild(Graphics g, Rectangle r, int n) {
super.paintChild(g, r, n);
View parent = this.getParent();
int previousLineCount = getPreviousLineCount();
int numberX = r.x - getLeftInset();
int numberY = r.y + r.height - 5;
// Update sizes when number of digits in the line number changes
int lines = getPreviousLineCount();
int digits = Math.max(String.valueOf(lines).length(), 2);
FontMetrics fontMetrics = g.getFontMetrics();
//get the width of a zero character times the number of digits
int width = (fontMetrics.charWidth('0') * digits) + numberX + 7;
// update NUMBERS_WIDTH with the new width
NUMBERS_WIDTH = (short)width;
// line numbers rectangle (x, y, width, height)
g.drawRect(0, 0, width, parent.getContainer().getHeight());
g.setColor(Color.YELLOW);
g.drawString(Integer.toString(previousLineCount + n + 1),
numberX, numberY);
}
public int getPreviousLineCount() {
int lineCount = 0;
View parent = this.getParent();
int count = parent.getViewCount();
for (int i = 0; i < count; i++) {
if (parent.getView(i) == this) {
break;
} else {
lineCount += parent.getView(i).getViewCount();
}
}
return lineCount;
}
}
先感谢您！