使用 Java，是否有任何内置方式来呈现文本，使其仅限于graphics2D对象上的矩形？
我知道我可以使用Graphics2D.drawString，但它只绘制一行文本。
我也知道我可以使用
FontMetrics fm= graphics.getFontMetrics(font);
Rectangle2D rect=fm.getStringBounds("Some Text",graphics);
Font font当在某个Graphics2D graphics对象上使用 some 渲染时，获取有关字符串边界的信息。
所以我可以开始循环，打破我的字符串等等，以迫使它适合某个矩形。
但我宁愿不必写那些......
是否有任何现成的功能可以为我做到这一点？
我写了一个可以提供帮助的小函数。447 是可用的宽度，您可以从所需的宽度中获得用于呈现文本的宽度。
private void drawTextUgly(String text, FontMetrics textMetrics, Graphics2D g2)
{
// Ugly code to wrap text
int lineHeight = textMetrics.getHeight();
String textToDraw = text;
String[] arr = textToDraw.split(" ");
int nIndex = 0;
int startX = 319;
int startY = 113;
while ( nIndex < arr.length )
{
String line = arr[nIndex++];
while ( ( nIndex < arr.length ) && (textMetrics.stringWidth(line + " " + arr[nIndex]) < 447) )
{
line = line + " " + arr[nIndex];
nIndex++;
}
GraphicsUtility.drawString(g2, line, startX, startY);
startY = startY + lineHeight;
}
}
这可能是您正在寻找的内容：
StringUtils.java：
import java.awt.FontMetrics;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
/**
* Globally available utility classes, mostly for string manipulation.
*
* @author Jim Menard, <a href="mailto:jimm@io.com">jimm@io.com</a>
*/
public class StringUtils {
/**
* Returns an array of strings, one for each line in the string after it has
* been wrapped to fit lines of <var>maxWidth</var>. Lines end with any of
* cr, lf, or cr lf. A line ending at the end of the string will not output a
* further, empty string.
* <p>
* This code assumes <var>str</var> is not <code>null</code>.
*
* @param str
* the string to split
* @param fm
* needed for string width calculations
* @param maxWidth
* the max line width, in points
* @return a non-empty list of strings
*/
public static List wrap(String str, FontMetrics fm, int maxWidth) {
List lines = splitIntoLines(str);
if (lines.size() == 0)
return lines;
ArrayList strings = new ArrayList();
for (Iterator iter = lines.iterator(); iter.hasNext();)
wrapLineInto((String) iter.next(), strings, fm, maxWidth);
return strings;
}
/**
* Given a line of text and font metrics information, wrap the line and add
* the new line(s) to <var>list</var>.
*
* @param line
* a line of text
* @param list
* an output list of strings
* @param fm
* font metrics
* @param maxWidth
* maximum width of the line(s)
*/
public static void wrapLineInto(String line, List list, FontMetrics fm, int maxWidth) {
int len = line.length();
int width;
while (len > 0 && (width = fm.stringWidth(line)) > maxWidth) {
// Guess where to split the line. Look for the next space before
// or after the guess.
int guess = len * maxWidth / width;
String before = line.substring(0, guess).trim();
width = fm.stringWidth(before);
int pos;
if (width > maxWidth) // Too long
pos = findBreakBefore(line, guess);
else { // Too short or possibly just right
pos = findBreakAfter(line, guess);
if (pos != -1) { // Make sure this doesn't make us too long
before = line.substring(0, pos).trim();
if (fm.stringWidth(before) > maxWidth)
pos = findBreakBefore(line, guess);
}
}
if (pos == -1)
pos = guess; // Split in the middle of the word
list.add(line.substring(0, pos).trim());
line = line.substring(pos).trim();
len = line.length();
}
if (len > 0)
list.add(line);
}
/**
* Returns the index of the first whitespace character or '-' in <var>line</var>
* that is at or before <var>start</var>. Returns -1 if no such character is
* found.
*
* @param line
* a string
* @param start
* where to star looking
*/
public static int findBreakBefore(String line, int start) {
for (int i = start; i >= 0; --i) {
char c = line.charAt(i);
if (Character.isWhitespace(c) || c == '-')
return i;
}
return -1;
}
/**
* Returns the index of the first whitespace character or '-' in <var>line</var>
* that is at or after <var>start</var>. Returns -1 if no such character is
* found.
*
* @param line
* a string
* @param start
* where to star looking
*/
public static int findBreakAfter(String line, int start) {
int len = line.length();
for (int i = start; i < len; ++i) {
char c = line.charAt(i);
if (Character.isWhitespace(c) || c == '-')
return i;
}
return -1;
}
/**
* Returns an array of strings, one for each line in the string. Lines end
* with any of cr, lf, or cr lf. A line ending at the end of the string will
* not output a further, empty string.
* <p>
* This code assumes <var>str</var> is not <code>null</code>.
*
* @param str
* the string to split
* @return a non-empty list of strings
*/
public static List splitIntoLines(String str) {
ArrayList strings = new ArrayList();
int len = str.length();
if (len == 0) {
strings.add("");
return strings;
}
int lineStart = 0;
for (int i = 0; i < len; ++i) {
char c = str.charAt(i);
if (c == '\r') {
int newlineLength = 1;
if ((i + 1) < len && str.charAt(i + 1) == '\n')
newlineLength = 2;
strings.add(str.substring(lineStart, i));
lineStart = i + newlineLength;
if (newlineLength == 2) // skip \n next time through loop
++i;
} else if (c == '\n') {
strings.add(str.substring(lineStart, i));
lineStart = i + 1;
}
}
if (lineStart < len)
strings.add(str.substring(lineStart));
return strings;
}
}
你可以把它放在它自己的类中，然后简单地使用你所拥有的：
FontMetrics fm= graphics.getFontMetrics(font);
Rectangle2D rect=fm.getStringBounds("Some Text",graphics);
调用 wrap(String str, FontMetrics fm, int maxWidth)将返回已根据您的相应包装List的s ，这将是文本的宽度将被放入：StringmaxWidthRectangle2D
String text="Some Text";
FontMetrics fm= graphics.getFontMetrics(font);
Rectangle2D rect=fm.getStringBounds(text,graphics);
List<String> textList=StringUtils.wrap(text, fm, int maxWidth);
参考：
See the LabelRenderTest source in this answer. It uses HTML/CSS, with the body width set using CSS, and thereby makes line wrap automatic.
使用临时 JTextArea 用大约 10 行代码进行完美的换行：
static void drawWrappedText(Graphics g, String text, int x, int y, int w, int h) {
JTextArea ta = new JTextArea(text);
ta.setLineWrap(true);
ta.setWrapStyleWord(true);
ta.setBounds(0, 0, w, h);
ta.setForeground(g.getColor());
ta.setFont(g.getFont());
Graphics g2 = g.create(x, y, w, h); // Use new graphics to leave original graphics state unchanged
ta.paint(g2);
}
private List<String> wrap(String txt, FontMetrics fm, int maxWidth){
StringTokenizer st = new StringTokenizer(txt) ;
List<String> list = new ArrayList<String>();
String line = "";
String lineBeforeAppend = "";
while (st.hasMoreTokens()){
String seg = st.nextToken();
lineBeforeAppend = line;
line += seg + " ";
int width = fm.stringWidth(line);
if(width < maxWidth){
continue;
}else { //new Line.
list.add(lineBeforeAppend);
line = seg + " ";
}
}
//the remaining part.
if(line.length() > 0){
list.add(line);
}
return list;
}