如何在java中渲染图像上的包装文本

问题描述 投票:6回答:4

使用Java,是否有任何内置的方式来渲染文本,使其仅限于graphics2D对象上的矩形?

我知道我可以使用Graphics2D.drawString,但它只绘制一行文字。

我也知道我可以用

FontMetrics fm= graphics.getFontMetrics(font);
Rectangle2D rect=fm.getStringBounds("Some Text",graphics);

在某些Font font对象上使用一些Graphics2D graphics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,迫使它适合某个矩形。

但我更不愿意写那些......

有没有现成的功能可以帮我吗?

java text graphics rendering awt
4个回答
6
投票

我写了一个可以提供帮助的小功能。 447是可用宽度,您可以从所需宽度获得以呈现文本。

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;
    }
}

4
投票

这可能是您正在寻找的:

string U替LS.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:[email protected]">[email protected]</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;
  }

}

你把它放在自己的课堂上,然后简单地用你所拥有的:

FontMetrics fm= graphics.getFontMetrics(font);
Rectangle2D rect=fm.getStringBounds("Some Text",graphics);

调用wrap(String str, FontMetrics fm, int maxWidth),它将返回ListString,这些maxWidth已经相应地包裹在你的Rectangle2D中,这将是文本将放入的String text="Some Text"; FontMetrics fm= graphics.getFontMetrics(font); Rectangle2D rect=fm.getStringBounds(text,graphics); List<String> textList=StringUtils.wrap(text, fm, int maxWidth); 的宽度:

http://www.java2s.com/Code/Java/2D-Graphics-GUI/WrapstringaccordingtoFontMetrics.htm

参考:

  • LabelRenderTest

4
投票

请参阅this answer中的 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; } 来源。它使用HTML / CSS,使用CSS设置主体宽度,从而自动换行。


1
投票
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