textutilities.java

用java 编写的源码开放的文本编辑器。有很多有用的特性

	 * Locates the end of the word at the specified position.
	 * @param line The text
	 * @param pos The position
	 * @param noWordSep Characters that are non-alphanumeric, but
	 * should be treated as word characters anyway
	 * @param joinNonWordChars Treat consecutive non-alphanumeric
	 * characters as one word
	 * @since jEdit 4.1pre2
	 */
	public static int findWordEnd(String line, int pos, String noWordSep,
					boolean joinNonWordChars)
	{
		if(pos != 0)
			pos--;

		char ch = line.charAt(pos);

		if(noWordSep == null)
			noWordSep = "";

		//{{{ the character under the cursor changes how we behave.
		int type;
		if(Character.isWhitespace(ch))
			type = WHITESPACE;
		else if(Character.isLetterOrDigit(ch)
			|| noWordSep.indexOf(ch) != -1)
			type = WORD_CHAR;
		else
			type = SYMBOL;
		//}}}

loop:		for(int i = pos; i < line.length(); i++)
		{
			ch = line.charAt(i);
			switch(type)
			{
			//{{{ Whitespace...
			case WHITESPACE:
				// only select other whitespace in this case
				if(Character.isWhitespace(ch))
					break;
				else
					return i; //}}}
			//{{{ Word character...
			case WORD_CHAR:
				if(Character.isLetterOrDigit(ch) ||
					noWordSep.indexOf(ch) != -1)
				{
					break;
				}
				else
					return i; //}}}
			//{{{ Symbol...
			case SYMBOL:
				if(!joinNonWordChars && i!=pos) return i;
				// if we see whitespace, set flag.
				if(Character.isWhitespace(ch))
				{
					return i;
				}
				else if(Character.isLetterOrDigit(ch) ||
					noWordSep.indexOf(ch) != -1)
					return i;
				else
				{
					break;
				} //}}}
			}
		}

		return line.length();
	} //}}}

	//{{{ regionMatches() method
	/**
	 * Checks if a subregion of a <code>Segment</code> is equal to a
	 * character array.
	 * @param ignoreCase True if case should be ignored, false otherwise
	 * @param text The segment
	 * @param offset The offset into the segment
	 * @param match The character array to match
	 * @since jEdit 2.7pre1
	 */
	public static boolean regionMatches(boolean ignoreCase, Segment text,
		int offset, char[] match)
	{
		int length = offset + match.length;
		if(length > text.offset + text.count)
			return false;
		char[] textArray = text.array;
		for(int i = offset, j = 0; i < length; i++, j++)
		{
			char c1 = textArray[i];
			char c2 = match[j];
			if(ignoreCase)
			{
				c1 = Character.toUpperCase(c1);
				c2 = Character.toUpperCase(c2);
			}
			if(c1 != c2)
				return false;
		}
		return true;
	} //}}}

	//{{{ spacesToTabs() method
	/**
	 * Converts consecutive spaces to tabs in the specified string.
	 * @param in The string
	 * @param tabSize The tab size
	 */
	public static String spacesToTabs(String in, int tabSize)
	{
		StringBuffer buf = new StringBuffer();
		int width = 0;
		int whitespace = 0;
		for(int i = 0; i < in.length(); i++)
		{
			switch(in.charAt(i))
			{
			case ' ':
				whitespace++;
				width++;
				break;
			case '\t':
				int tab = tabSize - (width % tabSize);
				width += tab;
				whitespace += tab;
				break;
			case '\n':
				if(whitespace != 0)
				{
					buf.append(MiscUtilities
						.createWhiteSpace(whitespace,tabSize));
				}
				whitespace = 0;
				width = 0;
				buf.append('\n');
				break;
			default:
				if(whitespace != 0)
				{
					buf.append(MiscUtilities
						.createWhiteSpace(whitespace,tabSize));
					whitespace = 0;
				}
				buf.append(in.charAt(i));
				width++;
				break;
			}
		}

		if(whitespace != 0)
		{
			buf.append(MiscUtilities.createWhiteSpace(whitespace,tabSize));
		}

                return buf.toString();
	} //}}}

	//{{{ tabsToSpaces() method
	/**
	 * Converts tabs to consecutive spaces in the specified string.
	 * @param in The string
	 * @param tabSize The tab size
	 */
	public static String tabsToSpaces(String in, int tabSize)
	{
		StringBuffer buf = new StringBuffer();
		int width = 0;
		for(int i = 0; i < in.length(); i++)
		{
			switch(in.charAt(i))
			{
			case '\t':
				int count = tabSize - (width % tabSize);
				width += count;
				while(--count >= 0)
					buf.append(' ');
				break;
			case '\n':
				width = 0;
				buf.append(in.charAt(i));
				break;
			default:
				width++;
				buf.append(in.charAt(i));
				break;
                        }
                }
                return buf.toString();
	} //}}}

	//{{{ format() method
	/**
	 * Formats the specified text by merging and breaking lines to the
	 * specified width.
	 * @param text The text
	 * @param maxLineLen The maximum line length
	 */
	public static String format(String text, int maxLineLength, int tabSize)
	{
		StringBuffer buf = new StringBuffer();

		int index = 0;

		for(;;)
		{
			int newIndex = text.indexOf("\n\n",index);
			if(newIndex == -1)
				break;

			formatParagraph(text.substring(index,newIndex),
				maxLineLength,tabSize,buf);
			buf.append("\n\n");
			index = newIndex + 2;
		}

		if(index != text.length())
		{
			formatParagraph(text.substring(index),
				maxLineLength,tabSize,buf);
		}

		return buf.toString();
	} //}}}

	//{{{ getStringCase() method
	public static final int MIXED = 0;
	public static final int LOWER_CASE = 1;
	public static final int UPPER_CASE = 2;
	public static final int TITLE_CASE = 3;

	/**
	 * Returns if the specified string is all upper case, all lower case,
	 * or title case (first letter upper case, rest lower case).
	 * @param str The string
	 * @since jEdit 4.0pre1
	 */
	public static int getStringCase(String str)
	{
		if(str.length() == 0)
			return MIXED;

		int state = -1;

		char ch = str.charAt(0);
		if(Character.isLetter(ch))
		{
			if(Character.isUpperCase(ch))
				state = UPPER_CASE;
			else
				state = LOWER_CASE;
		}

		for(int i = 1; i < str.length(); i++)
		{
			ch = str.charAt(i);
			if(!Character.isLetter(ch))
				continue;

			switch(state)
			{
			case UPPER_CASE:
				if(Character.isLowerCase(ch))
				{
					if(i == 1)
						state = TITLE_CASE;
					else
						return MIXED;
				}
				break;
			case LOWER_CASE:
			case TITLE_CASE:
				if(Character.isUpperCase(ch))
					return MIXED;
				break;
			}
		}

		return state;
	} //}}}

	//{{{ toTitleCase() method
	/**
	 * Converts the specified string to title case, by capitalizing the
	 * first letter.
	 * @param str The string
	 * @since jEdit 4.0pre1
	 */
	public static String toTitleCase(String str)
	{
		if(str.length() == 0)
			return str;
		else
		{
			return Character.toUpperCase(str.charAt(0))
				+ str.substring(1).toLowerCase();
		}
	} //}}}

	//{{{ Private members
	private static final int WHITESPACE = 0;
	private static final int WORD_CHAR = 1;
	private static final int SYMBOL = 2;

	//{{{ formatParagraph() method
	private static void formatParagraph(String text, int maxLineLength,
		int tabSize, StringBuffer buf)
	{
		// align everything to paragraph's leading indent
		int leadingWhitespaceCount = MiscUtilities.getLeadingWhiteSpace(text);
		String leadingWhitespace = text.substring(0,leadingWhitespaceCount);
		int leadingWhitespaceWidth = MiscUtilities.getLeadingWhiteSpaceWidth(text,tabSize);

		buf.append(leadingWhitespace);

		int lineLength = leadingWhitespaceWidth;
		StringTokenizer st = new StringTokenizer(text);
		while(st.hasMoreTokens())
		{
			String word = st.nextToken();
			if(lineLength == leadingWhitespaceWidth)
			{
				// do nothing
			}
			else if(lineLength + word.length() + 1 > maxLineLength)
			{
				buf.append('\n');
				buf.append(leadingWhitespace);
				lineLength = leadingWhitespaceWidth;
			}
			else
			{
				buf.append(' ');
				lineLength++;
			}
			buf.append(word);
			lineLength += word.length();
		}
	} //}}}

	//}}}
}