Added source for ByteEdit

src/org/fife/ui/rsyntaxtextarea/TokenUtils.java

@@ -0,0 +1,170 @@
+package org.fife.ui.rsyntaxtextarea;
+
+import javax.swing.text.TabExpander;
+
+
+/**
+ * Utility methods for dealing with tokens.
+ *
+ * @author Robert Futrell
+ * @version 1.0
+ */
+public final class TokenUtils {
+
+
+	private TokenUtils() {}
+
+
+	/**
+	 * Modifies the passed-in token list to start at the specified offset.
+	 * For example, if the token list covered positions 20-60 in the document
+	 * (inclusive) like so:
+	 * <pre>
+	 *   [token1] -&gt; [token2] -&gt; [token3] -&gt; [token4]
+	 *   20     30   31     40   41     50   51     60
+	 * </pre>
+	 * and you used this method to make the token list start at position 44,
+	 * then the token list would be modified to be the following:
+	 * <pre>
+	 *   [part-of-old-token3] -&gt; [token4]
+	 *   44                 50   51     60
+	 * </pre>
+	 * Tokens that come before the specified position are forever lost, and
+	 * the token containing that position is made to begin at that position if
+	 * necessary.  All token types remain the same as they were originally.<p>
+	 *
+	 * This method can be useful if you are only interested in part of a token
+	 * list (i.e., the line it represents), but you don't want to modify the
+	 * token list yourself.
+	 *
+	 * @param tokenList The list to make start at the specified position.
+	 *        This parameter is modified.
+	 * @param pos The position at which the new token list is to start.  If
+	 *        this position is not in the passed-in token list,
+	 *        returned token list will either be <code>null</code> or the
+	 *        unpaintable token(s) at the end of the passed-in token list.
+	 * @param e How to expand tabs.
+	 * @param textArea The text area from which the token list came.
+	 * @param x0 The initial x-pixel position of the old token list.
+	 * @return Information about the "sub" token list.  This will be
+	 *         <code>null</code> if <code>pos</code> was not a valid offset
+	 *         into the token list.
+	 * @see #getSubTokenList(Token, int, TabExpander, RSyntaxTextArea, float, TokenImpl)
+	 */
+	public static TokenSubList getSubTokenList(Token tokenList, int pos,
+									TabExpander e,
+									final RSyntaxTextArea textArea,
+									float x0) {
+		return getSubTokenList(tokenList, pos, e, textArea, x0, null);
+	}
+
+
+	/**
+	 * Modifies the passed-in token list to start at the specified offset.
+	 * For example, if the token list covered positions 20-60 in the document
+	 * (inclusive) like so:
+	 * <pre>
+	 *   [token1] -&gt; [token2] -&gt; [token3] -&gt; [token4]
+	 *   20     30   31     40   41     50   51     60
+	 * </pre>
+	 * and you used this method to make the token list start at position 44,
+	 * then the token list would be modified to be the following:
+	 * <pre>
+	 *   [part-of-old-token3] -&gt; [token4]
+	 *   44                 50   51     60
+	 * </pre>
+	 * Tokens that come before the specified position are forever lost, and
+	 * the token containing that position is made to begin at that position if
+	 * necessary.  All token types remain the same as they were originally.<p>
+	 *
+	 * This method can be useful if you are only interested in part of a token
+	 * list (i.e., the line it represents), but you don't want to modify the
+	 * token list yourself.
+	 *
+	 * @param tokenList The list to make start at the specified position.
+	 *        This parameter is modified.
+	 * @param pos The position at which the new token list is to start.  If
+	 *        this position is not in the passed-in token list,
+	 *        returned token list will either be <code>null</code> or the
+	 *        unpaintable token(s) at the end of the passed-in token list.
+	 * @param e How to expand tabs.
+	 * @param textArea The text area from which the token list came.
+	 * @param x0 The initial x-pixel position of the old token list.
+	 * @param tempToken A temporary token to use  when creating the token list
+	 *        result.  This may be <code>null</code> but callers can pass in
+	 *        a "buffer" token for performance if desired.
+	 * @return Information about the "sub" token list.  This will be
+	 *         <code>null</code> if <code>pos</code> was not a valid offset
+	 *         into the token list.
+	 * @see #getSubTokenList(Token, int, TabExpander, RSyntaxTextArea, float)
+	 */
+	public static TokenSubList getSubTokenList(Token tokenList, int pos,
+									TabExpander e,
+									final RSyntaxTextArea textArea,
+									float x0,
+									TokenImpl tempToken) {
+
+		if (tempToken==null) {
+			tempToken = new TokenImpl();
+		}
+		Token t = tokenList;
+
+		// Loop through the token list until you find the one that contains
+		// pos.  Remember the cumulative width of all of these tokens.
+		while (t!=null && t.isPaintable() && !t.containsPosition(pos)) {
+			x0 += t.getWidth(textArea, e, x0);
+			t = t.getNextToken();
+		}
+
+		// Make the token that contains pos start at pos.
+		if (t!=null && t.isPaintable()) {
+
+			if (t.getOffset()!=pos) {
+				// Number of chars between p0 and token start.
+				int difference = pos - t.getOffset();
+				x0 += t.getWidthUpTo(t.length()-difference+1, textArea, e, x0);
+				tempToken.copyFrom(t);
+				tempToken.makeStartAt(pos);
+
+				return new TokenSubList(tempToken, x0);
+
+			}
+			else { // t.getOffset()==pos
+				return new TokenSubList(t, x0);
+			}
+
+		}
+
+		// This could be a null token, so we need to just return it.
+		return new TokenSubList(tokenList, x0);
+		//return null;
+
+	}
+
+
+	/**
+	 * A sub-list of tokens.
+	 */
+	@SuppressWarnings({ "checkstyle:visibilitymodifier" })
+	public static class TokenSubList {
+
+		/**
+		 * The "sub" token list.
+		 */
+		public Token tokenList;
+
+		/**
+		 * The width, in pixels, of the part of the token list "removed from
+		 * the front."  This way, you know the x-offset of the "new" token list.
+		 */
+		public float x;
+
+		public TokenSubList(Token tokenList, float x) {
+			this.tokenList = tokenList;
+			this.x = x;
+		}
+
+	}
+
+
+}