changed the error message so that the ^ is always pointing to the right

character

bundles/org.eclipse.ui/src/org/eclipse/ui/internal/SearchDecoration.java

@@ -14,17 +14,20 @@
 
 package org.eclipse.ui.internal;
 
+
 import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
 
 import org.eclipse.jface.fieldassist.ControlDecoration;
 import org.eclipse.jface.fieldassist.FieldDecorationRegistry;
+import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Image;
 
 /**
  * This class contains methods to validate and decorate search fields.
  */
 public class SearchDecoration {
+ private static GC gc;
 
  private SearchDecoration() {
  // avoid instantiation
@@ -41,6 +44,8 @@ private SearchDecoration() {
  * the validation.
  */
  public static boolean validateRegex(String regex, ControlDecoration targetDecoration) {
+ gc = new GC(targetDecoration.getControl());
+
  String errorMessage = getValidationError(regex);
  if (errorMessage.isEmpty()) {
  targetDecoration.hide();
@@ -68,14 +73,39 @@ private static String getValidationError(String regex) {
  return ""; //$NON-NLS-1$
  } catch (PatternSyntaxException e) {
  String message = e.getLocalizedMessage();
+ StringBuilder sBuilder = new StringBuilder();
 
- // Only preserve the first line of the original error message.
  int i = 0;
  while (i < message.length() && "\n\r".indexOf(message.charAt(i)) == -1) { //$NON-NLS-1$
  i++;
  }
+ int j = i + 2;
+ while (j < message.length() && "\n\r".indexOf(message.charAt(j)) == -1) { //$NON-NLS-1$
+ j++;
+ }
+
+ String firstLine = message.substring(0, i);
+
+ String indexString = firstLine.replaceAll("\\D+", ""); //$NON-NLS-1$ //$NON-NLS-2$
+ int errorIndex = Integer.parseInt(indexString);
+
+ sBuilder.append(firstLine);
+ sBuilder.append(System.lineSeparator());
+
+ String secondLine = message.substring(i + 2, j); // the +2 because of the \n\r
+ sBuilder.append(secondLine);
+ sBuilder.append(System.lineSeparator());
+
+ String subsString = secondLine.substring(0, errorIndex);
+ String string = ""; //$NON-NLS-1$
+
+ while (gc.stringExtent(string).x < gc.stringExtent(subsString).x) {
+ string += " "; //$NON-NLS-1$
+ }
+ sBuilder.append(string);
 
- return message.substring(0, i);
+ sBuilder.append("^"); //$NON-NLS-1$
+ return sBuilder.toString();
  }
  }