[hg]: improve reference validator

* make common validator independent from Repository instance;
* make name restrictions more precise;

plugins/hg4idea/src/org/zmlx/hg4idea/util/HgBranchReferenceValidator.java

@@ -20,22 +20,12 @@ import org.jetbrains.annotations.Nullable;
 import org.zmlx.hg4idea.repo.HgRepository;
 
 import java.util.Collection;
-import java.util.regex.Pattern;
 
 public class HgBranchReferenceValidator extends HgReferenceValidator {
-  private static final Pattern DIGITS_ILLEGAL = Pattern.compile("[0-9]*");  // reference names couldn't contain only digits
+  private final HgRepository myRepository;
 
   public HgBranchReferenceValidator(@NotNull HgRepository repository) {
-    super(repository);
-  }
-
-  @Override
-  public boolean checkInput(@Nullable String name) {
-    if (name != null && DIGITS_ILLEGAL.matcher(name).matches()) {
-      myErrorText = "Invalid name for branch/tag";
-      return false;
-    }
-    return super.checkInput(name);
+    myRepository = repository;
   }
 
   @Override

plugins/hg4idea/src/org/zmlx/hg4idea/util/HgPatchReferenceValidator.java

@@ -15,13 +15,21 @@
  */
 package org.zmlx.hg4idea.util;
 
+import com.intellij.openapi.util.text.StringUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.zmlx.hg4idea.repo.HgRepository;
 
 public class HgPatchReferenceValidator extends HgReferenceValidator {
+  private final HgRepository myRepository;
+
   public HgPatchReferenceValidator(@NotNull HgRepository repository) {
-    super(repository);
+    myRepository = repository;
+  }
+
+  @Override
+  public boolean checkInput(@Nullable String name) {
+    return !StringUtil.isEmptyOrSpaces(name) && !containsIllegalSymbols(name) && !hasConflictsWithAnotherNames(name);
   }
 
   @Override

plugins/hg4idea/src/org/zmlx/hg4idea/util/HgReferenceValidator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2015 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,31 +17,51 @@ package org.zmlx.hg4idea.util;
 
 import com.intellij.openapi.ui.InputValidatorEx;
 import com.intellij.openapi.util.text.StringUtil;
-import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.zmlx.hg4idea.repo.HgRepository;
+
+import java.util.regex.Pattern;
 
 import static org.zmlx.hg4idea.util.HgUtil.TIP_REFERENCE;
 
-public abstract class HgReferenceValidator implements InputValidatorEx {
-
-  protected final HgRepository myRepository;
+public class HgReferenceValidator implements InputValidatorEx {
   protected String myErrorText;
+  private static final HgReferenceValidator INSTANCE = new HgReferenceValidator();
 
-  protected HgReferenceValidator(@NotNull HgRepository repository) {
-    myRepository = repository;
+  private static final Pattern DIGITS_ILLEGAL = Pattern.compile("[0-9]*");  // reference names couldn't contain only digits
+  private static final Pattern ILLEGAL = Pattern.compile(
+    "[:]"                                // contains ':' character
+  );
+
+  public static HgReferenceValidator getInstance() {
+    return INSTANCE;
+  }
+
+  protected HgReferenceValidator() {
   }
 
   @Override
-  public boolean checkInput(@Nullable String name) {
-    if (StringUtil.isEmptyOrSpaces(name)) {
+  public boolean checkInput(String inputString) {
+    if (StringUtil.isEmptyOrSpaces(inputString)) {
       return false;
     }
-    if (name.contains(":")) {
+    if (containsIllegalSymbols(inputString)) return false;
+    return !isReservedWord(inputString) && !onlyDigits(inputString) && !hasConflictsWithAnotherNames(inputString);
+  }
+
+  protected boolean containsIllegalSymbols(@Nullable String inputString) {
+    if (inputString != null && ILLEGAL.matcher(inputString).find()) {
       myErrorText = "Name could not contain colons";
-      return false;
+      return true;
     }
-    return !isReservedWord(name) && !hasConflictsWithAnotherNames(name);
+    return false;
+  }
+
+  private boolean onlyDigits(@Nullable String inputString) {
+    if (inputString != null && DIGITS_ILLEGAL.matcher(inputString).matches()) {
+      myErrorText = "Invalid name for hg reference";
+      return true;
+    }
+    return false;
   }
 
   @Override
@@ -54,7 +74,9 @@ public abstract class HgReferenceValidator implements InputValidatorEx {
     return myErrorText != null;
   }
 
-  protected abstract boolean hasConflictsWithAnotherNames(@Nullable String name);
+  protected boolean hasConflictsWithAnotherNames(@Nullable String name) {
+    return false;
+  }
 
   @Nullable
   @Override