IDEA-43962 Indentation error on deep nesting levels

Initial version.

Consists of code moved from AbstractJavaBlock class.

java/java-impl/src/com/intellij/psi/formatter/java/FormattingAstUtil.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2000-2010 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.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.psi.formatter.java;
+
+import com.intellij.lang.ASTNode;
+import com.intellij.psi.PsiBinaryExpression;
+import com.intellij.psi.TokenType;
+import com.intellij.psi.impl.source.SourceTreeToPsiMap;
+import com.intellij.psi.impl.source.tree.JavaElementType;
+import com.intellij.psi.tree.IElementType;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import static java.util.Arrays.asList;
+
+/**
+ * Contains various utility methods for <code>AST</code> processing during code formatting.
+ *
+ * @author Denis Zhdanov
+ * @since Apr 21, 2010 4:02:17 PM
+ */
+public class FormattingAstUtil {
+
+  /** Holds type of AST elements that are considered to be assignments. */
+  private static final Set<IElementType> ASSIGNMENT_ELEMENT_TYPES = new HashSet<IElementType>(asList(
+    JavaElementType.ASSIGNMENT_EXPRESSION, JavaElementType.LOCAL_VARIABLE, JavaElementType.FIELD
+  ));
+
+  private FormattingAstUtil() {
+  }
+
+  /**
+   * Tries to get previous non-white space <code>AST</code> node for the given one.
+   *
+   * @param node    base node which left non-white space sibling is to be found
+   * @return        left non-white space sibling of the given node if any; <code>null</code> otherwise
+   */
+  @Nullable
+  public static ASTNode getPrevElement(final ASTNode node) {
+    ASTNode result = node.getTreePrev();
+    while (result != null && result.getElementType() == TokenType.WHITE_SPACE) {
+      result = result.getTreePrev();
+    }
+    return result;
+  }
+
+  /**
+   * Allows to answer if given node wraps assignement operation.
+   *
+   * @param node    node to check
+   * @return        <code>true</code> if given node wraps assignement operation; <code>false</code> otherwise
+   */
+  public static boolean isAssignment(ASTNode node) {
+    return ASSIGNMENT_ELEMENT_TYPES.contains(node.getElementType());
+  }
+
+  /**
+   * Allows to check if given <code>AST</code> nodes refer to binary expressions and have the same priority.
+   *
+   * @param node1   node to check
+   * @param node2   node to check
+   * @return        <code>true</code> if given nodes are binary expressions and have the same priority;
+   *                <code>false</code> otherwise
+   */
+  public static boolean binaryExpressionHasTheSamePriority(ASTNode node1, ASTNode node2) {
+    if (node1 == null || node2 == null) {
+      return false;
+    }
+
+    if (node1.getElementType() != JavaElementType.BINARY_EXPRESSION || node2.getElementType() != JavaElementType.BINARY_EXPRESSION) {
+      return false;
+    }
+    PsiBinaryExpression expression1 = (PsiBinaryExpression)SourceTreeToPsiMap.treeElementToPsi(node1);
+    PsiBinaryExpression expression2 = (PsiBinaryExpression)SourceTreeToPsiMap.treeElementToPsi(node2);
+    return expression1.getOperationSign().getTokenType() == expression2.getOperationSign().getTokenType();
+  }
+}