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1   ///////////////////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3   // Copyright (C) 2001-2024 the original author or authors.
4   //
5   // This library is free software; you can redistribute it and/or
6   // modify it under the terms of the GNU Lesser General Public
7   // License as published by the Free Software Foundation; either
8   // version 2.1 of the License, or (at your option) any later version.
9   //
10  // This library is distributed in the hope that it will be useful,
11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  // Lesser General Public License for more details.
14  //
15  // You should have received a copy of the GNU Lesser General Public
16  // License along with this library; if not, write to the Free Software
17  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  ///////////////////////////////////////////////////////////////////////////////////////////////
19  
20  package com.puppycrawl.tools.checkstyle.checks.indentation;
21  
22  import com.puppycrawl.tools.checkstyle.api.DetailAST;
23  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
24  import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
25  
26  /**
27   * Handler for method calls.
28   *
29   */
30  public class MethodCallHandler extends AbstractExpressionHandler {
31  
32      /**
33       * The instance of {@code IndentationCheck} used by this class.
34       */
35      private final IndentationCheck indentCheck;
36  
37      /**
38       * Construct an instance of this handler with the given indentation check,
39       * abstract syntax tree, and parent handler.
40       *
41       * @param indentCheck   the indentation check
42       * @param ast           the abstract syntax tree
43       * @param parent        the parent handler
44       */
45      public MethodCallHandler(IndentationCheck indentCheck,
46          DetailAST ast, AbstractExpressionHandler parent) {
47          super(indentCheck, "method call", ast, parent);
48          this.indentCheck = indentCheck;
49      }
50  
51      @Override
52      protected IndentLevel getIndentImpl() {
53          final IndentLevel indentLevel;
54          // if inside a method call's params, this could be part of
55          // an expression, so get the previous line's start
56          if (getParent() instanceof MethodCallHandler) {
57              final MethodCallHandler container =
58                      (MethodCallHandler) getParent();
59              if (TokenUtil.areOnSameLine(container.getMainAst(), getMainAst())
60                      || isChainedMethodCallWrapped()
61                      || areMethodsChained(container.getMainAst(), getMainAst())) {
62                  indentLevel = container.getIndent();
63              }
64              // we should increase indentation only if this is the first
65              // chained method call which was moved to the next line
66              else {
67                  indentLevel = new IndentLevel(container.getIndent(),
68                      getIndentCheck().getLineWrappingIndentation());
69              }
70          }
71          else if (getMainAst().getFirstChild().getType() == TokenTypes.LITERAL_NEW) {
72              indentLevel = super.getIndentImpl();
73          }
74          else {
75              // if our expression isn't first on the line, just use the start
76              // of the line
77              final DetailAstSet astSet = new DetailAstSet(indentCheck);
78              findSubtreeAst(astSet, getMainAst().getFirstChild(), true);
79              final int firstCol = expandedTabsColumnNo(astSet.firstLine());
80              final int lineStart = getLineStart(getFirstAst(getMainAst()));
81              if (lineStart == firstCol) {
82                  indentLevel = super.getIndentImpl();
83              }
84              else {
85                  indentLevel = new IndentLevel(lineStart);
86              }
87          }
88          return indentLevel;
89      }
90  
91      /**
92       * Checks if ast2 is a chained method call that starts on the same level as ast1 ends.
93       * In other words, if the right paren of ast1 is on the same level as the lparen of ast2:
94       * {@code
95       *     value.methodOne(
96       *         argument1
97       *     ).methodTwo(
98       *         argument2
99       *     );
100      * }
101      *
102      * @param ast1 Ast1
103      * @param ast2 Ast2
104      * @return True if ast2 begins on the same level that ast1 ends
105      */
106     private static boolean areMethodsChained(DetailAST ast1, DetailAST ast2) {
107         final DetailAST rparen = ast1.findFirstToken(TokenTypes.RPAREN);
108         return TokenUtil.areOnSameLine(rparen, ast2);
109     }
110 
111     /**
112      * If this is the first chained method call which was moved to the next line.
113      *
114      * @return true if chained class are wrapped
115      */
116     private boolean isChainedMethodCallWrapped() {
117         boolean result = false;
118         final DetailAST main = getMainAst();
119         final DetailAST dot = main.getFirstChild();
120         final DetailAST target = dot.getFirstChild();
121 
122         final DetailAST dot1 = target.getFirstChild();
123         final DetailAST target1 = dot1.getFirstChild();
124 
125         if (dot1.getType() == TokenTypes.DOT
126             && target1.getType() == TokenTypes.METHOD_CALL) {
127             result = true;
128         }
129         return result;
130     }
131 
132     /**
133      * Get the first AST of the specified method call.
134      *
135      * @param ast
136      *            the method call
137      *
138      * @return the first AST of the specified method call
139      */
140     private static DetailAST getFirstAst(DetailAST ast) {
141         // walk down the first child part of the dots that make up a method
142         // call name
143 
144         DetailAST astNode = ast.getFirstChild();
145         while (astNode.getType() == TokenTypes.DOT) {
146             astNode = astNode.getFirstChild();
147         }
148         return astNode;
149     }
150 
151     /**
152      * Returns method or constructor name. For {@code foo(arg)} it is `foo`, for
153      *     {@code foo.bar(arg)} it is `bar` for {@code super(arg)} it is 'super'.
154      *
155      * @return TokenTypes.IDENT node for a method call, TokenTypes.SUPER_CTOR_CALL otherwise.
156      */
157     private DetailAST getMethodIdentAst() {
158         DetailAST ast = getMainAst();
159         if (ast.getType() != TokenTypes.SUPER_CTOR_CALL) {
160             ast = ast.getFirstChild();
161             if (ast.getType() == TokenTypes.DOT) {
162                 ast = ast.getLastChild();
163             }
164         }
165         return ast;
166     }
167 
168     @Override
169     public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
170         // for whatever reason a method that crosses lines, like asList
171         // here:
172         //            System.out.println("methods are: " + Arrays.asList(
173         //                new String[] {"method"}).toString());
174         // will not have the right line num, so just get the child name
175 
176         final DetailAST ident = getMethodIdentAst();
177         final DetailAST rparen = getMainAst().findFirstToken(TokenTypes.RPAREN);
178         IndentLevel suggestedLevel = new IndentLevel(getLineStart(ident));
179         if (!TokenUtil.areOnSameLine(child.getMainAst().getFirstChild(), ident)) {
180             suggestedLevel = new IndentLevel(suggestedLevel,
181                     getBasicOffset(),
182                     getIndentCheck().getLineWrappingIndentation());
183         }
184 
185         // If the right parenthesis is at the start of a line;
186         // include line wrapping in suggested indent level.
187         if (getLineStart(rparen) == rparen.getColumnNo()) {
188             suggestedLevel = IndentLevel.addAcceptable(suggestedLevel, new IndentLevel(
189                     getParent().getSuggestedChildIndent(this),
190                     getIndentCheck().getLineWrappingIndentation()
191             ));
192         }
193 
194         return suggestedLevel;
195     }
196 
197     @Override
198     public void checkIndentation() {
199         DetailAST lparen = null;
200         if (getMainAst().getType() == TokenTypes.METHOD_CALL) {
201             final DetailAST exprNode = getMainAst().getParent();
202             if (exprNode.getParent().getType() == TokenTypes.SLIST) {
203                 checkExpressionSubtree(getMainAst().getFirstChild(), getIndent(), false, false);
204                 lparen = getMainAst();
205             }
206         }
207         else {
208             // TokenTypes.CTOR_CALL|TokenTypes.SUPER_CTOR_CALL
209             lparen = getMainAst().getFirstChild();
210         }
211 
212         if (lparen != null) {
213             final DetailAST rparen = getMainAst().findFirstToken(TokenTypes.RPAREN);
214             checkLeftParen(lparen);
215 
216             if (!TokenUtil.areOnSameLine(rparen, lparen)) {
217                 checkExpressionSubtree(
218                     getMainAst().findFirstToken(TokenTypes.ELIST),
219                     new IndentLevel(getIndent(), getBasicOffset()),
220                     false, true);
221 
222                 checkRightParen(lparen, rparen);
223                 checkWrappingIndentation(getMainAst(), getCallLastNode(getMainAst()));
224             }
225         }
226     }
227 
228     @Override
229     protected boolean shouldIncreaseIndent() {
230         return false;
231     }
232 
233     /**
234      * Returns method or constructor call right paren.
235      *
236      * @param firstNode
237      *          call ast(TokenTypes.METHOD_CALL|TokenTypes.CTOR_CALL|TokenTypes.SUPER_CTOR_CALL)
238      * @return ast node containing right paren for specified method or constructor call. If
239      *     method calls are chained returns right paren for last call.
240      */
241     private static DetailAST getCallLastNode(DetailAST firstNode) {
242         return firstNode.getLastChild();
243     }
244 
245 }