Source code

001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018///////////////////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.indentation;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
025
026/**
027 * Handler for method calls.
028 *
029 */
030public class MethodCallHandler extends AbstractExpressionHandler {
031
032    /**
033     * The instance of {@code IndentationCheck} used by this class.
034     */
035    private final IndentationCheck indentCheck;
036
037    /**
038     * Construct an instance of this handler with the given indentation check,
039     * abstract syntax tree, and parent handler.
040     *
041     * @param indentCheck   the indentation check
042     * @param ast           the abstract syntax tree
043     * @param parent        the parent handler
044     */
045    public MethodCallHandler(IndentationCheck indentCheck,
046        DetailAST ast, AbstractExpressionHandler parent) {
047        super(indentCheck, "method call", ast, parent);
048        this.indentCheck = indentCheck;
049    }
050
051    @Override
052    protected IndentLevel getIndentImpl() {
053        final IndentLevel indentLevel;
054        // if inside a method call's params, this could be part of
055        // an expression, so get the previous line's start
056        if (getParent() instanceof MethodCallHandler container) {
057            if (TokenUtil.areOnSameLine(container.getMainAst(), getMainAst())
058                    || isChainedMethodCallWrapped()
059                    || areMethodsChained(container.getMainAst(), getMainAst())) {
060                indentLevel = container.getIndent();
061            }
062            // we should increase indentation only if this is the first
063            // chained method call which was moved to the next line
064            else {
065                indentLevel = new IndentLevel(container.getIndent(),
066                    getIndentCheck().getLineWrappingIndentation());
067            }
068        }
069        else if (getMainAst().getFirstChild().getType() == TokenTypes.LITERAL_NEW) {
070            indentLevel = super.getIndentImpl();
071        }
072        else {
073            // if our expression isn't first on the line, just use the start
074            // of the line
075            final DetailAstSet astSet = new DetailAstSet(indentCheck);
076            findSubtreeAst(astSet, getMainAst().getFirstChild(), true);
077            final int firstCol = expandedTabsColumnNo(astSet.firstLine());
078            final int lineStart = getLineStart(getFirstAst(getMainAst()));
079            if (lineStart == firstCol) {
080                indentLevel = super.getIndentImpl();
081            }
082            else {
083                indentLevel = new IndentLevel(lineStart);
084            }
085        }
086        return indentLevel;
087    }
088
089    /**
090     * Checks if ast2 is a chained method call that starts on the same level as ast1 ends.
091     * In other words, if the right paren of ast1 is on the same level as the lparen of ast2:
092     * {@code
093     *     value.methodOne(
094     *         argument1
095     *     ).methodTwo(
096     *         argument2
097     *     );
098     * }
099     *
100     * @param ast1 Ast1
101     * @param ast2 Ast2
102     * @return True if ast2 begins on the same level that ast1 ends
103     */
104    private static boolean areMethodsChained(DetailAST ast1, DetailAST ast2) {
105        final DetailAST rparen = ast1.findFirstToken(TokenTypes.RPAREN);
106        return TokenUtil.areOnSameLine(rparen, ast2);
107    }
108
109    /**
110     * If this is the first chained method call which was moved to the next line.
111     *
112     * @return true if chained class are wrapped
113     */
114    private boolean isChainedMethodCallWrapped() {
115        final DetailAST main = getMainAst();
116        final DetailAST dot = main.getFirstChild();
117        final DetailAST target = dot.getFirstChild();
118
119        final DetailAST dot1 = target.getFirstChild();
120        DetailAST target1 = dot1;
121        while (target1.getFirstChild() != null
122                && target1.getType() != TokenTypes.METHOD_CALL) {
123            target1 = target1.getFirstChild();
124        }
125
126        return dot1.getType() == TokenTypes.DOT
127                && target1.getType() == TokenTypes.METHOD_CALL;
128    }
129
130    /**
131     * Get the first AST of the specified method call.
132     *
133     * @param ast
134     *            the method call
135     *
136     * @return the first AST of the specified method call
137     */
138    private static DetailAST getFirstAst(DetailAST ast) {
139        // walk down the first child part of the dots that make up a method
140        // call name
141
142        DetailAST astNode = ast.getFirstChild();
143        while (astNode.getType() == TokenTypes.DOT) {
144            astNode = astNode.getFirstChild();
145        }
146        return astNode;
147    }
148
149    /**
150     * Returns method or constructor name. For {@code foo(arg)} it is `foo`, for
151     *     {@code foo.bar(arg)} it is `bar` for {@code super(arg)} it is 'super'.
152     *
153     * @return TokenTypes.IDENT node for a method call, TokenTypes.SUPER_CTOR_CALL otherwise.
154     */
155    private DetailAST getMethodIdentAst() {
156        DetailAST ast = getMainAst();
157        if (ast.getType() != TokenTypes.SUPER_CTOR_CALL) {
158            ast = ast.getFirstChild();
159            if (ast.getType() == TokenTypes.DOT) {
160                ast = ast.getLastChild();
161            }
162        }
163        return ast;
164    }
165
166    @Override
167    public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
168        // for whatever reason a method that crosses lines, like asList
169        // here:
170        //            System.out.println("methods are: " + Arrays.asList(
171        //                new String[] {"method"}).toString());
172        // will not have the right line num, so just get the child name
173
174        final DetailAST ident = getMethodIdentAst();
175        final DetailAST rparen = getMainAst().findFirstToken(TokenTypes.RPAREN);
176        IndentLevel suggestedLevel = new IndentLevel(getLineStart(ident));
177        if (!TokenUtil.areOnSameLine(child.getMainAst().getFirstChild(), ident)
178                && !isInvocationTarget(child)) {
179            suggestedLevel = new IndentLevel(suggestedLevel,
180                    getBasicOffset(),
181                    getIndentCheck().getLineWrappingIndentation());
182        }
183
184        // If the right parenthesis is at the start of a line;
185        // include line wrapping in suggested indent level.
186        if (getLineStart(rparen) == rparen.getColumnNo()) {
187            suggestedLevel = IndentLevel.addAcceptable(suggestedLevel, new IndentLevel(
188                    getParent().getSuggestedChildIndent(this),
189                    getIndentCheck().getLineWrappingIndentation()
190            ));
191        }
192
193        return suggestedLevel;
194    }
195
196    /**
197     * Returns true if the given child handler represents the invocation target
198     * of this method call (the expression before the dot), rather than one of
199     * the call's arguments.
200     *
201     * @param child the child handler to classify
202     * @return true if the child is the invocation target, not an argument
203     */
204    private boolean isInvocationTarget(AbstractExpressionHandler child) {
205        boolean crossedElist = false;
206        DetailAST node = child.getMainAst().getParent();
207        while (node != null && node != getMainAst()) {
208            if (node.getType() == TokenTypes.ELIST) {
209                crossedElist = true;
210                break;
211            }
212            node = node.getParent();
213        }
214        return !crossedElist;
215    }
216
217    @Override
218    public void checkIndentation() {
219        DetailAST lparen = null;
220        if (getMainAst().getType() == TokenTypes.METHOD_CALL) {
221            final DetailAST exprNode = getMainAst().getParent();
222            if (exprNode.getParent().getType() == TokenTypes.SLIST) {
223                checkExpressionSubtree(getMainAst().getFirstChild(), getIndent(), false, false);
224                lparen = getMainAst();
225            }
226        }
227        else {
228            // TokenTypes.CTOR_CALL|TokenTypes.SUPER_CTOR_CALL
229            lparen = getMainAst().getFirstChild();
230        }
231
232        if (lparen != null) {
233            final DetailAST rparen = getMainAst().findFirstToken(TokenTypes.RPAREN);
234            checkLeftParen(lparen);
235
236            if (!TokenUtil.areOnSameLine(rparen, lparen)) {
237                checkExpressionSubtree(
238                    getMainAst().findFirstToken(TokenTypes.ELIST),
239                    new IndentLevel(getIndent(), getBasicOffset()),
240                    false, true);
241
242                checkRparenIndent(lparen, rparen);
243                checkWrappingIndentation(getMainAst(), getCallLastNode(getMainAst()));
244            }
245        }
246    }
247
248    /**
249     * Checks the indentation of the right parenthesis for method calls.
250     *
251     * @param lparen left parenthesis associated with rparen
252     * @param rparen parenthesis to check
253     */
254    private void checkRparenIndent(DetailAST lparen, DetailAST rparen) {
255        final int rparenLevel = expandedTabsColumnNo(rparen);
256        final int lparenLevel = expandedTabsColumnNo(lparen);
257
258        final IndentLevel standardIndent = getIndent();
259
260        // For chained method calls, also allow rparen at the line start position
261        IndentLevel enhancedIndent = standardIndent;
262        if (getParent() instanceof MethodCallHandler) {
263            final int lineStart = getLineStart(getFirstAst(getMainAst()));
264            if (lineStart != standardIndent.getFirstIndentLevel()) {
265                enhancedIndent = IndentLevel.addAcceptable(standardIndent,
266                        new IndentLevel(lineStart));
267            }
268        }
269
270        if (rparenLevel != lparenLevel + 1
271                && !enhancedIndent.isAcceptable(rparenLevel)
272                && isOnStartOfLine(rparen)) {
273            logError(rparen, "rparen", rparenLevel);
274        }
275    }
276
277    @Override
278    protected boolean shouldIncreaseIndent() {
279        return false;
280    }
281
282    /**
283     * Returns method or constructor call right paren.
284     *
285     * @param firstNode
286     *          call ast(TokenTypes.METHOD_CALL|TokenTypes.CTOR_CALL|TokenTypes.SUPER_CTOR_CALL)
287     * @return ast node containing right paren for specified method or constructor call. If
288     *     method calls are chained returns right paren for last call.
289     */
290    private static DetailAST getCallLastNode(DetailAST firstNode) {
291        return firstNode.getLastChild();
292    }
293
294}