Source code

001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 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;
024
025/**
026 * Handler for method calls.
027 *
028 */
029public class MethodCallHandler extends AbstractExpressionHandler {
030
031    /**
032     * Construct an instance of this handler with the given indentation check,
033     * abstract syntax tree, and parent handler.
034     *
035     * @param indentCheck   the indentation check
036     * @param ast           the abstract syntax tree
037     * @param parent        the parent handler
038     */
039    public MethodCallHandler(IndentationCheck indentCheck,
040        DetailAST ast, AbstractExpressionHandler parent) {
041        super(indentCheck, "method call", ast, parent);
042    }
043
044    @Override
045    protected IndentLevel getIndentImpl() {
046        final IndentLevel indentLevel;
047        // if inside a method call's params, this could be part of
048        // an expression, so get the previous line's start
049        if (getParent() instanceof MethodCallHandler) {
050            final MethodCallHandler container =
051                    (MethodCallHandler) getParent();
052            if (areOnSameLine(container.getMainAst(), getMainAst())
053                    || isChainedMethodCallWrapped()
054                    || areMethodsChained(container.getMainAst(), getMainAst())) {
055                indentLevel = container.getIndent();
056            }
057            // we should increase indentation only if this is the first
058            // chained method call which was moved to the next line
059            else {
060                indentLevel = new IndentLevel(container.getIndent(),
061                    getIndentCheck().getLineWrappingIndentation());
062            }
063        }
064        else if (getMainAst().getFirstChild().getType() == TokenTypes.LITERAL_NEW) {
065            indentLevel = super.getIndentImpl();
066        }
067        else {
068            // if our expression isn't first on the line, just use the start
069            // of the line
070            final LineSet lines = new LineSet();
071            findSubtreeLines(lines, getMainAst().getFirstChild(), true);
072            final int firstCol = lines.firstLineCol();
073            final int lineStart = getLineStart(getFirstAst(getMainAst()));
074            if (lineStart == firstCol) {
075                indentLevel = super.getIndentImpl();
076            }
077            else {
078                indentLevel = new IndentLevel(lineStart);
079            }
080        }
081        return indentLevel;
082    }
083
084    /**
085     * Checks if ast2 is a chained method call that starts on the same level as ast1 ends.
086     * In other words, if the right paren of ast1 is on the same level as the lparen of ast2:
087     *
088     * {@code
089     *     value.methodOne(
090     *         argument1
091     *     ).methodTwo(
092     *         argument2
093     *     );
094     * }
095     *
096     * @param ast1 Ast1
097     * @param ast2 Ast2
098     * @return True if ast2 begins on the same level that ast1 ends
099     */
100    private static boolean areMethodsChained(DetailAST ast1, DetailAST ast2) {
101        final DetailAST rparen = ast1.findFirstToken(TokenTypes.RPAREN);
102        return rparen.getLineNo() == ast2.getLineNo();
103    }
104
105    /**
106     * If this is the first chained method call which was moved to the next line.
107     * @return true if chained class are wrapped
108     */
109    private boolean isChainedMethodCallWrapped() {
110        boolean result = false;
111        final DetailAST main = getMainAst();
112        final DetailAST dot = main.getFirstChild();
113        final DetailAST target = dot.getFirstChild();
114
115        final DetailAST dot1 = target.getFirstChild();
116        final DetailAST target1 = dot1.getFirstChild();
117
118        if (dot1.getType() == TokenTypes.DOT
119            && target1.getType() == TokenTypes.METHOD_CALL) {
120            result = true;
121        }
122        return result;
123    }
124
125    /**
126     * Get the first AST of the specified method call.
127     *
128     * @param ast
129     *            the method call
130     *
131     * @return the first AST of the specified method call
132     */
133    private static DetailAST getFirstAst(DetailAST ast) {
134        // walk down the first child part of the dots that make up a method
135        // call name
136
137        DetailAST astNode = ast.getFirstChild();
138        while (astNode.getType() == TokenTypes.DOT) {
139            astNode = astNode.getFirstChild();
140        }
141        return astNode;
142    }
143
144    /**
145     * Returns method or constructor name. For {@code foo(arg)} it is `foo`, for
146     *     {@code foo.bar(arg)} it is `bar` for {@code super(arg)} it is 'super'.
147     *
148     * @return TokenTypes.IDENT node for a method call, TokenTypes.SUPER_CTOR_CALL otherwise.
149     */
150    private DetailAST getMethodIdentAst() {
151        DetailAST ast = getMainAst();
152        if (ast.getType() != TokenTypes.SUPER_CTOR_CALL) {
153            ast = ast.getFirstChild();
154            if (ast.getType() == TokenTypes.DOT) {
155                ast = ast.getLastChild();
156            }
157        }
158        return ast;
159    }
160
161    @Override
162    public IndentLevel getSuggestedChildIndent(AbstractExpressionHandler child) {
163        // for whatever reason a method that crosses lines, like asList
164        // here:
165        //            System.out.println("methods are: " + Arrays.asList(
166        //                new String[] {"method"}).toString());
167        // will not have the right line num, so just get the child name
168
169        final DetailAST ident = getMethodIdentAst();
170        final DetailAST rparen = getMainAst().findFirstToken(TokenTypes.RPAREN);
171        IndentLevel suggestedLevel = new IndentLevel(getLineStart(ident));
172        if (!areOnSameLine(child.getMainAst().getFirstChild(), ident)) {
173            suggestedLevel = new IndentLevel(suggestedLevel,
174                    getBasicOffset(),
175                    getIndentCheck().getLineWrappingIndentation());
176        }
177
178        // If the right parenthesis is at the start of a line;
179        // include line wrapping in suggested indent level.
180        if (getLineStart(rparen) == rparen.getColumnNo()) {
181            suggestedLevel = IndentLevel.addAcceptable(suggestedLevel, new IndentLevel(
182                    getParent().getSuggestedChildIndent(this),
183                    getIndentCheck().getLineWrappingIndentation()
184            ));
185        }
186
187        return suggestedLevel;
188    }
189
190    @Override
191    public void checkIndentation() {
192        DetailAST lparen = null;
193        if (getMainAst().getType() == TokenTypes.METHOD_CALL) {
194            final DetailAST exprNode = getMainAst().getParent();
195            if (exprNode.getParent().getType() == TokenTypes.SLIST) {
196                checkExpressionSubtree(getMainAst().getFirstChild(), getIndent(), false, false);
197                lparen = getMainAst();
198            }
199        }
200        else {
201            // TokenTypes.CTOR_CALL|TokenTypes.SUPER_CTOR_CALL
202            lparen = getMainAst().getFirstChild();
203        }
204
205        if (lparen != null) {
206            final DetailAST rparen = getMainAst().findFirstToken(TokenTypes.RPAREN);
207            checkLeftParen(lparen);
208
209            if (rparen.getLineNo() != lparen.getLineNo()) {
210                checkExpressionSubtree(
211                    getMainAst().findFirstToken(TokenTypes.ELIST),
212                    new IndentLevel(getIndent(), getBasicOffset()),
213                    false, true);
214
215                checkRightParen(lparen, rparen);
216                checkWrappingIndentation(getMainAst(), getCallLastNode(getMainAst()));
217            }
218        }
219    }
220
221    @Override
222    protected boolean shouldIncreaseIndent() {
223        return false;
224    }
225
226    /**
227     * Returns method or constructor call right paren.
228     * @param firstNode
229     *          call ast(TokenTypes.METHOD_CALL|TokenTypes.CTOR_CALL|TokenTypes.SUPER_CTOR_CALL)
230     * @return ast node containing right paren for specified method or constructor call. If
231     *     method calls are chained returns right paren for last call.
232     */
233    private static DetailAST getCallLastNode(DetailAST firstNode) {
234        return firstNode.getLastChild();
235    }
236
237}