http://www.eclipse.org/jdt: Java Development Tools Core (Eclipse Foundation) 
Copyright (c) 2000, 2019 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Harry Terkelsen (het@google.com) - Bug 449262 - Allow the use of third-party Java formatters

/*******************************************************************************
 * Copyright (c) 2000, 2019 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Harry Terkelsen (het@google.com) - Bug 449262 - Allow the use of third-party Java formatters
 *******************************************************************************/
package org.eclipse.jdt.core.formatter;

import org.eclipse.jdt.internal.compiler.util.Util;
import org.eclipse.jface.text.IRegion;
import org.eclipse.text.edits.TextEdit;

import java.util.Map;


Specification for a generic source code formatter.

Since:3.0
/**
 * Specification for a generic source code formatter.
 *
 * @since 3.0
 */
public abstract class CodeFormatter {

	
Unknown kind


Since 3.6, if the corresponding comment options are set to
true then it is also possible to format the comments on the fly by adding the F_INCLUDE_COMMENTS flag to this kind of format. 


/**
	 * Unknown kind
	 *<p>
	 * <b>Since 3.6</b>, if the corresponding comment options are set to
	 * <code>true</code> then it is also possible to format the comments on the fly
	 * by adding the {@link #F_INCLUDE_COMMENTS} flag to this kind of format.
	 * </p>
	 */
	public static final int K_UNKNOWN = 0x00;

	
Kind used to format an expression


This kind is not applicable to module descriptions.


Note that using this constant, the comments encountered while formatting
the expression may be shifted to match the correct indentation but are not
formatted.


Since 3.6, if the corresponding comment options are set to
true then it is also possible to format the comments on the fly by adding the F_INCLUDE_COMMENTS flag to this kind of format. 


/**
	 * Kind used to format an expression
	 * <p>
	 * This kind is not applicable to module descriptions.
	 * </p><p>
	 * Note that using this constant, the comments encountered while formatting
	 * the expression may be shifted to match the correct indentation but are not
	 * formatted.
	 * </p><p>
	 * <b>Since 3.6</b>, if the corresponding comment options are set to
	 * <code>true</code> then it is also possible to format the comments on the fly
	 * by adding the {@link #F_INCLUDE_COMMENTS} flag to this kind of format.
	 * </p>
	 */
	public static final int K_EXPRESSION = 0x01;

	
Kind used to format a set of statements


This kind is not applicable to module descriptions.


Note that using this constant, the comments encountered while formatting
the statements may be shifted to match the correct indentation but are not
formatted.


Since 3.6, if the corresponding comment options are set to
true then it is also possible to format the comments on the fly by adding the F_INCLUDE_COMMENTS flag to this kind of format. 


/**
	 * Kind used to format a set of statements
	 * <p>
	 * This kind is not applicable to module descriptions.
	 * </p><p>
	 * Note that using this constant, the comments encountered while formatting
	 * the statements may be shifted to match the correct indentation but are not
	 * formatted.
	 * </p><p>
	 * <b>Since 3.6</b>, if the corresponding comment options are set to
	 * <code>true</code> then it is also possible to format the comments on the fly
	 * by adding the {@link #F_INCLUDE_COMMENTS} flag to this kind of format.
	 * </p>
	 */
	public static final int K_STATEMENTS = 0x02;

	
Kind used to format a set of class body declarations


This kind is not applicable to module descriptions.


Note that using this constant, the comments encountered while formatting
the body declarations may be shifted to match the correct indentation but
are not formatted.


Since 3.6, if the corresponding comment options are set to
true then it is also possible to format the comments on the fly by adding the F_INCLUDE_COMMENTS flag to this kind of format. 


/**
	 * Kind used to format a set of class body declarations
	 * <p>
	 * This kind is not applicable to module descriptions.
	 * </p><p>
	 * Note that using this constant, the comments encountered while formatting
	 * the body declarations may be shifted to match the correct indentation but
	 * are not formatted.
	 * </p><p>
	 * <b>Since 3.6</b>, if the corresponding comment options are set to
	 * <code>true</code> then it is also possible to format the comments on the fly
	 * by adding the {@link #F_INCLUDE_COMMENTS} flag to this kind of format.
	 * </p>
	 */
	public static final int K_CLASS_BODY_DECLARATIONS = 0x04;

	
Kind used to format a compilation unit


Note: since 3.14, if the formatted compilation unit is a module description (i.e. it's named module-info.java), the K_MODULE_INFO kind must be used instead. 

Since 3.4, if the corresponding comment option is set to
true then it is also possible to format the comments on the fly by adding the F_INCLUDE_COMMENTS flag to this kind of format. 


/**
	 * Kind used to format a compilation unit
	 * <p>
	 * <u>Note:</u> <b>since 3.14</b>, if the formatted compilation unit is a
	 * module description (i.e. it's named module-info.java), the
	 * {@link #K_MODULE_INFO} kind must be used instead.
	 * </p><p>
	 * <b>Since 3.4</b>, if the corresponding comment option is set to
	 * <code>true</code> then it is also possible to format the comments on the fly
	 * by adding the {@link #F_INCLUDE_COMMENTS} flag to this kind of format.
	 * </p>
	 */
	public static final int K_COMPILATION_UNIT = 0x08;

	
Kind used to format a single-line comment

Since:3.1
/**
	 * Kind used to format a single-line comment
	 * @since 3.1
	 */
	public static final int K_SINGLE_LINE_COMMENT = 0x10;

	
Kind used to format a multi-line comment

Since:3.1
/**
	 * Kind used to format a multi-line comment
	 * @since 3.1
	 */
	public static final int K_MULTI_LINE_COMMENT = 0x20;

	
Kind used to format a Javadoc comment

Since:3.1
/**
	 * Kind used to format a Javadoc comment
	 *
	 * @since 3.1
	 */
	public static final int K_JAVA_DOC = 0x40;

	
Kind used to format a module description (a module-info.java file).


If the corresponding comment option is set to true then it is also possible to format the comments on the fly by adding the F_INCLUDE_COMMENTS flag to this kind of format. 


Since:3.14
/**
	 * Kind used to format a module description (a module-info.java file).
	 * <p>
	 * If the corresponding comment option is set to <code>true</code> then it is
	 * also possible to format the comments on the fly by adding the
	 * {@link #F_INCLUDE_COMMENTS} flag to this kind of format.
	 * </p>
	 * @since 3.14
	 */
	public static final int K_MODULE_INFO = 0x80;

	
Flag used to include the comments during the formatting of the code
snippet.


This flag can be combined with the following kinds:



 Note also that it has an effect only when one or several format comments options for javadoc , block or line are set to true while calling format(int, String, int, int, int, String) or format(int, String, IRegion[], int, String) methods 
 For example, with the Eclipse default formatter options, the formatting of the following code snippet using K_COMPILATION_UNIT: 
public class X {
/**
 * This is just a simple example to show that comments will be formatted while processing a compilation unit only if the constant flag F_INCLUDE_COMMENT flag is set.
 * @param str The input string
 */
 void foo(String str){}}


will produce the following output:

public class X {
	/**
 	 * This is just a simple example to show that comments will be formatted while processing a compilation unit only if the constant flag F_INCLUDE_COMMENT flag is set.
 	 *
 	 * @param str The input string
 	 */
 	void foo(String str){
 	}
 }

 Adding this flavor to the kind given while formatting the same source (e.g. K_COMPILATION_UNIT | F_INCLUDE_COMMENTS) will produce the following output instead: 
public class X {
	/**
 	 * This is just a simple example to show that comments will be formatted
 	 * while processing a compilation unit only if the constant flag
 	 * F_INCLUDE_COMMENT flag is set.
 	 *
 	 * @param str
 	 * 		The input string
 	 */
 	void foo(String str){
 	}
 }




Note: Although we're convinced that the formatter should always include the comments while processing a kind of compilation unit, we have decided to add a specific flag to fix this formatter incorrect behavior. This will prevent all existing clients (e.g. 3.3 and previous versions) using the K_COMPILATION_UNIT kind to be broken while formatting.



Since:3.4
/**
	 * Flag used to include the comments during the formatting of the code
	 * snippet.
	 * <p>
	 * This flag can be combined with the following kinds:
	 * <ul>
	 * 		<li>{@link #K_COMPILATION_UNIT}</li>
	 * 		<li>{@link #K_UNKNOWN}</li>
	 * 		<li>{@link #K_CLASS_BODY_DECLARATIONS} <i>(since 3.6)</i></li>
	 * 		<li>{@link #K_EXPRESSION} <i>(since 3.6)</i></li>
	 * 		<li>{@link #K_STATEMENTS} <i>(since 3.6)</i></li>
	 * 		<li>{@link #K_MODULE_INFO} <i>(since 3.14)</i></li>
	 * </ul>
	 * <p>
	 * Note also that it has an effect only when one or several format comments
	 * options for
	 * {@link DefaultCodeFormatterConstants#FORMATTER_COMMENT_FORMAT_JAVADOC_COMMENT javadoc}
	 * ,
	 * {@link DefaultCodeFormatterConstants#FORMATTER_COMMENT_FORMAT_BLOCK_COMMENT block}
	 * or
	 * {@link DefaultCodeFormatterConstants#FORMATTER_COMMENT_FORMAT_LINE_COMMENT line}
	 * are set to {@link DefaultCodeFormatterConstants#TRUE true} while calling
	 * {@link #format(int, String, int, int, int, String)} or
	 * {@link #format(int, String, IRegion[], int, String)} methods
	 * </p><p>
	 * For example, with the Eclipse default formatter options, the formatting
	 * of the following code snippet using {@link #K_COMPILATION_UNIT}:
	 * <pre>
	 * public class X {
	 * &#047;&#042;&#042;
	 *  &#042; This is just a simple example to show that comments will be formatted while processing a compilation unit only if the constant flag <code>F_INCLUDE_COMMENT</code> flag is set.
	 *  &#042; &#064;param str The input string
	 *  &#042;&#047;
	 *  void foo(String str){}}
	 * </pre>
	 * will produce the following output:
	 * <pre>
	 * public class X {
	 * 	&#047;&#042;&#042;
	 *  	 &#042; This is just a simple example to show that comments will be formatted while processing a compilation unit only if the constant flag <code>F_INCLUDE_COMMENT</code> flag is set.
	 *  	 &#042;
	 *  	 &#042; &#064;param str The input string
	 *  	 &#042;&#047;
	 *  	void foo(String str){
	 *  	}
	 *  }
	 * </pre>
	 * Adding this flavor to the kind given while formatting the same source
	 * (e.g. {@link #K_COMPILATION_UNIT} | {@link #F_INCLUDE_COMMENTS})
	 * will produce the following output instead:
	 * <pre>
	 * public class X {
	 * 	&#047;&#042;&#042;
	 *  	 &#042; This is just a simple example to show that comments will be formatted
	 *  	 &#042; while processing a compilation unit only if the constant flag
	 *  	 &#042; <code>F_INCLUDE_COMMENT</code> flag is set.
	 *  	 &#042;
	 *  	 &#042; &#064;param str
	 *  	 &#042; 		The input string
	 *  	 &#042;&#047;
	 *  	void foo(String str){
	 *  	}
	 *  }
	 * </pre>
	 * <p>
	 * <i><u>Note</u>: Although we're convinced that the formatter should
	 * always include the comments while processing a
	 * {@link #K_COMPILATION_UNIT kind of compilation unit}, we
	 * have decided to add a specific flag to fix this formatter incorrect behavior.
	 * This will prevent all existing clients (e.g. 3.3 and previous versions) using
	 * the {@link #K_COMPILATION_UNIT} kind to be broken while formatting.</i>
	 * </p>
	 * @since 3.4
	 */
	public static final int F_INCLUDE_COMMENTS = 0x1000;

	
Format source,
and returns a text edit that correspond to the difference between the given
string and the formatted string.


It returns null if the given string cannot be formatted.


If the offset position is matching a whitespace, the result can include
whitespaces. It would be up to the caller to get rid of preceding
whitespaces.



Params:
  • kind – Use to specify the kind of the code snippet to format. It can
be any of these:

Since 3.4 for K_COMPILATION_UNIT and since 3.6 for other kinds unrelated to comments, the F_INCLUDE_COMMENTS flag can be used to format comments on the fly (see the flag documentation for more detailed explanation).
  • source – the source to format
  • offset – the given offset to start recording the edits (inclusive).
  • length – the given length to stop recording the edits (exclusive).
  • indentationLevel – the initial indentation level, used
     to shift left/right the entire source fragment. An initial indentation
     level of zero or below has no effect.
  • lineSeparator – the line separator to use in formatted source,
    if set to null, then the platform default one will be used.
Throws:
Returns:the text edit
/**
	 * Format <code>source</code>,
	 * and returns a text edit that correspond to the difference between the given
	 * string and the formatted string.
	 * <p>
	 * It returns null if the given string cannot be formatted.
	 * </p><p>
	 * If the offset position is matching a whitespace, the result can include
	 * whitespaces. It would be up to the caller to get rid of preceding
	 * whitespaces.
	 * </p>
	 *
	 * @param kind Use to specify the kind of the code snippet to format. It can
	 * be any of these:
	 * <ul>
	 * 	<li>{@link #K_EXPRESSION}</li>
	 * 	<li>{@link #K_STATEMENTS}</li>
	 * 	<li>{@link #K_CLASS_BODY_DECLARATIONS}</li>
	 * 	<li>{@link #K_COMPILATION_UNIT}</li>
	 * 	<li>{@link #K_MODULE_INFO}</li>
	 * 	<li>{@link #K_UNKNOWN}</li>
	 * 	<li>{@link #K_SINGLE_LINE_COMMENT}</li>
	 * 	<li>{@link #K_MULTI_LINE_COMMENT}</li>
	 * 	<li>{@link #K_JAVA_DOC}</li>
	 * </ul>
	 * <b>Since 3.4</b> for {@link #K_COMPILATION_UNIT} and <b>since 3.6</b> for other
	 * kinds unrelated to comments, the {@link #F_INCLUDE_COMMENTS} flag can be
	 * used to format comments on the fly (see the flag documentation for more
	 * detailed explanation).
	 * @param source the source to format
	 * @param offset the given offset to start recording the edits (inclusive).
	 * @param length the given length to stop recording the edits (exclusive).
	 * @param indentationLevel the initial indentation level, used
	 *      to shift left/right the entire source fragment. An initial indentation
	 *      level of zero or below has no effect.
	 * @param lineSeparator the line separator to use in formatted source,
	 *     if set to <code>null</code>, then the platform default one will be used.
	 * @return the text edit
	 * @throws IllegalArgumentException if offset is lower than 0, length is lower than 0 or
	 * length is greater than source length.
	 */
	public abstract TextEdit format(int kind, String source, int offset, int length, int indentationLevel, String lineSeparator);

	
Format source,
and returns a text edit that correspond to the difference between the given string and the formatted string.

It returns null if the given string cannot be formatted.


If an offset position is matching a whitespace, the result can include whitespaces. It would be up to the
caller to get rid of preceding whitespaces.


No region in regions must overlap with any other region in regions.
Each region must be within source. There must be at least one region. Regions must be sorted
by their offsets, smaller offset first.


Params:
Throws:
  • IllegalArgumentException – if there is no region, a region overlaps with another region, or the regions are not
sorted in the ascending order.
Returns:the text edit
Since:3.4
/**
	 * Format <code>source</code>,
	 * and returns a text edit that correspond to the difference between the given string and the formatted string.
	 * <p>It returns null if the given string cannot be formatted.</p>
	 *
	 * <p>If an offset position is matching a whitespace, the result can include whitespaces. It would be up to the
	 * caller to get rid of preceding whitespaces.</p>
	 *
	 * <p>No region in <code>regions</code> must overlap with any other region in <code>regions</code>.
	 * Each region must be within source. There must be at least one region. Regions must be sorted
	 * by their offsets, smaller offset first.</p>
	 *
	 * @param kind Use to specify the kind of the code snippet to format. It can
	 * be any of these:
	 * <ul>
	 * 	<li>{@link #K_EXPRESSION}</li>
	 * 	<li>{@link #K_STATEMENTS}</li>
	 * 	<li>{@link #K_CLASS_BODY_DECLARATIONS}</li>
	 * 	<li>{@link #K_COMPILATION_UNIT}</li>
	 * 	<li>{@link #K_MODULE_INFO}</li>
	 * 	<li>{@link #K_UNKNOWN}</li>
	 * 	<li>{@link #K_SINGLE_LINE_COMMENT}</li>
	 * 	<li>{@link #K_MULTI_LINE_COMMENT}</li>
	 * 	<li>{@link #K_JAVA_DOC}</li>
	 * </ul>
	 * <b>Since 3.4</b> for {@link #K_COMPILATION_UNIT} and <b>since 3.6</b> for other
	 * kinds unrelated to comments, the {@link #F_INCLUDE_COMMENTS} flag can be
	 * used to format comments on the fly (see the flag documentation for more
	 * detailed explanation).
	 * @param source the source to format
	 * @param regions a set of regions in source to format
	 * @param indentationLevel the initial indentation level, used
	 *      to shift left/right the entire source fragment. An initial indentation
	 *      level of zero or below has no effect.
	 * @param lineSeparator the line separator to use in formatted source,
	 *     if set to <code>null</code>, then the platform default one will be used.
	 * @return the text edit
	 * @throws IllegalArgumentException if there is no region, a region overlaps with another region, or the regions are not
	 * sorted in the ascending order.
	 * @since 3.4
	 */
	public abstract TextEdit format(int kind, String source, IRegion[] regions, int indentationLevel, String lineSeparator);

	
Answers the string that corresponds to the indentation to the given indentation level or an empty string
if the indentation cannot be computed.

This method needs to be overridden in a subclass.


The default implementation returns an empty string.


Params:
  • indentationLevel – the given indentation level
Throws:
Returns:the string corresponding to the right indentation level
Since:3.2
/**
	 * Answers the string that corresponds to the indentation to the given indentation level or an empty string
	 * if the indentation cannot be computed.
	 * <p>This method needs to be overridden in a subclass.</p>
	 *
	 * <p>The default implementation returns an empty string.</p>
	 *
	 * @param indentationLevel the given indentation level
	 * @return the string corresponding to the right indentation level
	 * @exception IllegalArgumentException if the given indentation level is lower than zero
	 * @since 3.2
	 */
	public String createIndentationString(int indentationLevel) {
		return Util.EMPTY_STRING;
	}

	
Sets the formatting options for this formatter.

The default implementation ignores the options.

Params:
  • options – the options for the formatter
Since:3.11
/**
	 * Sets the formatting options for this formatter.
	 * <p>The default implementation ignores the options.
	 *
	 * @param options the options for the formatter
	 * @since 3.11
	 */
	public void setOptions(Map<String, String> options) {
		// Do nothing by default
	}
}