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package javax.annotation.processing;

import java.util.Map;
import java.util.Locale;
import javax.lang.model.SourceVersion;
import javax.lang.model.util.Elements;
import javax.lang.model.util.Types;


An annotation processing tool framework will provide an annotation processor with an object
implementing this interface so the processor can use facilities provided by the framework to write new files, report error messages, and find other utilities. 
Third parties may wish to provide value-add wrappers around the facility objects from this interface, for example a Filer extension that allows multiple processors to coordinate writing out a single source file. To enable this, for processors running in a context where their side effects via the API could be visible to each other, the tool infrastructure must provide corresponding facility objects that are .equals, Filers that are .equals, and so on. In addition, the tool invocation must be able to be configured such that from the perspective of the running annotation processors, at least the chosen subset of helper classes are viewed as being loaded by the same class loader. (Since the facility objects manage shared state, the implementation of a wrapper class must know whether or not the same base facility object has been wrapped before.) 
Author:Joseph D. Darcy, Scott Seligman, Peter von der Ahé
Since:1.6
/**
 * An annotation processing tool framework will {@linkplain
 * Processor#init provide an annotation processor with an object
 * implementing this interface} so the processor can use facilities
 * provided by the framework to write new files, report error
 * messages, and find other utilities.
 *
 * <p>Third parties may wish to provide value-add wrappers around the
 * facility objects from this interface, for example a {@code Filer}
 * extension that allows multiple processors to coordinate writing out
 * a single source file.  To enable this, for processors running in a
 * context where their side effects via the API could be visible to
 * each other, the tool infrastructure must provide corresponding
 * facility objects that are {@code .equals}, {@code Filer}s that are
 * {@code .equals}, and so on.  In addition, the tool invocation must
 * be able to be configured such that from the perspective of the
 * running annotation processors, at least the chosen subset of helper
 * classes are viewed as being loaded by the same class loader.
 * (Since the facility objects manage shared state, the implementation
 * of a wrapper class must know whether or not the same base facility
 * object has been wrapped before.)
 *
 * @author Joseph D. Darcy
 * @author Scott Seligman
 * @author Peter von der Ah&eacute;
 * @since 1.6
 */
public interface ProcessingEnvironment {
    
{@return the processor-specific options passed to the annotation processing tool} Options are returned in the form of a map from option name to option value. For an option with no value, the corresponding value in the map is null. 
See documentation of the particular tool infrastructure being used for details on how to pass in processor-specific options. For example, a command-line implementation may distinguish processor-specific options by prefixing them with a known string like "-A"; other tool implementations may follow different conventions or provide alternative mechanisms. A given implementation may also provide implementation-specific ways of finding options passed to the tool in addition to the processor-specific options. 
/**
     * {@return the processor-specific options passed to the annotation
     * processing tool}  Options are returned in the form of a map from
     * option name to option value.  For an option with no value, the
     * corresponding value in the map is {@code null}.
     *
     * <p>See documentation of the particular tool infrastructure
     * being used for details on how to pass in processor-specific
     * options.  For example, a command-line implementation may
     * distinguish processor-specific options by prefixing them with a
     * known string like {@code "-A"}; other tool implementations may
     * follow different conventions or provide alternative mechanisms.
     * A given implementation may also provide implementation-specific
     * ways of finding options passed to the tool in addition to the
     * processor-specific options.
     */
    Map<String,String> getOptions();

    
{@return the messager used to report errors, warnings, and other
notices}

/**
     * {@return the messager used to report errors, warnings, and other
     * notices}
     */
    Messager getMessager();

    
{@return the filer used to create new source, class, or auxiliary
files}

/**
     * {@return the filer used to create new source, class, or auxiliary
     * files}
     */
    Filer getFiler();

    
{@return an implementation of some utility methods for
operating on elements}

/**
     * {@return an implementation of some utility methods for
     * operating on elements}
     */
    Elements getElementUtils();

    
{@return an implementation of some utility methods for
operating on types}

/**
     * {@return an implementation of some utility methods for
     * operating on types}
     */
    Types getTypeUtils();

    
{@return} the source version that any generated source and class files should conform to} 
See Also:
/**
     * {@return the source version that any generated {@linkplain
     * Filer#createSourceFile source} and {@linkplain
     * Filer#createClassFile class} files should conform to}
     *
     * @see Processor#getSupportedSourceVersion
     */
    SourceVersion getSourceVersion();

    
{@return} the current locale or null if no locale is in effect} The locale can be be used to provide localized messages. 
/**
     * {@return the current locale or {@code null} if no locale is in
     * effect}  The locale can be be used to provide localized
     * {@linkplain Messager messages}.
     */
    Locale getLocale();

    
Returns true if preview features are enabled and false otherwise. 
Returns:whether or not preview features are enabled
Implementation Requirements:The default implementation of this method returns false.
Since:13
/**
     * Returns {@code true} if <em>preview features</em> are enabled
     * and {@code false} otherwise.
     * @return whether or not preview features are enabled
     *
     * @implSpec The default implementation of this method returns
     * {@code false}.
     *
     * @since 13
     */
    default boolean isPreviewEnabled() {
        return false;
    }
}