/*******************************************************************************
* Copyright 2014 Analog Devices, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
********************************************************************************/
package com.analog.lyric.options;
import java.io.Serializable;
import java.util.Collection;
import org.eclipse.jdt.annotation.Nullable;
import com.analog.lyric.collect.ReleasableIterator;
import com.analog.lyric.util.misc.Matlab;
/**
* Interface for object that can hold option values.
* <p>
* Concrete implementations will typically extend either {@link LocalOptionHolder} or
* {@link StatelessOptionHolder}.
*/
public interface IOptionHolder
{
/**
* Clears all local options.
* <p>
* Unsets all options set directly on this object. This does not affect option settings
* on other option holders in the {@linkplain #getOptionDelegates() delegate chain}.
*/
public void clearLocalOptions();
/**
* Read-only collection describing options that are set directly on this object.
* <p>
* This does not include options set on {@linkplain #getOptionDelegates() delegates}.
*
* @since 0.07
*/
public Collection<IOption<? extends Serializable>> getLocalOptions();
/**
* Iterates over option holders in order in of lookup precedence.
* <p>
* This should be the first object returned by the iterator.
* <p>
* The default implementation provided by {@link AbstractOptionHolder}
* returns a {@link OptionParentIterator} instance,
* which simply walks up the chain of option parents.
* <p>
* @since 0.07
*/
public ReleasableIterator<? extends IOptionHolder> getOptionDelegates();
/**
* The "parent" of this option holder to which option lookup will be delegated for option
* keys that are not set on this object. Used by {@link #getOption(IOptionKey)}.
* <p>
* Implementors should ensure that chain of parents is not circular!
* <p>
* @return the parent object or null if there is none.
*/
public @Nullable IOptionHolder getOptionParent();
/**
* Returns value of option with given key or else its default value.
* <p>
* The same as {@link #getOption} but returns the key's
* {@linkplain IOptionKey#defaultValue() defaultValue} instead of null
* if option is not set.
* <p>
* @param key is a non-null option key.
* @since 0.07
*/
public <T extends Serializable> T getOptionOrDefault(IOptionKey<T> key);
/**
* Returns value of option with given key if set, else null.
* <p>
* Returns the value of the first option setting found in this object or
* in its list of delegates. Specifically it invokes {@link #getLocalOption}
* on each object in {@link #getOptionDelegates()} and returns the first non-null result.
* <p>
* @param key is a non-null option key.
* @since 0.07
*/
@Matlab
@Nullable
public <T extends Serializable> T getOption(IOptionKey<T> key);
/**
* Returns value and source of option with given key if set, else null.
* <p>
* Declaration moved up from {@link AbstractOptionHolder} in release 0.08.
* <p>
* @param key is a non-null option key.
* @param source if non-null with length at least one, the first element will
* be set to the object whose {@linkplain #getLocalOption(IOptionKey) local option}
* setting produced the return value. Nothing will be written if this method returns null.
* @see #getOption
* @since 0.08
*/
@Nullable
public <T extends Serializable> T getOptionAndSource(IOptionKey<T> key, @Nullable IOptionHolder[] source);
/**
* Returns value of option with given key if set directly on this object, else null.
* <p>
* @param key is a non-null option key.
* @since 0.07
*/
@Nullable
public <T extends Serializable> T getLocalOption(IOptionKey<T> key);
/**
* Sets option locally with given key to specified value.
* <p>
* @param key is a non-null option key.
* @param value is a non-null value with type compatible with key's {@linkplain IOptionKey#type type}.
* @since 0.07
* @throws UnsupportedOperationException if implementation does not support local option storage.
* @throws IllegalArgumentException if implementation does not support local option storage for given key.
*/
@Matlab
public <T extends Serializable> void setOption(IOptionKey<T> key, T value);
/**
* Indicates whether object supports local storage of options.
* <p>
* If true, then option values may be set directly on this object using the {@link #setOption} method;
* otherwise that method will throw an exception.
* <p>
* @since 0.07
*/
public boolean supportsLocalOptions();
/**
* Unsets local option with given key.
* <p>
* Removes option setting on this object for given key if such a setting exists. This does not affect
* option settings on other objects.
* <p>
* @param key is a non-null option key.
* @since 0.07
*/
public void unsetOption(IOptionKey<?> key);
}