/* InputMap.java --
Copyright (C) 2002, 2004, 2006, 2012, Free Software Foundation, Inc.
This file is part of GNU Classpath.
GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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02110-1301 USA.
Linking this library statically or dynamically with other modules is
making a combined work based on this library. Thus, the terms and
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permission to link this library with independent modules to produce an
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package cc.kune.common.client.actions;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
// TODO: Auto-generated Javadoc
/**
* Maps {@link KeyStroke}s to arbitrary objects, usually Strings. This is used
* in combination with ActionMaps.
*
* If a component receives an input event, this is looked up in the component's
* <code>InputMap</code>. The result is an object which serves as a key to the
* component's <code>ActionMap</code>. Finally the <code>Action</code> that is
* stored is executed.
*
* @author Andrew Selkirk
* @author Michael Koch
* @author Adapted version for GWT (C) The kune development team
*
* @since 1.3
*/
public class InputMap {
/**
* Storage for the KeyStroke --> Object mappings.
*/
private Map<KeyStroke, AbstractAction> inputMap;
/**
* An optional parent map.
*/
private InputMap parent;
/**
* Creates a new <code>InputMap</code> instance. This default instance
* contains no mappings and has no parent.
*/
public InputMap() {
// nothing to do
}
/**
* Returns all keys of entries in this <code>InputMap</code> and all its
* parents.
*
* @return An array of keys (may be <code>null</code> or have zero length).
*/
public KeyStroke[] allKeys() {
final Set<KeyStroke> set = new HashSet<KeyStroke>();
if (parent != null) {
final KeyStroke[] parentKeys = parent.allKeys();
if (parentKeys != null) {
set.addAll(Arrays.asList(parentKeys));
}
}
if (inputMap != null) {
set.addAll(inputMap.keySet());
}
if (set.isEmpty()) {
return null;
}
final KeyStroke[] array = new KeyStroke[set.size()];
return set.toArray(array);
}
/**
* Clears the entries from this <code>InputMap</code>. The parent map, if
* there is one, is not cleared.
*/
public void clear() {
if (inputMap != null) {
inputMap.clear();
}
}
/**
* Returns the binding for the specified keystroke, if there is one.
*
* @param keystroke
* the key of the entry (<code>null</code> is ignored).
*
* @return The binding associated with the specified keystroke (or
* <code>null</code>).
*/
public AbstractAction get(final KeyStroke keystroke) {
AbstractAction result = null;
if (inputMap != null) {
result = inputMap.get(keystroke);
}
if (result == null && parent != null) {
result = parent.get(keystroke);
}
return result;
}
/**
* Returns the parent of this <code>InputMap</code>. The default value is
* <code>null</code>.
*
* @return The parent map (possibly <code>null</code>).
*
* @see #setParent(InputMap)
*/
public InputMap getParent() {
return parent;
}
/**
* Returns all keys of entries in this <code>InputMap</code>. This does not
* include keys defined in the parent, if there is one (use the
*
* @return An array of keys (may be <code>null</code> or have zero length).
* {@link #allKeys()} method for that case). <br>
* <br>
* Following the behaviour of the reference implementation, this method will
* return <code>null</code> when no entries have been added to the map, and a
* zero length array if entries have been added but subsequently removed (or
* cleared) from the map.
*/
// @PMD:REVIEWED:ReturnEmptyArrayRatherThanNull: by vjrj on 21/05/09 15:33
public KeyStroke[] keys() {
if (inputMap != null) {
final KeyStroke[] array = new KeyStroke[size()];
return inputMap.keySet().toArray(array);
}
return null;
}
/**
* Puts a new entry into the <code>InputMap</code>. If
* <code>actionMapKey</code> is <code>null</code> any existing entry will be
* removed.
*
* @param keystroke
* the keystroke for the entry (<code>null</code> is ignored).
* @param actionMapKey
* the action (<code>null</code> permitted).
*/
public void put(final KeyStroke keystroke, final AbstractAction actionMapKey) {
if (keystroke == null) {
return;
}
if (inputMap == null) {
inputMap = new HashMap<KeyStroke, AbstractAction>();
}
if (actionMapKey == null) {
inputMap.remove(keystroke);
} else {
inputMap.put(keystroke, actionMapKey);
}
}
/**
* Removes an entry from this <code>InputMap</code>. Note that this will not
* remove any entry from the parent map, if there is one.
*
* @param keystroke
* the key of the entry to remove (<code>null</code> is ignored).
*/
public void remove(final KeyStroke keystroke) {
if (inputMap != null) {
inputMap.remove(keystroke);
}
}
/**
* Sets a parent for this <code>InputMap</code>. If a parent is specified, the
*
* @param parentMap the new parent (<code>null</code> permitted).
* {@link #get(KeyStroke)} method will look in the parent if it cannot find an
* entry in this map.
* @see #getParent()
*/
public void setParent(final InputMap parentMap) {
parent = parentMap;
}
/**
* Returns the number of entries in this <code>InputMap</code>. This count
* does not include any entries from the parent map, if there is one.
*
* @return The number of entries.
*/
public int size() {
int result = 0;
if (inputMap != null) {
result = inputMap.size();
}
return result;
}
}