nextapp.echo.app.SelectField Maven / Gradle / Ivy
/*
* This file is part of the Echo Web Application Framework (hereinafter "Echo").
* Copyright (C) 2002-2009 NextApp, Inc.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
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* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*/
package nextapp.echo.app;
import nextapp.echo.app.list.AbstractListComponent;
import nextapp.echo.app.list.DefaultListModel;
import nextapp.echo.app.list.ListModel;
/**
* SelectField component: a selection component which displays selection items in a drop-down field. Allows the
* selection of only one item at a time. Does not support child components.
*
* One item of the select field will always be displayed as being selected. If the model does not specify a selected item,
* the first item will be selected. Note that the getSelectedItem() and getSelectedIndex() methods
* of this object will reflect such selection, even when the model itself does not.
*/
public class SelectField extends AbstractListComponent {
/** Serial Version UID. */
private static final long serialVersionUID = 20070101L;
/**
* Creates a new, empty SelectField.
*/
public SelectField() {
this((ListModel) null);
}
/**
* Creates a new SelectField with the provided model.
*
* @param model the model for the SelectField
*/
public SelectField(ListModel model) {
super(model, null);
}
/**
* Creates a new SelectField that will initially contain the
* provided array of items.
*
* @param items the items the SelectField will initially
* contain
*/
public SelectField(Object[] items) {
this(new DefaultListModel(items));
}
/**
* Returns the index of the currently selected item. If the selection model does not specify a selection, a value of zero is
* returned indicating the default (first) item of the SelectField is selected. If the model itself has no items, a value of -1
* will be returned.
*
* @return the index of the currently selected item
*/
public int getSelectedIndex() {
int selectedIndex = getSelectionModel().getMinSelectedIndex();
if (selectedIndex == -1) {
// Return -1 only if model is empty, otherwise return default selected index of 0.
return getModel().size() > 0 ? 0 : -1;
} else {
return selectedIndex;
}
}
/**
* Returns the currently selected item. This is a convenience method that returns the item from the model whose index is
* selected. If the selection model is empty, the default (item) of the SelectField is returned. If the model itself has not
* item, null will be returned.
*
* @return the currently selected item
*/
public Object getSelectedItem() {
int selectedIndex = getSelectionModel().getMinSelectedIndex();
if (selectedIndex == -1) {
return getModel().size() > 0 ? getModel().get(0): null;
} else {
return getModel().get(selectedIndex);
}
}
/**
* Sets the selected index.
*
* @param index the new selected index
*/
public void setSelectedIndex(int index) {
if (index == -1) {
getSelectionModel().clearSelection();
} else {
getSelectionModel().setSelectedIndex(index, true);
}
}
/**
* Sets the selected item.
* This is a convenience method. It iterates the model and sets the
* selected index to that of the first item that is found to test equal
* (using Object.equals()) to the specified item.
*
* @param item the new selected item
*/
public void setSelectedItem(Object item) {
if (item != null) {
ListModel model = getModel();
int size = model.size();
for (int i = 0; i < size; i++) {
if (item.equals(model.get(i))) {
setSelectedIndex(i);
return;
}
}
}
setSelectedIndex(-1);
}
}