jakarta.faces.model.ScalarDataModel Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package jakarta.faces.model;
/**
*
* ScalarDataModel is a convenience implementation of {@link DataModel} that wraps an individual Java
* object.
*
*/
public class ScalarDataModel extends DataModel {
// ------------------------------------------------------------ Constructors
/**
*
* Construct a new {@link ScalarDataModel} with no specified wrapped data.
*
*/
public ScalarDataModel() {
this(null);
}
/**
*
* Construct a new {@link ScalarDataModel} wrapping the specified scalar object.
*
*
* @param scalar Scalar to be wrapped (if any)
*/
public ScalarDataModel(E scalar) {
super();
setWrappedData(scalar);
}
// ------------------------------------------------------ Instance Variables
// The currently selected row index (zero-relative)
private int index;
// The scalar we are wrapping
private E scalar;
// -------------------------------------------------------------- Properties
/**
*
* Return true if there is wrappedData available, and the current value of
* rowIndex is zero. Otherwise, return false.
*
*
* @throws jakarta.faces.FacesException if an error occurs getting the row availability
*/
@Override
public boolean isRowAvailable() {
if (scalar == null) {
return false;
} else if (index == 0) {
return true;
} else {
return false;
}
}
/**
*
* If there is wrappedData available, return 1. If no wrappedData is available, return -1.
*
*
* @throws jakarta.faces.FacesException if an error occurs getting the row count
*/
@Override
public int getRowCount() {
if (scalar == null) {
return -1;
}
return 1;
}
/**
*
* If wrapped data is available, return the wrapped data instance. Otherwise, return null.
*
*
* @throws jakarta.faces.FacesException if an error occurs getting the row data
* @throws IllegalArgumentException if now row data is available at the currently specified row index
*/
@Override
public E getRowData() {
if (scalar == null) {
return null;
} else if (!isRowAvailable()) {
throw new NoRowAvailableException();
} else {
// noinspection unchecked
return scalar;
}
}
/**
* @throws jakarta.faces.FacesException {@inheritDoc}
*/
@Override
public int getRowIndex() {
return index;
}
/**
* @throws jakarta.faces.FacesException {@inheritDoc}
* @throws IllegalArgumentException {@inheritDoc}
*/
@Override
public void setRowIndex(int rowIndex) {
if (rowIndex < -1) {
throw new IllegalArgumentException();
}
int old = index;
index = rowIndex;
if (scalar == null) {
return;
}
DataModelListener[] listeners = getDataModelListeners();
if (old != index && listeners != null) {
Object rowData = null;
if (isRowAvailable()) {
rowData = getRowData();
}
DataModelEvent event = new DataModelEvent(this, index, rowData);
int n = listeners.length;
for (int i = 0; i < n; i++) {
if (null != listeners[i]) {
listeners[i].rowSelected(event);
}
}
}
}
@Override
public Object getWrappedData() {
return this.scalar;
}
/**
* @throws ClassCastException {@inheritDoc}
*/
@Override
public void setWrappedData(Object data) {
if (data == null) {
scalar = null;
setRowIndex(-1);
} else {
scalar = (E) data;
index = -1;
setRowIndex(0);
}
}
}