org.eclipse.wb.swing.FocusTraversalOnArray Maven / Gradle / Ivy
Show all versions of JEntigrator Show documentation
/*******************************************************************************
* Copyright (c) 2011 Google, Inc.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Google, Inc. - initial API and implementation
*******************************************************************************/
package org.eclipse.wb.swing;
import java.awt.Component;
import java.awt.Container;
import java.awt.FocusTraversalPolicy;
/**
* Cyclic focus traversal policy based on array of components.
*
* This class may be freely distributed as part of any application or plugin.
*
* @author scheglov_ke
*/
public class FocusTraversalOnArray extends FocusTraversalPolicy {
private final Component m_Components[];
////////////////////////////////////////////////////////////////////////////
//
// Constructor
//
////////////////////////////////////////////////////////////////////////////
public FocusTraversalOnArray(Component components[]) {
m_Components = components;
}
////////////////////////////////////////////////////////////////////////////
//
// Utilities
//
////////////////////////////////////////////////////////////////////////////
private int indexCycle(int index, int delta) {
int size = m_Components.length;
int next = (index + delta + size) % size;
return next;
}
private Component cycle(Component currentComponent, int delta) {
int index = -1;
loop : for (int i = 0; i < m_Components.length; i++) {
Component component = m_Components[i];
for (Component c = currentComponent; c != null; c = c.getParent()) {
if (component == c) {
index = i;
break loop;
}
}
}
// try to find enabled component in "delta" direction
int initialIndex = index;
while (true) {
int newIndex = indexCycle(index, delta);
if (newIndex == initialIndex) {
break;
}
index = newIndex;
//
Component component = m_Components[newIndex];
if (component.isEnabled() && component.isVisible() && component.isFocusable()) {
return component;
}
}
// not found
return currentComponent;
}
////////////////////////////////////////////////////////////////////////////
//
// FocusTraversalPolicy
//
////////////////////////////////////////////////////////////////////////////
public Component getComponentAfter(Container container, Component component) {
return cycle(component, 1);
}
public Component getComponentBefore(Container container, Component component) {
return cycle(component, -1);
}
public Component getFirstComponent(Container container) {
return m_Components[0];
}
public Component getLastComponent(Container container) {
return m_Components[m_Components.length - 1];
}
public Component getDefaultComponent(Container container) {
return getFirstComponent(container);
}
}