org.havi.ui.HNavigationInputPreferred Maven / Gradle / Ivy
package org.havi.ui;
import org.havi.ui.event.HFocusEvent;
/*
* Copyright 2000-2003 by HAVi, Inc. Java is a trademark of Sun
* Microsystems, Inc. All rights reserved.
*/
/**
A component which implements {@link
org.havi.ui.HNavigationInputPreferred}
indicates that this component expects to receive {@link
org.havi.ui.event.HFocusEvent} events. The focus event
system in HAVi is designed to be compatible with standard AWT
focus mechanisms while supporting key event-based focus traversal
for HAVi UI components.
All interoperable implementations of the {@link
org.havi.ui.HNavigationInputPreferred}
interface must extend {@link org.havi.ui.HComponent HComponent}.
Components which implement {@link
org.havi.ui.HNavigationInputPreferred}
to handle {@link org.havi.ui.event.HFocusEvent} events
can optionally manage focus traversal based on keyboard input
events, in addition to the normal semantics of the {@link
org.havi.ui.event.HFocusEvent#FOCUS_GAINED} and
{@link org.havi.ui.event.HFocusEvent#FOCUS_LOST} event
types. The focus traversal mechanism specified by the HAVI UI
{@link org.havi.ui.HNavigable} interface is one such
system.
In the case where such an implementation requires specific keys to
manage focus traversal the {@link
org.havi.ui.HNavigationInputPreferred#getNavigationKeys}
method is provided to allow the HAVi platform
to query the set of keys for which a navigation target has been
set. When such a component has the input focus, platforms without
a physical means of generating the desired keystrokes shall
provide another means for navigation e.g. by offering an on-screen
"virtual" keyboard. Applications can query the system about
the support of specific keyCodes through the {@link
org.havi.ui.event.HKeyCapabilities#isSupported} method.
The keyCodes for navigation keystrokes generated on the {@link
org.havi.ui.HNavigationInputPreferred} will be passed to the {@link
org.havi.ui.HNavigationInputPreferred} as an {@link
org.havi.ui.event.HFocusEvent} transferId through the {@link
org.havi.ui.HNavigationInputPreferred#processHFocusEvent} method. No {@link
org.havi.ui.event.HKeyEvent} will be generated on the {@link
org.havi.ui.HNavigationInputPreferred} as a result of these keystrokes.
Note that the java.awt.Component method isFocusTraversable should
always return true for a java.awt.Component
implementing this interface. */
public interface HNavigationInputPreferred
{
/**
* Retrieve the set of key codes which this component maps to
* navigation targets.
*
* @return an array of key codes, or null if no
* navigation targets are set on this component.
*/
public int[] getNavigationKeys();
/**
* Process an {@link org.havi.ui.event.HFocusEvent
* HFocusEvent} sent to this {@link org.havi.ui.HNavigationInputPreferred
* HNavigationInputPreferred}.
*
* @param evt the {@link org.havi.ui.event.HFocusEvent
* HFocusEvent} to process.
*/
public void processHFocusEvent(org.havi.ui.event.HFocusEvent evt);
}