com.google.gwt.user.client.ui.Focusable.java Source code

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Here is the source code for com.google.gwt.user.client.ui.Focusable.java

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/*
 * Copyright 2008 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.google.gwt.user.client.ui;

/**
 * A widget that implements this interface can receive keyboard focus.
 */
public interface Focusable {

    /**
     * Gets the widget's position in the tab index.
     * 
     * @return the widget's tab index
     */
    int getTabIndex();

    /**
     * Sets the widget's 'access key'. This key is used (in conjunction with a
     * browser-specific modifier key) to automatically focus the widget.
     * 
     * @param key the widget's access key
     */
    void setAccessKey(char key);

    /**
     * Explicitly focus/unfocus this widget. Only one widget can have focus at a
     * time, and the widget that does will receive all keyboard events.
     * 
     * @param focused whether this widget should take focus or release it
     */
    void setFocus(boolean focused);

    /**
     * Sets the widget's position in the tab index. If more than one widget has
     * the same tab index, each such widget will receive focus in an arbitrary
     * order. Setting the tab index to <code>-1</code> will cause this widget to
     * be removed from the tab order.
     * 
     * @param index the widget's tab index
     */
    void setTabIndex(int index);
}