Java tutorial
/* * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing; import java.awt.event.*; import java.awt.*; import javax.swing.event.*; /** * State model for buttons. * <p> * This model is used for regular buttons, as well as check boxes * and radio buttons, which are special kinds of buttons. In practice, * a button's UI takes the responsibility of calling methods on its * model to manage the state, as detailed below: * <p> * In simple terms, pressing and releasing the mouse over a regular * button triggers the button and causes and <code>ActionEvent</code> * to be fired. The same behavior can be produced via a keyboard key * defined by the look and feel of the button (typically the SPACE BAR). * Pressing and releasing this key while the button has * focus will give the same results. For check boxes and radio buttons, the * mouse or keyboard equivalent sequence just described causes the button * to become selected. * <p> * In details, the state model for buttons works as follows * when used with the mouse: * <br> * Pressing the mouse on top of a button makes the model both * armed and pressed. As long as the mouse remains down, * the model remains pressed, even if the mouse moves * outside the button. On the contrary, the model is only * armed while the mouse remains pressed within the bounds of * the button (it can move in or out of the button, but the model * is only armed during the portion of time spent within the button). * A button is triggered, and an <code>ActionEvent</code> is fired, * when the mouse is released while the model is armed * - meaning when it is released over top of the button after the mouse * has previously been pressed on that button (and not already released). * Upon mouse release, the model becomes unarmed and unpressed. * <p> * In details, the state model for buttons works as follows * when used with the keyboard: * <br> * Pressing the look and feel defined keyboard key while the button * has focus makes the model both armed and pressed. As long as this key * remains down, the model remains in this state. Releasing the key sets * the model to unarmed and unpressed, triggers the button, and causes an * <code>ActionEvent</code> to be fired. * * @author Jeff Dinkins * @since 1.2 */ public interface ButtonModel extends ItemSelectable { /** * Indicates partial commitment towards triggering the * button. * * @return <code>true</code> if the button is armed, * and ready to be triggered * @see #setArmed */ boolean isArmed(); /** * Indicates if the button has been selected. Only needed for * certain types of buttons - such as radio buttons and check boxes. * * @return <code>true</code> if the button is selected */ boolean isSelected(); /** * Indicates if the button can be selected or triggered by * an input device, such as a mouse pointer. * * @return <code>true</code> if the button is enabled */ boolean isEnabled(); /** * Indicates if the button is pressed. * * @return <code>true</code> if the button is pressed */ boolean isPressed(); /** * Indicates that the mouse is over the button. * * @return <code>true</code> if the mouse is over the button */ boolean isRollover(); /** * Marks the button as armed or unarmed. * * @param b whether or not the button should be armed */ public void setArmed(boolean b); /** * Selects or deselects the button. * * @param b <code>true</code> selects the button, * <code>false</code> deselects the button */ public void setSelected(boolean b); /** * Enables or disables the button. * * @param b whether or not the button should be enabled * @see #isEnabled */ public void setEnabled(boolean b); /** * Sets the button to pressed or unpressed. * * @param b whether or not the button should be pressed * @see #isPressed */ public void setPressed(boolean b); /** * Sets or clears the button's rollover state * * @param b whether or not the button is in the rollover state * @see #isRollover */ public void setRollover(boolean b); /** * Sets the keyboard mnemonic (shortcut key or * accelerator key) for the button. * * @param key an int specifying the accelerator key */ public void setMnemonic(int key); /** * Gets the keyboard mnemonic for the button. * * @return an int specifying the accelerator key * @see #setMnemonic */ public int getMnemonic(); /** * Sets the action command string that gets sent as part of the * <code>ActionEvent</code> when the button is triggered. * * @param s the <code>String</code> that identifies the generated event * @see #getActionCommand * @see java.awt.event.ActionEvent#getActionCommand */ public void setActionCommand(String s); /** * Returns the action command string for the button. * * @return the <code>String</code> that identifies the generated event * @see #setActionCommand */ public String getActionCommand(); /** * Identifies the group the button belongs to -- * needed for radio buttons, which are mutually * exclusive within their group. * * @param group the <code>ButtonGroup</code> the button belongs to */ public void setGroup(ButtonGroup group); /** * Returns the group that the button belongs to. * Normally used with radio buttons, which are mutually * exclusive within their group. * * @implSpec The default implementation of this method returns {@code null}. * Subclasses should return the group set by setGroup(). * * @return the <code>ButtonGroup</code> that the button belongs to * @since 10 */ default ButtonGroup getGroup() { return null; } /** * Adds an <code>ActionListener</code> to the model. * * @param l the listener to add */ void addActionListener(ActionListener l); /** * Removes an <code>ActionListener</code> from the model. * * @param l the listener to remove */ void removeActionListener(ActionListener l); /** * Adds an <code>ItemListener</code> to the model. * * @param l the listener to add */ void addItemListener(ItemListener l); /** * Removes an <code>ItemListener</code> from the model. * * @param l the listener to remove */ void removeItemListener(ItemListener l); /** * Adds a <code>ChangeListener</code> to the model. * * @param l the listener to add */ void addChangeListener(ChangeListener l); /** * Removes a <code>ChangeListener</code> from the model. * * @param l the listener to remove */ void removeChangeListener(ChangeListener l); }