1. /*

  2.  * @(#)AccessibleComponent.java	1.12 00/02/02

  3.  *

  4.  * Copyright 1997-2000 Sun Microsystems, Inc. All Rights Reserved.

  5.  * 

  6.  * This software is the proprietary information of Sun Microsystems, Inc.  

  7.  * Use is subject to license terms.

  8.  * 

  9.  */

  10. 

  11. package javax.accessibility;

  12. 

  13. import java.awt.*;

  14. import java.awt.event.*;

  15. 

  16. /**

  17.  * The AccessibleComponent interface should be supported by any object 

  18.  * that is rendered on the screen.  This interface provides the standard 

  19.  * mechanism for an assistive technology to determine and set the 

  20.  * graphical representation of an object.  Applications can determine

  21.  * if an object supports the AccessibleComponent interface by first

  22.  * obtaining its AccessibleContext 

  23.  * and then calling the

  24.  * {@link AccessibleContext#getAccessibleComponent} method.

  25.  * If the return value is not null, the object supports this interface.

  26.  *

  27.  * @see Accessible

  28.  * @see Accessible#getAccessibleContext

  29.  * @see AccessibleContext

  30.  * @see AccessibleContext#getAccessibleComponent

  31.  *

  32.  * @version     1.7 10/05/99 14:00:28

  33.  * @author	Peter Korn

  34.  * @author	Hans Muller

  35.  * @author      Willie Walker

  36.  */

  37. public interface AccessibleComponent {

  38. 

  39.     /**

  40.      * Gets the background color of this object.

  41.      *

  42.      * @return the background color, if supported, of the object; 

  43.      * otherwise, null

  44.      * @see #setBackground

  45.      */

  46.     public Color getBackground();

  47. 

  48.     /**

  49.      * Sets the background color of this object.

  50.      *

  51.      * @param c the new Color for the background

  52.      * @see #setBackground

  53.      */

  54.     public void setBackground(Color c);

  55. 

  56.     /**

  57.      * Gets the foreground color of this object.

  58.      *

  59.      * @return the foreground color, if supported, of the object; 

  60.      * otherwise, null

  61.      * @see #setForeground

  62.      */

  63.     public Color getForeground();

  64. 

  65.     /**

  66.      * Sets the foreground color of this object.

  67.      *

  68.      * @param c the new Color for the foreground

  69.      * @see #getForeground

  70.      */

  71.     public void setForeground(Color c);

  72. 

  73.     /**

  74.      * Gets the Cursor of this object.

  75.      *

  76.      * @return the Cursor, if supported, of the object; otherwise, null

  77.      * @see #setCursor

  78.      */

  79.     public Cursor getCursor();

  80. 

  81.     /**

  82.      * Sets the Cursor of this object.

  83.      *

  84.      * @param c the new Cursor for the object

  85.      * @see #getCursor

  86.      */

  87.     public void setCursor(Cursor cursor);

  88. 

  89.     /**

  90.      * Gets the Font of this object.

  91.      *

  92.      * @return the Font,if supported, for the object; otherwise, null

  93.      * @see #setFont

  94.      */

  95.     public Font getFont();

  96. 

  97.     /**

  98.      * Sets the Font of this object.

  99.      *

  100.      * @param f the new Font for the object

  101.      * @see #getFont

  102.      */

  103.     public void setFont(Font f);

  104. 

  105.     /**

  106.      * Gets the FontMetrics of this object.

  107.      *

  108.      * @param f the Font

  109.      * @return the FontMetrics, if supported, the object; otherwise, null

  110.      * @see #getFont

  111.      */

  112.     public FontMetrics getFontMetrics(Font f);

  113. 

  114.     /**

  115.      * Determines if the object is enabled.  Objects that are enabled

  116.      * will also have the AccessibleState.ENABLED state set in their

  117.      * AccessibleStateSets.

  118.      *

  119.      * @return true if object is enabled; otherwise, false

  120.      * @see #setEnabled

  121.      * @see AccessibleContext#getAccessibleStateSet

  122.      * @see AccessibleState#ENABLED

  123.      * @see AccessibleStateSet

  124.      */

  125.     public boolean isEnabled();

  126. 

  127.     /**

  128.      * Sets the enabled state of the object.

  129.      *

  130.      * @param b if true, enables this object; otherwise, disables it 

  131.      * @see #isEnabled

  132.      */

  133.     public void setEnabled(boolean b);

  134. 

  135.     /**

  136.      * Determines if the object is visible.  Note: this means that the

  137.      * object intends to be visible; however, it may not be

  138.      * showing on the screen because one of the objects that this object

  139.      * is contained by is currently not visible.  To determine if an object is

  140.      * showing on the screen, use isShowing().

  141.      * <p>Objects that are visible will also have the 

  142.      * AccessibleState.VISIBLE state set in their AccessibleStateSets.

  143.      *

  144.      * @return true if object is visible; otherwise, false

  145.      * @see #setVisible

  146.      * @see AccessibleContext#getAccessibleStateSet

  147.      * @see AccessibleState#VISIBLE

  148.      * @see AccessibleStateSet

  149.      */

  150.     public boolean isVisible();

  151. 

  152.     /**

  153.      * Sets the visible state of the object.

  154.      *

  155.      * @param b if true, shows this object; otherwise, hides it 

  156.      * @see #isVisible

  157.      */

  158.     public void setVisible(boolean b);

  159. 

  160.     /**

  161.      * Determines if the object is showing.  This is determined by checking

  162.      * the visibility of the object and its ancestors.

  163.      * Note: this

  164.      * will return true even if the object is obscured by another (for example,

  165.      * it is underneath a menu that was pulled down).

  166.      *

  167.      * @return true if object is showing; otherwise, false

  168.      */

  169.     public boolean isShowing();

  170. 

  171.     /** 

  172.      * Checks whether the specified point is within this object's bounds,

  173.      * where the point's x and y coordinates are defined to be relative to the

  174.      * coordinate system of the object. 

  175.      *

  176.      * @param p the Point relative to the coordinate system of the object

  177.      * @return true if object contains Point; otherwise false

  178.      * @see #getBounds

  179.      */

  180.     public boolean contains(Point p);

  181. 

  182.     /** 

  183.      * Returns the location of the object on the screen.

  184.      *

  185.      * @return the location of the object on screen; null if this object

  186.      * is not on the screen

  187.      * @see #getBounds

  188.      * @see #getLocation

  189.      */

  190.     public Point getLocationOnScreen();

  191. 

  192.     /** 

  193.      * Gets the location of the object relative to the parent in the form 

  194.      * of a point specifying the object's top-left corner in the screen's 

  195.      * coordinate space.

  196.      *

  197.      * @return An instance of Point representing the top-left corner of the 

  198.      * object's bounds in the coordinate space of the screen; null if

  199.      * this object or its parent are not on the screen

  200.      * @see #getBounds

  201.      * @see #getLocationOnScreen

  202.      */

  203.     public Point getLocation();

  204. 

  205.     /** 

  206.      * Sets the location of the object relative to the parent.

  207.      * @param p the new position for the top-left corner

  208.      * @see #getLocation

  209.      */

  210.     public void setLocation(Point p);

  211. 

  212.     /** 

  213.      * Gets the bounds of this object in the form of a Rectangle object. 

  214.      * The bounds specify this object's width, height, and location

  215.      * relative to its parent. 

  216.      *

  217.      * @return A rectangle indicating this component's bounds; null if 

  218.      * this object is not on the screen.

  219.      * @see #contains

  220.      */

  221.     public Rectangle getBounds();

  222. 

  223.     /** 

  224.      * Sets the bounds of this object in the form of a Rectangle object. 

  225.      * The bounds specify this object's width, height, and location

  226.      * relative to its parent.

  227.      *	

  228.      * @param r rectangle indicating this component's bounds

  229.      * @see #getBounds

  230.      */

  231.     public void setBounds(Rectangle r);

  232. 

  233.     /** 

  234.      * Returns the size of this object in the form of a Dimension object. 

  235.      * The height field of the Dimension object contains this object's

  236.      * height, and the width field of the Dimension object contains this 

  237.      * object's width. 

  238.      *

  239.      * @return A Dimension object that indicates the size of this component; 

  240.      * null if this object is not on the screen

  241.      * @see #setSize

  242.      */

  243.     public Dimension getSize();

  244. 

  245.     /** 

  246.      * Resizes this object so that it has width and height. 

  247.      *	

  248.      * @param d The dimension specifying the new size of the object. 

  249.      * @see #getSize

  250.      */

  251.     public void setSize(Dimension d);

  252. 

  253.     /**

  254.      * Returns the Accessible child, if one exists, contained at the local 

  255.      * coordinate Point.

  256.      *

  257.      * @param p The point relative to the coordinate system of this object.

  258.      * @return the Accessible, if it exists, at the specified location; 

  259.      * otherwise null

  260.      */

  261.     public Accessible getAccessibleAt(Point p);

  262. 

  263.     /**

  264.      * Returns whether this object can accept focus or not.   Objects that 

  265.      * can accept focus will also have the AccessibleState.FOCUSABLE state 

  266.      * set in their AccessibleStateSets.

  267.      *

  268.      * @return true if object can accept focus; otherwise false

  269.      * @see AccessibleContext#getAccessibleStateSet

  270.      * @see AccessibleState#FOCUSABLE

  271.      * @see AccessibleState#FOCUSED

  272.      * @see AccessibleStateSet

  273.      */

  274.     public boolean isFocusTraversable();

  275. 

  276.     /**

  277.      * Requests focus for this object.  If this object cannot accept focus,

  278.      * nothing will happen.  Otherwise, the object will attempt to take

  279.      * focus.

  280.      * @see #isFocusTraversable

  281.      */

  282.     public void requestFocus();

  283. 

  284.     /**

  285.      * Adds the specified focus listener to receive focus events from this 

  286.      * component. 

  287.      *

  288.      * @param l the focus listener

  289.      * @see #removeFocusListener

  290.      */

  291.     public void addFocusListener(FocusListener l);

  292. 

  293.     /**

  294.      * Removes the specified focus listener so it no longer receives focus 

  295.      * events from this component.

  296.      *

  297.      * @param l the focus listener

  298.      * @see #addFocusListener

  299.      */

  300.     public void removeFocusListener(FocusListener l);

  301. }