1/* 2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package javax.accessibility; 27 28import java.awt.Color; 29import java.awt.Cursor; 30import java.awt.Dimension; 31import java.awt.Font; 32import java.awt.FontMetrics; 33import java.awt.Point; 34import java.awt.Rectangle; 35import java.awt.event.FocusListener; 36 37/** 38 * The {@code AccessibleComponent} interface should be supported by any object 39 * that is rendered on the screen. This interface provides the standard 40 * mechanism for an assistive technology to determine and set the graphical 41 * representation of an object. Applications can determine if an object supports 42 * the {@code AccessibleComponent} interface by first obtaining its 43 * {@code AccessibleContext} and then calling the 44 * {@link AccessibleContext#getAccessibleComponent} method. If the return value 45 * is not {@code null}, the object supports this interface. 46 * 47 * @author Peter Korn 48 * @author Hans Muller 49 * @author Willie Walker 50 * @see Accessible 51 * @see Accessible#getAccessibleContext 52 * @see AccessibleContext 53 * @see AccessibleContext#getAccessibleComponent 54 */ 55public interface AccessibleComponent { 56 57 /** 58 * Gets the background color of this object. 59 * 60 * @return the background color, if supported, of the object; otherwise, 61 * {@code null} 62 * @see #setBackground 63 */ 64 public Color getBackground(); 65 66 /** 67 * Sets the background color of this object. 68 * 69 * @param c the new color for the background 70 * @see #setBackground 71 */ 72 public void setBackground(Color c); 73 74 /** 75 * Gets the foreground color of this object. 76 * 77 * @return the foreground color, if supported, of the object; otherwise, 78 * {@code null} 79 * @see #setForeground 80 */ 81 public Color getForeground(); 82 83 /** 84 * Sets the foreground color of this object. 85 * 86 * @param c the new color for the foreground 87 * @see #getForeground 88 */ 89 public void setForeground(Color c); 90 91 /** 92 * Gets the cursor of this object. 93 * 94 * @return the cursor, if supported, of the object; otherwise, {@code null} 95 * @see #setCursor 96 */ 97 public Cursor getCursor(); 98 99 /** 100 * Sets the cursor of this object. 101 * 102 * @param cursor the new cursor for the object 103 * @see #getCursor 104 */ 105 public void setCursor(Cursor cursor); 106 107 /** 108 * Gets the font of this object. 109 * 110 * @return the font, if supported, for the object; otherwise, {@code null} 111 * @see #setFont 112 */ 113 public Font getFont(); 114 115 /** 116 * Sets the font of this object. 117 * 118 * @param f the new font for the object 119 * @see #getFont 120 */ 121 public void setFont(Font f); 122 123 /** 124 * Gets the {@code FontMetrics} of this object. 125 * 126 * @param f the font for which font metrics is to be obtained 127 * @return the {@code FontMetrics}, if supported, the object; otherwise, 128 * {@code null} 129 * @see #getFont 130 */ 131 public FontMetrics getFontMetrics(Font f); 132 133 /** 134 * Determines if the object is enabled. Objects that are enabled will also 135 * have the {@code AccessibleState.ENABLED} state set in their 136 * {@code AccessibleStateSets}. 137 * 138 * @return {@code true} if object is enabled; otherwise, {@code false} 139 * @see #setEnabled 140 * @see AccessibleContext#getAccessibleStateSet 141 * @see AccessibleState#ENABLED 142 * @see AccessibleStateSet 143 */ 144 public boolean isEnabled(); 145 146 /** 147 * Sets the enabled state of the object. 148 * 149 * @param b if {@code true}, enables this object; otherwise, disables it 150 * @see #isEnabled 151 */ 152 public void setEnabled(boolean b); 153 154 /** 155 * Determines if the object is visible. Note: this means that the object 156 * intends to be visible; however, it may not be showing on the screen 157 * because one of the objects that this object is contained by is currently 158 * not visible. To determine if an object is showing on the screen, use 159 * {@link #isShowing()} 160 * <p> 161 * Objects that are visible will also have the 162 * {@code AccessibleState.VISIBLE} state set in their 163 * {@code AccessibleStateSets}. 164 * 165 * @return {@code true} if object is visible; otherwise, {@code false} 166 * @see #setVisible 167 * @see AccessibleContext#getAccessibleStateSet 168 * @see AccessibleState#VISIBLE 169 * @see AccessibleStateSet 170 */ 171 public boolean isVisible(); 172 173 /** 174 * Sets the visible state of the object. 175 * 176 * @param b if {@code true}, shows this object; otherwise, hides it 177 * @see #isVisible 178 */ 179 public void setVisible(boolean b); 180 181 /** 182 * Determines if the object is showing. This is determined by checking the 183 * visibility of the object and its ancestors. Note: this will return 184 * {@code true} even if the object is obscured by another (for example, it 185 * is underneath a menu that was pulled down). 186 * 187 * @return {@code true} if object is showing; otherwise, {@code false} 188 */ 189 public boolean isShowing(); 190 191 /** 192 * Checks whether the specified point is within this object's bounds, where 193 * the point's x and y coordinates are defined to be relative to the 194 * coordinate system of the object. 195 * 196 * @param p the point relative to the coordinate system of the object 197 * @return {@code true} if object contains point; otherwise {@code false} 198 * @see #getBounds 199 */ 200 public boolean contains(Point p); 201 202 /** 203 * Returns the location of the object on the screen. 204 * 205 * @return the location of the object on screen; {@code null} if this object 206 * is not on the screen 207 * @see #getBounds 208 * @see #getLocation 209 */ 210 public Point getLocationOnScreen(); 211 212 /** 213 * Gets the location of the object relative to the parent in the form of a 214 * point specifying the object's top-left corner in the screen's coordinate 215 * space. 216 * 217 * @return An instance of {@code Point} representing the top-left corner of 218 * the object's bounds in the coordinate space of the screen; 219 * {@code null} if this object or its parent are not on the screen 220 * @see #getBounds 221 * @see #getLocationOnScreen 222 */ 223 public Point getLocation(); 224 225 /** 226 * Sets the location of the object relative to the parent. 227 * 228 * @param p the new position for the top-left corner 229 * @see #getLocation 230 */ 231 public void setLocation(Point p); 232 233 /** 234 * Gets the bounds of this object in the form of a {@code Rectangle} object. 235 * The bounds specify this object's width, height, and location relative to 236 * its parent. 237 * 238 * @return A rectangle indicating this component's bounds; {@code null} if 239 * this object is not on the screen. 240 * @see #contains 241 */ 242 public Rectangle getBounds(); 243 244 /** 245 * Sets the bounds of this object in the form of a {@code Rectangle} object. 246 * The bounds specify this object's width, height, and location relative to 247 * its parent. 248 * 249 * @param r rectangle indicating this component's bounds 250 * @see #getBounds 251 */ 252 public void setBounds(Rectangle r); 253 254 /** 255 * Returns the size of this object in the form of a {@code Dimension} 256 * object. The {@code height} field of the {@code Dimension} object contains 257 * this object's height, and the {@code width} field of the 258 * {@code Dimension} object contains this object's width. 259 * 260 * @return A {@code Dimension} object that indicates the size of this 261 * component; {@code null} if this object is not on the screen 262 * @see #setSize 263 */ 264 public Dimension getSize(); 265 266 /** 267 * Resizes this object so that it has width and height. 268 * 269 * @param d The dimension specifying the new size of the object 270 * @see #getSize 271 */ 272 public void setSize(Dimension d); 273 274 /** 275 * Returns the {@code Accessible} child, if one exists, contained at the 276 * local coordinate {@code Point}. 277 * 278 * @param p The point relative to the coordinate system of this object 279 * @return the {@code Accessible}, if it exists, at the specified location; 280 * otherwise {@code null} 281 */ 282 public Accessible getAccessibleAt(Point p); 283 284 /** 285 * Returns whether this object can accept focus or not. Objects that can 286 * accept focus will also have the {@code AccessibleState.FOCUSABLE} state 287 * set in their {@code AccessibleStateSets}. 288 * 289 * @return {@code true} if object can accept focus; otherwise {@code false} 290 * @see AccessibleContext#getAccessibleStateSet 291 * @see AccessibleState#FOCUSABLE 292 * @see AccessibleState#FOCUSED 293 * @see AccessibleStateSet 294 */ 295 public boolean isFocusTraversable(); 296 297 /** 298 * Requests focus for this object. If this object cannot accept focus, 299 * nothing will happen. Otherwise, the object will attempt to take focus. 300 * 301 * @see #isFocusTraversable 302 */ 303 public void requestFocus(); 304 305 /** 306 * Adds the specified focus listener to receive focus events from this 307 * component. 308 * 309 * @param l the focus listener 310 * @see #removeFocusListener 311 */ 312 public void addFocusListener(FocusListener l); 313 314 /** 315 * Removes the specified focus listener so it no longer receives focus 316 * events from this component. 317 * 318 * @param l the focus listener 319 * @see #addFocusListener 320 */ 321 public void removeFocusListener(FocusListener l); 322} 323