1/* 2 * Copyright (c) 1997, 2013, 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.swing; 27 28import javax.swing.event.*; 29 30 31/** 32 * Defines the data model used by components like <code>Slider</code>s 33 * and <code>ProgressBar</code>s. 34 * Defines four interrelated integer properties: minimum, maximum, extent 35 * and value. These four integers define two nested ranges like this: 36 * <pre> 37 * minimum <= value <= value+extent <= maximum 38 * </pre> 39 * The outer range is <code>minimum,maximum</code> and the inner 40 * range is <code>value,value+extent</code>. The inner range 41 * must lie within the outer one, i.e. <code>value</code> must be 42 * less than or equal to <code>maximum</code> and <code>value+extent</code> 43 * must greater than or equal to <code>minimum</code>, and <code>maximum</code> 44 * must be greater than or equal to <code>minimum</code>. 45 * There are a few features of this model that one might find a little 46 * surprising. These quirks exist for the convenience of the 47 * Swing BoundedRangeModel clients, such as <code>Slider</code> and 48 * <code>ScrollBar</code>. 49 * <ul> 50 * <li> 51 * The minimum and maximum set methods "correct" the other 52 * three properties to accommodate their new value argument. For 53 * example setting the model's minimum may change its maximum, value, 54 * and extent properties (in that order), to maintain the constraints 55 * specified above. 56 * 57 * <li> 58 * The value and extent set methods "correct" their argument to 59 * fit within the limits defined by the other three properties. 60 * For example if <code>value == maximum</code>, <code>setExtent(10)</code> 61 * would change the extent (back) to zero. 62 * 63 * <li> 64 * The four BoundedRangeModel values are defined as Java Beans properties 65 * however Swing ChangeEvents are used to notify clients of changes rather 66 * than PropertyChangeEvents. This was done to keep the overhead of monitoring 67 * a BoundedRangeModel low. Changes are often reported at MouseDragged rates. 68 * </ul> 69 * 70 * <p> 71 * 72 * For an example of specifying custom bounded range models used by sliders, 73 * see <a 74 href="http://www.oracle.com/technetwork/java/architecture-142923.html#separable">Separable model architecture</a> 75 * in <em>A Swing Architecture Overview.</em> 76 * 77 * @author Hans Muller 78 * @see DefaultBoundedRangeModel 79 * @since 1.2 80 */ 81public interface BoundedRangeModel 82{ 83 /** 84 * Returns the minimum acceptable value. 85 * 86 * @return the value of the minimum property 87 * @see #setMinimum 88 */ 89 int getMinimum(); 90 91 92 /** 93 * Sets the model's minimum to <I>newMinimum</I>. The 94 * other three properties may be changed as well, to ensure 95 * that: 96 * <pre> 97 * minimum <= value <= value+extent <= maximum 98 * </pre> 99 * <p> 100 * Notifies any listeners if the model changes. 101 * 102 * @param newMinimum the model's new minimum 103 * @see #getMinimum 104 * @see #addChangeListener 105 */ 106 void setMinimum(int newMinimum); 107 108 109 /** 110 * Returns the model's maximum. Note that the upper 111 * limit on the model's value is (maximum - extent). 112 * 113 * @return the value of the maximum property. 114 * @see #setMaximum 115 * @see #setExtent 116 */ 117 int getMaximum(); 118 119 120 /** 121 * Sets the model's maximum to <I>newMaximum</I>. The other 122 * three properties may be changed as well, to ensure that 123 * <pre> 124 * minimum <= value <= value+extent <= maximum 125 * </pre> 126 * <p> 127 * Notifies any listeners if the model changes. 128 * 129 * @param newMaximum the model's new maximum 130 * @see #getMaximum 131 * @see #addChangeListener 132 */ 133 void setMaximum(int newMaximum); 134 135 136 /** 137 * Returns the model's current value. Note that the upper 138 * limit on the model's value is <code>maximum - extent</code> 139 * and the lower limit is <code>minimum</code>. 140 * 141 * @return the model's value 142 * @see #setValue 143 */ 144 int getValue(); 145 146 147 /** 148 * Sets the model's current value to <code>newValue</code> if <code>newValue</code> 149 * satisfies the model's constraints. Those constraints are: 150 * <pre> 151 * minimum <= value <= value+extent <= maximum 152 * </pre> 153 * Otherwise, if <code>newValue</code> is less than <code>minimum</code> 154 * it's set to <code>minimum</code>, if its greater than 155 * <code>maximum</code> then it's set to <code>maximum</code>, and 156 * if it's greater than <code>value+extent</code> then it's set to 157 * <code>value+extent</code>. 158 * <p> 159 * When a BoundedRange model is used with a scrollbar the value 160 * specifies the origin of the scrollbar knob (aka the "thumb" or 161 * "elevator"). The value usually represents the origin of the 162 * visible part of the object being scrolled. 163 * <p> 164 * Notifies any listeners if the model changes. 165 * 166 * @param newValue the model's new value 167 * @see #getValue 168 */ 169 void setValue(int newValue); 170 171 172 /** 173 * This attribute indicates that any upcoming changes to the value 174 * of the model should be considered a single event. This attribute 175 * will be set to true at the start of a series of changes to the value, 176 * and will be set to false when the value has finished changing. Normally 177 * this allows a listener to only take action when the final value change in 178 * committed, instead of having to do updates for all intermediate values. 179 * <p> 180 * Sliders and scrollbars use this property when a drag is underway. 181 * 182 * @param b true if the upcoming changes to the value property are part of a series 183 */ 184 void setValueIsAdjusting(boolean b); 185 186 187 /** 188 * Returns true if the current changes to the value property are part 189 * of a series of changes. 190 * 191 * @return the valueIsAdjustingProperty. 192 * @see #setValueIsAdjusting 193 */ 194 boolean getValueIsAdjusting(); 195 196 197 /** 198 * Returns the model's extent, the length of the inner range that 199 * begins at the model's value. 200 * 201 * @return the value of the model's extent property 202 * @see #setExtent 203 * @see #setValue 204 */ 205 int getExtent(); 206 207 208 /** 209 * Sets the model's extent. The <I>newExtent</I> is forced to 210 * be greater than or equal to zero and less than or equal to 211 * maximum - value. 212 * <p> 213 * When a BoundedRange model is used with a scrollbar the extent 214 * defines the length of the scrollbar knob (aka the "thumb" or 215 * "elevator"). The extent usually represents how much of the 216 * object being scrolled is visible. When used with a slider, 217 * the extent determines how much the value can "jump", for 218 * example when the user presses PgUp or PgDn. 219 * <p> 220 * Notifies any listeners if the model changes. 221 * 222 * @param newExtent the model's new extent 223 * @see #getExtent 224 * @see #setValue 225 */ 226 void setExtent(int newExtent); 227 228 229 230 /** 231 * This method sets all of the model's data with a single method call. 232 * The method results in a single change event being generated. This is 233 * convenient when you need to adjust all the model data simultaneously and 234 * do not want individual change events to occur. 235 * 236 * @param value an int giving the current value 237 * @param extent an int giving the amount by which the value can "jump" 238 * @param min an int giving the minimum value 239 * @param max an int giving the maximum value 240 * @param adjusting a boolean, true if a series of changes are in 241 * progress 242 * 243 * @see #setValue 244 * @see #setExtent 245 * @see #setMinimum 246 * @see #setMaximum 247 * @see #setValueIsAdjusting 248 */ 249 void setRangeProperties(int value, int extent, int min, int max, boolean adjusting); 250 251 252 /** 253 * Adds a ChangeListener to the model's listener list. 254 * 255 * @param x the ChangeListener to add 256 * @see #removeChangeListener 257 */ 258 void addChangeListener(ChangeListener x); 259 260 261 /** 262 * Removes a ChangeListener from the model's listener list. 263 * 264 * @param x the ChangeListener to remove 265 * @see #addChangeListener 266 */ 267 void removeChangeListener(ChangeListener x); 268 269} 270