001 package com.croftsoft.core.animation.updater;
002
003 import java.awt.*;
004 import java.awt.event.*;
005 import javax.swing.*;
006
007 import com.croftsoft.core.animation.ComponentUpdater;
008
009 /*********************************************************************
010 * Scrolls the view when the mouse is on the edges.
011 *
012 * @version
013 * 2003-07-05
014 * @since
015 * 2003-03-08
016 * @author
017 * <a href="https://www.croftsoft.com/">David Wallace Croft</a>
018 *********************************************************************/
019
020 public final class EdgeScrollUpdater
021 implements ComponentUpdater
022 //////////////////////////////////////////////////////////////////////
023 //////////////////////////////////////////////////////////////////////
024 {
025
026 private final static int DEFAULT_SCROLL_RATE = 1;
027
028 private final static int EDGE_SIZE_DIVIDER = 10;
029
030 //
031
032 private final int width;
033
034 private final int height;
035
036 private final Dimension edgeSize;
037
038 private final Rectangle bounds;
039
040 private final int scrollRate;
041
042 private final boolean wrapAround;
043
044 //
045
046 private Point mousePoint;
047
048 private int translateX;
049
050 private int translateY;
051
052 //////////////////////////////////////////////////////////////////////
053 //////////////////////////////////////////////////////////////////////
054
055 public EdgeScrollUpdater (
056 JComponent component,
057 int width,
058 int height,
059 Dimension edgeSize,
060 int scrollRate,
061 boolean wrapAround )
062 //////////////////////////////////////////////////////////////////////
063 {
064 this.width = width;
065
066 this.height = height;
067
068 this.edgeSize = edgeSize;
069
070 if ( scrollRate < 1 )
071 {
072 throw new IllegalArgumentException ( "scrollRate < 1" );
073 }
074
075 this.scrollRate = scrollRate;
076
077 this.wrapAround = wrapAround;
078
079 bounds = new Rectangle ( );
080
081 component.addMouseMotionListener (
082 new MouseMotionAdapter ( )
083 {
084 public void mouseMoved ( MouseEvent mouseEvent )
085 {
086 mousePoint = mouseEvent.getPoint ( );
087 }
088 } );
089 }
090
091 public EdgeScrollUpdater (
092 JComponent component,
093 int width,
094 int height )
095 //////////////////////////////////////////////////////////////////////
096 {
097 this ( component, width, height, null, DEFAULT_SCROLL_RATE, false );
098 }
099
100 //////////////////////////////////////////////////////////////////////
101 //////////////////////////////////////////////////////////////////////
102
103 public int getTranslateX ( ) { return translateX; }
104
105 public int getTranslateY ( ) { return translateY; }
106
107 //////////////////////////////////////////////////////////////////////
108 //////////////////////////////////////////////////////////////////////
109
110 public void update ( JComponent component )
111 //////////////////////////////////////////////////////////////////////
112 {
113 if ( mousePoint == null )
114 {
115 return;
116 }
117
118 component.getBounds ( bounds );
119
120 int x = mousePoint.x;
121
122 int y = mousePoint.y;
123
124 boolean onEdge = false;
125
126 int edgeWidth;
127
128 int edgeHeight;
129
130 if ( edgeSize == null )
131 {
132 edgeWidth = bounds.width / EDGE_SIZE_DIVIDER;
133
134 edgeHeight = bounds.height / EDGE_SIZE_DIVIDER;
135 }
136 else
137 {
138 edgeWidth = edgeSize.width;
139
140 edgeHeight = edgeSize.height;
141 }
142
143 if ( x < edgeWidth )
144 {
145 if ( wrapAround || ( translateX < 0 ) )
146 {
147 onEdge = true;
148
149 translateX += scrollRate;
150
151 if ( translateX > 0 )
152 {
153 if ( wrapAround )
154 {
155 translateX -= width;
156 }
157 else
158 {
159 translateX = 0;
160 }
161 }
162 }
163 }
164 else if ( x > bounds.width - edgeWidth )
165 {
166 if ( wrapAround || ( translateX > -( width - bounds.width ) ) )
167 {
168 onEdge = true;
169
170 translateX -= scrollRate;
171 }
172 }
173
174 if ( translateX < -( width - bounds.width ) )
175 {
176 if ( wrapAround )
177 {
178 translateX += width;
179 }
180 else
181 {
182 translateX = -( width - bounds.width );
183 }
184 }
185
186 if ( y < edgeHeight )
187 {
188 if ( wrapAround || ( translateY < 0 ) )
189 {
190 onEdge = true;
191
192 translateY += scrollRate;
193
194 if ( translateY > 0 )
195 {
196 if ( wrapAround )
197 {
198 translateY -= height;
199 }
200 else
201 {
202 translateY = 0;
203 }
204 }
205 }
206 }
207 else if ( y > bounds.height - edgeHeight )
208 {
209 if ( wrapAround || ( translateY > -( height - bounds.height ) ) )
210 {
211 onEdge = true;
212
213 translateY -= scrollRate;
214 }
215 }
216
217 if ( translateY < -( height - bounds.height ) )
218 {
219 if ( wrapAround )
220 {
221 translateY += height;
222 }
223 else
224 {
225 translateY = -( height - bounds.height );
226 }
227 }
228
229 if ( !onEdge )
230 {
231 mousePoint = null;
232 }
233 else
234 {
235 component.repaint ( );
236 }
237 }
238
239 public void translate ( Graphics graphics )
240 //////////////////////////////////////////////////////////////////////
241 {
242 graphics.translate ( translateX, translateY );
243 }
244
245 public void translate ( Point point )
246 //////////////////////////////////////////////////////////////////////
247 {
248 point.x += translateX;
249
250 point.y += translateY;
251 }
252
253 public void translateReverse ( Graphics graphics )
254 //////////////////////////////////////////////////////////////////////
255 {
256 graphics.translate ( -translateX, -translateY );
257 }
258
259 public void translateReverse ( Point point )
260 //////////////////////////////////////////////////////////////////////
261 {
262 point.x -= translateX;
263
264 point.y -= translateY;
265 }
266
267 //////////////////////////////////////////////////////////////////////
268 //////////////////////////////////////////////////////////////////////
269 }