001 /*
002 * ScribbleCanvas class
003 * $Id: ScribbleCanvas.java,v 1.1.1.1 2002/06/05 21:56:35 root Exp $
004 *
005 * Developed for "Rethinking CS101", a project of Lynn Andrea Stein's AP Group.
006 * For more information, see <a href="http://www.ai.mit.edu/projects/cs101/">the
007 * CS101 homepage</a> or email <las@ai.mit.edu>.
008 *
009 * Copyright (C) 1996 Massachusetts Institute of Technology.
010 * Please do not redistribute without obtaining permission.
011 */
012
013 package scribble;
014
015 import java.awt.*;
016 import java.awt.event.*;
017 import cs101.awt.Line;
018
019 /**
020 * An extended SmartCanvas that echos user's mouse strokes as lines.
021 *
022 * <P>Handles mouse events (by creating lines to put in the repository),
023 * can be given a Color in which to draw, can be cleared.
024 *
025 * <P>Copyright 1996 Massachusetts Institute of Technology
026 *
027 * @author Todd C. Parnell, tparnell@ai.mit.edu
028 * @author Maciej Stachowiak, maciej@ai.mit.edu
029 * @author Lynn Andrea Stein, las@ai.mit.edu
030 * @version $Id: ScribbleCanvas.java,v 1.1.1.1 2002/06/05 21:56:35 root Exp $
031 *
032 * @see scribble.SmartCanvas
033 */
034 public class ScribbleCanvas extends SmartCanvas {
035
036 // Some integers to store a point in
037 protected int currX, currY;
038
039 /** The current color to draw lines in. */
040 protected Color currColor;
041
042
043 /**
044 * Creates a new ScribbleCanvas.
045 */
046 public ScribbleCanvas() {
047 this(new ScribbleData());
048 }
049
050 /**
051 * Creates a new ScribbleCanvas with associated ScribbleData.
052 */
053 public ScribbleCanvas(ScribbleData sd) {
054 super(sd);
055
056 this.addMouseListener(new MouseListener() {
057 public void mouseClicked(MouseEvent e) {}
058 public void mouseEntered(MouseEvent e) {}
059 public void mouseExited(MouseEvent e) {}
060 public void mousePressed(MouseEvent e) {
061 setCoords(e.getX(), e.getY());
062 }
063 public void mouseReleased(MouseEvent e) {
064 lineTo(e.getX(), e.getY());
065 resetCoords();
066 }
067 });
068
069 this.addMouseMotionListener(new MouseMotionListener() {
070 public void mouseDragged(MouseEvent e) {
071 lineTo(e.getX(), e.getY());
072 setCoords(e.getX(), e.getY());
073 }
074 public void mouseMoved(MouseEvent e) {}
075 });
076
077 this.resetCoords();
078 }
079
080 /**
081 * Removes all lines from the data repository.
082 *
083 * Then forces a call to the paint method.
084 */
085 public void clearLines() {
086 this.repository.clearLines();
087 this.repaint();
088 }
089
090 /**
091 * Changes the drawing color.
092 * @param c the new drawing color.
093 */
094 public void setColor ( Color c ) {
095 this.currColor = c;
096 }
097
098 /**
099 * Gives the x and y coords impossible values to signal
100 * that new coords are expected.
101 */
102 protected void resetCoords() {
103 this.currX = -1;
104 this.currY = -1;
105 }
106
107 /**
108 * Saves the starting point for drawing a line in currX, currY
109 * @param x the x coord of the starting point
110 * @param y the y coord of the starting point
111 */
112 protected void setCoords( int x, int y ) {
113 this.currX = x;
114 this.currY = y;
115 }
116
117 /**
118 * Adds a line (from the saved start point to the point passed)
119 * to the data repository.
120 * @param endX the x coord of the line's endpoint
121 * @param endY the y coord of the line's endpoint
122 */
123 protected void lineTo( int endX, int endY) {
124 this.repository.addLine(new Line(this.currX, this.currY,
125 endX, endY, this.currColor));
126 }
127 }
128
129
130 /* Comments:
131 *
132 * History:
133 * $Log: ScribbleCanvas.java,v $
134 * Revision 1.1.1.1 2002/06/05 21:56:35 root
135 * CS101 comes to Olin finally.
136 *
137 * Revision 1.2 2000/05/07 07:07:03 mharder
138 * Fixed javadoc @see tag.
139 *
140 * Revision 1.1 2000/05/06 22:30:58 mharder
141 * Moved to scribble subdirectory.
142 *
143 * Revision 1.8 1998/07/24 16:44:51 tparnell
144 * Placate new javadoc behavior
145 *
146 * Revision 1.7 1998/07/22 17:59:33 tparnell
147 * modifications to reflect new cs101.* package structure
148 *
149 * Revision 1.6 1998/07/21 19:06:38 tparnell
150 * added more javadoc
151 *
152 * Revision 1.5 1998/07/21 14:09:04 tparnell
153 * minor bugfixes necessary b/c 1.2 complier is more picky
154 *
155 * Revision 1.4 1998/07/20 18:55:32 tparnell
156 * Added javadoc and logging. Minor code mods for greater consistency
157 * between files.
158 *
159 * Revision 1.3 1998/06/04 19:01:11 tparnell
160 * minor mods
161 *
162 * Revision 1.2 1998/06/04 16:59:57 tparnell
163 * old version was incomplete. this version is an import from fall96
164 * with updates to Java 1.1 and corrrections to work with new files
165 *
166 * Revision 1.6 1996/10/28 18:06:47 nathanw
167 * Revert the change of putting them in a Scribble package.
168 *
169 * Revision 1.5 1996/10/26 21:04:17 nathanw
170 * Put all this stuff into a Scribble package
171 *
172 * Revision 1.4 1996/10/24 22:43:05 las
173 * Changed everything. Well, almost:
174 *
175 * Both DumbDemo.java and WhiteboardDemo.java are standalone
176 * applications. DumbDemo pops up the window w/all the appropriate
177 * widgets, but nothing much happens. WhiteboardDemo is the fully
178 * functioning solution version.
179 *
180 * Things have been broken up into what they write and what we give
181 * them. They get ScribbleData, SmartCanvas, and Whiteboard. They write
182 * DumbDemo and ScribbleCanvas, and (if they're ambitious) maybe
183 * WhiteboardSoln/Demo. They could even extend WhiteboardSoln further,
184 * putting in extra components, but then they'd have to significantly
185 * extend or at least override Whiteboard as well.
186 *
187 * ScribbleData remained roughly the same.
188 * ScribbleCanvas got broken into SmartCanvas (handles the repository &
189 * painting) and ScribbleCanvas (handles the mouse events & optionally
190 * the clear/color methods).
191 * Whiteboard got broken into Whiteboard (sets up the widgets, doesn't do
192 * anything with them and WhiteboardSoln (handles the action events).
193 * Also, the Applet's init was retained, since it does the Right Thing.
194 * There is some hair in (1) how constructor arguments are handled and
195 * (2) the (non-)overriding of drawingArea, but all appears to work
196 * smoothly. I don't expect students to come up with this particular
197 * solution.
198 * WhiteboardDemo and DumbDemo got added, as they turn things into a
199 * standalone.
200 *
201 * Revision 1.3 1996/08/04 05:37:26 reuben
202 * Changed setColor and setData methods to be protected.
203 * This allows access from non-subclass objects in the same package.
204 *
205 * Revision 1.2 1996/08/03 23:06:16 reuben
206 * Tweaked comments.
207 *
208 * Revision 1.1.1.1 1996/07/23 17:21:27 sit
209 * Import from summer 6.80s web tree
210 *
211 * Revision 1.1 1996/07/05 15:15:26 las
212 * Initial revision
213 *
214 *
215 */
216