1 /* PictureTime.java - This example illustrates the hierarchical use
2 * of components in a grid layout.
3 * This version uses Java 1.1 event model.
4 * New Version with colored circles on the canvas by Mehmet Sen 10/97.
5 */
6
7 import java.awt.*;
8 import java.awt.event.*;
9
10 public class PictureTime extends java.applet.Applet {
11
12 /* instance variable to hold the subpanel component */
13 ControlPanel control;
14
15 /* instance variable to hold the canvas component */
16 Display displaycanvas;
17
18
19 public void init() {
20
21 /* using grid layout with gap of 15 points separating each component */
22 setLayout(new BorderLayout(5,0));
23
24 displaycanvas = new Display(0); /* creating the canvas component */
25 displaycanvas.setBackground(Color.blue);
26 displaycanvas.start();
27
28 /* creating instance for PictureControl panel */
29 control = new ControlPanel(this);
30
31 /* adding the components to the panel */
32 add(displaycanvas,BorderLayout.CENTER);
33 add(control,BorderLayout.EAST);
34 }
35
36
37 void changeCanvasColor(String category) {
38 if (category.equals("Button 1"))
39 displaycanvas.draw(1,Color.green);
40 else if (category.equals("Button 2"))
41 displaycanvas.draw(2,Color.cyan);
42 else if (category.equals("Button 3"))
43 displaycanvas.draw(3,Color.pink);
44 else displaycanvas.draw(0,Color.black);
45 }
46 }
47
48
49
50
51
52
53
54 /* this class is a subclass of Panel */
55
56 class ControlPanel extends Panel implements ActionListener
57 {
58 /* instance variable to hold a pointer to calling class */
59 PictureTime outerparent;
60
61 /* the three control buttons */
62 Button b1,b2,b3;
63
64 ControlPanel(PictureTime target) {
65 this.outerparent = target;
66 setLayout(new BorderLayout(0,140));
67
68 /* putting the buttons */
69 setBackground(Color.lightGray);
70
71 b1=new Button("Button 1");
72 add(b1,BorderLayout.NORTH);
73 b1.setForeground(Color.black);
74 b1.setBackground(Color.green);
75 b1.addActionListener(this);
76
77 b2=new Button("Button 2");
78 add(b2,BorderLayout.CENTER);
79 b2.setForeground(Color.blue);
80 b2.setBackground(Color.cyan);
81 b2.addActionListener(this);
82
83 b3=new Button("Button 3");
84 add(b3,BorderLayout.SOUTH);
85 b3.setForeground(Color.black);
86 b3.setBackground(Color.pink);
87 b3.addActionListener(this);
88
89 }
90
91 public void actionPerformed(ActionEvent evt) {
92 /* getActionCommand will return label of the button clicked
93 or we could have used getSource() to return pointer to the button,
94 i.e. either t, d, or s */
95 String label = evt.getActionCommand();
96 this.outerparent.changeCanvasColor(label);
97 }
98 }
99
100
101 // Display canvas show animated little balls from left towards pressed buton
102 class Display extends Canvas implements Runnable
103 {
104 int Target;
105 Thread animate;
106 Display(int _target)
107 {
108 Target=_target;
109 }
110 public void draw(int _target,Color bg) {
111 setBackground(bg);
112 Target=_target;
113 repaint();
114 }
115 public void start() {
116 if (animate==null){
117 animate=new Thread(this);
118 animate.start();
119 }
120 }
121 public void stop() {
122 if (animate!=null){
123 animate.stop();
124 animate=null;
125 }
126 }
127
128 public void run() {
129 while(true){
130 try {
131 Thread.sleep(100);
132 }
133 catch (InterruptedException e) {
134 }
135 repaint();
136 }
137 }
138
139 public void paint(Graphics g)
140 {
141 int X,Y,source_x,source_y,target_x,target_y;
142 int h=20;
143 int w=20;
144 int i=0;
145 int wstep=h*4/3;
146 int hstep=h*4/3;
147 X=getSize().width;
148 Y=getSize().height;
149 source_x=0;
150 source_y=Y/3;
151 target_x=X;
152 if (Target==1 )
153 target_y=5;
154 else if (Target==2)
155 target_y=Y/2;
156 else if (Target==3)
157 target_y=Y-20;
158 else {
159 target_x=X/2;
160 target_y=-50;
161 }
162
163 for (i=source_x;i<X/4;i+=wstep+8){
164 g.setColor(Color.black);
165 g.fillOval(i-5,source_y-5,w+10,h+10);
166 g.setColor(new Color((float)Math.random(),(float)Math.random(),(float)Math.random()));
167 g.fillOval(i,source_y,w,h);
168 }
169 for (int x=i,y=source_y;x<target_x;){
170 g.setColor(Color.black);
171 g.fillOval(x-5,y-5,w+10,h+10);
172 g.setColor(new Color((float)Math.random(),(float)Math.random(),(float)Math.random()));
173 g.fillOval(x,y,w,h);
174 if(x<target_x) x+=wstep;
175 if((y<target_y+10)&&(y>target_y-10)) x+=8;
176 else if(y<target_y) y+=hstep;
177 else y-=hstep;
178 }
179 }
180
181 }
182