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/Users/lyon/j4p/src/bookExamples/ch27BusinessGraphics/charts/BarGraph.java
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1 package bookExamples.ch27BusinessGraphics.charts;
2
3 import gui.ClosableJFrame;
4
5 import javax.swing.*;
6 import java.awt.*;
7
8 /**
9 * BarGraph implements the Paintable interface to draw a bar
10 * graphics.graph on a frame. Requires an instance of DoubleDataBean in order
11 * to be constructed.<BR>
12 * Global variables:
13 * <UL>
14 * <LI> DoubleDataBean: instance of DoubleDataBean so the graphics.graph is drawn
15 * with the proper data
16 * <LI> barwidth: an arbitrary width for each bar in the bar graphics.graph
17 * </UL>
18 *
19 * @author Allison McHenry
20 * @author Douglas Lyon, PhD
21 * @since JDK 1.3
22 */
23
24
25 public class BarGraph extends JComponent
26 implements Paintable {
27
28 //GLOBAL VARIABLES
29 private DoubleDataBean dd;
30 private int barwidth = 6;
31
32 //CONSTRUCTORS
33
34
35
36 /**
37 * Constructor used if only height and width should be set, using defaults for all
38 * global variables. Probably would only use this as a test case.
39 * @param w Image width (not frame width)
40 * @param h Image height (not frame height)
41 */
42 public BarGraph(DoubleDataBean _dd) {
43 dd = _dd;
44 setSize(dd.getWidth(), dd.getHeight());
45 }
46
47 public Dimension getPreferredSize() {
48 return new Dimension(dd.getWidth(), dd.getHeight());
49 }
50
51 public Dimension getMinimumSize() {
52 return new Dimension(dd.getWidth(), dd.getHeight());
53 }
54
55 /**
56 * Sets the arbitrary width of the bars.
57 *
58 * @param _barwidth Width of each bar
59 */
60 public void setBarWidth(int _barwidth) {
61 barwidth = _barwidth;
62 }
63
64
65
66 //UTILITY METHODS
67
68 /**
69 * Actually paints this data from DoubleDataBean onto an image. The DrawUtil class is a
70 * generic utilities class containing all methods which actually
71 * handle the painting.
72 *
73 * @param g Graphics context for drawing
74 * @see drawGraph
75 * @see DrawUtil.#drawAxes2
76 * @see DrawUtil.#drawXAxisLabel
77 * @see DrawUtil.#drawYAxisLabel
78 * @see DrawUtil.#drawTitle
79 */
80 public void paint(Graphics g) {
81
82 DrawUtil du = new DrawUtil(dd);
83 Ticks t = new Ticks(dd, getSize());
84 t.setNumberOfTicks(10, 10);
85 ;
86 t.paint(g);
87 //du.drawGrid(g);
88 drawGraph(g);
89 //du.drawXAxisLabel(g);
90 //du.drawYAxisLabel(g);
91 du.drawTitle(g);
92 }
93
94
95 /**
96 * Draws the bars for the bar graphics.graph. The height of the bars
97 * is determined by the values in the Y array. The values in
98 * the X array are irrelevant.
99 *
100 * @param g Graphics context for drawing
101 * @see paint
102 * @see DoubleDataBean.#getYAxisCoord
103 * @see DoubleDataBean.#getYIncrement
104 * @see getXCoord
105 * @see getYCoord
106 * @see java.awt.#fillRect
107 */
108 private void drawGraph(Graphics g) {
109
110 int barheight = 0;
111 g.setColor(Color.red);
112 int x;
113 int y;
114 int width = dd.getWidth();
115
116 double yOrigin = dd.getYAxisCoord();
117 double yNums[] = dd.getYVals();
118 int pxPerY = (int) dd.getYIncrement();
119
120 System.out.println("width=" + width);
121
122 for (int j = 0; j < yNums.length; j++) {
123 x = (int) getXCoord(j + 1, (dd.getIncrement(width, yNums.length)));
124
125 y = (int) getYCoord(yNums[j], pxPerY);
126
127 //center the bar
128 x = x - (barwidth);
129
130 if (y > yOrigin) { // ie Y is a negative value
131 barheight = y - (int) yOrigin;
132 y = (int) yOrigin;
133 } else {
134 barheight = (int) Math.abs(yOrigin - y);
135 }
136
137 System.out.println("x=" + x);
138 System.out.println("y=" + y);
139 System.out.println("barwidth=" + barwidth);
140 System.out.println("barheight=" + barheight);
141 g.fillRect(x, y, barwidth, barheight);
142 }
143 }
144
145 /**
146 * Method used to by the bar graphics.graph to calculate where on the x axis
147 * to start drawing the rectangle for the graphics.graph: the increment * the
148 * x value
149 *
150 * @return xCoord The X coordinate of the top left corner of this bar
151 * @see drawGraph
152 */
153
154 private double getXCoord(double numX, int xPixelsWide) {
155 double xCoord = numX * xPixelsWide;
156 return xCoord;
157 }
158
159 /**
160 * Method used to by the bar graphics.graph to calculate where on the y axis
161 * to start drawing the rectangle for the graphics.graph( the increment * the y value)
162 * subtracted from the y origin because the zero value for Y is the top of the screen
163 *
164 * @return yCoord The Y coordinate of the top left corner of this bar
165 * @see drawGraph
166 */
167 private double getYCoord(double numY, int yPixelsHigh) {
168 double yOrigin = dd.getYAxisCoord();
169 double yCoord = yOrigin - (numY * yPixelsHigh);
170 return yCoord;
171 }
172
173 public static void main(String args[]) {
174 ClosableJFrame cf = new ClosableJFrame();
175 Container c = cf.getContentPane();
176 DoubleDataBean dd = new DoubleDataBean(200, 200);
177 double yVals[] = {10, -20, -40, 80};
178 dd.setYVals(yVals);
179 BarGraph bg = new BarGraph(dd);
180 bg.setBarWidth(6);
181 c.add(bg);
182 c.setLayout(
183 new FlowLayout());
184 cf.setBackground(Color.white);
185 cf.setSize(200, 200);
186 cf.setVisible(true);
187 }
188
189
190 }
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