Biblioteca Java - Blame information for rev 32
Subversion Repositories:
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 32 | mihai | 1 | /* |
| 2 | * To change this license header, choose License Headers in Project Properties. | ||
| 3 | * To change this template file, choose Tools | Templates | ||
| 4 | * and open the template in the editor. | ||
| 5 | */ | ||
| 6 | package guidemo; | ||
| 7 | |||
| 8 | import javax.swing.*; | ||
| 9 | import java.awt.*; | ||
| 10 | |||
| 11 | /** | ||
| 12 | * Example demonstrating drawPolyline(). | ||
| 13 | */ | ||
| 14 | public class SinExample extends JFrame { | ||
| 15 | |||
| 16 | public SinExample() { | ||
| 17 | |||
| 18 | this.setSize(new Dimension(300, 200)); | ||
| 19 | int width = getSize().width; | ||
| 20 | int height = getSize().height; | ||
| 21 | |||
| 22 | int num_points = 21; | ||
| 23 | |||
| 24 | // Create an instance of DrawingPanel | ||
| 25 | Polygon1Panel polygon1_panel | ||
| 26 | = new Polygon1Panel(width, height, num_points); | ||
| 27 | // Add the DrawingPanel to the contentPane. | ||
| 28 | add(polygon1_panel); | ||
| 29 | pack(); | ||
| 30 | setVisible(true); | ||
| 31 | |||
| 32 | } | ||
| 33 | |||
| 34 | public static void main(String[] args) { | ||
| 35 | new SinExample(); | ||
| 36 | } | ||
| 37 | } | ||
| 38 | |||
| 39 | /** | ||
| 40 | * Draw a polygon with drawPolyline() on this JPanel subclass. * | ||
| 41 | */ | ||
| 42 | class Polygon1Panel extends JPanel { | ||
| 43 | |||
| 44 | int fWidth, fHeight; | ||
| 45 | int fNumPoints; | ||
| 46 | double fFactor; | ||
| 47 | |||
| 48 | Polygon1Panel(int width, int height, int nPoints) { | ||
| 49 | fNumPoints = nPoints; | ||
| 50 | fWidth = width; | ||
| 51 | fHeight = height; | ||
| 52 | fFactor = 2.0 * Math.PI / fWidth; | ||
| 53 | this.setPreferredSize(new Dimension(width, height)); | ||
| 54 | } // ctor | ||
| 55 | |||
| 56 | public void paintComponent(Graphics g) { | ||
| 57 | // First paint background unless you will | ||
| 58 | // paint whole area yourself. | ||
| 59 | super.paintComponent(g); | ||
| 60 | |||
| 61 | // Create arrays of points for each | ||
| 62 | // segment of the polygon | ||
| 63 | int[] x = new int[fNumPoints]; | ||
| 64 | int[] y = new int[fNumPoints]; | ||
| 65 | |||
| 66 | // Select horizontal step size | ||
| 67 | double x_del = ((double) fWidth) / (fNumPoints - 1); | ||
| 68 | |||
| 69 | // Find coordinates of the display center | ||
| 70 | int x_offset = fWidth / 2; | ||
| 71 | int y_offset = fHeight / 2; | ||
| 72 | |||
| 73 | // Choose amplitude for the sine curve | ||
| 74 | int amp = (int) (y_offset * 0.9); | ||
| 75 | |||
| 76 | // Create a sine curve from a sequence | ||
| 77 | // of short line segments | ||
| 78 | for (int i = 0; i < fNumPoints; i++) { | ||
| 79 | x[i] = (int) (i * x_del); | ||
| 80 | y[i] = (int) (amp * Math.sin(fFactor * x[i])) | ||
| 81 | + y_offset; | ||
| 82 | } | ||
| 83 | |||
| 84 | // Set the line color to red | ||
| 85 | g.setColor(Color.red); | ||
| 86 | |||
| 87 | // Draw curve with single call to drawPolyline | ||
| 88 | g.drawPolyline(x, y, fNumPoints); | ||
| 89 | |||
| 90 | // Change the line color and draw the x-y axes | ||
| 91 | g.setColor(Color.green); | ||
| 92 | g.drawLine(0, y_offset, fWidth - 1, y_offset); | ||
| 93 | g.drawLine(x_offset, 0, x_offset, fHeight - 1); | ||
| 94 | |||
| 95 | } // paintComponent | ||
| 96 | |||
| 97 | } // class Polygon1Panel |