geom
Creating basic shapes example
In this tutorial we shall show you how to construct a simple graphic by creating basic shapes. We are going to use some the built in classes that Java offers.
Basically to create simple shapes in Java:
- Use
Line2D
,Ellipse2D
,Rectangle2D
,RoundRectangle2D
,Arc2D
,Area
to create some simple shapes - Then use
Graphics2D
class and its draw function ton paint each shape an a newFrame
.
Let’s see how the code looks like:
001 002 003 004 005 006 007 008 009 010 011 012 013 014 015 016 017 018 019 020 021 022 023 024 025 026 027 028 029 030 031 032 033 034 035 036 037 038 039 040 041 042 043 044 045 046 047 048 049 050 051 052 053 054 055 056 057 058 059 060 061 062 063 064 065 066 067 068 069 070 071 072 073 074 075 076 077 078 079 080 081 082 083 084 085 086 087 088 089 090 091 092 093 094 095 096 097 098 099 100 101 | package com.javacodegeeks.snippets.desktop; import java.awt.Component; import java.awt.Frame; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Shape; import java.awt.geom.Arc2D; import java.awt.geom.Ellipse2D; import java.awt.geom.Line2D; import java.awt.geom.Rectangle2D; import java.awt.geom.RoundRectangle2D; public class BasicShapes { public static void main(String[] args) { // Create a frame Frame frame = new Frame(); // Add a component with a custom paint method frame.add( new CustomPaintComponent()); // Display the frame int frameWidth = 300 ; int frameHeight = 300 ; frame.setSize(frameWidth, frameHeight); frame.setVisible( true ); } /** * To draw on the screen, it is first necessary to subclass a Component * and override its paint() method. The paint() method is automatically called * by the windowing system whenever component's area needs to be repainted. */ static class CustomPaintComponent extends Component { public void paint(Graphics g) { // Retrieve the graphics context; this object is used to paint shapes Graphics2D g2d = (Graphics2D)g; /** * The coordinate system of a graphics context is such that the origin is at the * northwest corner and x-axis increases toward the right while the y-axis increases * toward the bottom. */ int x = 0 ; int y = 0 ; int w = getSize().width- 1 ; int h = getSize().height- 1 ; Shape line = new Line2D.Float(x, y, w, h); Shape oval = new Ellipse2D.Float(x, y, w, h); Shape rectangle = new Rectangle2D.Float(x, y, w, h); Shape roundRectangle = new RoundRectangle2D.Float(x, y, w, h, w/ 2 , h/ 2 ); // A start angle of 0 represents a 3 o'clock position, 90 represents a 12 o'clock position, // and -90 (or 270) represents a 6 o'clock position int startAngle = 45 ; int arcAngle = - 60 ; Shape arc = new Arc2D.Float(x, y, w/ 2 , h/ 2 , startAngle, arcAngle, Arc2D.OPEN); g2d.draw(line); g2d.draw(oval); g2d.draw(rectangle); g2d.draw(roundRectangle); g2d.draw(arc); } } } |
This was an example on how to create basic shapes in Java.