obstacleX = (int) (obstacleX - 0.1);
if(obstacleX <= 0){
obstacleX = 600;
}
repaint();
Thats my code, and the rectangle (ObstacleX is the X cordinate for the rectangle) goes fine on the first few times across the screen, then starts to go hyperspeed....
I found this method from the same link from which I found the Pandigital method. This method uses the algorithm of sieve of eratosthenes who was a greek mathematician and showed how to find prime numbers by taking an individual number and finding the multiples of it and cut them out for they will not be a prime number. From what I've seen this program gives the results much faster than the traditional way of searching for prime numbers by diving that number by the digits upto half of that number and check for divisiblity.
Well, here's the code
public int[] ESieve(int upperLimit) {
int sieveBound = (int)(upperLimit - 1) / 2;
int upperSqrt = ((int)Math.Sqrt(upperLimit) - 1) / 2;
BitArray PrimeBits = new BitArray(sieveBound + 1, true);
for (int i = 1; i <= upperSqrt; i++) {
if (PrimeBits.Get(i)) {
[Code] .....
As seen from the full program on the site [URL] .... this program was formely writen in C++ and from there I've scrapped out this method as the syntax are corresponding to that of Java, but one problem I faced was in finding the BitArray class in Java. I was unable to understand the approach of this program to find the prime numbers.
I don't know if this is appropriate to Swing/AWT, or even if this is a Java issue, but I had quite a shock recently. I have been working on a kind of drawing program in which the user can select tiny control rectangles and drag them around, causing the shape of a polygon to change. (They are not implemented as Java Polygons or Shapes because some are one-dimensional). I have gotten it into pretty good shape, so I exported it from Eclipse, my development platform, into a standalone Java application. In the standalone application, each time I drag the mouse, the redrawing shows nasty flickering, as if it's running too slowly. While I was developing the application inside Eclipse, it ran perfectly, with no flickering whatsoever.
What gives? I'd expect that the in-Eclipse runs would be slower, because they're burdened with extra debugging baggage, while the exported standalone version should run faster. But the reverse is the case.
I have to do the following: A bounding rectangle is the minimum rectangle that encloses a set of points in a two-dimensional plane. Write a method that returns a bounding rectangle for a set of points in a two-dimensional plane, as follows:
public static MyRectangle2D getRectangle(double[][] points)
The Rectangle2D class is defined in Programming Exercise 10.13. Write a test program that prompts the user to enter five points and displays the bounding rectangle's center, width, and height. Here is a sample run:
Enter five points: 1.0 2.5 3 4 5 6 7 8 9 10.The bounding rectangle's center (5.0, 6.25), width 8.0, height 7.5
This is my code so far, taking in account that Rectangle2D is already done in a previous problem.the thing is that i don't know if i have to erase public static void or do i leave it or how do i start it?
package theboundingrectangle;
import java.util.Scanner;
public static MyRectangle2D getRectangle(double[][] points)
public class TheBoundingRectangle {
public static void main(String[] args) {
// TODO code application logic here
}
}
in order to speed up my application I want 'paintComponent(Graphics g)' to only write the visible area in my viewport. I can not find how to get that Rectangle from my JScrollPane.
View Replies View RelatedSo I've been getting back into Java and downloaded eclipse back onto my laptop. However when I go to make a simple rectangle into a JFrame, the frame will pop up but no rectangle will be shown. Here is my main class, which sets up the JFrame...
mport javax.swing.JFrame;
public class Frame{
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setTitle("I hope this fucking works");
frame.setSize(400,400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
[code]....
Is there a way to simply slap a rectangle into a JPanel (make it appear) with out creating an inner Class or helper Method, all within "Main"? And if not, why?
Making a JFrame is easy.
Adding a JPanel is a snap.
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class TheJFrame {
public static void main(String[] args) {
// TODO Auto-generated method stub
[code]....
MyGraphics worked before I added a background but, even now when I take the background away it isn't showing up.
package com.snow.game;
import javax.swing.*;
import java.awt.*;
class MyGraphics extends JComponent { //creating a class for graphics
public void draw(Graphics g){
//calling Graphics making a new graphics (g) now you can use it to make objects
g.drawRect(10, 10, 50, 50); //Draws a rectangle
[Code] ......
I was tasked with building a program that, when is given a string by the user, takes it and prints it out as a rectangle. For example, if the user types in "COMPUTER", the output would be:
COMPUTER
OMPUTERC
MPUTERCO
PUTERCOM
UTERCOMP
TERCOMPU
ERCOMPUT
RCOMPUTE
So far, I have created 2 separate strings, and have gotten the output to look like:
COMPUTER
OMPUTERC
OMPUTERO
OMPUTERO
OMPUTERO
OMPUTERO
OMPUTERO
OMPUTERO
OMPUTERO
So, it works once, but then it doesn't work again. Here is my code:
i was tasked with building a program that, when is given a string by the user, takes it and prints it out as a rectangle. For example, if the user types in "COMPUTER", the output would be:
COMPUTER
OMPUTERC
MPUTERCO
PUTERCOM
UTERCOMP
TERCOMPU
ERCOMPUT
RCOMPUTE
So far, I have created 2 separate strings, and have gotten the output to look like:
COMPUTER
OMPUTERC
OMPUTERO
OMPUTERO
OMPUTERO
OMPUTERO
OMPUTERO
OMPUTERO
OMPUTERO
So, it works once, but then it doesn't work again. Here is my code:
import java.util.Scanner;
public class WordRectangle {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
Scanner userInput = new Scanner (System.in);
[code]....
I have a problem with creating a rectangle in Java. When I create the first rectangle all is ok. But the next, is the problem.
View Replies View RelatedSo I also am working on this problem. My frame does print each new rectangle; however, it is printed each time from the top left corner, and the bottom right is where I click.
Here is my RectangleComponent:
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.Shape;
import java.util.ArrayList;
import javax.swing.JComponent;
public class RectangleComponent extends JComponent
[Code] ....
I want that the cursor change when the mouse is over one of the rectangles. Rectangles are displayed but nothing happens when the mouse is over.
class Resizing extends JPanel {
java.awt.List myGuiList = new java.awt.List();
java.util.List<Rectangle> paths = new ArrayList<Rectangle>();
public Resizing() {
paths.add(new Rectangle(100, 100, 75, 50));
paths.add(new Rectangle(200, 100, 75, 50));
[Code] .....
I need to do a rectangle using boolean array where true elements are the borders of the rectangle, and false elements are the inner space. I imagine that the first and last rows and columns must give the true element,
public class Functionality {
public static boolean[][] rectangleArray(int n, int m){
boolean[ ][ ] matrix = new boolean[n][m];
for(int i = 0; i <matrix.length; i++){
for(int j = 0; j < matrix[i].length; j++){
[code]....
So here's my code as it is right now:
Java Code:
public class PrintHoledRectangle
{
public static void main(String[] args)
{
int width = Integer.parseInt(args[0]) / 2 * 2 + 1;
int height = Integer.parseInt(args[1]) / 2 * 2 + 1;
int centre = width * height / 2 + 1;
int index = 0;
[Code] ....
The width of the rectangle to be printed is given by the first argument, the height by the second
The centre tile ("[_]") of the rectangle (to be printed as " ") is given by the formula: ((width*height)/2)+1, assuming you count each tile left-to-right, top-to-bottom
My thinking is that the programme keeps a running count (seen as 'index') so that, when the centre tile is to be printed, it outputs " ", otherwise "[_]", hence the if-else statement
Currently, it prints "[_]" to infinity
Here is the code:
the window opens, no errors, but the rectangle does not appear
Java Code:
import javax.swing.*;
import java.awt.Graphics;
public class myGame {
public int x = 20;
public int y = 20;
myGame(){
[Code] ....
I am using a text editor
I am just trying to move a rectangle in a diagonal line. When the applet pops up, the rectangle is there but doesn't move. If I drag the sides of the applet to make it bigger or smaller the rectangle will redraw itself and move, but I want it to move without touching the window.
Java Code:
package javaapplication3;
import java.applet.Applet;
import java.awt.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Random;
[Code] .....
Why does it only repaint when I resize the window?
I have created a method Rectangle and added a loop in my class Resizer (MouseAdapter) but impossible to resize the rectangles of the arraylist independantly !
class Rectangle extends Rectangle2D.Float{
private String name;
public Rectangle(float x, float y, float width, float height, String name) {
setRect(x, y, width, height);
this.name = name;
[Code] .....
I want that the cursor change when the mouse is over one of the rectangles. Rectangles are displayed but nothing happens when the mouse is over.
class Resizing extends JPanel {
java.awt.List myGuiList = new java.awt.List();
java.util.List<Rectangle> paths = new ArrayList<Rectangle>();
public Resizing() {
paths.add(new Rectangle(100, 100, 75, 50));
paths.add(new Rectangle(200, 100, 75, 50));
[Code] ......
I was told to design a class named Rectangle to represent a rectangle.The class contains:
■ Two double data fields named width and height that specify the width and height of the rectangle. The default values are 1 for both width and height.
■ A no-arg constructor that creates a default rectangle.
■ A constructor that creates a rectangle with the specified width and height.
■ A method named getArea() that returns the area of this rectangle.
■ A method named getPerimeter() that returns the perimeter.
Draw the UML diagram for the class and then implement the class. Write a test program that creates two Rectangle objects one with width 4 and height 40 and the other with width 3.5 and height 35.9. Display the width, height, area,and perimeter of each rectangle in this order.Here is my code for the Rectangle Class:
class Rectangle
{
double width;
double height;
public Rectangle() {
width = 1;
height = 1;
[code]....
The error that I am given when I compile the driver is as follows:constructor Rectangle in class Rectangle cannot be applied to given types; required: no arguments; found:int,int; reason: actual and formal argument lists differ in length.
I have run into a bit of a head scratcher, at least to me. I am building multiple rectangles using double precision. I had to switch from int to double due to another issue that requires decimal places. Now, my fillRect (last line in the code section I posted) is causing an error as it only wants to work with int.
public void draw(Graphics2D g2) {
// check that sizes are above 0
if ((rectWidth <= 0) || (rectHeight <= 0))
[Code]....
I'm trying to build a program which sets a fill color for a rectangle. Each time the mouse is clicked the fill color changes according to the position of the mouse's X and Y. I succeeded to create a JFrame with a changing background according to the Mouse's position, but I can't seem to change the color of the rectangle (defined in MyPanel class).
This is the current code,
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.SwingUtilities;
import javax.swing.JFrame;
[Code]...
I want to write a method which would give us a rectangle with numbers. The input is an integer which represents the length of a line in rectangle and the result type is void. The example for n=4 is:
3210
0321
1032
2103
[color]
public class MyColorChooser extends JPanel implements ChangeListener{
private JSlider redSlider;
private JSlider greenSlider;
private JSlider blueSlider;
private JTextField txt1;
private JTextField txt2;
private JTextField txt3;
private final Color[] colorValues =
[code]....
Do i have to make a new no argument constructor for my sliders?
I have a class that implements JComponent and draw a rectangle and if a key pressed(for example UP) I want to draw it up, and then when down key pressed to draw it down... But I want not only to disappear, but somehow to move, so the user can see the rectangle moving...
View Replies View RelatedI am writing a program where i am trying to control a rectangle and determine where it moves, everything is working fine it is moving but i am trying to figure out how to change direction using the "WASD" keys. This is what I have and I am not sure why its not working.
Java Code:
addKeyListener( new KeyAdapter() {
public void keyReleased(KeyEvent event) {
for (MoveableShape creature : creatures) {
if (((Creature)creature).isPlayer()) {
if (event.getKeyCode() == KeyEvent.VK_W) //up
[Code] ....
package areatest;
import javax.swing.JOptionPane;
public class AreaTest {
public static double areaTriangle (double length, double width){ //How to calculate the area of a triangle
return .5f * length * width;
[Code] .....
When I try to get the area of a rectangle it gives me 9 no matter what input I give it. When I try to get the area of a triangle it gives me .5 no matter what input I give it. Same with the circle but it always gives me 12.56370...