So as of right now, I'm trying to swap my bar arrays and repaint it. For now, I'm using the index 5 and swapping it with index 23. When I click the shuffle button, It swaps, but the highest bar still remains the same.
Here's my code.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AssortedAssortmentsOfSorts extends JFrame
If the user for example enter the number 2 for index I need to swap the matrix from this index two lines with two line so this is the result what I need
It has to be from another class because the other class controls the fps timer, and I want it to repaint() the panel every tick. However, I cannot seem to find a way to do this because repaint() is not static, and therefor can not be called in any way from another class.
Why is paintComponent not being called by repaint();? Also, paintComponent is called twice when the program starts, that works, repaint is the thing that doesn't work.
I am trying to repaint a window from another class. the class Window handles an interface that displays pictures of movies. Via a JMenuBar you can add a new movie and its picture but in order for it to show in the Window i need to repaint certain aspects in the Window class GUI;
The window class constructor:
public Window() { addComponents(); configurFrame(); addMenu(); }
The functions i want to repaint:
public void repaintWindow() { this.getContentPane().validate(); this.getContentPane().repaint(); }
From my other class where i add a movie to an ArrayList i have made a "private Window myWindow;" there i call the function repaintWindow via mywindow.repaintWindow(); But this gives me an NullPointerException related to the repaintWindow function.
I have two classes. One constructs my a rectangle using Graphics2D (the class is called Rectangles). The second takes a user input for the triangle, which I am passing back to the first class. I am trying to trigger a repaint of class one from the action listener I have on a button in the second class. how to trigger this event?
I have the following code where I call panel repaint method from the action listener of the calc button but it causes stack over flow but when I modify it to call paint component method and removing the super term, the program executes. here is the code
I'm trying to make a simple program that will feature some graphics. It will have a JCombobox that the user selects to draw various shapes. I can't get the repaint function to work however.
Java/Swing dialog box appears on the user's screenIt allows the user to enter 2 values into labelled text fields (fname/sname)They select a "Click Me" push button which I hope will write the data into the table. But the table does not get refreshed.
If I minimise the dialog box and then open it again, the data still does not appear.
The code I originally built using eclipse/WindowBuilder. I've cut it back and tried to isolate the issue. But I still cannot figure it out.
I've added some diagnostic log messages to ensure that I am seeing the various events I think I need to see and have put code in the action callbacks etc.
I am teaching myself AWT/Swing ... It concerns an application that creates dynamic graphics using the Graphics class. I understand that the code that creates graphics should be put in a "paintComponent" method of a (descendant of a) JPanel class. And that when you want to change something on this panel outside "paintComponent", you have to call the "repaint" method, that somehow causes "paintComponent" to be invoked.
However, I don't fully understand the explanation of the example at [URL]... . It concerns an application that moves a red square when a mouse button is clicked. The code can be found at the link, but I also repeat it below.
This code indeed works. However, I don't understand why. The explanation at the Oracle site is the following.
Because we are manually setting the clip, our moveSquare method invokes the repaint method not once, but twice. The first invocation tells Swing to repaint the area of the component where the square previously was (the inherited behavior uses the UI Delegate to fill that area with the current background color.) The second invocation paints the area of the component where the square currently is.
However, what I don't understand: when repaint is first invoked, squareX and squareY still have their old values. If the invocation of repaint simply causes an invocation of paintComponent, then paintComponent should draw a red square at (squareX, squareY). Just like the second invocation of repaint causes paintComponent to draw a red suare at the new values of (squareX, squareY). Instead, the first invocation results in the red square being wiped out by the background color.
So apparently, the first invocation of repaint does not simply cause an invocation of paintComponent. What does it do?
I have a problem using JFreeChart with JavaFX. I wrote a small program here . At first the graph likes this:
I use fullScreen function to display the JFreeChart Line Chart Demo 2. Here I use SwingNode, ChartPanel to embedded JFreeChart into JavaFX Panel.(Detail part will be included in code later)
Then I press ESC to exit fullScreen. Then it looks like this:
So far, it's as expected. Then I use mouse drag to enlarge the window. Here comes the problem, as the following picture.
Can you see that, seems like appear another graph. And I must click on the window, then everything will become good. I wish the graph shows well even when I drag the window to enlarge, is there something I missed? And here is my code:
I mainly would like to know is a int[4][4] or a int [4*4] is more efficient to use. Which takes more storage? Which requires more to process? that kind of stuff.
public void paintComponent (Graphics g) { g.setColor(Color.white); g.fillRect(0,0,this.getWidth(), this.getHeight()); g.setColor(Color.green); g.fillOval(x, y, 40, 40); }
I had done all the previous code (in my own style) and found that the background rectangle was either being redrawn on its own, or there was something else removing the old circles from the screen. I then typed in the code from the previous page exactly as it was, to see if I had some change in syntax that would cause this, and it did the same thing.
Here's my code:
import javax.swing.*; import java.awt.*; public class SimpleAnimation { int x, y; private static final int HEIGHT = 600; private static final int WIDTH = 600;
[Code] .....
Is this because I'm using JRE7? I can't find any documentation that indicates the repaint() method has changed since Java 5.
I would like to be able to draw things onto the panel (via paintComponent), but I'd like it to draw 'on top' of what's already there. The default seems to be that it resets every time I call repaint.
I have been baffled by the functioning of repaint() - and the SwingPaintDemo3 with the moving square seems mysterious - you call repaint(x,y,w,h) twice and the first time it clears the clip area and the 2nd time it paints the red box. The code in paintComponent tells it to paint the box both times, yet somehow it ignores the initial box and only paints the 2nd one.
I've been writing code to bounce some balls in a box to try and understand the behavior. I set up an array of ball objects, loop through them, move them adjusting for collisions with walls and each other, then repaint(). I call repaint x2 for each ball, just like in the example. In my paintComponenet code, if I try to just paint the current ball only one ball will move, even if I send a different ball object each time. The only way to get all the balls to show up is to put a loop in paintComponenet that goes through all 100 balls every time I call it. I was worried that to move 100 balls I was painting 100x100 times.
So I put some System.out.println commands in my ball move loop, inside my object ball draw commands, and inside the paint component.
So even though I called repaint() 200 times (twice for each ball), repaint was actually only called once, drew all the balls at once, and then went back. And I just noticed it appears to have waited until I exited the calculateMoveBall loop to go into paintComponent! The spooky things is how does it know to do that? Does the Java machine 'see' that it is inside of a loop, and perhaps also sees the loop inside of paintComponent, and somehow correctly guesses that it doesn't have to do it 200 times, but can wait and do it once? If I attempt to do the same thing in code, take the loop out of paintComponent() and call repaint() with the current ball, expecting the machine to do exactly what I tell it, it refuses and does it's own thing, waiting to call paintComponent on the 100th ball, drawing only the last ball (so I guess the loop inside paintComponent is not in the logic).
So a call to repaint() is a request for a higher being to decide if it has the time or energy to repaint the clip. If not, it ignores the call, or stacks them up for later (maybe I should try a million and see if it has room for that!) - well so far up to 4000 it behaves the same. This is useful if you are happy with "this is how it works so use it that way". However I really don't like having some kind of hidden logic that I have to trust to work the right way. If I don't want it to wait until later I'm not sure what to do. And I don't trust the machine to do whatever whenever. How do you debug that???
Questions: Is there documentation to know what repaint() will do or how it decides when to call paintComponent? The Swing tutorial gives the example but not the why. "By now you know that the paintComponent method is where all of your painting code should be placed. It is true that this method will be invoked when it is time to paint" "An important point worth noting is that although we have invoked repaint twice in a row in the same event handler, Swing is smart enough to take that information and repaint those sections of the screen all in one single paint operation. In other words, Swing will not repaint the component twice in a row, even if that is what the code appears to be doing." (What the code appears to be doing - now we have to guess what it is doing)
Is there a way to force repaint() to call paintComponent on a clip rectangle (not just on the whole thing?) I would think invalidate() would force repainting of the whole componenet.
Perhaps this is when you draw to a bitmap in memory and paint the whole thing on the screen...
I'm wonder about the issue of constructor for arrays. Let say I have a class tablica, and one component int[] tab. If I get it right until now tab is nothing more than empty reference to some unexisting array?
import java.util.Random; class tablica{ int[] tab; tablica (){ // i wish it was constructor
[code]....
Then, I'm trying to build the constructor for class tablica. What can be the parameter of such constructor? Is it fields of array? It is simple forf for basic variable
- I liken values defined in constructor with those global defined in class. But how to do it with array component tab.
If I create array object in main method then how can I use this constructor?
In the program below I populated three arrays: student id, name, and GPA. The findStudent() method attempts to match users input with the input stored in the studentID array using an if/ else statement. When I use the if/ else statement the else always executes regardless if the IDs match? I am trying to get JOptionPane.showMessageDialog(null, "Incorrect entry"); to print only if the IDs don't match.
Java Code:
//FILE: StudentIDArray.java import javax.swing.*; //Used for the JOption dialog boxes import java.util.*; //Used for Scanner input public class StudentIDArray { boolean nameFound = true; final int numOfElements = 2; //Final int to control to loop for data
I'm working on a side project, which will eventually hopefully be a Pokedex, and I've just been going to it at the end of every chapter and using the stuff I've learned to work on it.So I just read chapter 3, which is all about variables and teaches how to use arrays.
my question is, does an array have to be declared inside a method? Because I'm trying to create an array inside a class without any methods and without the main, and I continuously get errors. Here's a quick working of my code that won't compile.
class blah { blah a[] = new blah[7]; a[0] = new blah(); }
The error message focuses on a[0] = new blah(); Telling me the 0 should be a ], the = is an illegal start of type, so on and so forth. The program compiles completely fine if it's within a method, like this:
class blah { void a() { blah a[] = new blah[7]; a[0] = new blah();
}
}
Or if I have public static void main (String[]args); But I'm trying to practice working outside of main.So does an array have to be within a method,
I have created a class and a matrix of doubles (or at least, I think I have, that's partly what I want to verify).I need to return the values of the array,Here is my class:
public class example{ double[][] Position=new double[2][11]; double calculate(){ for (int time=0;time<=10;time=time+1){ Position[1][time]=time; Position[2][time]=time+1; double A=Position[2][time]; return A; } } }
I am getting the error: "This method must return a result of type double", though to me it looks like I am returning double (A).
I am having trouble conceptualizing how to fill arrays. I understand that I can declare one and number it's elements, and it stores values of a certain data types. I don't really understand beyond that. Like how I would fill and use data in it.
I can be more specific with an assignment I have for school, but need to get started understanding how to fill arrays with data and then how to use that data.
So im making this ghost game where i display an 8x8 filled with 0s and a randomly generator five 1s in there I can get it to display 0s and add 1s, however sometimes the 1s that are randomly generated sometimes go on the same spot making it look like there are only four 1s. How would i go about fixing that?
package Grade12; import java.util.Random; public class Ghost { public static void main(String[] args) { Random generator = new Random(); int gameboard [][] = new int [8][8]; int randomx, randomy, counter = 0, sum = 0; for(int row = 0; row < 8; row++){ for(int col = 0; col < 8; col++){ (gameboard[row][col]) = 0; }
hours - An array of seven integers to hold the number of hours worked by each employee.payRate - An array of seven doubles to hold each employee's hourly pay rate.wages - An array of seven doubles to hold each employee's gross wages.The class should relate the data in each array through the subscripts.
For example, the number in element 0 of the hours array should be the number of hours worked by the employee whose identification number is stored in element 0 of the employeeID array. That same employee's pay rate should be stored in element 0 of the payRate array. In addition to the appropriate accessor and mutator methods, the class should have a method that accepts an employee's identification number as an argument and returns the gross pay for that employee.Demonstrate the class in a complete program that displays each employee number and asks the user to enter that employee's hours and pay rate. It should then display each employee's identification number and gross wages.Input Validation: Do not accept negative values for hours or numbers less than 6.0 for a pay rate.
My problem with this program is that everytime I try to print the employee ID's or the wages, I get hashcode or something like it (#[I1a77cdc or something like that). I tried using the toString method, but it lists all of the values, when I'm trying to display one at a time. Here is the code for the class:
// moduleArray class public class moduleArray { final int NUM_EMPLOYEES = 7; int[] employeeID = {5658845, 4520125, 7895122, 8777541, 8451277, 1302850, 7580489}; int[] hours = new int[NUM_EMPLOYEES];
[code]...
This is the demo program to list the ID's. I've been messing with it for some time, and right now I just want it to display values.
import java.util.Scanner; public class moduleArrayDemo { public static void main(String[] args) { final int NUM_EMPLOYEES = 7; int[] ID = new int[NUM_EMPLOYEES];
Okay, so the assignment was creating a word search for the given array. I've created all the code necessary, but I've ran into trouble. This problem occurs with the Up-Forward, Up-Backward, Down-Forward, and Down-Backward sections. If I only set one of these to run, it works. But if I have all 4 set at the same time, it errors out on the first one that runs.
public class P_WordSearch { public static void main(String[] args) { char[][] puzzle = { {'B','O','O','G','S','R','O','W','I','N','G'}, {'E','B','L','G','N','I','M','M','I','W','S'}, {'L','C','E','A','T','I','P','U','P','I','S'}, {'C','M','I','N','C','A','X','Y','O','S','N'},
I am trying to concatenate two arrays but on on compiling it is showing
Java Code: import static java.util.Arrays.*; class Mergesort { public static void main(String...s) { Mergesort r=new Mergesort(); int x[]={1,2,3,4,5,6}; int y[]={9,8,7,15,14,13,12,11};
