Swing/AWT/SWT :: Where Is Event Source Object
Feb 28, 2015
java.awt.Component is an abstract class, and it's direct Sub-classes are Button, Canvas, Checkbox, Choice, Container, Label, List, Scrollbar, Text Component
So, when I use addXListener(mylistenerclass m);//which is a method of Component class which object is holding the list of all listeners, for a particular Event Source?
I am under the assumption that - there is an Event Source Object(possibly static) for every Event Source type(mouse, keyboard etc) that holds a list of destinations(classes that implements their listener interface) - added to the the object via addXListener method. When an event happens(mouse click, drag etc) the Event Source Object creates an Event Object and send it to all the destinations. Is my assumption correct? I can't seem to find the location or declaration of Event Source Object and the list where it stores it's registered destinations.
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Sep 22, 2014
I’m teaching myself Java. I am a fairly proficient programmer in other languages, but this is the first OO language I’m doing.I have a question that is a bit hard to summarize. Or it should be: how can I pass on an object (or variable) to an event listener?
I am writing an application in which you can play a Sudoku game. I have separated the “logic” or the “model”(the classes with Sudoku data structures and methods to manipulate them) from the presentation (the view and the controller).The main method starts off as follows:
SudokuModel model = new SudokuModel();
SudokuView viewController = new SudokuViewController(model);
The first line creates class for the logic and the second line creates the class for the view and the controller. Since the view and the controller need access to the business logic, the model is passed on to the ViewController class.The SudokuViewController class creates the user interface in Swing and it handles the user input. For the user input I have created a number of listeners, like this:
table.addKeyListener(this);
Now these listeners need access to the model since they update it. However, as far as I’m aware the only parameter passed on to an event listener is the event itself. So these event listeners do not have direct access to the model, even though it is passed on to the constructor of the class SudokuViewController.
To circumvent this, I made model2 an attribute (variable) of the class SudokuViewController. The constructor of the class sets this variable as follows:
model2 = model;
Now the event listeners have access to model2, which they can manipulate.This works. However, I think it is an ugly solution, introducing an additional object (model2). I’d like to pass on the object named model to the event listener, but this doesn’t seem to be possible.
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Jun 18, 2014
We are doing a Timeline project, So this is what i want to do:
Pressing a "New Event" button opens the New event window where you are supposed to write input in three fields, name, date, and information. There is also a button "Create" that when i press that button, i want to take all the input from the fields and save/send it to our database, and go back to the timeline GUI. With this, i want a new event object to be created(in this case i have done several shapes in a group) so basically a new group i want to be added. All the information is suppose to be taken from the database right after i create it.
I'm pretty stuck on how i should solve this, for the moment have a group called event that i add on the canvas. First thing that pops up in my head is a void method that draws the event, or maybe a temporary array.. P
package application;
import controllers.CreateEventController;
import application.EventPop;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Cursor;
[Code] ....
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Mar 10, 2015
I have an application that uses an object that is declared globally for the class. Within a method that is triggered by a user event, it creates a new object and assigns it to this global object declaration. My question is, when the object is overwritten multiple times by the user selecting the button that calls this method, will the older instances be garbage collected or is there still a reference to them? Is there any downfall to this logic and if so what would be a solution.
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Jan 25, 2014
My problem is that I want to load an Image from the source directory in Canavas' paint() method.
My code is currently (in a try/catch)
g.drawImage(ImageIO.read(new File(imageLocation)), imageX, imageY, null);
Where imageLocation leads to an image on my HDD ("C:UsersVladdeDocumentsFolders-Filesfolder.png")
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Apr 23, 2014
I am new to threads, This is a project about 2048 game to be more accurate, and i want this project to run in this thread that i make in main...
My main:
public class Execute {
public static void main(String[] args){
Display d = new Display();
Shell s = new Shell(d);
Model m = new Game2048Model();
View ui = new Game2048View(m.getBoardArr(),d,s);
[Code] ....
And the error is:
Exception in thread "Thread-0" org.eclipse.swt.SWTException: Invalid thread access
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.widgets.Display.error(Unknown Source)
at org.eclipse.swt.widgets.Display.checkDevice(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at view.Game2048View.run(Game2048View.java:55) //problem at Run
at java.lang.Thread.run(Unknown Source)
Here is the problem....
@Override
public void run() {
while(!shell.isDisposed()){
if(!display.readAndDispatch()){
display.sleep();
}
}
display.dispose();
}
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Feb 22, 2014
I think will be easy for me start with a GUI and then make things happens when the user clic on Buttons.Is there a good book about Event driven development on Java?
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Jan 1, 2015
Which event is generated when a scrollbar is update?
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May 3, 2014
I'm having difficulty implementing keyboard and mouse event handlers at the same time for a program designed to notify the user when a key has been pressed or a mouse button clicked.
I can make and understand a program that does one or the other, but when I try to combine them, either the keyboard only or the mouse only works.
here is the code:
import java.awt.Color;
import java.awt.event.KeyListener;
import java.awt.event.KeyEvent;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import java.awt.event.MouseListener;
[Code] ....
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Feb 18, 2014
I'm trying to can make right button event to show a popup of copy/paste in a jtable but I put these code and doesn't works:
public class UI implements ActionListener, DocumentListener, MouseListener{
private JFrame ventana;
private JTable table;
private JPanel panel;
private JScrollPane tableScrollPane;
[Code] .....
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Oct 11, 2014
I have a bunch of textboxes in a panel and I wanted to perform the same code when the user clicks into a textbox (select all the text in it). Right now I've started adding a focusgained listener to each textbox like this:
private void textField1FocusGained(java.awt.event.FocusEvent evt) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
textField1.selectAll();
}
});
}
[Code]...
Is there a way I can have one focusgained listener that all the textfields can point to but have it pick the right textfield in the textFieldx.selectAll();?
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Feb 23, 2015
The scenario:
* A pop-up menu generates an array of rectangle objects; each rectangle having random x.y coords and colour.
* The number of rectangles in the array is user selected from the popup list.
* The APopUp class has a 'getter' method that returns the array.
* The pop-up object is instantiated in an object of the AFrame class.
* The AFrame object needs to get the array each time the popup changes its state.
The problem:
.
* As I see it, the AFrame object needs to informed of the pop-up's state of change event or does the problem lie in how I have decided
which responsibilities each class is to have? I've tried to be as logical as possible during planning.
In the days of FORTRAN or BASIC we would hammer a solution through with brute force, but I would like to keep to Java's philosophy
of encapsulation and clean interfaces and that it seems to has generated a impasse of brain warping proportions.
import java.awt.Frame;
import java.awt.Label;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
public class AFrame extends Frame implements ItemListener {
[code]....
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Aug 13, 2014
I would like to detect when the user change de JFrame. I make:
public class UI implements ActionListener, ComponentListener, DocumentListener, MouseListener{
private JFrame ventana;
private JTable table;
private JPanel panel;
private JScrollPane tableScrollPane;
[Code] ....
I put componentResized but when I change JFrame I cant see the string that I put in the method.
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Feb 21, 2015
How to deploy Java Swing application as windows software. I have tried the following to do this :
I have created jar file for my project after that created exe file using Launch4j and Advanced installer, exe file produced by both software are working fine but those are placing the jar file inside that exe file, My problem is any one who has that exe file can extract and view the source code by decompiling java class file. Is there any way to deploy java application without decompiling the code.
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Feb 10, 2015
I would like to get a checkbox within a table to fire an event when it's clicked rather. I gave tried putting in a TableModelListener but the the event only seems to trigger when I click on another column (as if the table is waiting to see if I will change my mind) before moving on.
I have also looked at the setValue of the TableModel itself.
Do I need to put an ActionListener on each checkbox or have I missed something ?
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Apr 15, 2009
I have a JTable that is within a JScrollPane. If I try to write add a MouseListener to the JTable it never fires. However, a mouse event does fire for the JScrollPane which it is added to. Is there a way to prevent the JScrollPane from capturing the event or passing it along to the JTable?
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Apr 28, 2015
I have in my application a button that when it is pressed, runs a long running task (usually takes a couple of seconds....).
My problem is that while the task runs, I want to stop the button from receiving clicks. Unfortunately this is something I have not achieved.
I have tried creating a new thread and calling the long running method, and using the Display.geCurrent().asyncExec...
Examples of what I have tried so far:
myButton.addSelectionListener(new SelectionAdapter() {
@Override
public void widgetSelected(SelectionEvent e) {
if (myList.size() > 0) {
myButton.setEnabled(false);
myButton.setGrayed(true);
[Code] .....
In both cases, while the button is disabled and the cursor busy, if the user clicks the button, the long running method is ran several times - and this is what I want to avoid.
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Mar 29, 2014
I want show one image when i click on one "href". I have write this code....
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Desktop;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.IOException;
[Code] ......
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Nov 23, 2014
In JButton's click event, I wanto to show a JPanel to print the message "Processing" on the screen. Before JButton's click logic end, hide the JPanel.
Actually, JPanel is not displayed. I do not know why.When msgPanel .setVisible(false); is commented out, JPanel is normally displayed .But do not know how to hide it when JButton's click logic is finished.
Here is the code.
loadBtn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
JPanel msgPanel = new JPanel(rootFrame);
// Show the message JPanel
[Code] .....
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Mar 25, 2014
I use the right term, release resources because after clicking the close button, the DOS prompts becomes unresponsive. So I have to close the DOS prompt, then reopen it, then type in the path again for the Java folders. Can you check where did I go wrong with my code? Is my placement of the WindowListener and WindowAdapter incorrect? Please refer to my code below:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
public class Proj6exe1 extends JFrame implements ActionListener
{
DataOutputStream dataLabas;
JTextField rainFallField;
JButton submit;
String strRainFall;
JPanel proj6Panel;
[code]...
I have other programs where the placement of the WindowListener and WindowAdapter are as exactly like this (within the class constructor block) where they close correctly and some that behave like this, that renders the DOS prompt unresponsive.
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Feb 12, 2014
I have a JFrame where some elements (one, for now) have to be centered manually on the contentPane when resizing the window or changing the window state. Resizing event (componentResized) works fine but the windowStateChanged event is causing problems because it doesn't seem to "update" the contentPane's new size properly - it keeps the previous value although the window's size is obviously changed. This can be seen by simply printing the result of getSize called on contentPane.
Centering is done by programmatically changing the constraint of the component (using putConstraint, SpringLayout). The issue is that getWidth used in that method returns "wrong" values which results in an uncentered component. Maybe another listener is needed here?
Additional info: Eclipse with WindowBuilder, Linux Mint 15, Java 1.7
I know about SSCCE guidelines but I cannot make this particular example both ready to compile and short.For unknown reasons, I am unable to post the code example. I keep getting this - "Post denied. New posts are limited by number of URLs it may contain and checked if it doesn't contain forbidden words."
addWindowStateListener(new WindowStateListener()
{
// no "@Override" was generated but it is the same with it
public void windowStateChanged(WindowEvent e)
{
System.out.println("EVENT: " + contentPane.getSize() + ", "
+ getExtendedState() + ", " + e.getOldState()); // amusingly, states are actually correct - interchanging between 0 (Frame.NORMAL) and 6 (Frame.MAXIMIZED_BOTH) when I maximize and "unmaximize"
tfArrayPanelCenter();
[code]....
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Dec 30, 2014
I have two classes involved in this portion. CheckIn_Search
(class #1) is my main UI and I am collecting search information from the user in a jPanel form. When they click "Search" it passes the search criteria to a method that contacts a web service and gets the results. These results are passed to coSearchResults
(class #2) that opens a jFrame and jTable (in modal format, over the main window created by CheckIn_Search.
The user selects a row in the table and that selection data is passed back to coSearchResults to populate a new jPanel form. When the data is passed from coSearchResults, I want to close its window, hide the first jPanel in CheckIn_Search and make the second jPanel visible. To accomplish this, I created a method in CheckIn_Search that simply hides/shows the panels (it will do more later).
I instantiate and call the method in CoSearchResults as part of the button click event. The problem is, it doesn't work. The panels are unaffected and there are no errors. I've put in break-points and it goes into the method.. Here is the coSearch_Results code.
Here is am retrieving the jtable row id and using the first value in the row to get the data from the table model as there is more data than what is displayed in the table. I'm sending that whole row of data to the method that changes visibility.
private void btnOKActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_btnOKActionPerformed
// TODO add your handling code here:
int rowNum = jTable1.getSelectedRow();
String coNum = jTable1.getValueAt(rowNum,0).toString();
String[] text;
[code]....
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Mar 27, 2015
can a keyevent in java make the space ship and the laser too ?
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Feb 18, 2014
I'm trying to right a GUI in swing, and as part of my program, I want to open a secondary window out of the main window when a mouse clicks on the main window. Then, once I click a button on the secondary window, I want that window to close and submit data to the main window (like an info form). I have almost figured out how to do this, except for one problem. By putting a variable inside my form window called "ready," and then in my main window running a loop that constantly checks if ready is true and doesn't proceed until its true, I can create the form window, modify the values in it (currently just one value called "difficulty" that's modified by a jSlider), and then when i click the "begin" button, ready is changed to true, the form window closes, and the main window can proceed. However, when I try to put the while loop checking the ready variable inside a mouseClicked method in the main window, the form window freezes when it opens, and you can't see any of its content or modify it in any way (you can't even close it).
Here is my code:
//form window class
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class formWindow extends JFrame {
private JTextField instructions1;
[Code]...
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Jan 15, 2015
What I want to do is have a label that is updated whenever an object gets some new, relevant data.The way you do it in Java looks different from the way we do it in Objective-C. In Objective-C, we have what's known as a protocol. An Objective-C protocol is almost exactly like a Java "implementation." In Obj-C, if I want the user to see the address of where he is, I can have an object that gets the information and invokes a view controller's method; at that point, the view controller would then take the data passed to it and display the data in a label. However, the view controller is an instance of a subclass of the bundled view controller class.
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Jun 11, 2014
I am trying to find either some references to point me on the right track with passing an object with all of it's properties still in tact after it's been created. Currently I am trying to do this through an interface but it seems to just create a new object everytime without the properties. Example below :
import java.util.ArrayList;
import java.util.List;
public interface TPerson{
//public Person p = null;
}
class Thrower {
Person p;
[code]....
When I implement the interface on the other objects as soon as I call the setP method shown above it seems to just create a new one even though I pass the object to the method I want to use.
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