how to implement action listeners for an array of buttons. The program has an array of buttons like the number pad on a keyboard, when the user clicks a button the number/button clicked will append to the textfield. So far I'm just working on the GUI.
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
[code].....
regionsBuilder.setMultiChoiceItems(
displayNames, regionsEnabled,
new DialogInterface.OnMultiChoiceClickListener()
{
@Override
[code]...
Questions:
1. Describe what the code displays. A error message would be shown when the use has selected an insufficient number of options.
2. Describe when an event handler (included in the code) gets executed? The event handler gets executed every time a user selects an option(???)
3. Explain a feature of what is displayed
4. Explain the meaning of all of the parameters in the central, complicated call of the code.
5. Describe how the code handles two possible situations.When the user has selected a sufficient number of options (no less than or equal to 0), then no error message would be shown. On the other hand, an error message will be shown when the user has not selected a sufficient number of options (0). (???)
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] ....
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
[Code]....
I am trying to program an A* algorithm and I cannot even get past the buttons. I need a 2D array of buttons to handle this problem but I am getting the following errors.
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
at java.awt.AWTEventMulticaster.componentShown(AWTEventMulticaster.java:162)
[Code] ....
This is related to the book Head first JSP and Servlets 2nd edition. The books says that there are two types of custom tag handlers - Simple and classic. Classic tags are rarely used, so I'd like to skip them for now. I skipped a few pages related to classic and saw some new pages. I am not sure if these new pages are related to classic tags.
IterationTag lets you repeat the body When you write a tag handler that extends TagSupport, you get all the lifecycle methods from the Tag interface, plus the one method from IterationTag—doAfterBody(). Without doAfterBody(), you can’t iterate over the body because doStartTag() is too early, and doEndTag() is too late. But with doAfterBody(), your return value tells the Container whether it should repeat the body again (EVAL_BODY_AGAIN) or call the doEndTag() method (SKIP_BODY).
Default return values from TagSupport.If you don’t override the TagSupport lifecycle methods that return an integer, be aware of the default values the TagSupport method implementations return. The TagSupport class assumes that your tag doesn’t have a body (by returning SKIP_BODY) from do StartTag()), and that if you DO have a body that’s evaluated, you want it evaluated only once (by returning SKIP_BODY from doAfterBody()). It also assumes that you want the rest of the page to evaluate (by returning EVAL-PAGE from doEndtag()).
Using the code from the Java Docs (listed below) I am getting behavior that was a bit unexpected. The only changes were to add JTextField and additional output within the ComponentEvent handlers. Run the code and when the frame appears, think of each side as North, South, East (right side) and West (left side) as you are looking at it. This was run using JDK 1.7.0_25.
Run the code.
1 - Click the East edge (right) of the frame and drag to be wider or more narrow. Only the "Resized" is executed for all components which makes sense.
2 - Click the West edge (left) of the frame and drag to be wider or more narrow. This time "Resized" is executed for all components EXCEPT it is "Moved" for JFrame. Why is it "Moved" here for JFrame but not in Step 1?
3 - Click the South edge (bottom) of the frame and drag to be taller or shorter. This time only 2 components are affected. JPanel is "Moved" while JFrame is "Resized".Why isn't both JFrame and JPanel just "Resized"?
4 - Click the North edge (top) of the frame and drag to be taller or shorter. This time only 2 components are affected again but the output is slightly different. JPanel is "Moved" while JFrame is BOTH "Resized" and "Moved".
There just doesn't seem to be consistency here. What are the guidelines or criteria for when these Events are to be executed?
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class ComponentEventDemo extends JPanel
implements ComponentListener,
ItemListener {
[code]....
I have a WindowClosing(WindowEvent e) method, but when I close my window it isn't doing anything inside the method. I am making a launcher and I want to make it so when the actual game window is closed it makes the launcher window visible again.
Java Code: public void windowClosing(WindowEvent e) {
this.jf.setVisible(true);
} mh_sh_highlight_all('java');
How the event Listeners work in java,To get the data based on the event occurs in outside the application. I have this method in one of my API class I am not understanding how this methods are going to work.
public interface SBXPCXMLEventListener {
public void OnReceiveEventXML(String eventXML);
}
private static List<SBXPCXMLEventListener> listenerList = new ArrayList<SBXPCXMLEventListener>();
protected static void fireXMLEvent(String xml) {
[Code] ....
I have done like this.This is used to capture the events from the fingerprint machine when run this class I am not getting any data from the machine when i did thumb impression in the machine.
public class EventListnere implements SBXPCXMLEventListener {
public static void main(String[] args) {
boolean flag = SBXPCProxy.ConnectTcpip(1, "10.0.0.8", 5005, 1234);
System.out.println("flag = " + flag);
// SBXPCProxy.st
[Code] .....
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.
this is the first code
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
public class ChickenListener implements ActionListener {
int loopctrl;
static Connection cn;
static Statement st;
static ResultSet rs;
static PreparedStatement ps;
[Code]...
the second code
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
public class QuantityCounterListener implements ActionListener {
String tempStrng;
int tempInt;
int x = 0;
[Code]...
what my problem is i need to transfer what does "tempString" from code 1 holds to code 2 in the //x part in the prepared statement.
I'm not so new to java i know the basics. I want to make a mastermind game. Just for training purpose.
Now i am at the comparison phase where it is comparing your chosen "colors" with the actual "color code"
This is my code for that part:
guesChars is a char array of 4 of the actual code
readGuess is a string of 4 of which the players has filled in the console
goodGuess is a char at the right position with the right "color"
avgGues is a char with the right "color" at the wrong position
Java Code:
for(int i = 0; i < guessChars.length; i++){
for(int ii = 0; ii < readGuess.length(); ii++){
if(readGuess.charAt(ii) == guessChars[i]){
if(ii == i){
[Code] .....
The problem is when the code is for example
ACDD
and the player guess is
ADDD
Result is
2 right spot right color
1 right color wrong spot
It have to be
2 right spot right color
0 right color wrong spot
How would you begin a program that schedules events? I've found codes that are similar like Calendars, but I need something that will still import the real day, month, year. But I want to have columns that show Room numbers, and rows that shows time slots. How to get started such as which GUI components to use, what packages to import, etc.?
View Replies View RelatedI used java and jsf. I created dynamic datatable in java file. Can i call java method from setOnchange() event?
I am able to call java script function from setOnchange() event. See the below code which is working fine for java script.
HtmlSelectOneMenu selectOneMenu = new HtmlSelectOneMenu();
selectOneMenu.setStyleClass("dropdownStyleTwo");
selectOneMenu.setOnchange("openWin(this);IGNORE_UN LOAD=false");
I wrote openwin() function in java script. But i am not able to call java method change().
Code which is not working.
HtmlSelectOneMenu selectOneMenu = new HtmlSelectOneMenu();
selectOneMenu.setStyleClass("dropdownStyleTwo");
selectOneMenu.setOnchange("myclass.change();IGNORE _UNLOAD=false");
myclass is the bean of class Test. If user select any value from dropdown i want to call change java method. This function will apply the same selected dropdown value to the other record also.
I have one requirement where when i click on the attribute i would like to create an action and display the same in OutputText.
Ex:
This is Attribute Description outputText :
<rich:columnGroup id="CMAttributeBrowserDescriptionRow2">
<rich:column id="CMAttributeBrowserDescriptionColumn2" styleClass="selectedObj"
rendered="#{CMBrowserBean.attributePresent}" >
<!--<h:outputText id="SelectedObjectDescription1" render="true" value="#{currentAttribute.value}"/>-->
[b][quote]<h:outputText styleClass="attributeTableFont1" readonly="false" id="attributeTextdescription" disabled="false"/>[/quote][/b]
</rich:column>
</rich:columnGroup>
The action should be for :
<rich:column id="AttributeColumn2" styleClass="parentBrowserColumn">
[b]<a onclick="document.getElementById('CMBrowser:0:CMAttributeBrowserDescriptionForm:attributeTextdescription').value=#{currentAttribute.name}" >[/b]<h:outputText id="AttributeName" title="#{currentAttribute.name}" value="#{currentAttribute.name}"
styleClass="attributeValueFont" /></a>
</rich:column>
I am unable to get the text coming on outputText, when i click on the above attribute.
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?
View Replies View RelatedI have a list of Row objects and want to listen to changes in the name property of a Row object.
public class Row implements Serializable {
private final SimpleStringProperty name = new SimpleStringProperty(this, "name", "");
public Row() {
this("");
}
public Row(String name) {
this.name.set(name);
[Code] ....
I would expect to be notified 4 times. Line 23: Added, Line25, 26, 27: Update
But there are only 2 change events. For Line 26 and 27 there is no change event.
You're given a number between 0 and 1 that corresponds to the probability of an event occurring.
0.7 is 70%, 0.235 is 23.5%, 0 is 0%, etc.
Someone tries to perform the event, but the event only has the given probability of occurring. Run the probability, and then if it's true, run the event. Otherwise don't run the event.
All I know how to do is generate random numbers (kind of), but if you have 0.2245 I really don't see how generating random numbers can efficiently perform that probability.....
Which event is generated when a scrollbar is update?
View Replies View RelatedI'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] .....
I am trying to create an event handler for two JTextFields to only allow numerical input. It consumes all letter but for some reason the "n" key still gets through. I have the spaghetti code below.
public void keyTyped(KeyEvent in) {
char input = in.getKeyChar();
if (in.getSource() == scaleField){
if (!(Character.isDigit(input) ||
(input==KeyEvent.VK_BACK_SPACE) ||
[Code] ......
I'm reading a book titled 'Intro to Java Programming'. I understand all the Main Method stuff. I'm now reading a chapter that talks about event driven programming. I know how to do this in VBA and in C#, ut I can't figure out how this works in Java. Here's the sample code that I'm trying to run.
import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
[code]....
I'm using Net Beans IDE. When I paste that code into the IDE, I get all kinds of errors. Also, since there is no Main, I don't know how this is supposed to run. Java needs a Main Method for everything, I think. Does the Main call some kind of class?
I have a frame showing some textfields and a couple of buttons, the classical "Ok" and "Reset" buttons, which are supposed to confirm the values of the textfields (closing the frame) and reset them respectively.
I think I thoroughly followed the "delegation method procedure" for managing event, that is , create the button object, define a listener class (implementing the ActionListener interface) , and add the listener class to the button using the "addActionListener" method . But there's no way to make the whole thing work.
No exception. Only when I click the button the "actionPerformed" method of the listener is simply ignored, as if it didn't exist.
Here is the code :
public FrameViewAddEstrazione (String ExtrPath) {
try
{
FilePath = ExtrPath;
F = new JFrame ();
PP = new JPanel();
PD = new JPanel(); // pannello data
[Code] ....
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] ....
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();?
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.
I have a servlet which sends HTML5 server sent events to the jsp client. The servlet sends data to the client every one second. The jsp client instantiates a new eventsource and recieves the data. When the window is about to close, the jsp client closes eventsource at the "beforeunload" event (shown in the code below).
However, I have noticed that even after the client closes the eventsource and the browser exits, the server continues sending data. As far as the documentation on eventsource goes, using eventsource.close() is enough to stop client from reconnecting to the server and the server will stop sending any further push notifications.
Why the server does not stop sending push notifications even after eventsource.close() and the browser exit? Do I write any other piece of code to notify the server to stop sending data once client exits?
Pasted below are the servlet (server ) code and the client code.
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
[Code] .....