Modify GUI from object created inside the gui in c++ - java

I would like to ask about how can I add some text on the screen.
I have button, when I click on that, I create new object. It has a function which provide some data for me.
How can I acces that data from the gui? I cannot have a getter because it gives me data after some time(after connection to the server).
Is there possibilit to put text to textEdit within the object created inside of gui class?
thanks
I adding the code, explaining a little more, sry for confusing, thx for trying to help:
I have EchoClient object created inside of gui class:
void Comunication::startListening(){
if (this->client == NULL)
{
this->client = new EchoClient(QUrl(QStringLiteral("ws://localhost:1234")), 0);
QObject::connect(client, &EchoClient::closed, this, &QApplication::quit);
}
else
qWarning() << "Carefull, the client is already running";
}
then in my EchoClient i have function
void EchoClient::onTextMessageReceived(QString message)
{
if (!m_debug)
qDebug() << "Message received:" << message;
HERE I would like to change the ui stuff.
}

Yes, It's possible. But your question at the moment seems too broad or unclear [at least] to me. I assume that you're using Qt Creator with its designer. So you should be able to access a ui object (in your MainWindow class). Having this object in hand you can change UI at anytime and at anywhere.
So, first assign that text box (i.e. QLineEdit) an id (for example myLineEdit). Now, ui->myLineEdit gives you a QLineEdit * which is actually a reference to that text box. So wherever you'd like to update UI, you should have that reference. For example if you're using TCP socket programming for contacting remote services, in onReadyRead signal of a QTcpSocket, you can update the text box with data you just received:
QLineEdit *textbox = ui->myLineEdit;
textbox->setText("updated data");

I solved this problem with a getter and setter and another button
First button: start listening...creates EchoClient object, this opens the websocket, connects to websocket server. In case the message has arrived from server it goes to method from EchoClient class called onTextMessageRecieved, there it sets atribute message to the value of incoming message.
void EchoClient::onTextMessageReceived(QString message)
{
if (!m_debug)
qDebug() << "Message received:" << message;
setData(message); //setting atribute message
}
Second button: get data... this will call get method from EchoClient class. Comunication is my gui class.
void Comunication::on_getData_clicked()
{
ui->textEdit_2->setText(this->client->getData());
}
But this solution is not good enough, could yo please advice how to make it that as soon as there is new message my textEdit will be automaticly updated?
Should I do it in another thread? I dont have much experiences.
Thanks.

Related

JAVA gwt - saving info after refreshing page

At the moment , im working with java gwt and i stopped studdenly because one problem occured. I want that my information (for example string) will save after refresh button is clicked.
// user enters something in TextArea textArea1 object
Window.addWindowClosingHandler(new Window.ClosingHandler() {
public void onWindowClosing(Window.ClosingEvent closingEvent) {
//maybe there is a function or what
pleaseSaveInfomation(textArea1);
}
});
I tried this , but i know how to implement it correctly to my source code:
https://stackoverflow.com/a/14220746/5010218
The last(worst) chance is to store data from textArea in file.txt , after refreshing i could read info from file and thats all. But maybe GWT has a specific handler/method/class or what to handle this.
Thats for your opinion and help.
I had the same problem. You can easily overcome it with this.
import com.google.gwt.storage.client.Storage;
private Storage stockStore = null;
stockStore = Storage.getLocalStorageIfSupported();
Please read documentation
http://www.gwtproject.org/doc/latest/DevGuideHtml5Storage.html#UsingStorage
When a browser close a window (because of a refresh, or the user has closed the window, changed the url, etc), a script is not allowed to prevent this action. It's not specific to GWT.
However, you can suggest to the browser-agent to show a confirmation to the user. You can do this with the message property of the closing event.
In GWT:
Window.addWindowClosingHandler(new Window.ClosingHandler() {
public void onWindowClosing(Window.ClosingEvent closingEvent) {
closingEvent.setMessage("Confirm ?");
}
});
You shouldn't rely on this event to store your data, as a lot of condition can prevent you to do this. You should maybe periodically store a draft to the local-storage or to the server.
You probably want to store your data in sessionStorage. In GWT, this the Storage class.

Why doesn't the value passed to a method of a different class reflect in Java (using NetBeans 7.01)?

Before I start, Hi. This is is my first question here. I am not good with Java so have been trying and improve that and here it goes.
I am trying to create an email client and server application using sockets in Java. However I have been running into a problem. I have created a jFrame which is basically the Welcome window. The code is too huge to post so I'll post the relevant portions. There is a preferences jDialog. When the OK button on the dialog, an action handler comes in to play. The code:
private void okActionPerformed(java.awt.event.ActionEvent evt) {
Welcome wel = new Welcome();
wel.setStatusBar("Pressed OK");
dispose();
}
Obviously, the setStatusBar() sets the text of the statusLabel. The code for setStatusBar():
public void setStatusBar(String s)
{
statusLabel.setText(s);
}
Also, the preferences dialog is opened through menu item with this code:
private void jMenuItem2ActionPerformed(java.awt.event.ActionEvent evt) {
settings pref=new settings(null,true);
pref.show();
}
The problem is if I set the status label from any other class, for instance settings class, it does not reflect but if I do so from the Welcome class ( the class where the statusLabel is present), it works fine. This problem is not only limited to this setStatus() but virtually pops up whenever I try to use a method of a different class.
If you guys need more of the code, I could post it. I would be grateful if could help a Java beginner out.
Thanks.
private void okActionPerformed(java.awt.event.ActionEvent evt) {
Welcome wel = new Welcome();
wel.setStatusBar("Pressed OK");
dispose();
}
You're creating a new (hence the keyword new) object of type Welcome. This new object is different from the already existing object of type Welcome, that you have created earlier. It thus has its own label, and you're setting the text of this different label, which is not displayed anywhere in the screen.
Java objects work like regular object. Let's say you would like a cool logo on one of your blue t-shirts. You go to a T-shirt vendor and ask him to print a cool logo. The vendor doesn't have your blue t-shirt. If the vendor gets another red t-shirt from his shop and prints the logo on this red t-shirt, your blue t-shirt will still have no logo at all.
For the vendor to be able to print a logo on your blue t-shirt, you need to give him this blue t-shirt. Same in Java: you need to pass the existing Welcome object to the preferences dialog, and the actionPerformed method must set the label on this Welcome object. Not on a new Welcome object.

Listening for LogCat Entires made by my own application

Am I able to listen for messages being places into the LogCat by my own application?
For example something like...
// Somewhere in my application (on a background service):
Log.i("myModule", "Something been done");
and....
// Somewhere else something like...
LogCatListener logCatListener = new LogCatListener()
{
public void onInfoRecieved(String tag, String message)
{
//Do whatever you want with the message
}
}
I'm an Android noob so be gentle with me!
Thanks.
Unfortunately it looks like you directly can't do that for typical Log calls (.d, .i, .w). If you look at the source code of the Log class (https://android.googlesource.com/platform/frameworks/base/+/android-4.3_r2.1/core/java/android/util/Log.java) you'll see that these calls are just translated into a println_native, a private function mapped to a native implementation.
Also, the Log class is final, so you can't extend it and hook into .d , .i , .e, .w
I'm afraid your only solution is to write a Log class wrapper if you need to capture those calls. This will work for your custom Log's but obviously not for the system-issued calls to the Log class.
But good news is there's a special Log function that allows listeners. There's a funny method on the Log class:
public static TerribleFailureHandler setWtfHandler(TerribleFailureHandler handler)
And you can set a handler that will be called when you do
Log.wtf (TAG, message)
funny google method names :)

How can I detect a close in the browser tab?

Hello I am looking for information on the close tab (not browser) event if there is one in java for a applet. I am wondering if there is an event for that or a way to check a way to check for that. I would like to just capture the event and make a little popup box , stating Your session will expire or something along those lines. Is that possible at all or to a point with java or Javascript?
UPDATE: okay with the information you guys pointed me into i was able to get information on a simple enough javascript. Now it is working fine in IE , Chrome and Firefox but for some reason Safari 5.1.7 isn't liking the code. Not sure why. Here is the code if it helps.
jQuery(function() {
var hiddenBtn = document.getElementById("javaform:browserCloseSubmit");
try{
opera.setOverrideHistoryNavigationMode('compatible');
history.navigationMode = 'compatible';
}catch(e){}
//Sends the information to the javaBean.java file.
function ReturnMessage()
{
return hiddenBtn.click();
}
//UnBind Function
function UnBindWindow()
{
jQuery(window).unbind('beforeunload', ReturnMessage);
}
//Bind Exit Message Dialogue
jQuery(window).bind('beforeunload', ReturnMessage);
});
You have the onBeforeUnload event you can catch in JavaScript. See here.
Use window.onbeforeunload
window.onbeforeunload = function () {
return "Are you sure you want to exit?";
};
Note that it will also end in Are you sure you want to leave this page (or are you sure you want to reload this page if you are reloading)

Bridge between the Java applet and the text input controls on the web page

I have been working with a Java applet which is an applet that helps to write using only a mouse. For my case, I am trying to incorporate this into my webiste project as follows:
When the user clicks on any input element (textbox/textarea) on the page, this JAVA applet loads on the webpage itself. In the screenshot of the JAVA applet seen below, the user points to an alphabet to and the corresponding text gets written in the text box of the applet.
Now what I am trying to do is to get this text from the TextBox of the applet to the input element on the webpage. I know that this needs an interaction between the Java and JavaScript, but not being a pro, I really do not have the catch. Here's the Java applet and the code I have written.
Java applet and jQuery code (298kB): http://bit.ly/jItN9m
Please could somebdoy help for extending this code.
Thanks a lot!
Update
I searched somewhere and found this -> To get the text inside of Java text box, a getter method in the Applet to retrieve the text:
public class MyApplet extends JApplet {
// ...
public String getTextBoxText() { return myTextBox.getText(); }
}
In the JQuery code, the following lines are to be added I think:
var textBoxText = $("#applet-id")[0].getTextBoxText();
//Now do something with the text
For the code of the applet, I saw a GNOME git page here. The getText call already exists -- look at the bottom of this file: http://git.gnome.org/browse/dasher/tree/java/dasher/applet/JDasherApplet.java
I'd need to call 'getCurrentEditBoxText' but when should this method 'getCurrentEditBoxText' be called?
In my case, I would probably have to do it when the user clicks in a new input control etc.
You can have full communication between your Applet and any javascript method on the page. Kyle has a good post demonstrating how the Javascript can call the applet and request the text value. However, I presume you want the HTML Textfield to update with each mouse click, meaning the applet needs to communicate with the page. I would modify your javascript to something like this:
var activeTextArea = null;
$('textarea, input').click(function() {
$(this).dasher();
activeTextArea = this;
});
function updateText(text) {
// Careful: I think textarea and input have different
// methods for setting the value. Check the
// jQuery documentation
$(activeTextArea).val(text);
}
Assuming you have the source for the applet, you can have it communicate with the above javascript function. Add this import:
import netscape.javascript.JSObject;
And then, in whatever onClick handler you have for the mouse clicks, add:
// After the Applet Text has been updated
JSObject win = null;
try {
win = (JSObject) JSObject.getWindow(Applet.this);
win.call("updateText", new Object[] { textBox.getText() });
} catch (Exception ex) {
// oops
}
That will update the text each time that chunk of code is called. If you do NOT have access to the applet source, things get trickier. You'd need to set some manner of javascript timeout that constantly reads the value from the applet, but this assumes the applet has such a method that returns the value of the textbox.
See Also: http://java.sun.com/products/plugin/1.3/docs/jsobject.html
Update Modifying the applet is your best shot since that is where any event would be triggered. For example, if you want the HTML TextField to change on every click, the click happens in the applet which would need to be modified to trigger the update, as described above. Without modifying the applet, I see two options. Option #1 uses a timer:
var timer;
var activeTextArea;
$('textarea, input').click(function() {
$(this).dasher();
activeTextArea = this;
updateText();
}
function updateText() {
// Same warnings about textarea vs. input
$(activeTextArea).val($('#appletId')[0].getCurrentEditBoxText());
timer = setTimeout("updateText()", 50);
}
function stopUpdating() {
clearTimeout(timer);
}
This is similar to the code above except clicking on a text area triggers the looping function updateText() which will set the value of the HTML text field to the value of the Applet text field every 50ms. This will potentially introduce a minor delay between click and update, but it'll be small. You can increase the timer frequency, but that will add a performance drain. I don't see where you've 'hidden' the applet, but that same function should call stopUpdating so that we are no longer trying to contact a hidden applet.
Option #2 (not coded)
I would be to try and capture the click in the Applet as it bubbles through the HTML Dom. Then, you could skip the timer and put a click() behavior on the Applet container to do the same update. I'm not sure if such events bubble, though, so not sure if this would work. Even if it did, I'm not sure how compatible it would be across browsers.
Option #3
Third option is to not update the HTML text field on every click. This would simply be a combination of Kyle's and my posts above to set the value of the text field whenever you 'finish' with the applet.
Here's a possible solution. To get the text inside of your Java text box, write a getter method in the Applet to retrieve the text:
public class MyApplet extends JApplet {
// ...
public String getTextBoxText() { return myTextBox.getText(); }
}
In your JQuery code, add the following lines:
var textBoxText = $("#applet-id")[0].getTextBoxText();
//Now do something with the text
I found most of what I posted above here. Hope this helps.
This page explains how to manipulate DOM from a Java applet. To find the input element, simply call the document.getElementById(id) function with id of an id attribute of the text input box.

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