QPointerEvent throws error

curiosity

i switched to qt creator.

i have an error here with signals and slots

looks like i have right signals and slots. but not getting about this errorgetting about

JonB

@curiosity
Start by showing definition of the two slot functions you use.
Is this an error only in the code completion inside Qt Creator, or do you get these errors when you actually compile?

jsulm

@curiosity You probably need to tell the compiler which overload you want to connect, see https://wiki.qt.io/New_Signal_Slot_Syntax#Overload

curiosity

@JonB
these are errors in QtCreator. i am yet to compile.

jsulm

@curiosity Well, then compile.
Code model can produce false errors in QtCreator.

curiosity

@jsulm

i am trying to print the edited text(values entered by the user) onto the console. but still getting this error

Christian Ehrlicher

SIGNAL(&QLineEdit::textEdited)

really?

You should read the Qt signals and slot documentation and also re-read the wiki page which @jsulm already pointed you to.

curiosity

@Christian-Ehrlicher

connect(echoComboBox, &QComboBox::editTextChanged(echoLineEdit),
        this, [=](const QString &edited){qDebug() << edited;});

i made the above change. but signal is giving error
"call to non static function without an object argument". editTextChanged has qstring . i tried with qsting and qlineEdit as arg. its giving same error with both

jsulm

@curiosity Please read the documentation! What you're doing is simply wrong and not even valid C++!
You do not pass parameters when calling connect! Parameters are passed to the signal when it is emitted and then from the signal to slot.

connect(echoComboBox, &QComboBox::editTextChanged,
        this, [=](const QString &edited){qDebug() << edited;});

curiosity

@jsulm

thanks for correcting.

i am trying to echo the text entered by the user into QCombobox in the next line.

connect(echoComboBox, &QComboBox::currentTextChanged,this, &Window::onCurrentTextChanged);

    auto text = echoComboBox->currentText();
 passwordLineEdit = new QLineEdit;

    passwordLineEdit->setPlaceholderText("Password entered is : ");     //But this line is displayed in a new window. and password is not echoed.

passwordLineEdit->show();

    echoComboBox->show();

JonB

@curiosity said in QPointerEvent throws error:

//But this line is displayed in a new window

You have created a new QLineEdit but not put it anywhere (e.g. on an existing window), so where do you expect it to go? I do not know why you are choosing to create a new QLineEdit dynamically, but give it a parent and/or place it on some widget's layout.

I really don't know what you are doing with a combobox."i am trying to echo the text entered by the user into QCombobox" --- what text is being entered how by user into combobox. Why in the world would you have a combobox, to choose an existing item from, if you want a user to enter a line of text for a password?

passwordLineEdit->setPlaceholderText("Password entered is : "); //But this line is displayed in a new window. and password is not echoed.

"Password is not echoed", what do you mean or expect? All you have done here is set the placeholder text of a QLineEdit to a fixed string. I see nothing in your code which perhaps copes/displays the auto text = echoComboBox->currentText(); anywhere.

@jsulm gave you sample code for picking up changed edited text. All you have to do is change his lambda slot to (preferably using his signal) to call a method of you own, like you show with &Window::onCurrentTextChanged, and write the code in that to access the current text or the text parameter sent from void QComboBox::editTextChanged(const QString &text) signal.

jsulm

@curiosity said in QPointerEvent throws error:

auto text = echoComboBox->currentText();
passwordLineEdit = new QLineEdit;
passwordLineEdit->setPlaceholderText("Password entered is : ");

Please think about this code and why it can't do what you want it to do and why you get a new window.
@JonB gave you all needed hints.

curiosity

@jsulm @JonB

echoLayout->addWidget(passwordLabel, 2, 0);
echoLayout->addWidget(passwordLineEdit, 2, 1, 2, 3 );
this is added to the grid layout

QObject::connect(echoComboBox, &QComboBox::editTextChanged, this, [=](const QString &text) {
Window::onCurrentTextChanged(text);
});

void onCurrentTextChanged(const QString &text)
{
    passwordLineEdit->setPlaceholderText("Password entered is : ");
    passwordLineEdit->setText(text);  //Is this the right way to set the text   received from above signal. }

value entered is still not reflecting

jsulm

@curiosity said in QPointerEvent throws error:

QObject::connect(echoComboBox, &QComboBox::editTextChanged, this, [=](const QString &text) {
Window::onCurrentTextChanged(text);
});

There is no need for a lambda, just connect onCurrentTextChanged directly to the signal.

curiosity

@curiosity

JonB

@curiosity said in QPointerEvent throws error:

value entered is still not reflecting

Not sure where you are at now. Yes, calling passwordLineEdit->setText(text); should set the text from the string. Check what is in the string. Check you are getting the signal by putting a qDebug() or something in the slot so that you know it is being called.

curiosity

@JonB
Ialready checked by planting a breakpoint in onCurrentTextChanged . on running and entering the text in the place holder i was expecting to hit the breakpoint, but it didnt hit.
this is my connect statement

connect(echoComboBox,&QComboBox::editTextChanged, this, &Window::onCurrentTextChanged);

void onCurrentTextChanged(const QString &text)
{
    qDebug() << QString(" entered text is ")<<  text;

//nothing is printed here in the application tab in qtcreator. it is not even hitting this breakpoint
passwordLineEdit->setPlaceholderText("Password entered is : ");
passwordLineEdit->setText(text);
passwordLineEdit->show();
passwordLineEdit->setEchoMode(QLineEdit::PasswordEchoOnEdit);

Christian Ehrlicher

@curiosity said in QPointerEvent throws error:

void onCurrentTextChanged(const QString &text)...

This is a free function... How does this even compile?

Please provide your full relevant code which actually compiles.

curiosity

@Christian-Ehrlicher
but i am using this as a slot. Please check the connect statement

Christian Ehrlicher

void MainWindow::onCurrentTextChanged() and void onCurrentTextChanged() are two different functions. Provide your full code including the header.