QPointerEvent throws error

curiosity

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.

curiosity

This post is deleted!

Christian Ehrlicher

And now please format your code with the code (</>) tags so it is readable for others.
Your header does not match the source - this does not compile. And then you have a local variable echoLabel but connect the member later on...

curiosity

@Christian-Ehrlicher
//NewWidget.cpp

#include "NewWidget.h"
#include <iostream>
using namespace std;

#include <QComboBox>
#include <QGridLayout>
#include <QGroupBox>
#include <QLabel>
#include <QLineEdit>
#include <QtWidgets>


Window::Window(QWidget *parent) QWidget(parent)
{
    QGroupBox *echoGroup = new QGroupBox(tr("Echo"));

QLabel *echoLabel = new QLabel(tr("Mode:"));
QComboBox *echoComboBox = new QComboBox;
echoComboBox->addItem(tr("Normal"));
echoComboBox->addItem(tr("Password"));
echoComboBox->addItem(tr("PasswordEchoOnEdit"));
echoComboBox->addItem(tr("No Echo"));


echoLineEdit = new QLineEdit;
echoLineEdit->setPlaceholderText("Placeholder Text");

QLabel *passwordLabel = new QLabel(tr("Password entered is :"));
passwordLineEdit = new QLineEdit;

QGroupBox *validatorGroup = new QGroupBox(tr("Validator"));

QLabel *validatorLabel = new QLabel(tr("Type:"));
QComboBox *validatorComboBox = new QComboBox;
validatorComboBox->addItem(tr("No validator"));
validatorComboBox->addItem(tr("Integer validator"));
validatorComboBox->addItem(tr("Double validator"));

validatorLineEdit = new QLineEdit;
validatorLineEdit->setPlaceholderText("Placeholder Text");

QGroupBox *alignmentGroup = new QGroupBox(tr("Alignment"));

QLabel *alignmentLabel = new QLabel(tr("Type:"));
QComboBox *alignmentComboBox = new QComboBox;
alignmentComboBox->addItem(tr("Left"));
alignmentComboBox->addItem(tr("Centered"));
alignmentComboBox->addItem(tr("Right"));

alignmentLineEdit = new QLineEdit;
alignmentLineEdit->setPlaceholderText("Placeholder Text");/>

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

connect(validatorComboBox, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated),this, &Window::validatorChanged);
connect(alignmentComboBox, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated), this, &Window::alignmentChanged);

QGridLayout *echoLayout = new QGridLayout;
echoLayout->addWidget(echoLabel, 0, 0);
echoLayout->addWidget(echoComboBox, 0, 1, Qt::AlignLeft);
echoLayout->addWidget(echoLineEdit, 1, 0, 1, 2);
echoLayout->addWidget(passwordLabel, 2, 0);
echoLayout->addWidget(passwordLineEdit, 2, 2, 1, 2 );
echoLayout->setRowStretch(0, 5);
echoGroup->setLayout(echoLayout);

QGridLayout *validatorLayout = new QGridLayout;
validatorLayout->addWidget(validatorLabel, 0, 0);
validatorLayout->addWidget(validatorComboBox, 0, 1);
validatorLayout->addWidget(validatorLineEdit, 1, 0, 1, 2);
validatorGroup->setLayout(validatorLayout);

QGridLayout *alignmentLayout = new QGridLayout;
alignmentLayout->addWidget(alignmentLabel, 0, 0);
alignmentLayout->addWidget(alignmentComboBox, 0, 1);
alignmentLayout->addWidget(alignmentLineEdit, 1, 0, 1, 2);
alignmentGroup-> setLayout(alignmentLayout);


QGridLayout *grid = new QGridLayout;
grid->addWidget(createFirstGroup(), 0, 1);
grid->heightForWidth(10);
grid->setRowStretch(0,50);

//setWindowTitle(tr("Radio Buttons"));


QGridLayout *layout = new QGridLayout;
layout->addWidget(echoGroup, 0, 0);
layout->addWidget(validatorGroup, 1, 0);
layout->addWidget(alignmentGroup, 2, 0);
layout->addWidget(createFirstGroup(), 0, 1);
//layout->addWidget(accessGroup, 1, 1);
setLayout(layout);

setWindowTitle(tr("Line Edits"));

}

QGroupBox *Window::createFirstGroup()
{
    QGroupBox *groupBox = new QGroupBox(tr("Radio Buttons group"));

    QRadioButton *radio1 = new QRadioButton(tr("&Radio button 1"));
    QRadioButton *radio2 = new QRadioButton(tr("R&adio button 2"));
    QRadioButton *radio3 = new QRadioButton(tr("Ra&dio button 3"));

    radio1->setChecked(true);

    QVBoxLayout *vbox = new QVBoxLayout;
    vbox->addWidget(radio1);
    vbox->addWidget(radio2);
    vbox->addWidget(radio3);
    vbox->addStretch(1);
    groupBox->setLayout(vbox);
    resize(100, 200);

    return groupBox;
}

void Window::echoChanged(int index)
{
    switch (index) {
    case 0:
        echoLineEdit->setEchoMode(QLineEdit::Normal);
        break;
    case 1:
        echoLineEdit->setEchoMode(QLineEdit::Password);
        break;
    case 2:
        echoLineEdit->setEchoMode(QLineEdit::PasswordEchoOnEdit);
        break;
    case 3:
        echoLineEdit->setEchoMode(QLineEdit::NoEcho);
        break;
    }
}

void Window::validatorChanged(int index)
{
    switch (index) {
    case 0:
        validatorLineEdit->setValidator(nullptr);
        break;
    case 1:
        validatorLineEdit->setValidator(new QIntValidator(
            validatorLineEdit));
        break;
    case 2:
        validatorLineEdit->setValidator(new QDoubleValidator(-999.0,
            999.0, 2, validatorLineEdit));
        break;
    }

    validatorLineEdit->clear();
}

void Window::alignmentChanged(int index)
{
    switch (index) {
    case 0:
        alignmentLineEdit->setAlignment(Qt::AlignLeft);
        break;
    case 1:
        alignmentLineEdit->setAlignment(Qt::AlignCenter);
        break;
    case 2:
        alignmentLineEdit->setAlignment(Qt::AlignRight);
        break;
    }
}

void Window::onCurrentTextChanged(const QString &text)
{
qDebug() << QString(" entered text is ")<< text;
passwordLineEdit->setPlaceholderText("Password entered is : ");
passwordLineEdit->setText(text);
passwordLineEdit->show();
passwordLineEdit->setEchoMode(QLineEdit::PasswordEchoOnEdit);
}

curiosity

@Christian-Ehrlicher

I tried formatting it. but this was how it shoed up after posting NewWidget.cpp

#ifndef WINDOW_H
#define WINDOW_H

#include <QWidget>
#include <QLineEdit>
#include <QDebug>

QT_BEGIN_NAMESPACE
class QLineEdit;
class QGroupBox;
QT_END_NAMESPACE


class Window : public QWidget
{
    Q_OBJECT

public:
    QLineEdit *passwordLineEdit;

    Window(QWidget *parent = nullptr);

private:
    QLineEdit *echoLineEdit;
    QLineEdit *validatorLineEdit;
    QLineEdit *alignmentLineEdit;

public slots:
    void echoChanged(int);
    void validatorChanged(int);
    void alignmentChanged(int);
    QGroupBox *createFirstGroup();

};

#endif

//Main.cpp

#include <QApplication>

#include "NewWidget.h"

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Window window;
    window.show();
    return app.exec();
}

code is compiling and running.. except that it is not echoing the text entered

Christian Ehrlicher

Please read my post carefully and fix the errors in your code.