Solved same signal-slot connection in two windows
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@russjohn834
No, because you show the case which works OK. We need to see exactly howSettings
callsPatients
, plus the signal connections, with whatever is relevant to that case, to judge where the problem is. -
This is how I call
Patients
fromSettings
void Settings::on_pushButton_patients_clicked() { this->close(); stagetwo = new Patients(this); stagetwo -> show(); }
where
stagetwo
is publicpublic: Settings(QString,QWidget *parent = nullptr); ~Settings(); Patients *stagetwo;
In the
Patients
signal connection is as below:Patients::Patients( QWidget *parent) : QMainWindow(parent), ui(new Ui::Patients) { ui->setupUi(this); connect(&api, &tetra_grip_api::tetraGripEvent,this, &StageTwoPatients::eventHandlerTwo); }
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@russjohn834 said in same signal-slot connection in two windows:
void Settings::on_pushButton_patients_clicked()
{
this->close();
stagetwo = new Patients(this);
stagetwo -> show();
}Just to humour me, replace by
void Settings::on_pushButton_patients_clicked() { // this->close(); // stagetwo = new Patients(this); stagetwo = new Patients(nullptr); stagetwo -> show(); }
Any better behaviour?
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Can't see any change.
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@russjohn834
Very last thing: how do you know slot is not being called? Please place a breakpoint on it. -
@JonB
I did try with a breakpoint, and convinced that the slot is not being called when thePatients
window is constructed.
So I guess that's a serious issue using global class instance. Though I was trying to understand why this is happening .. -
@russjohn834
There should be no problem. I don't know what the difference is in your working vs non-working situations, I'm afraid. -
@mrjj
can you think of a reason why this second scenario not working?I have signal connection in two windows ,
Settings
andPatients
In
Settings
:Settings::Settings( QWidget *parent) : QMainWindow(parent), ui(new Ui::Settings) { ui->setupUi(this); connect(&api, &tetra_grip_api::tetraGripEvent,this, &Settings::eventHandler); ... }
api
is global instance of a class.And in
Patients
:Patients::Patients( QWidget *parent) : QMainWindow(parent), ui(new Ui::Patients) { ui->setupUi(this); connect(&api, &tetra_grip_api::tetraGripEvent,this, &Patients::eventHandlerTwo); }
Situation1 - Working
I construct both
Settings
andPatients
window fromMain
#include <QApplication> tetra_grip_api api; int main(int argc, char *argv[]) { QApplication a(argc, argv); api.openSerialPort(); QObject::connect(api.serial, SIGNAL(readyRead()), &api, SLOT(readData())); Settings w(nullptr); //---->this behaves right Patients v(nullptr); //---- >this behaves right v.show(); w.show(); return a.exec(); }
By working I mean , both the slots are being called , and
QLabel
set text accordinglySituation 2 - Not working
I call
Patients
fromSettings
:void Settings::on_pushButton_patients_clicked() { this->close(); stagetwo = new Patients(this); stagetwo -> show(); }
where
stagetwo
is publicpublic: Settings(QString,QWidget *parent = nullptr); ~Settings(); Patients *stagetwo;
Here
Settings
works just fine (slot being called) but slot inPatients
,eventhandlerTwo
is not being called at all. -
@russjohn834 Can you test what happens if you
hide()
the Settings instead ofclose()
them?void Settings::on_pushButton_patients_clicked() { this->hide(); stagetwo = new Patients(this); stagetwo -> show(); }
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@jazzco2 Did try that, in both case (
hide
orclose
) slot in thePatients
not being called -
@russjohn834
Try commenting out inSettings::Settings
connect(&api, &tetra_grip_api::tetraGripEvent,this, &Settings::eventHandler);
Let's not have
Settings
connected to the signal while we sort outPatients
. -
Ok, I just wondered what happens, because
close()
may delete yourSettings
afterwards and you have no access to neitherSettings
norPatients
. What about the other tests:-
Did it help to pass the pointer to Settings and to Patients in the constructor?
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In what order are the debug messages when you add them in
Settings::eventHandler()
and after connecting and disconnecting (destructor) in Settings and Patients? (I wonder if the connection is cut off before it is called)
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@jazzco2
I suggested earlier that OP run for now withvoid Settings::on_pushButton_patients_clicked() { // this->close(); // stagetwo = new Patients(this); stagetwo = new Patients(nullptr); stagetwo -> show(); }
Although it apparently did not solve, I suggest he revert to that code while sorting this out. It will remove some irrelevant paths of investigation.
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Maybe it would be easier if the OP could provide a minimal, compilable example of his problem so we can try it out by ourself. I see a good chance here that the current code is that confusing that no suggestion from here will ever help.
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@JonB Yes that's fine. It also should be ensured that
-
both
&api
references point to the same instance.
-> add debug messages at eachconnect(..)
to display the pointer -
the connection is alive
-> add several debug messages as I pointed out earlier -
the signal
tetraGripEvent()
is emitted in both cases
-> keepSettings
alive (usinghide()
instead ofclose()
) and add a debug message inSettings::eventHandler
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@Christian-Ehrlicher
Please find here the minimal version of both the class files (.cpp and .h and main)main.cpp
#include "settings.h" #include "tetra_grip_api.h" #include <QApplication> tetra_grip_api api; int main(int argc, char *argv[]) { QApplication a(argc, argv); api.openSerialPort(); QObject::connect(api.serial, SIGNAL(readyRead()), &api, SLOT(readData())); Settings w(nullptr); w.show(); return a.exec(); }
Settings.cpp
#include "settings.h" #include "ui_settings.h" #include "tetra_grip_api.h" Settings :: Settings (QWidget *parent) : QMainWindow(parent) QMainWindow(parent) , ui(new Ui::Settings ) { ui->setupUi(this); connect(&api, &tetra_grip_api::tetraGripEvent,this, &Settings::eventHandler); } Settings ::~Settings () { delete ui; } void Settings::on_pushButton_exit_clicked() { QApplication::quit(); } void Settings::on_pushButton_patients_clicked() { this->hide(); stagetwo = new Patients(this); stagetwo -> show(); } void Settings::eventHandler(STIM_GUI_TOPIC_T topic, uint8_t reg, uint32_t value) { if (topic==TOPIC_STIMULATOR) { switch(reg) { case STIM_REG_BATTERY_CAPACITY_REMAINING: ui->label_statusBat->setText("Battery remaining: "+QString::number(value)+"%"); break; } } }
settings.h
#ifndef SETTINGS_H #define SETTINGS_H #include <QMainWindow> #include "patients.h" #include <QtSerialPort/QSerialPort> #include "tetra_grip_api.h" #include <QDebug> QT_BEGIN_NAMESPACE namespace Ui { class Settings; } QT_END_NAMESPACE class Settings : public QMainWindow { Q_OBJECT public: Settings(QWidget *parent = nullptr); ~Settings(); Patients *stagetwo; private slots: void on_pushButton_exit_clicked(); void on_pushButton_patients_clicked(); public slots: void eventHandler(STIM_GUI_TOPIC_T topic, uint8_t reg, uint32_t value); private: Ui::Settings *ui; }; #endif
patients.cpp
(I'm giving a bit more details here because here the slot not being called fromSettings
)..I have a table here , user can select an entry to do something else...#include "patients.h" #include "ui_patients.h" #include "settings.h" #include <QDebug> #include <QFile> #include <QDirIterator> #include <QXmlStreamReader> #include <QMessageBox> #include "tetra_grip_api.h" Patients::Patients(QWidget *parent) : QMainWindow(parent), ui(new Ui::Patients) { ui->setupUi(this); connect(&api, &tetra_grip_api::tetraGripEvent,this, &Patients::eventHandlerTwo); // Setup table ui->tableWidget->setColumnCount(5); ui->tableWidget->setHorizontalHeaderLabels(QStringList{"Patient ID","Name", "Surname", "LastSession", "Note"}); ui->tableWidget->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch); ui->tableWidget->setSelectionBehavior(QAbstractItemView::SelectRows); QString path = QCoreApplication::applicationDirPath()+"/data/"; QStringList qdiFilter("*.xml"); // patientData data; QDirIterator qdi( path, qdiFilter, QDir::Files); while (qdi.hasNext()) { parseDataEntry(qdi.next()); //data.parseDataEntry(qdi.next()); } } void Patients::parseDataEntry(const QString dataPath) { QString patientID, firstName, surName, lastSession = "", pNote; // Load our XML file. QFile *xmlFile; xmlFile = new QFile(dataPath); if(!xmlFile->open(QIODevice::ReadOnly | QIODevice::Text)) { QMessageBox::critical(this, "Error Loading Patient Data File", QString("Could not load the patient XML data file at:\r\n %0").arg(dataPath), QMessageBox::Ok); return; } // Create an XML reader. QXmlStreamReader *xmlReader; xmlReader = new QXmlStreamReader(xmlFile); // Parse each element of the XML until we reach the end. while(!xmlReader->atEnd() && !xmlReader->hasError()) { // Read next element QXmlStreamReader::TokenType token = xmlReader->readNext(); // If token is just StartDocument - go to next if(token == QXmlStreamReader::StartDocument) { continue; } // If token is StartElement - read it if(token == QXmlStreamReader::StartElement) { if(xmlReader->name() == "Name") { firstName = xmlReader->readElementText(); } else if(xmlReader->name() == "Surname") { surName = xmlReader->readElementText(); } else if(xmlReader->name() == "Patient_ID") { patientID = xmlReader->readElementText(); } else if(xmlReader->name() == "Date") { lastSession = xmlReader->readElementText(); } else if(xmlReader->name() == "Clinician_Note") { pNote = xmlReader->readElementText(); } } } if(xmlReader->hasError()) { QMessageBox::critical(this, "Error Parsing Patient Data File", QString("Error reading the patient file at:\r\n %0,\r\nError: %1").arg(dataPath, xmlReader->errorString()), QMessageBox::Ok); return; } // close reader and flush file xmlReader->clear(); xmlFile->close(); // Delete delete xmlFile; delete xmlReader; // Add a new row to the table, with the data we parsed. ui->tableWidget->insertRow(ui->tableWidget->rowCount()); ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 0, new QTableWidgetItem(patientID)); ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 1, new QTableWidgetItem(firstName)); ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 2, new QTableWidgetItem(surName)); ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 3, new QTableWidgetItem(lastSession)); ui->tableWidget->setItem(ui->tableWidget->rowCount() - 1, 4, new QTableWidgetItem(pNote)); // ui->tableWidget->setCellWidget(ui->tableWidget->rowCount()-1,3, new QTableWidgetItem(lastSession)) } Patients::~Patients() { delete ui; } void Patients::on_pushButton_Open_clicked() { QModelIndexList selection=ui->tableWidget->selectionModel()->selectedRows(0); qDebug()<<"\n The content is"<<selection[0].data().toString(); ... } void Patients::eventHandlerTwo( STIM_GUI_TOPIC_T topic, uint8_t reg, uint32_t value) { ui->label_test->setText("Slot called"); }
and
patients.h
#ifndef PATIENTS_H #define PATIENTS_H #include <QMainWindow> #include "tetra_grip_api.h" namespace Ui { class Patients; } class Patients : public QMainWindow { Q_OBJECT public: Patients( QWidget *parent = nullptr); ~Patients(); void parseDataEntry(const QString dataPath); public slots: void eventHandlerTwo(STIM_GUI_TOPIC_T topic, uint8_t reg, uint32_t value); void on_pushButton_Open_clicked(); private: Ui::Patients *ui; }; #endif
and the API class
tetra_grip_api.h
#ifndef TETRA_GRIP_API_H #define TETRA_GRIP_API_H #include <QObject> #include <stdio.h> #include <stdlib.h> #include <iostream> #include <string> #include <QtSerialPort/QSerialPort> #include <QtSerialPort/QSerialPortInfo> #include <QLabel> #include <QMessageBox> #define _CRT_SECURE_NO_DEPRECATE class tetra_grip_api : public QObject { Q_OBJECT public: explicit tetra_grip_api(QObject *parent = nullptr); #define MAX_CONFIG_FILE_LENGTH (10000) bool static send_short_block(STIM_GUI_MESSAGE_S_BLOCK_T *pblock); void static battery_percentage(void); QSerialPort *serial = nullptr; signals: void tetraGripEvent(STIM_GUI_TOPIC_T topic, uint8_t reg, uint32_t value); public slots: void openSerialPort(); void closeSerialPort(); void readData(); private: QString comPortName; }; extern tetra_grip_api api; #endif // TETRA_GRIP_API_H
and
tetra_grip_api.cpp
#include "tetra_grip_api.h" #include "tetra_grip_reporter.h" #include <QDebug> #include <stdio.h> #include <stdlib.h> #define _CRT_SECURE_NO_DEPRECATE using namespace::std; tetra_grip_api::tetra_grip_api(QObject *parent) : QObject(parent) { } void tetra_grip_api::openSerialPort() { serial = new QSerialPort(); QList <QSerialPortInfo>stim; QSerialPortInfo info; foreach (const QSerialPortInfo &info, QSerialPortInfo::availablePorts()) { if(info.description() == "USB Serial Port" && info.manufacturer() == "FTDI" && QString::number(info.vendorIdentifier(), 16)== "403" && QString::number(info.productIdentifier(), 16)== "6015") { comPortName = info.portName(); } } serial->setPortName(comPortName); serial->setBaudRate(1000000); / serial->setDataBits(QSerialPort::Data8); serial->setParity(QSerialPort::NoParity); serial->setStopBits(QSerialPort::OneStop); serial->setFlowControl(QSerialPort::HardwareControl); if(serial->open(QIODevice::ReadWrite)) { qDebug()<<"Opend port OK"; } else { qDebug()<<"Failed to open port. Error code: "<< serial->error() << serial->errorString(); } } void tetra_grip_api::readData() { const QByteArray data = api.serial->readAll(); STIM_GUI_PROTOCOL_Process_Received_Bytes((uint8_t*)data.data(), (size_t)data.length()); } void tetra_grip_api::closeSerialPort() { if (serial->isOpen()) serial->close(); } void tetra_grip_reporter(STIM_GUI_TOPIC_T topic, uint8_t reg, uint32_t value) { emit api.tetraGripEvent(topic, reg, value); }
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@russjohn834 said in same signal-slot connection in two windows:
StageTwoPatients::~StageTwoPatients() { delete ui; }
What is this definition doing in the middle of the
Patients
class?Meanwhile, I don't see any
~Patients()
definition as per declared in the header file. -
@russjohn834 said in same signal-slot connection in two windows:
tetra_grip_api api;
I would rename this to something other, use an own 'extern' definition and try again.
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Sorry about that typo. Originally the name of my class was a bit lengthier so I use
Settings
andPatients
for better understanding.. -
@russjohn834
Typo?? This is a copy & paste of your actual code, I trustPlease find here the minimal version of both the class files (.cpp and .h and main)
We have had way too many people who claim to paste but then say it's not actually a paste of running code, if you're saying that's what you did....