text append waits until hcitoo scan is finished

[SGaist]

There's an example in the finished signal documentation using a lambda.
There's a chapter dedicated to the explanation on how signal and slots work.

[J.Hilk]

@AnneRanch said in text append waits until hcitoo scan is finished:

Tep, that is what I am doing and as usual I am stuck on "connect".
Sure could use a real example of connect to get me going...
This "wait for completion" sure was of no help to really understand QProcess...

does this help?

#ifndef HCITOOLPROCESS_H
#define HCITOOLPROCESS_H

#include <QObject>
#include <QProcess>
#include <QElapsedTimer>
#include <iostream>

class HciToolProcess : public QObject
{
    Q_OBJECT
public:
    enum HciCommands : uint8_t {
        Dev,
        Inq,
        Scan,
    };

    explicit HciToolProcess(QObject *parent = nullptr) : QObject(parent), m_currentCommand{HciCommands::Dev}
    {
        connect(&m_process, QOverload<int,QProcess::ExitStatus>::of(&QProcess::finished), this, &HciToolProcess::nextCommand);
    }

    bool startProcess(){
        if(m_currentCommand != HciCommands::Dev)
            return false;

        m_elapsedTime.start();

        m_process.start(QStringLiteral("hcitool"), QStringList(HciCommandToString(m_currentCommand)), QIODevice::ReadWrite);

        return true;
    }

signals:
    void timeElapsed(const QString &time); // to update your textEdit_2
    void allProcessesDone();

private:
    void nextCommand(int exitCode, QProcess::ExitStatus exitStatus){
        std::cout<<"\n * Program to demonstrate the usage of linux commands in qt * \n";

        QString StdOut      =   m_process.readAllStandardOutput();  //Reads standard output
        QString StdError    =   m_process.readAllStandardError();   //Reads standard error

        std::cout<<"\n Printing the standard output..........\n";
        std::cout<<std::endl<<StdOut.toStdString();
        std::cout<<"\n Printing the standard error..........\n";
        std::cout<<std::endl<<StdError.toStdString();
        std::cout<<"\n Printing exit code..........\n";
        std::cout<<std::endl<<exitCode;
        std::cout<<"\n Printing exitStatus..........\n";
        std::cout<<std::endl<<exitStatus;
        std::cout<<"\n\n";

        QString elapsedTime = QString::number(m_elapsedTime.restart());
        emit timeElapsed(elapsedTime);

        m_currentCommand = static_cast<HciCommands>(m_currentCommand + 1);
        if(static_cast<uint8_t>(m_currentCommand) <= static_cast<uint8_t>(HciCommands::Scan)){
            m_process.start(QStringLiteral("hcitool"), QStringList(HciCommandToString(m_currentCommand)), QIODevice::ReadWrite);
        } else {
            m_currentCommand = HciCommands::Dev;
            emit allProcessesDone();
        }
    }

    QString HciCommandToString( HciCommands cmd) {
        switch (cmd) {
        case HciCommands::Dev: return QStringLiteral("dev");
        case HciCommands::Inq: return QStringLiteral("inq");
        case HciCommands::Scan: return QStringLiteral("scan");
        default:
            Q_UNREACHABLE();
            return QLatin1String();
        }
    }

private:
    QElapsedTimer m_elapsedTime;
    HciCommands m_currentCommand;
    QProcess m_process;
};

#endif // HCITOOLPROCESS_H

[JonB]

@J-Hilk
I was thinking about writing something like this, but assumed the effort would be ignored.

If you were to get rid of your enumeration/switch statement and instead create some list of the commands (plus parameters) to be used, which the caller passes/sets on the class, it would be a generic "execute any arbitrary list of commands sequentially" class.

[J.Hilk]

@JonB sure, here ya go :D

#ifndef HCITOOLPROCESS_H
#define HCITOOLPROCESS_H

#include <QObject>
#include <QProcess>
#include <QElapsedTimer>
#include <iostream>

class HciToolProcess : public QObject
{
    Q_OBJECT
public:

    struct CommandAndArguments{
        QString command;
        QStringList arguments;
    };

    explicit HciToolProcess(QObject *parent = nullptr) : QObject(parent), m_index{-1}
    {
        connect(&m_process, QOverload<int,QProcess::ExitStatus>::of(&QProcess::finished), this, &HciToolProcess::onProcessFinished);
    }

    bool startProcess(QList<CommandAndArguments> commands){
        if(m_index != -1 || commands.isEmpty())
            return false;

        m_cmdAndArgs = commands;

        m_elapsedTime.start();

        //m_index is -1 so the function will set it to 0
        processCommandAndArguments();

        return true;
    }

signals:
    void timeElapsed(const QString &time); // to update your textEdit_2
    void allProcessesDone();

private:
    void processCommandAndArguments(){
        m_index++;
        if(m_index < m_cmdAndArgs.size()){
            m_process.start(m_cmdAndArgs.at(m_index).command, m_cmdAndArgs.at(m_index).arguments, QIODevice::ReadWrite);
        } else {
            m_index = -1;
            emit allProcessesDone();
        }
    }

    void onProcessFinished(int exitCode, QProcess::ExitStatus exitStatus){
        std::cout<<"\n * Program to demonstrate the usage of linux commands in qt * \n";

        QString StdOut      =   m_process.readAllStandardOutput();  //Reads standard output
        QString StdError    =   m_process.readAllStandardError();   //Reads standard error

        std::cout<<"\n Printing the standard output..........\n";
        std::cout<<std::endl<<StdOut.toStdString();
        std::cout<<"\n Printing the standard error..........\n";
        std::cout<<std::endl<<StdError.toStdString();
        std::cout<<"\n Printing exit code..........\n";
        std::cout<<std::endl<<exitCode;
        std::cout<<"\n Printing exitStatus..........\n";
        std::cout<<std::endl<<exitStatus;
        std::cout<<"\n\n";

        QString elapsedTime = QString::number(m_elapsedTime.restart());
        emit timeElapsed(elapsedTime);

        processCommandAndArguments();
    }

private:
    QElapsedTimer m_elapsedTime;
    QProcess m_process;
    QList<CommandAndArguments> m_cmdAndArgs;
    int32_t m_index;
};

#endif // HCITOOLPROCESS_H