Signals and slots or whatever

[jrod2much]

Hello everyone, I am a complete noob at Qt with 2 semesters of C++ under my belt. I am stuck with the task of editing someone else's QT code so that I can monitor a certain value.

There is an 'int' in a class and I have created a textBrowser so that I can have the value of this 'int' constantly displayed while the program is in use.

In the past week I have watched every signal and slot video on the web, I have tried every combination of code I could come up with. I have tried making a global variable. I have even tried accessing the Mainwindow from this other class which many forums say is "bad programming". I just want to have this program display the value of the integer so that I can move on with my work assignment.

If anyone can help me please, I have been going in circles.
I would try to show my code but there are thousands of lines of code and I don't know what you would need to see.

Also, just to let you all know, I have no problem with data types. I understand that the int must be changed to QString. My Problem is really just trying to get a value from one class to fill the textBroswer in the Mainwindow.cpp

Thank You

[VRonin]

There is an 'int' in a class and I have created

Something like the below?

class ValueClass : public QObject
{
    Q_OBJECT
    Q_DISABLE_COPY(ValueClass)
public:
    explicit ValueClass(QObject* parent = Q_NULLPTR)
        :QObject(parent)
        ,m_value(0)
    {}
    int value() const
    {
        return m_value;
    }
    void setValue(int val)
    {
        if (val != m_value){
            m_value = val;
            valueChanged(m_value);
        }
    }
signals:
    void valueChanged(int);
private:
    int m_value;
};

[jrod2much]

Here is a snippet from the class file:

cccmodule.cpp

void CccModule::paramChange()
{

    int i;
    QVariant val;
    char id[128];
    uint32_t sigLen;
    uint8_t *sigData;
    QByteArray ba;
    bool setPalette;
//Maybe something to do with signatures

    // check to see if any signatures have changed
    for (i=0, setPalette=false; i<CL_NUM_SIGNATURES; i++)
    {
        sprintf(id, "signature%d", i+1);
        if (pixyParameterChanged(id, &val))
        {
            ba = val.toByteArray();
            Chirp::deserialize((uint8_t *)ba.data(), val.toByteArray().size(), &sigLen, &sigData, END);
            if (sigLen==sizeof(ColorSignature))
            {
                memcpy(m_signatures+i, sigData, sizeof(ColorSignature));

              
                m_palette[i] = m_signatures[i].m_rgb;
                //I want to send m_palette[i]
                //to the textBrowser in the Mainwindow

                QString print = "HINT(";
                setPalette = true;
            }
        }
    }
    if (setPalette)
        m_renderer->setPalette(m_palette);

    // create label dictionary
    Parameters &params = m_interpreter->m_pixyParameters.parameters();
    QStringList words;
    uint32_t signum;
    m_labels.clear();
   // go through all parameters and find labels
    for (i=0; i<params.length(); i++)
    {
        if (params[i].id().startsWith("Signature label"))
        {
            words = params[i].id().split(QRegExp("\\s+"));
            if (words.length()<3) // bogus!
                continue;
            signum = words[2].toUInt();
            m_labels.push_back(QPair<uint16_t, QString>(convert10to8(signum), params[i].value().toString().remove(QRegExp("^\\s+")))); // remove leading whitespace
        }
    }
}

[VRonin]

• inside the declaration of CccModule, in the public section, add Q_SIGNAL void paletteChanged(int index, uint32_t palette);
• replace m_palette[i] = m_signatures[i].m_rgb; with

if(m_palette[i] != m_signatures[i].m_rgb){
m_palette[i] = m_signatures[i].m_rgb;
paletteChanged(i,m_palette[i]);
}

• connect the CccModule::paletteChanged signal with a slot in Mainwindow that updates the textBrowser

[jrod2much]

paletteChanged(i,m_palette);

149:34: error: cannot initialize a parameter of type 'uint32_t' (aka 'unsigned int') with an lvalue of type 'uint32_t [7]'
cccmodule.h:38:54: note: passing argument to parameter 'palette' here

[VRonin]

corrected above

[jrod2much]

Sweet! and how would the connect look like? The way I have been changing the textBrowser so far is:

 m_ui->textBrowser->setText("Hello World");

No Slots.

[jrod2much]

What goes for the const QObject *sender?

[jsulm]

@jrod2much said in Signals and slots or whatever:

how would the connect look like

http://doc.qt.io/qt-5/signalsandslots.html

[VRonin]

// cModule is of type CccModule*
connect(cModule, &CccModule::paletteChanged, this, [=](int index, uint32_t palette)->void{
m_ui->textBrowser->append(QStringLiteral("Palette changed. Index %1, Palette: %2").arg(index).arg(palette));
});

[jrod2much]

I'm pretty sure that I declared it correctly but I am getting back:

119:13: error: use of undeclared identifier 'cModule'

and now I'm getting back:

mainwindow.cpp:123: error: no matching function for call to 'MainWindow::connect(CccModule*&, void (CccModule::*)(int, uint32_t), MainWindow* const, MainWindow::MainWindow(int, char**, QWidget*)::__lambda0)'
     });
      ^

mainwindow.cpp:123: error: template argument for 'template<class Func1, class Func2> static QMetaObject::Connection QObject::connect(const typename QtPrivate::FunctionPointer<Func>::Object*, Func1, const typename QtPrivate::FunctionPointer<Func2>::Object*, Func2, Qt::ConnectionType)' uses local type 'MainWindow::MainWindow(int, char**, QWidget*)::__lambda0'
     });
      ^

mainwindow.cpp:123: error: template argument for 'template<class Func1, class Func2> static typename QtPrivate::QEnableIf<(((int)(QtPrivate::FunctionPointer<Func2>::ArgumentCount) >= 0) && (! QtPrivate::FunctionPointer<Func2>::IsPointerToMemberFunction)), QMetaObject::Connection>::Type QObject::connect(const typename QtPrivate::FunctionPointer<Func>::Object*, Func1, const QObject*, Func2, Qt::ConnectionType)' uses local type 'MainWindow::MainWindow(int, char**, QWidget*)::__lambda0'
     });
      ^

mainwindow.cpp:123: error: template argument for 'template<class Func1, class Func2> static typename QtPrivate::QEnableIf<(QtPrivate::FunctionPointer<Func2>::ArgumentCount == (-1)), QMetaObject::Connection>::Type QObject::connect(const typename QtPrivate::FunctionPointer<Func>::Object*, Func1, const QObject*, Func2, Qt::ConnectionType)' uses local type 'MainWindow::MainWindow(int, char**, QWidget*)::__lambda0'
     });
      ^

[VRonin]

@jrod2much said in Signals and slots or whatever:

use of undeclared identifier 'cModule'

yes, that's just a name I used, you have to change it to the one of your instance of CccModule

@jrod2much said in Signals and slots or whatever:

and now I'm getting back:
mainwindow.cpp:123: error: no matching function for call to 'MainWindow::connect(CccModule*&, void (CccModule::)(int, uint32_t), MainWindow const

MainWindow const ? how are you passing the 3rd argument? [edit, it was just bad formatting by the forum]

You are calling the connect from a const method. That's a problem as a connection alters the objects

[jrod2much]

I really apologize for having to ask these kinds of questions, but, how do I check what "my instance of CccModule" are. I added this in above the connect and in the header of CccModule.cpp in public:

CccModule* cModule;

Also, I don't know how to fix the const issue.

[VRonin]

Ok big step back.

I added this in above the connect and in the header of CccModule.cpp in public:
CccModule* cModule;

No, undo that

---

• do you use CccModule anywhere else inside your MainWindow?
• where did you put that connect statement?

[jrod2much]

No, I do not use CccModule anywhere else in the Mainwindow.

I put the connect in the Mainwindow.cpp

MainWindow::MainWindow(int argc, char *argv[], QWidget *parent) :
    QMainWindow(parent),
    m_ui(new Ui::MainWindow)
{
    QCoreApplication::setOrganizationName(PIXYMON_COMPANY);
    QCoreApplication::setApplicationName(PIXYMON_TITLE);

    qRegisterMetaType<Device>("Device");

    m_ui->setupUi(this);
    setWindowTitle(PIXYMON_TITLE);


    m_interpreter = NULL;
    m_flash = NULL;
    m_pixyConnected = false;
    m_pixyDFUConnected = false;
    m_configDialog = NULL;
    m_fwInstructions = NULL;
    m_fwMessage = NULL;
    m_versionIncompatibility = false;
    m_testCycle = false;
    m_waiting = WAIT_NONE;

    parseCommandline(argc, argv);

    m_settings = new QSettings(QSettings::NativeFormat, QSettings::UserScope, PIXYMON_COMPANY, PIXYMON_TITLE);
    m_console = new ConsoleWidget(this);
    m_video = new VideoWidget(this);

    m_ui->imageLayout->addWidget(m_video);
    m_ui->imageLayout->addWidget(m_console);

    // hide console
    m_showConsole = m_testCycle;
    m_console->setVisible(m_testCycle);
    m_ui->actionConsole->setChecked(m_testCycle);

    m_ui->toolBar->addAction(m_ui->actionPlay_Pause);

    m_ui->actionDefault_program->setIcon(QIcon(":/icons/icons/home.png"));
    m_ui->toolBar->addAction(m_ui->actionDefault_program);

    m_ui->actionRaw_video->setIcon(QIcon(":/icons/icons/raw.png"));
    m_ui->toolBar->addAction(m_ui->actionRaw_video);

    m_ui->actionConfigure->setIcon(QIcon(":/icons/icons/config.png"));
    m_ui->toolBar->addAction(m_ui->actionConfigure);

    m_ui->menuProgram->setToolTipsVisible(true);

    m_status = new QLabel;
    // give the status a little of a left margin
    m_ui->statusBar->setContentsMargins(6, 0, 0, 0);
    m_ui->statusBar->addPermanentWidget(m_status, 1);
    updateButtons();

    m_parameters.add("Pixy start command", PT_STRING, "",
        "The command that is sent to Pixy upon initialization");

    // start looking for devices
    m_connect = new ConnectEvent(this);
    if (m_connect->getConnected()==NONE)
        error("No Pixy devices have been detected.\n");




    connect(cModule, &CccModule::paletteChanged, this, [=](int index, uint32_t palette)->void{
    m_ui->textBrowser->append(QStringLiteral("Palette changed. Index %1, Palette: %2").arg(index).arg(palette));
    });

}

MainWindow::~MainWindow()
{
    if (m_connect)
        delete m_connect;

    DBG("deleting mainWindow");
    // we don't delete any of the widgets because the parent deletes it's children upon deletion

    delete m_settings;
}

[VRonin]

@jrod2much said in Signals and slots or whatever:

I put the connect in the Mainwindow.cpp

Ok, this is correct

I do not use CccModule anywhere else in the Mainwindow.

So where are you using that class?

[jrod2much]

So here is the entire CccModule.cpp source file:

#include <QPainter>
#include <QString>
#include <stdio.h>
#include "cccmodule.h"
#include "interpreter.h"
#include "renderer.h"
#include "qqueue.h"
#include "colorlut.h"
#include "calc.h"

// declare module
MON_MODULE(CccModule);



CccModule::CccModule(Interpreter *interpreter) : MonModule(interpreter)
{
    int i;

    m_crc = 0;
    m_qvals = new uint32_t[0x8000];
    m_numQvals = 0;


    for (i=0; i<CL_NUM_SIGNATURES; i++)
        m_palette[i] = Qt::black;
}

CccModule::~CccModule()
{
    delete [] m_qvals;
}

bool CccModule::render(uint32_t fourcc, const void *args[])
{
    if (fourcc==FOURCC('C', 'C', 'B', '1'))
    {
        renderCCB1(*(uint8_t *)args[0], *(uint16_t *)args[1], *(uint32_t *)args[2], *(uint32_t *)args[3], (uint8_t *)args[4]);
        return true;
    }
    else if (fourcc==FOURCC('C', 'C', 'B', '2'))
    {
        renderCCB2(*(uint8_t *)args[0], *(uint16_t *)args[1], *(uint32_t *)args[2], *(uint32_t *)args[3], (uint16_t *)args[4], *(uint32_t *)args[5], (uint16_t *)args[6]);
        return true;
    }
    else if (fourcc==FOURCC('C','C','Q','F'))
    {
        renderCCQF(*(uint8_t *)args[0], *(uint16_t *)args[1], *(uint16_t *)args[2]);
        return true;
    }
    else if (fourcc==FOURCC('C','C','Q','S'))
    {
        renderCCQS(*(uint32_t *)args[0], (uint32_t *)args[1]);
        return true;
    }
    return false;
}

bool CccModule::command(const QStringList &argv)
{
    return false;
}

uint16_t convert10to8(uint32_t signum)
{
    uint16_t res=0;
    uint32_t q;

    q = signum/10000;
    if (q)
    {
        res += q*8*8*8*8;
        signum -= q*10000;
    }
    q = signum/1000;
    if (q)
    {
        res += q*8*8*8;
        signum -= q*1000;
    }
    q = signum/100;
    if (q)
    {
        res += q*8*8;
        signum -= q*100;
    }
    q = signum/10;
    if (q)
    {
        res += q*8;
        signum -= q*10;
    }
    if (signum)
        res += signum;

    return res;
}

void CccModule::paramChange()
{   
    CccModule* cModule
    QString m_paletteOne;
    int i;
    QVariant val;
    char id[128];
    uint32_t sigLen;
    uint8_t *sigData;
    QByteArray ba;
    bool setPalette;
//Maybe something to do with signatures

    // check to see if any signatures have changed
    for (i=0, setPalette=false; i<CL_NUM_SIGNATURES; i++)
    {
        sprintf(id, "signature%d", i+1);
        if (pixyParameterChanged(id, &val))
        {
            ba = val.toByteArray();
            Chirp::deserialize((uint8_t *)ba.data(), val.toByteArray().size(), &sigLen, &sigData, END);
            if (sigLen==sizeof(ColorSignature))
            {
                memcpy(m_signatures+i, sigData, sizeof(ColorSignature));


                //m_palette[i] = m_signatures[i].m_rgb;


//THIS IS THE CODE YOU HAD ME INSERT
                if(m_palette[i] != m_signatures[i].m_rgb)
                {
                    m_palette[i] = m_signatures[i].m_rgb;
                    m_paletteOne = QString::number(m_signatures[i].m_rgb);
                    paletteChanged(i,m_palette[i]);
                }



                //I want to send m_palette[i]
                //to the textBrowser in the Mainwindow

                QString print = "HINT(";
                setPalette = true;
            }
        }
    }
    if (setPalette)
        m_renderer->setPalette(m_palette);

    // create label dictionary
    Parameters &params = m_interpreter->m_pixyParameters.parameters();
    QStringList words;
    uint32_t signum;
    m_labels.clear();
   // go through all parameters and find labels
    for (i=0; i<params.length(); i++)
    {
        if (params[i].id().startsWith("Signature label"))
        {
            words = params[i].id().split(QRegExp("\\s+"));
            if (words.length()<3) // bogus!
                continue;
            signum = words[2].toUInt();
            m_labels.push_back(QPair<uint16_t, QString>(convert10to8(signum), params[i].value().toString().remove(QRegExp("^\\s+")))); // remove leading whitespace
        }
    }
}


QString CccModule::lookup(uint16_t signum)
{
    int i;

    for (i=0; i<m_labels.length(); i++)
    {
        if (m_labels[i].first==signum)
            return m_labels[i].second;
    }
    return "";
}



void CccModule::renderCCQF(uint8_t renderFlags, uint16_t width, uint16_t height)
{
    if (renderFlags&RENDER_FLAG_START)
        m_numQvals = 0;
    else
        m_renderer->renderCCQ1(renderFlags, width, height, m_numQvals, m_qvals);
}

void CccModule::renderCCQS(uint32_t numVals, uint32_t *vals)
{
    uint32_t i;

    for (i=0; i<numVals && m_numQvals<0x8000; i++)
        m_qvals[m_numQvals++] = vals[i];
}

int CccModule::renderCCB1(uint8_t renderFlags, uint16_t width, uint16_t height, uint32_t numBlobs, uint8_t *blobs)
{
    float scale = (float)m_renderer->m_video->activeWidth()/width;
    QImage img(width*scale, height*scale, QImage::Format_ARGB32);

    if (renderFlags&RENDER_FLAG_BLEND) // if we're blending, we should be transparent
        img.fill(0x00000000);
    else
        img.fill(0xff000000); // otherwise, we're just black

    numBlobs /= sizeof(BlobC);
    renderBlobsC(renderFlags&RENDER_FLAG_BLEND, &img, scale, (BlobC *)blobs, numBlobs);

    m_renderer->emitImage(img, renderFlags, "CCC Blobs");

    return 0;
}

int CccModule::renderCCB2(uint8_t renderFlags, uint16_t width, uint16_t height, uint32_t numBlobs, uint16_t *blobs, uint32_t numCCBlobs, uint16_t *ccBlobs)
{
    float scale = (float)m_renderer->m_video->activeWidth()/width;
    QImage img(width*scale, height*scale, QImage::Format_ARGB32);

    if (renderFlags&RENDER_FLAG_BLEND) // if we're blending, we should be transparent
        img.fill(0x00000000);
    else
        img.fill(0xff000000); // otherwise, we're just black

    numBlobs /= sizeof(BlobA2)/sizeof(uint16_t);
    numCCBlobs /= sizeof(BlobA2)/sizeof(uint16_t);
    renderBlobsA(renderFlags&RENDER_FLAG_BLEND, &img, scale, (BlobA2 *)blobs, numBlobs);
    renderBlobsA(renderFlags&RENDER_FLAG_BLEND, &img, scale, (BlobA2 *)ccBlobs, numCCBlobs);

    m_renderer->emitImage(img, renderFlags, "CCC Blobs");

    return 0;
}

void CccModule::renderBlobsA(bool blend, QImage *image, float scale, BlobA2 *blobs, uint32_t numBlobs)
{
    QPainter p;
    QString str, modelStr;
    uint x, y, w, h, i;

    p.begin(image);

    for (i=0; i<numBlobs; i++)
    {
        if (blobs[i].m_model==0)
            continue;
        x = scale*blobs[i].m_left;
        y = scale*blobs[i].m_top;
        w = scale*blobs[i].m_right - x;
        h = scale*blobs[i].m_bottom - y;

        //DBG("%d %d %d %d", left, right, top, bottom);
        if (blend || blobs[i].m_model>CL_NUM_SIGNATURES+1)
            Renderer::drawRect(&p, QRect(x, y, w, h), QColor(Qt::white), 0x40);
        else
            Renderer::drawRect(&p, QRect(x, y, w, h), m_palette[blobs[i].m_model-1], 0xff);
        // color code
        if (blobs[i].m_model>CL_NUM_SIGNATURES+1)
        {
            if ((str=lookup(blobs[i].m_model))=="")
            {
                modelStr = QString::number(blobs[i].m_model, 8);
                str = "s=" + modelStr + ", " + QChar(0xa6, 0x03) + "=" + "0";//QString::number(blobs[i].m_angle);
            }
            else
                str += QString(", ") + QChar(0xa6, 0x03) + "=" + "0"; //QString::number(blobs[i].m_angle);

        }
        else if ((str=lookup(blobs[i].m_model))=="")
            str = str.sprintf("s=%d", blobs[i].m_model);

       Renderer::drawText(&p, x+w/2, y+h/2, str);
    }
    p.end();
}

void CccModule::renderBlobsC(bool blend, QImage *image, float scale, BlobC *blobs, uint32_t numBlobs)
{
    QPainter p;
    QString str, modelStr;
    uint x, y, w, h, i;

    p.begin(image);

    for (i=0; i<numBlobs; i++)
    {
        if (blobs[i].m_model==0)
            continue;
        w = scale*blobs[i].m_width;
        h = scale*blobs[i].m_height;
        x = scale*blobs[i].m_x-w/2;
        y = scale*blobs[i].m_y-h/2;

        //DBG("%d %d %d %d", left, right, top, bottom);
        if (blend || blobs[i].m_model>CL_NUM_SIGNATURES+1)
            Renderer::drawRect(&p, QRect(x, y, w, h), QColor(Qt::white), 0x40);
        else
            Renderer::drawRect(&p, QRect(x, y, w, h), m_palette[blobs[i].m_model-1], 0xff);
        // color code
        if (blobs[i].m_model>CL_NUM_SIGNATURES+1)
        {
            if ((str=lookup(blobs[i].m_model))=="")
            {
                modelStr = QString::number(blobs[i].m_model, 8);
                str = "s=" + modelStr + ", " + QChar(0xa6, 0x03) + "=" + QString::number(blobs[i].m_angle);
            }
            else
                str += QString(", ") + QChar(0xa6, 0x03) + "=" + QString::number(blobs[i].m_angle);

        }
        else if ((str=lookup(blobs[i].m_model))=="")
            str = str.sprintf("s=%d", blobs[i].m_model);

       Renderer::drawText(&p, x+w/2, y+h/2, str);
    }
    p.end();
}

If I search the entire project, 'CccModule' only comes up in this file and its header.

[VRonin]

So how does the palette change if it's never even used?

[jrod2much]

Welcome to my world haha. I don't know how it changes, but it does because I set a printf statement to print it every time the program runs through that section of code and it changes.

Can't we just make it emit the value? I'm not sure I understand anything about the emit function but it sounds like it might work.

[J.Hilk]

@jrod2much
ok, you'll need to know where CccModule is instantiated, for you be able to listen/connect to signals that are emitted.

Do you know where that happens? If not and, you 're using QtCreator, you can simply right-click on the constructor and click on find uses that will list all places where the an instance of that class is created, even when it's done in a ui file.

Than you can use QObject:connect to connect that instance with your textbrowser