Signals and slots or whatever

[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

[jrod2much]

I think I found it:
cccmodule.h

class CccModule : public MonModule
{
public:
    CccModule(Interpreter *interpreter);
    ~CccModule(); //Is this the constructor?

    virtual bool render(uint32_t fourcc, const void *args[]);
    virtual bool command(const QStringList &argv);
    virtual void paramChange();

There are no instantiations in the ui file

[J.Hilk]

@jrod2much
you should refresh your c++ skills

https://www.tutorialspoint.com/cplusplus/cpp_constructor_destructor.htm

what you're pointing out is the destructor.

Also, to use QObject::connet your class needs to be a sublass of QObject somewhere. I don't know the context of MonModule but make sure that QObject is somere the baseclass in the hirachy.

Also you should add the Q_Object macro in the header filke, as you're planning to use signals.

[jrod2much]

@J.Hilk Alright, I have added the Q_OBJECT macro to the header. I found the header and source of MonModule if you'd like to take a look.
monmodule.h

#define MAX_MONMODULES 0x40 // this should be way more than neeeded....

class MonModule;
class Interpreter;
class Parameter;
class Renderer;

typedef MonModule *(*NewMonModuleFunc)(Interpreter *);
typedef QList <MonModule *> MonModules;


#define MON_MODULE(module) \
    MonModule *newFunc ## module(Interpreter *interpreter) {\
        return new module(interpreter); } \
    MonModuleUtil g_register ## module(newFunc ## module);


class MonModule
{
public:
    MonModule(Interpreter *interpreter);
    virtual ~MonModule();

    virtual bool render(uint32_t fourcc, const void *args[]);
    virtual bool command(const QStringList &argv);
    virtual void paramChange();

protected:
    bool pixyParameterChanged(const QString &id, QVariant *val=NULL);
    bool pixymonParameterChanged(const QString &id, QVariant *val=NULL);
    QVariant pixyParameter(const QString &id);
    QVariant pixymonParameter(const QString &id);

    Interpreter *m_interpreter;
    Renderer *m_renderer;
};


struct MonModuleUtil
{
    MonModuleUtil(NewMonModuleFunc func)
    {
        m_modules[m_index++] = func;
    }

    static void createModules(MonModules *modules, Interpreter *interpreter)
    {
        for (uint i=0; i<m_index; i++)
            modules->push_back((*m_modules[i])(interpreter));
    }

    static void destroyModules(MonModules *modules)
    {
        // delete modules in reverse order
        for (int i=modules->size()-1; i>=0; i--)
            delete (*modules)[i];
    }

    static NewMonModuleFunc m_modules[MAX_MONMODULES];
    static uint m_index;
    static Interpreter *m_interpreter;
};

void cprintf(const char *format, ...);

monmodule.cpp

NewMonModuleFunc MonModuleUtil::m_modules[MAX_MONMODULES];
unsigned int MonModuleUtil::m_index = 0;
Interpreter *MonModuleUtil::m_interpreter = NULL;



MonModule::MonModule(Interpreter *interpreter)
{
    m_interpreter = interpreter;
    m_renderer = m_interpreter->m_renderer;
    MonModuleUtil::m_interpreter = interpreter;

}

MonModule::~MonModule()
{
}

bool MonModule::render(uint32_t fourcc, const void *args[])
{
    return false;
}

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

void MonModule::paramChange()
{
}

bool MonModule::pixyParameterChanged(const QString &id, QVariant *val)
{
    QMutexLocker lock(m_interpreter->m_pixyParameters.mutex());
    Parameter *param = m_interpreter->m_pixyParameters.parameter(id);
    if (param && val)
        *val = param->value();
    if (param && param->dirty())
        return true;
    return false;
}

bool MonModule::pixymonParameterChanged(const QString &id, QVariant *val)
{
    QMutexLocker lock(m_interpreter->m_pixymonParameters->mutex());
    Parameter *param = m_interpreter->m_pixymonParameters->parameter(id);
    if (param && val)
        *val = param->value();
    if (param && param->dirty())
        return true;
    return false;
}

QVariant MonModule::pixyParameter(const QString &id)
{
    return m_interpreter->m_pixyParameters.value(id);
}

QVariant MonModule::pixymonParameter(const QString &id)
{
    return m_interpreter->m_pixymonParameters->value(id);
}


void cprintf(const char *format, ...)
{
    char buffer[256];
    va_list args;
    va_start(args, format);
    vsnprintf(buffer, 256, format, args);
    MonModuleUtil::m_interpreter->cprintf(buffer);
    va_end(args);
}

[VRonin]

@jrod2much said in Signals and slots or whatever:

I set a printf statement to print it every time the program runs through that section of code and it changes.

Ok, baby steps. Can you put a breakpoint in that section of code and post us the stack trace you see when it gets hit?

[jrod2much]

@VRonin
So, I have placed many breakpoints in many places and the program does not terminate at all. The value of m_palette[i] only prints to the output once I manually exit the application running.
The good part is that if I make many changes to m_palette[i], then they all print out in list form. The bad part is that for some reason, the break points Arent being triggered. I took the time to read up on breakpoint implementation so I don't think I am doing it wrong, but nothing is triggering the breakpoints.

[VRonin]

@jrod2much said in Signals and slots or whatever:

if I make many changes to m_palette[i]

How are you making that change?

[jrod2much]

@VRonin So the application is made to run a camera that detects objects. For instance, you can shoot a live video feed, then create a "signature" by selecting the signature option, the frame freezes, and you can use your mouse to highlight an area on the video feed, lets say a red rubber ball. Then the application stores that data and any time a red rubber ball comes into the live video feed, the application tracks it. The application is capable of storing up to 7 different signatures. Hence the m_palette[i]. If you want to read more on it, the camera is called PixyCam 2 and the application it comes with is called PixyMon.

What I have done here and for the last 2 weeks is tried to take the open source application code that is built on Qt, and add a textBrowser that can display the current signature RGB code. I have found the data variable for the first signature (m_palette[0]). But the application is very complex for a beginner like me and frankly, I thought it would be easier of a task so that I can continue with my project.

So when I 'make changes' I am just setting a new Signature 1 on the application as it runs.

[VRonin]

ok, one last try, add Q_ASSERT(false); after the m_palette[i] = m_signatures[i].m_rgb;. this will force your program to crash, when it does, look at the stack trace and post it here please

[jrod2much]

@VRonin You are going to hate me Ronin. I have searched all over the internet, I am 99% sure that Qt Creator does not have a stack trace. There are a bunch of forums saying I have to add a huge amount of code to the debug library in order to create a stack trace and I don't think I am skilled enough to do this.

Here is the Application Output if that is what you mean by stack trace, but it does not seem helpful:
09:51:55: Starting C:\Users\rodriguez\Desktop\pixy2-master\src\host\build-pixymon-Desktop_Qt_5_2_1_MinGW_32bit-Debug\debug\PixyMon...
ASSERT: "false" in file ..\pixymon\cccmodule.cpp, line 155
QObject::killTimers: timers cannot be stopped from another thread
09:52:01: C:/Users/rodriguez/Desktop/pixy2-master/src/host/build-pixymon-Desktop_Qt_5_2_1_MinGW_32bit-Debug/debug/PixyMon exited with code 3

The Q_ASSERT(false); did work. In fact, it worked instantly. It closes the program as soon as the program opens and loads without me pressing anything.

Honestly, I did not think that such a simple thing as printing a value to the UI would be so difficult. I'm baffled. Is there any way around this that you can think of. I tried to make a global variable to carry the data of m_palette[0] to the Mainwindow.cpp but obviously even that is drawing an error…

[VRonin]

@jrod2much said in Signals and slots or whatever:

I am 99% sure that Qt Creator does not have a stack trace.

The one in the red rectangle is the stack trace

@jrod2much said in Signals and slots or whatever:

I did not think that such a simple thing as printing a value to the UI would be so difficult.

It is not. Sorry to be brutal but it's your inexperience with the language and the tools that is making this difficult. The good news is that once you do it once and you understand it, the next time it will be a breeze

[jrod2much]

@VRonin I hope so haha

Okay so take a look, nothing is writing to the stack trace but I did notice that for the breakpoints we have different icons.

[VRonin]

Did you start the debugger? it's the play button with a bug on it. Just above the hammer in the bottom left corner

[jrod2much]

@VRonin Still nothing and I got this warning

Would this warning effect the stack trace? I can take a moment to try and fix it if so. It says that the breakpoints are failing because of it.

[VRonin]

Tools->options->Kits->select the kit that you are using

Can you take a screenshot of the page?

[jrod2much]

@VRonin

Yeah, as you can imagine, the process of getting the project to build was a nightmare for me as a person with no experience so i probably did something wrong. Hence the yellow warnings.

[VRonin]

The fact that it says "no compiler" and you are compiling makes me think you didn't select the correct kit. If I had to bet I'd say you are using the MinGW kit.

P.S.
Qt 5.2 has not been supported for a long while. Any reason why you are not updating?

[jrod2much]

@VRonin :( On the pixyMon website, the forum people said that 5.2 is the only one that works, I could try other versions but it would take me hours. I don't mind doing that though if you think it would be lucrative.

[VRonin]

@jrod2much said in Signals and slots or whatever:

5.2 is the only one that works

Nevermind then, focus on the main point i.e. the screenshot of the kit you are actually using

[JKSH]

@jrod2much said in Signals and slots or whatever:

@VRonin :( On the pixyMon website, the forum people said that 5.2 is the only one that works, I could try other versions but it would take me hours. I don't mind doing that though if you think it would be lucrative.

If the authors found that Qt 5.2 is most stable, then it's best to stick to Qt 5.2.

An important point from http://cmucam.org/projects/cmucam5/wiki/Building_PixyMon : The authors used the MinGW compiler, not the MSVC compiler. So, close Qt Creator, launch MaintenanceTool.exe (found in the root folder of your Qt installation) and:

• Remove (Uninstall) all the MSVC-based versions of Qt.
• Add (Install) Tools > MinGW 4.8 (this is the version of MinGW that goes with Qt 5.2)

Some questions for sanity checks:

1. How did you install Qt in the first place?
2. How/Why did you create the "Desktop" and "Qt Version 1" kits?