qt6 migration issue

[Actarus]

@JonB Can it be related to the error message on the top of the editor window?
Stating:
Error:Could not decode "colorrange.cpp" with "UTF-8"-encoding. Editing not possible.

[JonB]

@Actarus
That's not good! There would appear to be a problem if editor says the .cpp is not editable I would be worried :) Which may lead to a problem when trying to compile it to the .o file....

[Actarus]

@JonB I've just checked and I have the same message on the other PC with QT5 but, in that case, it compiles without errors and I can find the colorrange.o file in the debug folder.

[Actarus]

@JonB Jon, just opened it with text editor and saved it in UTF-8, the encoding error disappeared but the Error 1 is still present.

[JonB]

@Actarus
I would delete the debug folder and do a full, clean rebuild from scratch. If it errors look carefully at the compile output, because what you show seems "strange".

[Actarus]

@JonB Did it but it didn't change, but the colorrange.cpp file is "casually" the same where I have the error mentioned above about backgroundcolor that is the last one code issue that had not yet been corrected.

Could you please give me a tip about it and maybe it fixes also the Error1?

"Can you help in correcting the sintax for QT6 for the following line of QTableWidgetItem:

colorPicker = new QColorDialog(ui->table->item(r, 0)->backgroundColor(), nullptr

I corrected replacing backgroundColor with background, but I can't get the correct sintax."

Thanks.

[JonB]

@Actarus
The line you show simply seems to be missing the trailing );. Other than that I don't think it has changed from Qt5. If you get an error copy & paste exactly what the compiler shows you about it.

[Actarus]

@JonB Sorry, just didn't pasted here the ); but it's in the code.
Actually in QT6 it's no longer possible to use 'backgroundColor', indeed I replaced it with 'background' in all the other situations where I had the same error message and it worked.

The error text is the following:

error: 'class QTableWidgetItem' has no member named 'backgroundColor'; did you mean 'background'?
307 | colorPicker = new QColorDialog(ui->table->item(r, 0)->backgroundColor(), nullptr/ui->table/);
| ^~~~~~~~~~~~~~~
| background

But replacing it with 'background', then I get the message :

colorrange.cpp:307:27: No matching constructor for initialization of 'QColorDialog'
qcolordialog.h:36:14: candidate constructor not viable: no known conversion from 'QBrush' to 'const QColor' for 1st argument
qcolordialog.h:35:14: candidate constructor not viable: allows at most single argument 'parent', but 2 arguments were provided
:74:20: note: candidate constructor not viable: requires 1 argument, but 2 were provided

[Actarus]

@JonB Jon, fixed both with the correct sintax:

colorPicker = new QColorDialog(ui->table->item(r, 0)->background().color(), nullptr);

This also fixed the error1 and now the .o file is generated

[Actarus]

@JonB Jon, now that I fixed all the errors, if I compile I suddenly get around 1600 errors like the following one but in QT5 it has always compiled and run perfectly.

error: conversion from 'const char [2]' to 'QChar' is ambiguous
: conversion from 'const char [2]' to 'QChar' is ambiguous
933 | if(formula.at(i) == "'" && i+1 < formula.length())
| ^~~

Invalid operands to binary expression ('const QChar' and 'const char[2]')
qchar.h:582:34: candidate function not viable: no known conversion from 'const char[2]' to 'QChar' for 2nd argument

Here the code:

QString can;
                                            for(int i = 0; i < formula.size(); i++)
                                            {
                                                if(formula.at(i) == "'" && i+1 < formula.length())
                                                {
                                                    i += 1;
                                                    while(i < formula.length() && formula.at(i) != "'")
                                                    {
                                                        can.append(formula.at(i));
                                                        i += 1;
                                                    }
                                                    if(cBoxChannel_1->findText(can) != -1)
                                                    {
                                                        nChannels += 1;
                                                        if(nChannels == 1)
                                                            cBoxChannel_1->setCurrentIndex(cBoxChannel_1->findText(can));
                                                        else
                                                            if(nChannels == 2)
                                                                cBoxChannel_2->setCurrentIndex(cBoxChannel_2->findText(can));
                                                            else
                                                                if(nChannels == 3)
                                                                    cBoxChannel_3->setCurrentIndex(cBoxChannel_3->findText(can));
                                                                else
                                                                    if(nChannels == 4)
                                                                        cBoxChannel_4->setCurrentIndex(cBoxChannel_4->findText(can));
                                                                    else
                                                                        if(nChannels == 5)
                                                                            cBoxChannel_5->setCurrentIndex(cBoxChannel_5->findText(can));
                                                                        else
                                                                            if(nChannels == 6)
                                                                                cBoxChannel_6->setCurrentIndex(cBoxChannel_6->findText(can));
                                                                            else
                                                                                if(nChannels == 7)
                                                                                    cBoxChannel_7->setCurrentIndex(cBoxChannel_7->findText(can));
                                                                                else
                                                                                    if(nChannels == 8)
                                                                                        cBoxChannel_8->setCurrentIndex(cBoxChannel_8->findText(can));
                                                    }
                                                    can.clear();
                                                }
                                            }

The claimed part is the ==:

if(formula.at(i) == "'" && i+1 < formula.length())

[Christian Ehrlicher]

error: conversion from 'const char [2]' to 'QChar' is ambiguous
: conversion from 'const char [2]' to 'QChar' is ambiguous

We already discussed this problem ...

[Actarus]

@Christian-Ehrlicher Thanks, fixed.

I'm facing a couple of situations that in QT5 compile without problem but not in QT6:

connect(xychart->m_ChartViewer, &QChartViewer::needTrackLineXYChart, this, &AnalysisWindow::trackLineAxis);

and

connect(m_ChartViewer, &QChartViewer::MouseIsPressed, this, &BaseViewPortComp::mousePressEvent);

In both cases the problem is error:
static assertion failed: Signal and slot arguments are not compatible.
214 | static_assert((QtPrivate::CheckCompatibleArguments<typename SignalType::Arguments, typename SlotType::Arguments>::value),

I assume it's because it's not possible to connect a QPointerEvent to a QMouseEvent, but how to get out of this?

[Christian Ehrlicher]

Qt has no class named QChartViewer so I don't know this class. Most likely the signature of the signals changed so you have to adjust your slots accordingly - normal developer stuff.

[Actarus]

@Christian-Ehrlicher Thanks Christian, fixed adjusting slots.