MaximaExpression::imageChanged() has a different logic and implementation. Can we try to unify the handling here?

what happens if we have two images from two expressions and they arrive at the wrong order (second image is faster than the first one)?

Are QTextStream and QChar really required in this file?

use c++11 range based loop instead of the foreach macro.

is this int variable still required in the new code?

All will worked, because each expressions have own m_tempFile.

QTextStream no needed, but QChar used in recordSep, unitSep. Though, maybe i could change it to char.

OK.

You right, the variable not needed, I just had forggoten to remove it.

Not sure. MaximaExpression knows, where image placed, and imageChanged() handle this. Also, in maxima output there is placeholder for image.
PythonExpression has another conditions, so the code different from MaximaExpression code.
So, in this moment, I don't see general logic for both classes.

I had mistaken, this variable contains value about variableManagement (enabled or not) from python settings. PythonSession haven't own settings, so we need use session method.

QString() is obsolete here.

QString() is obsolete here.

Qt has already qApp.

const QString&?

KProcess or QProcess?

Please add some comments for the number 17 here.

c++11 support the initialization in the header. Let's start using it for every new code:

Cantor::Expression* m_expression{nullptr};

qApp does not fit, but I will just use QCoreApplication::instance() and remove appRef var.

QProcess