@rizzitello This is your code, can you check @patrickelectric comment?

@rizzitello same here.

? I'm reading 'const'

why names with underscore ? That's not KDE code style.

5:17: error: ISO C++ forbids declaration of 'name' with no type [-fpermissive]
sorry, I was writing in the cell.
const is a keyword, not a type, should be const QString&, const float, const int`, not only const itself.

This is not my code...

Remove Function.

auto disconnectAction = new QAction(style()->standardIcon(QStyle::SP_DialogCloseButton),i18n("Disconnect"));

you do not need to change the state AtCore will do that on its own.

Do not set the state for atcore , it will do it itself when you close the connection

printAction should be a private QAction* member of the class so you can change it how your trying without crashing..
Also suggest this for the below connect.

printAction = new QAction(style()->standardIcon(QStyle::SP_MediaPlay),i18n("Print"));
    connect(printAction, &QAction::triggered, [ & ](){
        if(m_core.state() == AtCore::BUSY) {
            pausePrint();
            printAction->setText(i18n("Resume Print"));
            printAction->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
            return;
        }
        if (m_core.state() == AtCore::IDLE){
                print();
        } else if (m_core.state() == AtCore::PAUSE) {
                m_core.resume();
        }
        printAction->setText(i18n("Pause"));
        printAction->setIcon(style()->standardIcon(QStyle::SP_MediaPause));
    });

This removes the need for the build actions function as all other actions do not use the set checked attribute.

Should be a member of the class if you are going to use it this way.

auto stopAction = new QAction(style()->standardIcon(QStyle::SP_MediaStop),i18n("Stop"));

auto disableMotorsAction = new QAction(style()->standardIcon(QStyle::SP_MediaStop),i18n("Disable Motors"));

initConnectsToAtCore();

if( fw != QString("Auto-Detect")){
            m_core.loadFirmwarePlugin(fw);
        }

If you don't provide a fw plugin to load atcore will automaticly attempt to auto detect.

QAction *printAction = nullptr;

Remove this function No needed

This name comes from a previous commit that is already in master. So its not part of this review.
I can update this later in the future.

Removed.

Hmm I did that based on test client:
https://github.com/KDE/atcore/blob/master/testclient/mainwindow.cpp#L320

This method needs to be called on the constructor. Since the connection that calls this method is inside initConnectsToAtCore.
Was a mistake that I missed to add the method on the correct place.

sorry, didnt noticed that the QString was removed when I added the const &

Change m_printAction text and icons in the handlePrinterStatusChanged() function based on the new state

AtCore::BUSY is set for both the start print and resume actions.
AtCore::FinishedPrint is set when a print job finishes or gets stoped
AtCore::Pause is set when the job is paused.

Remove

We need icons made for some of our actions.

For a few icons I'm using this:
https://fontawesome.com/v4.7.0/icons/

We can see if some of those can fit to this, otherwise we can ask VDG to make ones.

Font Awesome -1
Shipping icons made by VGD : +1..
We will address this later of course.

this ^^