Wt

Hi,

your mTextArea is never added to the widget tree. And if you would do it later, you would have to move it out of mTextArea making the pointer invalid.
If you want to keep the textarea around for later changes, you should use a raw pointer. Something like:

WTextArea *mTextArea = container->addWidget(std::make_unique<WTextArea>("Status"));

WTimer events are handled in the event-loop, so threading is not an issue.

Thanks Korneel.

TextArea *mTextArea = container->addWidget(std::make_unique("Status")) caused an compiler error:

error: no match for ‘operator=’ (operand types are ‘std::unique_ptrWt::WTextArea’ and ‘Wt::WTextArea*’)

I made a little bit clean up:

class BootloaderImplement : public Wt::WContainerWidget {
};

void BootloaderImplement::Run(void) {
auto *t = this->addWidget(std::make_uniqueWt::WTemplate(tr("home.bootloader.status")));
// this->mTextArea = this->addWidget(std::make_uniqueWt::WTextArea("Status:")); // compile error: no match for ‘operator=’
this->mTextArea = std::make_uniqueWt::WTextArea("Status:");
t->bindWidget("install-bootloader-status", std::move(this->mTextArea));
this->mTimer = std::make_uniqueWt::WTimer();
this->mTimer->setInterval(std::chrono::milliseconds{this->mIntervalMillisecond});
this->mTimer->timeout().connect(this, &BootloaderImplement::Inspection);
this->mTimer->start();
}

Are there anything wrong or missing in above code? The this->mTextArea is still an invalid pointer in BootloaderImplement::Inspection.

Thank you.

Kind regards,

• jupiter

The same kind of function exists for templates

this->mTextArea = t->bindWidget("install-bootloader-status", std::make_unique<Wt::WTextArea>("Status:"));

You don't need to store smart pointers to widgets yourself, Wt manages it all in a widget tree. Use raw pointers as your member variables.

Thanks Korneel, use raw pointer does the trick.

Thank you so much.