Re: [E-devel] Crash using C++ Layout signal API

Am 24.06.21 um 21:25 schrieb Felipe Magno de Almeida:
> Hello Andreas
> 
> On Thu, Jun 24, 2021 at 4:22 PM Andreas Volz <[email protected]> wrote:
>>
>> I just add another question now as it's working without crash. :-)
>>
>> With signal_callback_add() I could only add a C function or static C++
>> member function. But practically I design my callback functions to
>> hand-over them the this-pointer that they could access members.
>>
>> But here is no possibility to add a data pointer to
>> signal_callback_add() that is hand-over to the callback. Any ideas to
>> attach the this pointer to the Eo object and then get it back from the
>> efl::layout::Signal from inside the callback?
>>
>> BTW: I would love if the C++ interface would use libsigc++ as signaling
>> system. It's so a well designed signaling system, documented and easy to
>> use.
> 
> You can use any function object, not just pointers. You can use a
> lambda for example:
> 
> ```
> std::shared_ptr<MyClass> my_object;
> layout.signal_callback_add("edje", "func", [=] (auto&& signal, auto&&
> emission, auto&& source) { my_object->do_something(signal, emission,
> source); });
> ```


This is a very good idea! Works great.

Just a question about the signal prototype. I used this one and it 
works. I tried to use type std::string as emission/source but this 
result in another crash. Any ideas why conversation from 
efl::eina::basic_string_view<char>  to std::string has problems?

void allFunc2(efl::layout::Signal s, efl::eina::basic_string_view<char> 
emission, efl::eina::basic_string_view<char>  source)