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

Am 26.06.21 um 00:24 schrieb Felipe Magno de Almeida:
> Hello Andreas,
> 
> On Fri, Jun 25, 2021 at 7:15 PM Andreas Volz <[email protected]> wrote:
>>
>>
>>
>> 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)
> 
> I have to investigate. That should not happen.

I worked around for now by using c_str() from eina::basic_string_view 
and then contructing my std::string from that.