Imgui::InputText with callback

[dcnieho]

Currently the callback argument is dropped when imgui.input_text is wrapped (ImGuiInputTextCallback callback = nullptr is the signature). I wonder if it would be possible to wrap this (and thereby callbacks more generally i guess), since i'd like to use the input text with ImGuiInputTextFlags_CallbackHistory.

[pthom]

Hello again,

I cannot work on this, during this christmas period. This modification is a bit more involved, since callbacks are C function pointers (unbindable with pybind).

If you want to give it a try, a possible path would be:

1. Modify imgui.h like this: (imgui_bundle/external/imgui/imgui/imgui.h) (imgui_bundle is alread using a fork)

   // Callback and functions types
   #ifdef IMGUI_BUNDLE_PYTHON_API
   using ImGuiInputTextCallback = std::function<int(ImGuiInputTextCallbackData*)>;  // Callback function for ImGui::InputText()
   using ImGuiSizeCallback = std::function<void(ImGuiSizeCallbackData*)>;           // Callback function for ImGui::SetNextWindowSizeConstraints()
   #else
   #ifdef IMGUI_BUNDLE_PYTHON_UNSUPPORTED_API
   typedef int     (*ImGuiInputTextCallback)(ImGuiInputTextCallbackData* data);    // Callback function for ImGui::InputText()
   typedef void    (*ImGuiSizeCallback)(ImGuiSizeCallbackData* data);              // Callback function for ImGui::SetNextWindowSizeConstraints()
   #endif
   #endif

i.e. replace C function pointers (unbindable) by std::function, when compiling the python bindings.

2. Modify external/imgui/bindings/litgen_options_imgui.py and change: options.fn_params_exclude_types__regex = r"Callback$|size_t[ ]\"

3. run external/imgui/bindings/generate_imgui.py (it requires to install litgen

Merry christmas!

[dcnieho]

Hi Pascal,

No worries, this is another nice to have (sorry, should have specified that). Like for the other case, i won't be able to try this out myself.

There is maybe a dirty trick (I don't quite oversee it after a quick read, but seems like not cheap) to make this work without changing the signatures of all the callback functions: https://stackoverflow.com/a/18422878/3103767

But thats a lot of work on the generator side i suppose!

Merry christmas!

[pthom]

This should be fixed by https://github.com/pthom/imgui_bundle/commit/b722ca917e48311a49aa7e0bd6353e29fa3f4c59 and its cousin https://github.com/pthom/imgui/commit/43d9ae1afa035bc3285ed5d49366e51cd0145be9

[dcnieho]

Super cool. Can't wait to try it out :)

[dcnieho]

I just realize i have two usecases for this callback: I want to add a button to my GUI that allows inserting a path at the cursor position in the textbox. Right now the only way to get the cursor position in the callback is through this callback. So, double super nice you've enabled it!

[dcnieho]

@pthom: This is working very well, thanks a lot!