Add optional parameter to ImGui::Separator for user-defined vertical or horizontal separator

[jnyfah]

Version/Branch of Dear ImGui:

Version 1.91.7, Branch: master

Back-ends:

imgui_impl_XXX.cpp + imgui_impl_XXX.cpp

Compiler, OS:

Windows 11 + MSVC 2022

Full config/build information:

No response

Details:

My Issue/Question:

Currently, ImGui::Separator only supports horizontal separators by default. Internally, IMGUI does support vertical separators via the ImGuiSeparatorFlags_Vertical flag, but this functionality is not exposed to users.

I want to fix this by allowing users to explicitly create vertical separators by adding an optional parameter to ImGui::Separator. This would make it easier to create custom layouts that require vertical separators.

After checking the code, I noticed that ImGuiSeparatorFlags and ImGuiLayoutType_ are used internally, but ImGuiLayoutType_ is marked as "in development" and isn't exposed publicly. I’m unsure whether exposing ImGuiLayoutType_ directly would be acceptable or if a new public enum should be introduced for this purpose.

Would exposing a new enum or flag for user-defined separators be an acceptable approach? I'd like to get feedback before proceeding with implementation. Thanks!

Screenshots/Video:

No response

Minimal, Complete and Verifiable Example code:

// Here's some code anyone can copy and paste to reproduce your issue
ImGui::Begin("Example Bug");
MoreCodeToExplainMyIssue();
ImGui::End();

[ocornut]

Hello Jennifer,

This still needs to be designed, and unfortunately answering your question would constitute part of the work.
It could be quite ambiguous what a vertical separator means, depending on context. What is your precise usage context?
Presently it is de-facto supported inside menu-bar which have a fixed height and a tendency to be single line layout.

For now, could you call SeparatorEx(ImGuiSeparatorFlags_Vertical) using imgui_internal.h ?

Also linking to #7360, #319, #97. That last one is one of our oldest open issue. I'm going to unlock it as part of a wider refactor of layout system.