Multi-column layout isn't aware of scroll bar

[mkeeter]

Normally, things that are told to fill their window (with a size of -1.0f) adjust based on whether the scroll bar is displayed or not.

This doesn't work when drawing more than one column:

Notice that the full-width buttons change size, but the first multi-column buttons do not.

Here's a minimal reproduction:

    ImGui::SetNextWindowSize({300, 100}, ImGuiSetCond_Once);
    ImGui::Begin("Demo");
    ImGui::Columns(2);
    ImGui::Button("dear", {100, 0});
    ImGui::NextColumn();
    ImGui::Button("imgui", {-1, 0});
    ImGui::Columns(1);
    ImGui::Button("hello world", {-1, 0});
    ImGui::Button("goodbye world", {-1, 0});
    ImGui::Button("hello there", {-1, 0});
    ImGui::End();

I'd be glad to dig into this myself if you can give me a few pointers for where to look!

[ocornut]

I forgot the exact reason now, but it was intentional as it made lots of problems easier to solve. Last time I looked into it (1+ year ago) came to the conclusion it was better not fixing.

I may dig back into it at some point, ideally we'd fix it. It is causing you a specific problem or it is just a thing you noticed?

[mkeeter]

It's not particularly critical, but I did run into this while doing real work:
I'm doing a layout that uses both columns and ImGui::SameLine, and noticed the discrepancy in where the right edge lines up.

I fixed it by shrinking the SameLine layout by ImGui::GetStyle().ScrollbarSize, which is inelegant but makes the edges line up nicely.

[ocornut]

This should be fixed now. @mkeeter. As you are using Columns, would be interested in seeing if you are seeing any issue with the latest update.