Drawing underneath scrollbars?

[parbo]

Version/Branch of Dear ImGui:

Version: 1.84.1
Branch: docking

Back-end/Renderer/Compiler/OS
OpenGL/GLFW
Windows

My Issue/Question:

I would like to be able to draw underneath the scrollbar (e.g. to have an image or gradient as the background), and have the scrollbar be drawn (with alpha) on top. I tried drawing like that by pushing OuterRectClipped as the clip rect and then filling that with what I want as a background. But the scrollbar is drawn before my content, so it doesn't work.

Is this possible to achieve? Would it e.g. be possible to draw the decorations in ImGui::End instead of in ImGui::Begin?

Screenshots/Video

This is with drawing using InnerRect instead, which doesn't hide the scrollbar, but I get that slightly ugly looking scrollbar.

I'd like for the image/gradient to extend underneath the scrollbar.

[ocornut]

Is this possible to achieve? Would it e.g. be possible to draw the decorations in ImGui::End instead of in ImGui::Begin?

The problem is that would conflict with drawing over the scrollbar as in #3114

One possible hacky workaround would be specifying ImGuiWindowFlags_NoScrollbar and then before End(), fill in window->ScrollbarSizes[] and call ImGui::Scrollbar() yourself. One issue with that is some code rely on the value of bool ScrollbarX, ScrollbarY (there are 2 instances of checking for ScrollbarX == true in code).

[parbo]

Thanks, I can give that hack a try!

[parbo]

This seems to work for me. I ended up copy/pasting the calculations of whether there should be scrollbars to a function that I call right after Begin, and then right before End I draw the scrollbars like you said. I also had to push a bigger clip rect in order for the scrollbar to draw properly. I used ImGui::PushClipRect(window->OuterRectClipped.Min, window->OuterRectClipped.Max, false);

[parbo]

Scrollbars are looking very nice now. 😁