In Table, Selectable highlight doesn't automatically fill row height to match TextWrapped wrapped text

[GuardianDll]

Version/Branch of Dear ImGui:

Version v1.91.5, but bug can be reproduced on v1.92.7 as well

Back-ends:

imgui_impl_sdl2.cpp + imgui_impl_sdl2.cpp

Compiler, OS:

W10 + VS2022

Full config/build information:

Dear ImGui 1.91.5 (19150)
--------------------------------
sizeof(size_t): 8, sizeof(ImDrawIdx): 2, sizeof(ImDrawVert): 20
define: __cplusplus=199711
define: _WIN32
define: _WIN64
define: _MSC_VER=1944
define: _MSVC_LANG=201703
--------------------------------
io.BackendPlatformName: imgui_impl_sdl2
io.BackendRendererName: imgui_impl_sdlrenderer2
io.ConfigFlags: 0x00000003
 NavEnableKeyboard
 NavEnableGamepad
io.ConfigNavCaptureKeyboard
io.ConfigInputTextCursorBlink
io.ConfigWindowsResizeFromEdges
io.ConfigMemoryCompactTimer = 60.0
io.BackendFlags: 0x0000000E
 HasMouseCursors
 HasSetMousePos
 RendererHasVtxOffset
--------------------------------
io.Fonts: 2 fonts, Flags: 0x00000000, TexSize: 512,256
io.DisplaySize: 2560.00,1377.00
io.DisplayFramebufferScale: 1.00,1.00
--------------------------------
style.WindowPadding: 8.00,8.00
style.WindowBorderSize: 1.00
style.FramePadding: 4.00,3.00
style.FrameRounding: 0.00
style.FrameBorderSize: 0.00
style.ItemSpacing: 8.00,4.00
style.ItemInnerSpacing: 4.00,4.00

Details:

I am having a table column, inside which is a ListBox with each line being Selectable. There are cases where the length of text is too long, in which case it correctly wraps the text via TextWrapped(); unfortunately the selectable area in this case is still limited to the first line of table, so does the highlighting of the column

Screenshots/Video:

Same behavior is in https://pthom.github.io/imgui_explorer:

In demo screen used in my game

and in it's natural habitat in my game

Minimal, Complete and Verifiable Example code:

Sorry, my code muscle isn't strong enough to separate the bit in question, but reproducible this way

1. Go to Demo -> Tables & Columns -> Advanced
2. Turn "show_wrapped_text" on
3. Rearrange the description so "Description" column can be resized
4. Resize so the wrapping starts to work

[ocornut]

This not specific to any individual widget but rather at the intersection of various things.

• The code in Demo->Tables->Advanced submit an empty Selectable() and THEN a TextWrapped() element. Their size are uncorrelated.

• The "show wrapped text" in that Demo is extraordinary misleading. It only works as expected because the text is the same value every time. But if you change that, e.g. ImGui::TextWrapped((row_n & 1) ? "Hello" : "Lorem ipsum dolor sit amet"); then you have variable height lines, and variable height lines cannot trivially be used with the ImGuiListClipper without additional code. I think it may be reasonable that I remove this from the demo not to mislead people.

• You can calculate the height of the Selectable() by using feeding your text to CalcTextSize(...., ...., wrap_width).y; where wrap_width = GetContentRegionAvail().x. However that would make your list items variable height and then you can't use ImGuiListClipper the same way. If your list box is not very big (say < 200 items) it won't matter so much.

Having the Selectable() automatically fill the whole row constitute a difficult problem with our system.
We could making the highlight fill it easily by postponing the rendering into setting row background color, but we can't reliably alter hit-testing as we don't know the row height ahead of time.

There are variety of ways to approach this but sincerely it is the sort of problem that's not simple and it is better to avoid them in dear imgui land. If I were you I would remove the text wrapping in this list box.