ImGui::InputTextMultiline assertion failed with ImGui::TreeNodeEx

[tim-tim707]

Version/Branch of Dear ImGui:

Version 1.85 WIP

Back-ends:

imgui_impl_glfw.cpp + imgui_impl_opengl3.cpp

Compiler, OS:

Windows 10 + gcc

Full config/build information:

No response

Details:

The following code creates the following assertion fail

Assertion failed at imgui_widgets.cpp line 627
IM_ASSERT(mouse_button >= 0 && mouse_button < ImGuiMouseButton_COUNT);

if (ImGui::TreeNodeEx("Shader edition:")) {
    ImGui::InputTextMultiline("", &imgui_state.vertex_shd, ImVec2(480, 320));
    ImGui::TreePop();
}

It is fixed by adding the proper PushID and PopID calls like so:

if (ImGui::TreeNodeEx("Some Text")) {
        ImGui::PushID("blabla");
        ImGui::InputTextMultiline("", &someText, ImVec2(480, 320));
        ImGui::PopID();
        ImGui::TreePop();
    }

I was surprised by it since I'm a beginner in ImGui, maybe there could be an assertion failed before, or a line of documentation / an answer in the QA at http://dearimgui.org/faq about it ? The documentation of PushID in imgui.h hinted me that adding the calls would fix the issue and it indeed worked, but there were no indication that it was related except Q: Why is my widget not reacting when I click on it?

I'm leaving an issue as documentation for others since I didn't find this when looking in the closed issues. You can consider this issue as solved, but I would like if it were added to the QA or the documentation of TreeNodeEx or similar.

Thanks !

Screenshots/Video:

No response

Minimal, Complete and Verifiable Example code:

Fixed with

if (ImGui::TreeNodeEx("Some Text")) {
        ImGui::PushID("blabla");
        ImGui::InputTextMultiline("", &someText, ImVec2(480, 320));
        ImGui::PopID();
        ImGui::TreePop();
    }

[ocornut]

if (ImGui::TreeNodeEx("Shader edition:")) {
    ImGui::InputTextMultiline("")

You have an ID conflict here: both item are using the same identifier since identifiers are appended/stacked together.

This is indeed covered by the giant FAQ blurb about how the ID Stack works. I think if you read that section carefully you would fully understand that using "" as an identifier is rarely the right thing (but sometimes it can be, notably right after a PushID()).

You don't need to use PushID() you can directly specify an identifier for your input, e.g.

if (ImGui::TreeNodeEx("Shader edition:")) {
    ImGui::InputTextMultiline("##blabla")

PS: "Version 1.85 WIP" is very old in dear imgui land, this is beyond the unsupported mark. Please update.