Child Window edge/splitter resize Z error.

[lailoken]

Version/Branch of Dear ImGui:

1.92.0 WIP (19194) - docking

Back-ends:

SDL2 & DX11

Compiler, OS:

Windows 11 & Linux

Full config/build information:

No response

Details:

In the sample the Begin is missing an IF block to conditionally draw the child windows.

This is not ideal and is inefficient. But should otherwise work (and it does in all other cases).

However, when I drag and dock the two windows over each other, so that they are both part of a tab group, then the first child resizer is triggered even if that window is not foremost.

Screenshots/Video:

this is the splitter window (in foremost tab):

then I switch to the blank window tab, and hover my mouse over where the splitter is in the back window:

(clicking now brings the back window to the front as well)

Minimal, Complete and Verifiable Example code:

void RenderSplitterDebug()
{
    ImGui::Begin("Window with Splitter");

    ImGui::BeginChild("child1", ImVec2(0, 0), ImGuiChildFlags_ResizeX | ImGuiChildFlags_Borders);
    ImGui::EndChild();

    ImGui::BeginChild("child2");
    ImGui::EndChild();

    ImGui::End();

    ImGui::Begin("Blank Window");
    ImGui::End();
}

[GamingMinds-DanielC]

Can confirm the bug on Win32 and DX12 backends. This probably was introduced back in version 1.90. I made a quick test in a project that is on version 1.90.5 (minus the ImGuiChildFlags_Borders flag) and the bug is already there.

[ocornut]

Hello, thanks for reporting!
Should be fixed by ea613e1.
(I'll merge in docking soon. You can cherry-pick now but there'll be a minor conflict where the bool handle_borders_and_resize_grips = true; should be changed to bool handle_borders_and_resize_grips = (window->DockNodeAsHost || !window->DockIsActive);).