From 56b37bf93c3cbead5f2d4d4369848415a3b0a8b2 Mon Sep 17 00:00:00 2001
From: ocornut <omar@miracleworld.net>
Date: Thu, 7 May 2026 21:22:02 +0200
Subject: [PATCH] Inputs: SetItemKeyOwner(): does not set ownership is key is
 already taken.

(#456, #2637, #2620, #2891, #3370, #3724, #4828, #5108, #5242, #5641)
---
 docs/CHANGELOG.txt | 4 ++++
 imgui.cpp          | 2 ++
 imgui_demo.cpp     | 2 +-
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index e8f4776b7..a35a7de07 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -156,6 +156,10 @@ Other Changes:
   - SetItemKeyOwner(): return true if ownership has been requested, which typically
     needs to to checked for gating further tests. This is important as the function
     may fail. (#456, #2637, #2620, #2891, #3370, #3724, #4828, #5108, #5242, #5641)
+  - SetItemKeyOwner(): does not set ownership is key is already taken. Effectively
+    this makes using `SetItemKeyOwner(ImGuiKey_MouseWheelY)` over an item work as
+    expected while not having item react if a scroll wheel is actively in progress.
+    May be subject to further redesign, e.g. conditional flags. Feedback welcome!
 - Style:
   - Fixed vertical scrollbar top coordinates when using thick borders on windows
     with no title bar and no menu bar. (#9366)
diff --git a/imgui.cpp b/imgui.cpp
index cd21c2735..8615cc0c6 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -10726,6 +10726,8 @@ bool ImGui::SetItemKeyOwner(ImGuiKey key, ImGuiInputFlags flags)
     if ((g.HoveredId == id && (flags & ImGuiInputFlags_CondHovered)) || (g.ActiveId == id && (flags & ImGuiInputFlags_CondActive)))
     {
         IM_ASSERT((flags & ~ImGuiInputFlags_SupportedBySetItemKeyOwner) == 0); // Passing flags not supported by this function!
+        if (!TestKeyOwner(key, id))
+            return false;
         SetKeyOwner(key, id, flags & ~ImGuiInputFlags_CondMask_);
         return true;
     }
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index 39d9e1f07..d251616ea 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -875,7 +875,7 @@ static void ExampleImageViewer_DrawCanvas(ExampleImageViewerData* data, ImVec2 c
     data->ViewReset = false;
 
     // Handle inputs
-    if (ImGui::SetItemKeyOwner(ImGuiKey_MouseWheelY)) // FIXME: Not while scrolling?
+    if (ImGui::SetItemKeyOwner(ImGuiKey_MouseWheelY))
         if (io.MouseWheel != 0.0f)
             data->Zoom = IM_CLAMP(data->Zoom * (1.0f + io.MouseWheel * 0.10f), data->ZoomMin, data->ZoomMax);
     float zoom = data->Zoom; // (float)(int)ViewZoom;