From 2c8cc58fd16819c56a4eb36edebc591dc9878d83 Mon Sep 17 00:00:00 2001
From: ocornut <omarcornut@gmail.com>
Date: Fri, 21 Jun 2024 14:45:30 -0700
Subject: [PATCH] Internals: storing HoveredWindowBeforeClear for use by
 multi-context compositor drag and drop propagation.

# Conflicts:
#	imgui.cpp
#	imgui_internal.h
---
 imgui.cpp        | 1 +
 imgui_internal.h | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/imgui.cpp b/imgui.cpp
index 517df51eb..8822dd934 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -4571,6 +4571,7 @@ void ImGui::UpdateHoveredWindowAndCaptureFlags()
     // - We also support the moved window toggling the NoInputs flag after moving has started in order to be able to detect windows below it, which is useful for e.g. docking mechanisms.
     bool clear_hovered_windows = false;
     FindHoveredWindowEx(g.IO.MousePos, false, &g.HoveredWindow, &g.HoveredWindowUnderMovingWindow);
+    g.HoveredWindowBeforeClear = g.HoveredWindow;
 
     // Modal windows prevents mouse from hovering behind them.
     ImGuiWindow* modal_window = GetTopMostPopupModal();
diff --git a/imgui_internal.h b/imgui_internal.h
index f2940d211..a02f01b85 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -1959,6 +1959,7 @@ struct ImGuiContext
     ImGuiWindow*            CurrentWindow;                      // Window being drawn into
     ImGuiWindow*            HoveredWindow;                      // Window the mouse is hovering. Will typically catch mouse inputs.
     ImGuiWindow*            HoveredWindowUnderMovingWindow;     // Hovered window ignoring MovingWindow. Only set if MovingWindow is set.
+    ImGuiWindow*            HoveredWindowBeforeClear;           // Window the mouse is hovering. Filled even with _NoMouse. This is currently useful for multi-context compositors.
     ImGuiWindow*            MovingWindow;                       // Track the window we clicked on (in order to preserve focus). The actual window that is moved is generally MovingWindow->RootWindow.
     ImGuiWindow*            WheelingWindow;                     // Track the window we started mouse-wheeling on. Until a timer elapse or mouse has moved, generally keep scrolling the same window even if during the course of scrolling the mouse ends up hovering a child window.
     ImVec2                  WheelingWindowRefMousePos;
@@ -2276,6 +2277,7 @@ struct ImGuiContext
         CurrentWindow = NULL;
         HoveredWindow = NULL;
         HoveredWindowUnderMovingWindow = NULL;
+        HoveredWindowBeforeClear = NULL;
         MovingWindow = NULL;
         WheelingWindow = NULL;
         WheelingWindowStartFrame = WheelingWindowScrolledFrame = -1;