From d6c40727f761ee11c6f0106532c2253a8342b2f5 Mon Sep 17 00:00:00 2001
From: PaddleStroke <pierrelouis.boyer@gmail.com>
Date: Fri, 23 Jan 2026 16:01:06 +0100
Subject: [PATCH] Assembly: prevent assembly collapse when editing sketch.
 (#26956)

* Gui: View provider: isAutoCollapseOnDeactivation

* Update ViewProvider.h

* Update ActiveObjectList.cpp

* Update ViewProviderAssembly.cpp

* Update ActiveObjectList.cpp
---
 src/Gui/ActiveObjectList.cpp                  | 2 +-
 src/Gui/ViewProvider.h                        | 6 ++++++
 src/Mod/Assembly/Gui/ViewProviderAssembly.cpp | 2 ++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/Gui/ActiveObjectList.cpp b/src/Gui/ActiveObjectList.cpp
index 612e0a0aff..6d27c0f22c 100644
--- a/src/Gui/ActiveObjectList.cpp
+++ b/src/Gui/ActiveObjectList.cpp
@@ -73,7 +73,7 @@ void ActiveObjectList::setHighlight(const ObjectInfo& info, HighlightMode mode,
         return;
     }
 
-    if (TreeParams::getTreeActiveAutoExpand()) {
+    if (TreeParams::getTreeActiveAutoExpand() && (enable || vp->isAutoCollapseOnDeactivation())) {
         vp->getDocument()->signalExpandObject(
             *vp,
             enable ? TreeItemMode::ExpandPath : TreeItemMode::CollapseItem,
diff --git a/src/Gui/ViewProvider.h b/src/Gui/ViewProvider.h
index 1adc5e8b70..4f13d15edb 100644
--- a/src/Gui/ViewProvider.h
+++ b/src/Gui/ViewProvider.h
@@ -445,6 +445,11 @@ public:
     {
         return true;
     }
+    /** Tell if the tree item should be auto collapsed*/
+    bool isAutoCollapseOnDeactivation() const
+    {
+        return autoCollapseOnDeactivation;
+    }
 
     /** @name Signals of the view provider */
     //@{
@@ -707,6 +712,7 @@ protected:
     /// The root separator for annotations
     SoSeparator* pcAnnotation {nullptr};
     ViewProviderPy* pyViewObject {nullptr};
+    bool autoCollapseOnDeactivation {true};
     std::string overrideMode;
     std::bitset<32> StatusBits;
     /// whether visibility can toggled
diff --git a/src/Mod/Assembly/Gui/ViewProviderAssembly.cpp b/src/Mod/Assembly/Gui/ViewProviderAssembly.cpp
index 5029c1296a..5056ad9201 100644
--- a/src/Mod/Assembly/Gui/ViewProviderAssembly.cpp
+++ b/src/Mod/Assembly/Gui/ViewProviderAssembly.cpp
@@ -152,6 +152,7 @@ void ViewProviderAssembly::setupContextMenu(QMenu* menu, QObject* receiver, cons
 bool ViewProviderAssembly::doubleClicked()
 {
     if (isInEditMode()) {
+        autoCollapseOnDeactivation = true;
         getDocument()->resetEdit();
     }
     else {
@@ -280,6 +281,7 @@ bool ViewProviderAssembly::setEdit(int mode)
     if (mode == ViewProvider::Default) {
         // Ask that this edit mode be restored. For example if it is quit to edit a sketch.
         getDocument()->setEditRestore(true);
+        autoCollapseOnDeactivation = false;
 
         // Set the part as 'Activated' ie bold in the tree.
         Gui::Command::doCommand(