From 1a4639f71f1a8416c8df266809d04f6e45829276 Mon Sep 17 00:00:00 2001
From: Kacper Donat <kadet1090@gmail.com>
Date: Thu, 18 Jan 2024 23:28:13 +0100
Subject: [PATCH] Gui: Fix scroll behaviour in preference pages selector

This fixes problem with scroll jumping after selecting page on bottom of
the pages tree view. It was caused by collapsing group of the current
item and then re-expanding it few lines after.

Fixes: #12000
---
 src/Gui/DlgPreferencesImp.cpp | 45 +++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/src/Gui/DlgPreferencesImp.cpp b/src/Gui/DlgPreferencesImp.cpp
index 1c31064a85..cd37e6fc88 100644
--- a/src/Gui/DlgPreferencesImp.cpp
+++ b/src/Gui/DlgPreferencesImp.cpp
@@ -56,6 +56,28 @@
 
 using namespace Gui::Dialog;
 
+bool isParentOf(const QModelIndex& parent, const QModelIndex& child)
+{
+    for (auto it = child; it.isValid(); it = it.parent()) {
+        if (it == parent) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+QModelIndex findRootIndex(const QModelIndex& index)
+{
+    auto root = index;
+
+    while (root.parent().isValid()) {
+        root = root.parent();
+    }
+
+    return root;
+}
+
 QWidget* PreferencesPageItem::getWidget() const
 {
     return _widget;
@@ -714,17 +736,6 @@ void DlgPreferencesImp::showEvent(QShowEvent* ev)
     }
 }
 
-QModelIndex findRootIndex(const QModelIndex& index)
-{
-    auto root = index;
-
-    while (root.parent().isValid()) {
-        root = root.parent();
-    }
-    
-    return root;
-}
-
 void DlgPreferencesImp::onPageSelected(const QModelIndex& index)
 {
     auto* currentItem = static_cast<PreferencesPageItem*>(_model.itemFromIndex(index));
@@ -790,14 +801,20 @@ void DlgPreferencesImp::onStackWidgetChange(int index)
         return;
     }
 
-    ui->groupsTreeView->selectionModel()->select(currentItem->index(), QItemSelectionModel::ClearAndSelect);
+    auto currentIndex = currentItem->index();
 
     auto root = _model.invisibleRootItem();
     for (int i = 0; i < root->rowCount(); i++) {
         auto currentGroup = static_cast<PreferencesPageItem*>(root->child(i));
+        auto currentGroupIndex = currentGroup->index();
+
+        // don't do anything to group of selected item
+        if (isParentOf(currentGroupIndex, currentIndex)) {
+            continue;
+        }
 
         if (!currentGroup->isExpanded()) {
-            ui->groupsTreeView->collapse(currentGroup->index());
+            ui->groupsTreeView->collapse(currentGroupIndex);
         }
     }
 
@@ -807,6 +824,8 @@ void DlgPreferencesImp::onStackWidgetChange(int index)
         ui->groupsTreeView->expand(parentItem->index());
         parentItem->setExpanded(wasExpanded);
     }
+    
+    ui->groupsTreeView->selectionModel()->select(currentIndex, QItemSelectionModel::ClearAndSelect);
 }
 
 void DlgPreferencesImp::changeEvent(QEvent *e)