From 43e3b41afda2682ed0725327d55bac5e683bcd06 Mon Sep 17 00:00:00 2001
From: hjk <hjk@qt.io>
Date: Wed, 19 Apr 2023 16:20:33 +0200
Subject: [PATCH] Core: Delay creation of settings page widgets

... until they are actually shown.

Change-Id: Ibf47fe57c69557f9c514cc5a7c7c8aff369b1324
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
---
 .../coreplugin/dialogs/settingsdialog.cpp     | 28 ++++++++++++-------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/plugins/coreplugin/dialogs/settingsdialog.cpp b/src/plugins/coreplugin/dialogs/settingsdialog.cpp
index 017b8dc8846..f429994edd9 100644
--- a/src/plugins/coreplugin/dialogs/settingsdialog.cpp
+++ b/src/plugins/coreplugin/dialogs/settingsdialog.cpp
@@ -331,14 +331,26 @@ public:
 class SmartScrollArea : public QScrollArea
 {
 public:
-    explicit SmartScrollArea(QWidget *parent)
-        : QScrollArea(parent)
+    explicit SmartScrollArea(QWidget *parent, IOptionsPage *page)
+        : QScrollArea(parent), m_page(page)
     {
         setFrameStyle(QFrame::NoFrame | QFrame::Plain);
         viewport()->setAutoFillBackground(false);
         setWidgetResizable(true);
     }
+
 private:
+    void showEvent(QShowEvent *event) final
+    {
+        if (!widget()) {
+            QWidget *inner = m_page->widget();
+            setWidget(inner);
+            inner->setAutoFillBackground(false);
+        }
+
+        QScrollArea::showEvent(event);
+    }
+
     void resizeEvent(QResizeEvent *event) final
     {
         QWidget *inner = widget();
@@ -387,6 +399,8 @@ private:
             return 0;
         return list.first()->sizeHint().width();
     }
+
+    IOptionsPage *m_page = nullptr;
 };
 
 // ----------- SettingsDialog
@@ -604,14 +618,8 @@ void SettingsDialog::ensureCategoryWidget(Category *category)
     m_model.ensurePages(category);
     auto tabWidget = new QTabWidget;
     tabWidget->tabBar()->setObjectName("qc_settings_main_tabbar"); // easier lookup in Squish
-    for (IOptionsPage *page : std::as_const(category->pages)) {
-        QWidget *widget = page->widget();
-        ICore::setupScreenShooter(page->displayName(), widget);
-        auto ssa = new SmartScrollArea(this);
-        ssa->setWidget(widget);
-        widget->setAutoFillBackground(false);
-        tabWidget->addTab(ssa, page->displayName());
-    }
+    for (IOptionsPage *page : std::as_const(category->pages))
+        tabWidget->addTab(new SmartScrollArea(this, page), page->displayName());
 
     connect(tabWidget, &QTabWidget::currentChanged,
             this, &SettingsDialog::currentTabChanged);