perf: Speed Up Opening of Settings Dialog (#4193)

fix https://github.com/Chatterino/chatterino2/issues/1266

CHANGELOG.md

@@ -9,6 +9,7 @@
 - Bugfix: Fixed the wrong right-click menu showing in the chat input box. (#4177)
 - Bugfix: Fixed popup windows not appearing/minimizing correctly on the Windows taskbar. (#4181)
 - Bugfix: Fixed white border appearing around maximized window on Windows. (#4190)
+- Bugfix: Fixed window scaling being applied too many times on startup, causing windows like Settings to be slow. (#4193)
 
 ## 2.4.0-beta
 

src/widgets/BaseWindow.cpp

@@ -81,7 +81,7 @@ BaseWindow::BaseWindow(FlagsEnum<Flags> _flags, QWidget *parent)
                 this->updateScale();
             });
         },
-        this->connections_);
+        this->connections_, false);
 
     this->updateScale();
 
@@ -786,8 +786,12 @@ bool BaseWindow::handleSHOWWINDOW(MSG *msg)
 #ifdef USEWINSDK
     if (auto dpi = getWindowDpi(msg->hwnd))
     {
-        this->nativeScale_ = dpi.get() / 96.f;
+        float currentScale = (float)dpi.get() / 96.F;
-        this->updateScale();
+        if (currentScale != this->nativeScale_)
+        {
+            this->nativeScale_ = currentScale;
+            this->updateScale();
+        }
     }
 
     if (!this->shown_ && this->isVisible())

src/widgets/dialogs/SettingsDialog.cpp

@@ -32,6 +32,10 @@ SettingsDialog::SettingsDialog(QWidget *parent)
 {
     this->setObjectName("SettingsDialog");
     this->setWindowTitle("Chatterino Settings");
+    // Disable the ? button in the titlebar until we decide to use it
+    this->setWindowFlags(this->windowFlags() &
+                         ~Qt::WindowContextHelpButtonHint);
+
     this->resize(915, 600);
     this->themeChangedEvent();
     this->scaleChangedEvent(this->scale());
@@ -41,9 +45,6 @@ SettingsDialog::SettingsDialog(QWidget *parent)
     this->overrideBackgroundColor_ = QColor("#111111");
     this->scaleChangedEvent(this->scale());  // execute twice to width of item
 
-    // Disable the ? button in the titlebar until we decide to use it
-    this->setWindowFlags(this->windowFlags() &
-                         ~Qt::WindowContextHelpButtonHint);
     this->addShortcuts();
     this->signalHolder_.managedConnect(getApp()->hotkeys->onItemsUpdated,
                                        [this]() {