Start legend update immediately when render starts instead of when

nyalldawson · nyalldawson · commit b9ffb10f3856 · 2023-03-08T19:28:18.000+10:00
it finishes

Since the operation is now executed in a background thread, we
may as well get it processing at the same time as the render
occurs
diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
@@ -4888,7 +4888,7 @@ void QgisApp::initLayerTreeView()
   addDockWidget( Qt::LeftDockWidgetArea, mLayerOrderDock );
   mLayerOrderDock->hide();
 
-  connect( mMapCanvas, &QgsMapCanvas::mapCanvasRefreshed, this, &QgisApp::updateFilterLegend );
+  connect( mMapCanvas, &QgsMapCanvas::renderStarting, this, &QgisApp::updateFilterLegend );
   connect( mMapCanvas, &QgsMapCanvas::renderErrorOccurred, badLayerIndicatorProvider, &QgsLayerTreeViewBadLayerIndicatorProvider::reportLayerError );
   connect( mMapCanvas, &QgsMapCanvas::renderErrorOccurred, mInfoBar, [this]( const QString & error, QgsMapLayer * layer )
   {

Original file line number	Diff line number	Diff line change
`@@ -4888,7 +4888,7 @@ void QgisApp::initLayerTreeView()`
`4888`	`4888`	`addDockWidget( Qt::LeftDockWidgetArea, mLayerOrderDock );`
`4889`	`4889`	`mLayerOrderDock->hide();`
`4890`	`4890`
`4891`		`- connect( mMapCanvas, &QgsMapCanvas::mapCanvasRefreshed, this, &QgisApp::updateFilterLegend );`
	`4891`	`+ connect( mMapCanvas, &QgsMapCanvas::renderStarting, this, &QgisApp::updateFilterLegend );`
`4892`	`4892`	`connect( mMapCanvas, &QgsMapCanvas::renderErrorOccurred, badLayerIndicatorProvider, &QgsLayerTreeViewBadLayerIndicatorProvider::reportLayerError );`
`4893`	`4893`	`connect( mMapCanvas, &QgsMapCanvas::renderErrorOccurred, mInfoBar, [this]( const QString & error, QgsMapLayer * layer )`
`4894`	`4894`	`{`