Fix too small symbol layer preview icon on hidpi displays

nyalldawson · nyalldawson · commit 9014be0d37aa · 2019-01-17T09:47:20.000+11:00
diff --git a/src/gui/symbology/qgssymbolselectordialog.cpp b/src/gui/symbology/qgssymbolselectordialog.cpp
@@ -36,6 +36,7 @@
 #include "qgssvgcache.h"
 #include "qgsimagecache.h"
 #include "qgsproject.h"
+#include "qgsguiutils.h"
 
 #include <QColorDialog>
 #include <QPainter>
@@ -147,11 +148,16 @@ class SymbolLayerItem : public QStandardItem
 
     void updatePreview()
     {
+      if ( !mSize.isValid() )
+      {
+        const int size = QgsGuiUtils::scaleIconSize( 16 );
+        mSize = QSize( size, size );
+      }
       QIcon icon;
       if ( mIsLayer )
-        icon = QgsSymbolLayerUtils::symbolLayerPreviewIcon( mLayer, QgsUnitTypes::RenderMillimeters, QSize( 16, 16 ) ); //todo: make unit a parameter
+        icon = QgsSymbolLayerUtils::symbolLayerPreviewIcon( mLayer, QgsUnitTypes::RenderMillimeters, mSize ); //todo: make unit a parameter
       else
-        icon = QgsSymbolLayerUtils::symbolPreviewIcon( mSymbol, QSize( 16, 16 ) );
+        icon = QgsSymbolLayerUtils::symbolPreviewIcon( mSymbol, mSize );
       setIcon( icon );
 
       if ( parent() )
@@ -214,6 +220,7 @@ class SymbolLayerItem : public QStandardItem
     QgsSymbolLayer *mLayer = nullptr;
     QgsSymbol *mSymbol = nullptr;
     bool mIsLayer;
+    QSize mSize;
 };
 
 ///@endcond
