add option to keep background color in PDF export

resources/etc/OpenBoard.config

@@ -124,11 +124,12 @@ RefreshRateInFramePerSecond=2
 
 [PDF]
 enableQualityLossToIncreaseZoomPerfs=true
+ExportBackgroundGrid=false
+ExportBackgroundColor=false
 Margin=20
 PageFormat=A4
 Resolution=300
 ZoomBehavior=4
-ExportBackgroundGrid=false
 
 [Podcast]
 AudioRecordingDevice=Default

src/adaptors/UBExportPDF.cpp

@@ -107,13 +107,15 @@ bool UBExportPDF::persistsDocument(UBDocumentProxy* pDocumentProxy, const QStrin
         bool isDark = scene->isDarkBackground();
         UBPageBackground pageBackground = scene->pageBackground();
 
+        bool exportDark = isDark && UBSettings::settings()->exportBackgroundColor->get().toBool();
+
         if (UBSettings::settings()->exportBackgroundGrid->get().toBool())
         {
-            scene->setBackground(false, pageBackground);
+            scene->setBackground(exportDark, pageBackground);
         }
         else
         {
-            scene->setBackground(false, UBPageBackground::plain);
+            scene->setBackground(exportDark, UBPageBackground::plain);
         }
 
         // pageSize is the output PDF page size; it is set to equal the scene's boundary size; if the contents

src/core/UBSettings.cpp

@@ -410,6 +410,7 @@ void UBSettings::init()
     pdfZoomBehavior = new UBSetting(this, "PDF", "ZoomBehavior", "4");
     enableQualityLossToIncreaseZoomPerfs = new UBSetting(this, "PDF", "enableQualityLossToIncreaseZoomPerfs", true);
     exportBackgroundGrid = new UBSetting(this, "PDF", "ExportBackgroundGrid", false);
+    exportBackgroundColor = new UBSetting(this, "PDF", "ExportBackgroundColor", false);
 
     podcastFramesPerSecond = new UBSetting(this, "Podcast", "FramesPerSecond", 10);
     podcastVideoSize = new UBSetting(this, "Podcast", "VideoSize", "Medium");

src/core/UBSettings.h

@@ -362,6 +362,7 @@ class UBSettings : public QObject
         UBSetting* pdfZoomBehavior;
         UBSetting* enableQualityLossToIncreaseZoomPerfs;
         UBSetting* exportBackgroundGrid;
+        UBSetting* exportBackgroundColor;
 
         UBSetting* podcastFramesPerSecond;
         UBSetting* podcastVideoSize;