Fix PdfExport of PDF background

src/core/control/PrintHandler.cpp

@@ -48,8 +48,11 @@ void drawPage(GtkPrintOperation* /*operation*/, GtkPrintContext* context, int pa
         }
     }
 
+    xoj::view::BackgroundFlags flags = xoj::view::BACKGROUND_SHOW_ALL;
+    flags.showPDF = xoj::view::HIDE_PDF_BACKGROUND;  // Already printed (if any)
+
     DocumentView view;
-    view.drawPage(page, cr, true /* dont render eraseable */, true /* dont show pdf background*/);
+    view.drawPage(page, cr, true /* dont render eraseable */, flags);
 }
 
 void requestPageSetup(GtkPrintOperation* /*op*/, GtkPrintContext* /*ctx*/, int pageNr, GtkPageSetup* setup,

src/core/control/jobs/ImageExport.cpp

@@ -183,13 +183,17 @@ void ImageExport::exportImagePage(size_t pageId, size_t id, double zoomRatio, Ex
         }
     }
 
+    xoj::view::BackgroundFlags flags;
+    flags.showPDF = xoj::view::HIDE_PDF_BACKGROUND;  // Already exported (if any)
+    flags.showImage = exportBackground == EXPORT_BACKGROUND_NONE ? xoj::view::HIDE_IMAGE_BACKGROUND :
+                                                                   xoj::view::SHOW_IMAGE_BACKGROUND;
+    flags.showRuling = exportBackground <= EXPORT_BACKGROUND_UNRULED ? xoj::view::HIDE_RULING_BACKGROUND :
+                                                                       xoj::view::SHOW_RULING_BACKGROUND;
+
     if (layerRange) {
-        view.drawLayersOfPage(*layerRange, page, this->cr, true /* dont render eraseable */,
-                              true /* don't rerender the pdf background */, exportBackground == EXPORT_BACKGROUND_NONE,
-                              exportBackground <= EXPORT_BACKGROUND_UNRULED);
+        view.drawLayersOfPage(*layerRange, page, this->cr, true /* dont render eraseable */, flags);
     } else {
-        view.drawPage(page, this->cr, true /* dont render eraseable */, true /* don't rerender the pdf background */,
-                      exportBackground == EXPORT_BACKGROUND_NONE, exportBackground <= EXPORT_BACKGROUND_UNRULED);
+        view.drawPage(page, this->cr, true /* dont render eraseable */, flags);
     }
 
     if (!freeSurface(id)) {

src/core/control/jobs/PreviewJob.cpp

@@ -21,7 +21,7 @@
 #include "view/DocumentView.h"                                    // for Doc...
 #include "view/LayerView.h"                                       // for Lay...
 #include "view/View.h"                                            // for Con...
-#include "view/background/BackgroundView.h"                       // for BAC...
+#include "view/background/BackgroundFlags.h"                      // for BAC...
 
 PreviewJob::PreviewJob(SidebarPreviewBaseEntry* sidebar): sidebarPreview(sidebar) {}
 
@@ -82,7 +82,7 @@ void PreviewJob::drawPage() {
                 flags.forceVisible = xoj::view::FORCE_VISIBLE;
                 view.drawBackground(flags);
             } else {
-                view.drawBackground(xoj::view::BACKGROUND_SHOW_ONLY_BACKGROUND_COLOR);
+                view.drawBackground(xoj::view::BACKGROUND_FORCE_PAINT_BACKGROUND_COLOR_ONLY);
                 Layer* drawLayer = (*page->getLayers())[layer - 1];
                 xoj::view::LayerView layerView(drawLayer);
                 layerView.draw(context);

src/core/control/jobs/SaveJob.cpp

@@ -70,6 +70,8 @@ void SaveJob::updatePreview(Control* control) {
         cairo_t* cr = cairo_create(crBuffer);
         cairo_scale(cr, zoom, zoom);
 
+        xoj::view::BackgroundFlags flags = xoj::view::BACKGROUND_SHOW_ALL;
+
         // We don't have access to a PdfCache on which DocumentView relies for PDF backgrounds.
         // We thus print the PDF background by hand.
         if (page->getBackgroundType().isPdfPage()) {
@@ -78,10 +80,13 @@ void SaveJob::updatePreview(Control* control) {
             if (popplerPage) {
                 popplerPage->render(cr);
             }
+            flags.showPDF = xoj::view::HIDE_PDF_BACKGROUND;  // Already printed (if any)
+        } else {
+            flags.forceBackgroundColor = xoj::view::FORCE_AT_LEAST_BACKGROUND_COLOR;
         }
 
         DocumentView view;
-        view.drawPage(page, cr, true /* don't render erasable */, true /* Don't rerender the pdf background */);
+        view.drawPage(page, cr, true /* don't render erasable */, flags);
         cairo_destroy(cr);
         doc->setPreview(crBuffer);
         cairo_surface_destroy(crBuffer);

src/core/pdf/base/XojCairoPdfExport.cpp

@@ -148,13 +148,17 @@ void XojCairoPdfExport::exportPage(size_t page) {
         popplerPage->renderForPrinting(cr);
     }
 
+    xoj::view::BackgroundFlags flags;
+    flags.showPDF = xoj::view::HIDE_PDF_BACKGROUND;  // Already exported (if any)
+    flags.showImage = exportBackground == EXPORT_BACKGROUND_NONE ? xoj::view::HIDE_IMAGE_BACKGROUND :
+                                                                   xoj::view::SHOW_IMAGE_BACKGROUND;
+    flags.showRuling = exportBackground <= EXPORT_BACKGROUND_UNRULED ? xoj::view::HIDE_RULING_BACKGROUND :
+                                                                       xoj::view::SHOW_RULING_BACKGROUND;
+
     if (layerRange) {
-        view.drawLayersOfPage(*layerRange, p, this->cr, true /* dont render eraseable */,
-                              true /* don't rerender the pdf background */, exportBackground == EXPORT_BACKGROUND_NONE,
-                              exportBackground <= EXPORT_BACKGROUND_UNRULED);
+        view.drawLayersOfPage(*layerRange, p, this->cr, true /* dont render eraseable */, flags);
     } else {
-        view.drawPage(p, this->cr, true /* dont render eraseable */, true /* don't rerender the pdf background */,
-                      exportBackground == EXPORT_BACKGROUND_NONE, exportBackground <= EXPORT_BACKGROUND_UNRULED);
+        view.drawPage(p, this->cr, true /* dont render eraseable */, flags);
     }
 
     // next page

src/core/view/DocumentView.cpp

@@ -65,24 +65,10 @@ void DocumentView::drawBackground(xoj::view::BackgroundFlags bgFlags) const {
     bgView->draw(cr);
 }
 
-/**
- * Draw the full page, usually you would like to call this method
- * @param page The page to draw
- * @param cr Draw to thgis context
- * @param dontRenderEditingStroke false to draw currently drawing stroke
- * @param hideBackground true to hide the background
- */
-void DocumentView::drawPage(PageRef page, cairo_t* cr, bool dontRenderEditingStroke, bool hidePdfBackground,
-                            bool hideImageBackground, bool hideRulingBackground) {
+void DocumentView::drawPage(PageRef page, cairo_t* cr, bool dontRenderEditingStroke, xoj::view::BackgroundFlags flags) {
     initDrawing(page, cr, dontRenderEditingStroke);
 
-    {  // Draw background
-        xoj::view::BackgroundFlags bgFlags;
-        bgFlags.showImage = (xoj::view::ImageBackgroundTreatment)!hideImageBackground;
-        bgFlags.showPDF = (xoj::view::PDFBackgroundTreatment)!hidePdfBackground;
-        bgFlags.showRuling = (xoj::view::RulingBackgroundTreatment)!hideRulingBackground;
-        drawBackground(bgFlags);
-    }
+    drawBackground(flags);
 
     xoj::view::Context context{cr, (xoj::view::NonAudioTreatment)this->markAudioStroke,
                                (xoj::view::EditionTreatment) !this->dontRenderEditingStroke, xoj::view::NORMAL_COLOR};
@@ -98,17 +84,10 @@ void DocumentView::drawPage(PageRef page, cairo_t* cr, bool dontRenderEditingStr
 
 
 void DocumentView::drawLayersOfPage(const LayerRangeVector& layerRange, PageRef page, cairo_t* cr,
-                                    bool dontRenderEditingStroke, bool hidePdfBackground, bool hideImageBackground,
-                                    bool hideRulingBackground) {
+                                    bool dontRenderEditingStroke, xoj::view::BackgroundFlags flags) {
     initDrawing(page, cr, dontRenderEditingStroke);
 
-    {  // Draw background
-        xoj::view::BackgroundFlags bgFlags;
-        bgFlags.showImage = (xoj::view::ImageBackgroundTreatment)!hideImageBackground;
-        bgFlags.showPDF = (xoj::view::PDFBackgroundTreatment)!hidePdfBackground;
-        bgFlags.showRuling = (xoj::view::RulingBackgroundTreatment)!hideRulingBackground;
-        drawBackground(bgFlags);
-    }
+    drawBackground(flags);
 
     size_t layerCount = page->getLayerCount();
     std::vector<bool> visible(layerCount, false);

src/core/view/DocumentView.h

@@ -15,6 +15,7 @@
 
 #include "model/PageRef.h"  // for PageRef
 #include "util/ElementRange.h"
+#include "view/background/BackgroundFlags.h"
 
 class PdfCache;
 
@@ -33,26 +34,21 @@ class DocumentView {
      * @param page The page to draw
      * @param cr Draw to thgis context
      * @param dontRenderEditingStroke false to draw currently drawing stroke
-     * @param hidePdfBackground true to hide the PDF background
-     * @param hideImageBackground true to hide the PDF background
-     * @param hideRulingBacground true to hide the ruling background
+     * @param flags show/hide various background components
      */
-    void drawPage(PageRef page, cairo_t* cr, bool dontRenderEditingStroke, bool hidePdfBackground = false,
-                  bool hideImageBackground = false, bool hideRulingBackground = false);
+    void drawPage(PageRef page, cairo_t* cr, bool dontRenderEditingStroke,
+                  xoj::view::BackgroundFlags flags = xoj::view::BACKGROUND_SHOW_ALL);
 
     /**
      * Only draws the prescribed layers of the given page, regardless of the layer's current visibility.
      * @param layerRange Range of layers to draw
      * @param page The page to draw
      * @param cr Draw to this context
      * @param dontRenderEditingStroke false to draw currently drawing stroke
-     * @param hidePdfBackground true to hide the PDF background
-     * @param hideImageBackground true to hide the PDF background
-     * @param hideRulingBacground true to hide the ruling background
+     * @param flags show/hide various background components
      */
     void drawLayersOfPage(const LayerRangeVector& layerRange, PageRef page, cairo_t* cr, bool dontRenderEditingStroke,
-                          bool hidePdfBackground = false, bool hideImageBackground = false,
-                          bool hideRulingBackground = false);
+                          xoj::view::BackgroundFlags flags = xoj::view::BACKGROUND_SHOW_ALL);
 
     /**
      * Mark stroke with Audio

src/core/view/background/BackgroundFlags.h

@@ -0,0 +1,37 @@
+/*
+ * Xournal++
+ *
+ * Flags for background painting
+ *
+ * @author Xournal++ Team
+ * https://github.com/xournalpp/xournalpp
+ *
+ * @license GNU GPLv2 or later
+ */
+
+#pragma once
+
+namespace xoj::view {
+
+enum PDFBackgroundTreatment : bool { SHOW_PDF_BACKGROUND = true, HIDE_PDF_BACKGROUND = false };
+enum ImageBackgroundTreatment : bool { SHOW_IMAGE_BACKGROUND = true, HIDE_IMAGE_BACKGROUND = false };
+enum RulingBackgroundTreatment : bool { SHOW_RULING_BACKGROUND = true, HIDE_RULING_BACKGROUND = false };
+enum BackgroundColorTreatment : bool { FORCE_AT_LEAST_BACKGROUND_COLOR = true, DONT_FORCE_BACKGROUND_COLOR = false };
+enum VisibilityTreatment : bool { FORCE_VISIBLE = true, USE_DOCUMENT_VISIBILITY = false };
+
+struct BackgroundFlags {
+    PDFBackgroundTreatment showPDF;
+    ImageBackgroundTreatment showImage;
+    RulingBackgroundTreatment showRuling;
+    BackgroundColorTreatment forceBackgroundColor = DONT_FORCE_BACKGROUND_COLOR;
+    VisibilityTreatment forceVisible = USE_DOCUMENT_VISIBILITY;
+};
+
+static constexpr BackgroundFlags BACKGROUND_SHOW_ALL = {SHOW_PDF_BACKGROUND, SHOW_IMAGE_BACKGROUND,
+                                                        SHOW_RULING_BACKGROUND, DONT_FORCE_BACKGROUND_COLOR,
+                                                        USE_DOCUMENT_VISIBILITY};
+
+static constexpr BackgroundFlags BACKGROUND_FORCE_PAINT_BACKGROUND_COLOR_ONLY = {
+        HIDE_PDF_BACKGROUND, HIDE_IMAGE_BACKGROUND, HIDE_RULING_BACKGROUND, FORCE_AT_LEAST_BACKGROUND_COLOR,
+        FORCE_VISIBLE};
+}  // namespace xoj::view

src/core/view/background/BackgroundView.cpp

@@ -86,6 +86,10 @@ auto BackgroundView::createForPage(PageRef page, BackgroundFlags bgFlags, PdfCac
             return createRuled(width, height, page->getBackgroundColor(), pt);
         }
     }
-    // Only colorize the page
-    return std::make_unique<PlainBackgroundView>(width, height, page->getBackgroundColor());
+
+    if (bgFlags.forceBackgroundColor) {
+        return std::make_unique<PlainBackgroundView>(width, height, page->getBackgroundColor());
+    } else {
+        return std::make_unique<BackgroundView>(width, height);  // Dummy no-op view
+    }
 }

src/core/view/background/BackgroundView.h

@@ -18,30 +18,13 @@
 #include "model/PageRef.h"  // for PageRef
 #include "util/Color.h"     // for Color
 
+#include "BackgroundFlags.h"
+
 class PdfCache;
 class PageType;
 
 namespace xoj {
 namespace view {
-
-enum PDFBackgroundTreatment : bool { SHOW_PDF_BACKGROUND = true, HIDE_PDF_BACKGROUND = false };
-enum ImageBackgroundTreatment : bool { SHOW_IMAGE_BACKGROUND = true, HIDE_IMAGE_BACKGROUND = false };
-enum RulingBackgroundTreatment : bool { SHOW_RULING_BACKGROUND = true, HIDE_RULING_BACKGROUND = false };
-enum VisibilityTreatment : bool { FORCE_VISIBLE = true, USE_DOCUMENT_VISIBILITY = false };
-
-struct BackgroundFlags {
-    PDFBackgroundTreatment showPDF;
-    ImageBackgroundTreatment showImage;
-    RulingBackgroundTreatment showRuling;
-    VisibilityTreatment forceVisible = USE_DOCUMENT_VISIBILITY;
-};
-
-static constexpr BackgroundFlags BACKGROUND_SHOW_ALL = {SHOW_PDF_BACKGROUND, SHOW_IMAGE_BACKGROUND,
-                                                        SHOW_RULING_BACKGROUND};
-
-static constexpr BackgroundFlags BACKGROUND_SHOW_ONLY_BACKGROUND_COLOR = {HIDE_PDF_BACKGROUND, HIDE_IMAGE_BACKGROUND,
-                                                                          HIDE_RULING_BACKGROUND, FORCE_VISIBLE};
-
 class BackgroundView {
 public:
     BackgroundView(double pageWidth, double pageHeight): pageWidth(pageWidth), pageHeight(pageHeight) {}