Refactor storage of PDF render output, and remove red preview bg col

examples/HelloWorld.tex

@@ -24,4 +24,8 @@ \subsubsection{Article Information}
 
 \emph{hello} hello $x^2, \mathbb R, \mathcal C, \mathfrak F, \int_0^1 \sin(x) \mathrm d x$
 
+\pagebreak
+
+This content is on a separate page.
+
 \end{document}

texedit/gui/pdf_viewer/pdf_canvas.cpp

@@ -13,31 +13,25 @@
 
 namespace te::gui {
     PDFCanvas::PDFCanvas(wxWindow *parent) : wxScrolledWindow{parent, wxID_ANY} {
-        SetBackgroundColour(*wxRED);
-
         SetScrollbars(5, 50, 0, 100);
     }
 
     void PDFCanvas::RenderDocument(const pdfr::PDFDocument *doc) {
-        for (wxImage *img : _page_images) {
-            delete img;
-        }
-
         // render document into list of bitmaps
-        _page_images = doc->RenderAll();
+        _rendered_pages = doc->RenderAll();
     }
 
     void PDFCanvas::OnPaint(wxPaintEvent &event) {
         wxPaintDC dc(this);
         DoPrepareDC(dc);
 
         int yi = 0;
-        for (wxImage *img : _page_images) {
-            wxBitmap bmp = wxBitmap(*img, 32);
-
+        for (const pdfr::RenderedPage &page : _rendered_pages) {
+            // images have to be converted to a bitmap before being drawn
+            wxBitmap bmp = wxBitmap(*page.image, 32);
             dc.DrawBitmap(bmp, 0, yi);
 
-            yi++;
+            yi += page.page_height + 50;
         }
     }
 

texedit/gui/pdf_viewer/pdf_canvas.hpp

@@ -9,6 +9,7 @@
 #ifndef __texedit__pdf_canvas_hpp__
 #define __texedit__pdf_canvas_hpp__
 
+#include "pdf_render/rendered_page.hpp"
 #include <wx/scrolwin.h>
 #include <wx/image.h>
 #include <vector>
@@ -27,7 +28,7 @@ namespace te::gui {
         void OnPaint(wxPaintEvent &event);
 
     private:
-        std::vector<wxImage *> _page_images{};
+        std::vector<pdfr::RenderedPage> _rendered_pages{};
 
         wxDECLARE_EVENT_TABLE();
     };

texedit/pdf_render/pdf_document.cpp

@@ -10,6 +10,7 @@
 #include "except.hpp"
 
 #include <wx/log.h>
+#include <wx/image.h>
 
 namespace te::pdfr {
     PDFDocument::PDFDocument(const wxString &path) : _path{path} {
@@ -34,9 +35,9 @@ namespace te::pdfr {
         }
     }
 
-    std::vector<wxImage *> PDFDocument::RenderAll() const {
+    std::vector<RenderedPage> PDFDocument::RenderAll() const {
         int pagen = _pages.size();
-        std::vector<wxImage *> ret(pagen);
+        std::vector<RenderedPage> ret(pagen);
 
         int i = 0;
         for (poppler::page *page : _pages) {
@@ -51,7 +52,9 @@ namespace te::pdfr {
             unsigned char *rgb = (unsigned char *) malloc(sizeof(unsigned char) * img.width() * img.height() * 3);
             unsigned char *a = (unsigned char *) malloc(sizeof(unsigned char) * img.width() * img.height());
 
-            int dims = img.width() * img.height();
+            int width = img.width(),
+                height = img.height();
+            int dims = width * height;
             char *data = img.data();
 
             for (int j = 0, k = 0; k < dims; j += 4, k++) {
@@ -63,9 +66,11 @@ namespace te::pdfr {
                 rgb[j + 2 - k] = data[j];
             }
 
-            // converting from poppler image to wxImage
-            wxImage *wx = new wxImage(img.width(), img.height(), rgb, a, false);
-            ret[i] = wx;
+            ret[i] = RenderedPage {
+                std::make_unique<wxImage>(width, height, rgb, a, false),
+                width,
+                height
+            };
 
             i++;
         }

texedit/pdf_render/pdf_document.hpp

@@ -9,10 +9,10 @@
 #ifndef __texedit__pdf_document_hpp__
 #define __texedit__pdf_document_hpp__
 
-#include <vector>
+#include "rendered_page.hpp"
 
+#include <vector>
 #include <wx/string.h>
-#include <wx/bitmap.h>
 #include <poppler-document.h>
 #include <poppler-page-renderer.h>
 
@@ -24,8 +24,8 @@ namespace te::pdfr {
     public:
         PDFDocument(const wxString &path);
 
-        // Render all pages in the document into a vector of wxImages (note they must be freed after this).
-        std::vector<wxImage *> RenderAll() const;
+        // Render all pages in the document into a vector of RenderedPages (note they must be freed after this).
+        std::vector<RenderedPage> RenderAll() const;
 
     private:
         const wxString &_path;

texedit/pdf_render/rendered_page.hpp

@@ -0,0 +1,25 @@
+/*
+ *   Copyright (c) 2024 Jack Bennett.
+ *   All Rights Reserved.
+ *
+ *   See the LICENCE file for more information.
+ */
+
+#pragma once
+#ifndef __texedit__rendered_page_hpp__
+#define __texedit__rendered_page_hpp__
+
+#include <memory>
+
+class wxImage;
+
+namespace te::pdfr {
+    struct RenderedPage {
+    public:
+        std::unique_ptr<wxImage> image;
+        int page_width;
+        int page_height;
+    };
+}
+
+#endif