Support custom themes (by passing a JSON file).

cmd/md2pdf/md2pdf.go

@@ -26,7 +26,7 @@ var author = flag.String("author", "", "Author; used if -footer is passed")
 var unicodeSupport = flag.String("unicode-encoding", "", "e.g 'cp1251'")
 var fontFile = flag.String("font-file", "", "path to font file to use")
 var fontName = flag.String("font-name", "", "Font name ID; e.g 'Helvetica-1251'")
-var themeArg = flag.String("theme", "light", "[light|dark]")
+var themeArg = flag.String("theme", "light", "[light | dark | /path/to/custom/theme.json]")
 var hrAsNewPage = flag.Bool("new-page-on-hr", false, "Interpret HR as a new page; useful for presentations")
 var printFooter = flag.Bool("with-footer", false, "Print doc footer (author  title  page number)")
 var pageSize = flag.String("page-size", "A4", "[A3 | A4 | A5]")
@@ -140,38 +140,49 @@ func main() {
 	}
 
 	theme := mdtopdf.LIGHT
-	textColor := mdtopdf.Colorlookup("black")
-	fillColor := mdtopdf.Colorlookup("white")
-	backgroundColor := "white"
+	themeFile := ""
 	if *themeArg == "dark" {
 		theme = mdtopdf.DARK
-		backgroundColor = "black"
-		textColor = mdtopdf.Colorlookup("darkgray")
-		fillColor = mdtopdf.Colorlookup("black")
+	}else if _, err := os.Stat(*themeArg); err == nil {
+		theme = mdtopdf.CUSTOM
+		themeFile = *themeArg
 	}
 
-	pf := mdtopdf.NewPdfRenderer(*orientation, *pageSize, *output, *logFile, opts, theme)
+	params := mdtopdf.PdfRendererParams{
+	    Orientation: *orientation, 
+	    Papersz: *pageSize, 
+	    PdfFile: *output, 
+	    TracerFile: *logFile,
+	    Opts: opts, 
+	    Theme: theme, 
+	    CustomThemeFile: themeFile,
+	    FontFile: *fontFile,
+	    FontName: *fontName,
+	}
+
+	pf := mdtopdf.NewPdfRenderer(params)
 	if inputBaseURL != "" {
 		pf.InputBaseURL = inputBaseURL
 	}
 	pf.Pdf.SetSubject(*title, true)
 	pf.Pdf.SetTitle(*title, true)
-	pf.BackgroundColor = mdtopdf.Colorlookup(backgroundColor)
 	pf.Extensions = parser.NoIntraEmphasis | parser.Tables | parser.FencedCode | parser.Autolink | parser.Strikethrough | parser.SpaceHeadings | parser.HeadingIDs | parser.BackslashLineBreak | parser.DefinitionLists
 
 	if *fontFile != "" && *fontName != "" {
 		pf.Pdf.AddFont(*fontName, "", *fontFile)
 		pf.Pdf.SetFont(*fontName, "", 12)
-		pf.Normal = mdtopdf.Styler{Font: *fontName, Style: "",
+		pf.Normal = mdtopdf.Styler{
+			Font: *fontName, 
+			Style: "",
 			Size: 12, Spacing: 2,
-			FillColor: fillColor,
-			TextColor: textColor}
+			TextColor: pf.Normal.TextColor,
+		}
+
 	}
 
 	if *printFooter {
 		pf.Pdf.SetFooterFunc(func() {
-			color := mdtopdf.Colorlookup(backgroundColor)
-			pf.Pdf.SetFillColor(color.Red, color.Green, color.Blue)
+			pf.Pdf.SetFillColor(pf.BackgroundColor.Red, pf.BackgroundColor.Green, pf.BackgroundColor.Blue)
 			// Position at 1.5 cm from bottom
 			pf.Pdf.SetY(-15)
 			// Arial italic 8

mdtopdf.go

@@ -23,8 +23,10 @@ package mdtopdf
 import (
 	"bufio"
 	"fmt"
+	"log"
 	"io"
 	"os"
+	"encoding/json"
 
 	"strings"
 
@@ -60,10 +62,12 @@ type RenderOption func(r *PdfRenderer)
 type Theme int
 
 const (
-	// DARK const
+	// DARK theme const
 	DARK Theme = 1
-	// LIGHT const
+	// LIGHT theme const
 	LIGHT Theme = 2
+	// CUSTOM theme const
+	CUSTOM Theme = 3
 )
 
 // PdfRenderer is the struct to manage conversion of a markdown object
@@ -229,48 +233,72 @@ func (r *PdfRenderer) SetDarkTheme() {
 
 }
 
+func (r *PdfRenderer) SetCustomTheme(themeJsonFile string) {
+
+    config, err := os.ReadFile(themeJsonFile)
+    if err != nil {
+	log.Fatal(err)
+    }
+    // Fill the instance from the JSON file content
+    err = json.Unmarshal(config, &r)
+    log.Printf("BackgroundColor: %v\n", r.BackgroundColor)
+    // Check if is there any error while filling the instance
+    if err != nil {
+	panic(err)
+    }
+}
+
+type PdfRendererParams struct {
+  Orientation, Papersz, PdfFile, TracerFile, FontFile, FontName string
+  Opts []RenderOption
+  Theme Theme
+  CustomThemeFile string
+}
+
 // NewPdfRenderer creates and configures an PdfRenderer object,
 // which satisfies the Renderer interface.
-func NewPdfRenderer(orient, papersz, pdfFile, tracerFile string, opts []RenderOption, theme Theme) *PdfRenderer {
+func NewPdfRenderer(params PdfRendererParams) *PdfRenderer {
 
 	r := new(PdfRenderer)
 
 	// set filenames
-	r.pdfFile = pdfFile
-	r.tracerFile = tracerFile
+	r.pdfFile = params.PdfFile
+	r.tracerFile = params.TracerFile
 
 	// Global things
 	r.orientation = "portrait"
-	if orient != "" {
-		r.orientation = orient
+	if params.Orientation != "" {
+		r.orientation = params.Orientation
 	}
 
 	r.units = "pt"
 	r.papersize = "Letter"
-	if papersz != "" {
-		r.papersize = papersz
+	if params.Papersz != "" {
+		r.papersize = params.Papersz
 	}
 
 	r.fontdir = "."
 
-	r.Theme = theme
-	if theme == 0 {
-		r.Theme = LIGHT
-	}
+	r.Theme = params.Theme
 
 	r.Pdf = fpdf.New(r.orientation, r.units, r.papersize, r.fontdir)
 
 	r.Pdf.SetHeaderFunc(func() {
 		r.SetPageBackground("", r.BackgroundColor)
 	})
 
-	r.Pdf.AddPage()
 	switch r.Theme {
 	case DARK:
-		r.SetDarkTheme()
+	    r.SetDarkTheme()
 	case LIGHT:
-		r.SetLightTheme()
+	    r.SetLightTheme()
+	case CUSTOM:
+	    if params.CustomThemeFile != "" {
+		log.Printf("Custom: %s\n", params.CustomThemeFile)
+		r.SetCustomTheme(params.CustomThemeFile) 
+	    }
 	}
+	r.Pdf.AddPage()
 	// set default font
 	r.setStyler(r.Normal)
 	r.mleft, r.mtop, r.mright, r.mbottom = r.Pdf.GetMargins()
@@ -283,7 +311,7 @@ func NewPdfRenderer(orient, papersz, pdfFile, tracerFile string, opts []RenderOp
 		textStyle: r.Normal, leftMargin: r.mleft}
 	r.cs.push(initcurrent)
 
-	for _, o := range opts {
+	for _, o := range params.Opts {
 		o(r)
 	}
 
@@ -297,8 +325,16 @@ func NewPdfRendererWithDefaultStyler(orient, papersz, pdfFile, tracerFile string
 	opts = append(opts, func(r *PdfRenderer) {
 		r.Normal = defaultStyler
 	})
+	params := PdfRendererParams{
+	    Orientation: orient, 
+	    Papersz: papersz, 
+	    PdfFile: pdfFile, 
+	    TracerFile: tracerFile,
+	    Opts: opts, 
+	    Theme: theme, 
+	}
 
-	return NewPdfRenderer(orient, papersz, pdfFile, tracerFile, opts, theme)
+	return NewPdfRenderer(params)
 }
 
 // Process takes the markdown content, parses it to generate the PDF