Adds "DRAFT" watermark to the PDF.

_extensions/leovan/watermark/_extension.yml

@@ -0,0 +1,7 @@
+title: Watermark
+author: 范叶亮 | Leo Van
+version: 1.0.0
+quarto-required: ">=1.4.0"
+contributes:
+  filters:
+    - watermark.lua

_extensions/leovan/watermark/watermark.lua

@@ -0,0 +1,181 @@
+local function ensure_html_deps()
+  quarto.doc.add_html_dependency({
+    name = "watermark",
+    version = "1.0.11",
+    scripts = { "watermark.min.js" }
+  })
+end
+
+local function ensure_latex_deps()
+  quarto.doc.use_latex_package("fontspec")
+  quarto.doc.use_latex_package("draftwatermark")
+  quarto.doc.use_latex_package("xcolor")
+  quarto.doc.use_latex_package("forloop")
+end
+
+local function html_watermark(options)
+  local angle = tonumber(options.angle * -1)
+
+  local script = string.format(
+    [[<script>
+    const baseFontSize = parseFloat(getComputedStyle(document.documentElement).fontSize);
+    const watermark = new XWatermark.XWatermark();
+    watermark.init("%s", {
+      parentSelector: "body",
+      prevent: true,
+      observer: true,
+      mode: "normal",
+      font: "%s",
+      fontsize: baseFontSize * %f,
+      angle: %f,
+      color: "%s",
+      alpha: %f,
+      cols: %d,
+      rows: %d,
+      xSpace: baseFontSize * %f,
+      ySpace: baseFontSize * %f,
+      zIndex: %d
+    });
+    </script>]],
+    options.text,
+    options.html_font,
+    options.size,
+    angle,
+    options.color,
+    options.opacity,
+    options.cols,
+    options.rows,
+    options.col_space,
+    options.row_space,
+    options.z_index
+  )
+  quarto.doc.include_text("after-body", script)
+end
+
+local function latex_watermark(options)
+  local text = string.gsub(options.text, " ", "\\ ")
+  local color = string.gsub(options.color, "#", "")
+  local font_define = ""
+  local font_command = ""
+
+  if options.pdf_font then
+    font_define = string.format("\\newfontfamily{\\watermarkfont}{%s}", options.pdf_font)
+    font_command = "\\watermarkfont"
+  end
+
+  local opacity = tonumber(options.opacity * 100)
+
+  local script = string.format(
+    [[
+    \definecolor{watermark}{HTML}{%s}
+    %s
+    \newcounter{watermarkrow}
+    \newcounter{watermarkcol}
+
+    \DraftwatermarkOptions{
+      text={
+        \begin{tabular}{c}
+          \forloop{watermarkrow}{0}{\value{watermarkrow} < %d}{
+            \forloop{watermarkcol}{0}{\value{watermarkcol} < %d}{
+              {%s %s}\hspace{%fem}
+            }
+            \\[%fem]
+          }
+        \end{tabular}
+      },
+      fontsize=%fem,
+      angle=%f,
+      color=watermark!%d
+    }
+    ]],
+    color,
+    font_define,
+    options.rows,
+    options.cols,
+    font_command,
+    text,
+    options.col_space,
+    options.row_space,
+    options.size,
+    options.angle,
+    opacity
+  )
+  quarto.doc.include_text("in-header", script)
+end
+
+function Pandoc(doc)
+  local options = {
+    text = "Watermark",
+    size = 1.0,
+    angle = 15,
+    color = "#000000",
+    opacity = 0.1,
+    cols = 10,
+    rows = 50,
+    col_space = 4.0,
+    row_space = 4.0,
+    z_index = -1,
+    html_font = "system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', 'Noto Sans', 'Liberation Sans', Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Color Emoji'",
+    pdf_font = nil
+  }
+
+  if doc.meta["watermark"] then
+    watermark_meta = doc.meta["watermark"]
+
+    if watermark_meta["text"] then
+      options.text = pandoc.utils.stringify(watermark_meta["text"])
+    end
+
+    if watermark_meta["size"] then
+      options.size = tonumber(pandoc.utils.stringify(watermark_meta["size"]))
+    end
+
+    if watermark_meta["angle"] then
+      options.angle = tonumber(pandoc.utils.stringify(watermark_meta["angle"]))
+    end
+
+    if watermark_meta["color"] then
+      options.color = pandoc.utils.stringify(watermark_meta["color"])
+    end
+
+    if watermark_meta["opacity"] then
+      options.opacity = tonumber(pandoc.utils.stringify(watermark_meta["opacity"]))
+    end
+
+    if watermark_meta["cols"] then
+      options.cols = tonumber(pandoc.utils.stringify(watermark_meta["cols"]))
+    end
+
+    if watermark_meta["rows"] then
+      options.rows = tonumber(pandoc.utils.stringify(watermark_meta["rows"]))
+    end
+
+    if watermark_meta["col-space"] then
+      options.col_space = tonumber(pandoc.utils.stringify(watermark_meta["col-space"]))
+    end
+
+    if watermark_meta["row-space"] then
+      options.row_space = tonumber(pandoc.utils.stringify(watermark_meta["row-space"]))
+    end
+
+    if watermark_meta["z-index"] then
+      options.z_index = pandoc.utils.stringify(watermark_meta["z-index"])
+    end
+
+    if watermark_meta["html-font"] then
+      options.html_font = pandoc.utils.stringify(watermark_meta["html-font"])
+    end
+
+    if watermark_meta["pdf-font"] then
+      options.pdf_font = pandoc.utils.stringify(watermark_meta["pdf-font"])
+    end
+  end
+
+  if quarto.doc.is_format("html") then
+    ensure_html_deps()
+    html_watermark(options)
+  elseif quarto.doc.is_format("latex") then
+    ensure_latex_deps()
+    latex_watermark(options)
+  end
+end

_quarto.yml

@@ -1,6 +1,7 @@
 project:
   type: manuscript
 
+
 manuscript:
   article: index.qmd
 
@@ -17,5 +18,8 @@ format:
 
   pdf: default
 
+filters:
+  - watermark
+
 number-sections: true
 bibliography: references.bib

index.qmd

@@ -1,3 +1,10 @@
+---
+filters:
+  - watermark
+watermark:
+  text: "DRAFT"
+---
+
 # Abstract
 
 Recent progress in machine learning and artificial intelligence promises to