Ocideck/lib/services/marp_html_service.dart

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import 'dart:convert';
import 'dart:math' as math;
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import 'dart:typed_data';
import 'package:flutter/services.dart' show rootBundle;
import '../models/chart.dart';
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import '../models/settings.dart';
import '../utils/log.dart';
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/// Builds a single, self-contained HTML file from a deck's Marp Markdown.
///
/// The output embeds (inlines) `marked` for Markdown, `highlight.js` for code,
/// `MathJax` (tex-svg, so no external font files are needed) for math, and
/// `mermaid` for diagrams — so the resulting `.html` renders fully offline.
///
/// Note: this is a Marp-*flavoured* deck rendered with `marked`, not Marp Core,
/// so theme fidelity differs from the in-app preview / PDF / PPTX. The strength
/// here is a portable, dependency-free presentation that opens in any browser.
class MarpHtmlService {
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/// Reads a bundled text asset (defaults to the Flutter asset bundle).
/// Injectable so the builder can be unit-tested against the on-disk files.
final Future<String> Function(String asset) loadAsset;
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/// Reads a bundled binary asset (used to embed the EB Garamond font).
final Future<Uint8List> Function(String asset) loadBytes;
MarpHtmlService({
Future<String> Function(String asset)? loadAsset,
Future<Uint8List> Function(String asset)? loadBytes,
}) : loadAsset = loadAsset ?? rootBundle.loadString,
loadBytes =
loadBytes ??
((a) async => (await rootBundle.load(a)).buffer.asUint8List());
static const _assetDir = 'assets/web_export';
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/// Builds the HTML. When [theme] is given, the slides take that profile's
/// colours and font so the export matches the in-app / PDF look.
Future<String> build(String deckMarkdown, {ThemeProfile? theme}) async {
final marked = await loadAsset('$_assetDir/marked.min.js');
final purify = await loadAsset('$_assetDir/purify.min.js');
final hljs = await loadAsset('$_assetDir/highlight.min.js');
final hljsCss = await loadAsset('$_assetDir/highlight.css');
final mathjax = await loadAsset('$_assetDir/tex-svg.js');
final mermaid = await loadAsset('$_assetDir/mermaid.min.js');
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final css = theme == null ? _baseCss : await _themedCss(theme);
final sections = StringBuffer();
for (final slide in marpSlides(deckMarkdown)) {
sections
..write('<section class="slide"><script type="text/markdown">')
..write(_guard(renderChartBlocks(slide, theme: theme)))
..write('</script></section>');
}
String inline(String code) => '<script>${_guard(code)}</script>';
return '<!doctype html>\n'
'<html lang="nl"><head><meta charset="utf-8">'
'<meta name="viewport" content="width=device-width, initial-scale=1">'
'<title>OciDeck export</title>'
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'<style>$css\n$hljsCss</style>'
'<script>$_mathjaxConfig</script>'
'${inline(marked)}'
'${inline(purify)}'
'${inline(hljs)}'
'${inline(mathjax)}'
'${inline(mermaid)}'
'</head><body>'
'$sections'
'${inline(_renderScript)}'
'</body></html>';
}
/// Split Marp Markdown into per-slide Markdown chunks: drop the leading YAML
/// front-matter, then break on lines that contain only `---`.
static List<String> marpSlides(String markdown) {
var text = markdown.replaceAll('\r\n', '\n');
// Strip a leading YAML front-matter block: ---\n ... \n---\n
if (text.startsWith('---\n')) {
final close = text.indexOf('\n---', 4);
if (close != -1) {
final nl = text.indexOf('\n', close + 1);
text = nl == -1 ? '' : text.substring(nl + 1);
}
}
final slides = <String>[];
final buf = StringBuffer();
for (final line in text.split('\n')) {
if (line.trim() == '---') {
slides.add(buf.toString().trim());
buf.clear();
} else {
buf.writeln(line);
}
}
slides.add(buf.toString().trim());
return slides.where((s) => s.isNotEmpty).toList();
}
/// Neutralise any `</script` inside inlined content so it can't break out of
/// the surrounding <script> element. Case-insensitive — `</ScRiPt>` must not
/// slip through. Safe for both JS (string contexts) and the embedded Markdown
/// payloads.
static final RegExp _scriptClose = RegExp(
r'</(script)',
caseSensitive: false,
);
static String _guard(String s) =>
s.replaceAllMapped(_scriptClose, (m) => '<\\/${m.group(1)}');
// ── Charts → inline SVG ────────────────────────────────────────────────────
static final RegExp _chartFence = RegExp(
r'```chart[ \t]*\n([\s\S]*?)\n```',
multiLine: true,
);
/// Replace ```chart fenced blocks with a self-contained inline SVG, so the
/// exported HTML renders charts without any JS chart library.
static String renderChartBlocks(String slideMarkdown, {ThemeProfile? theme}) {
return slideMarkdown.replaceAllMapped(_chartFence, (m) {
final spec = ChartSpec.parse(m.group(1)!);
return '\n<div class="chart">${_chartSvg(spec, theme)}</div>\n';
});
}
static String _esc(String s) => s
.replaceAll('&', '&amp;')
.replaceAll('<', '&lt;')
.replaceAll('>', '&gt;');
static String _color(ChartSpec spec, int i, ThemeProfile? theme) {
final series = spec.series[i];
if (series.color == null && i == 0 && theme != null) {
return theme.accentColor;
}
return chartSeriesColor(series, i);
}
static String _chartSvg(ChartSpec spec, ThemeProfile? theme) {
if (!spec.hasInlineData) {
return '<svg viewBox="0 0 800 450" xmlns="http://www.w3.org/2000/svg"></svg>';
}
final textColor = theme?.textColor ?? '#111827';
final titleBackground = theme?.titleBackgroundColor ?? '#F8FAFC';
final titleColor = theme?.titleTextColor ?? textColor;
final accent = theme?.accentColor ?? '#2563EB';
final b = StringBuffer()
..write(
'<svg viewBox="0 0 800 450" xmlns="http://www.w3.org/2000/svg" '
'font-family="inherit" width="100%">',
);
if (spec.title.isNotEmpty) {
final title = spec.title.length > 52
? '${spec.title.substring(0, 51)}'
: spec.title;
b
..write(
'<rect x="38" y="12" width="724" height="44" rx="9" '
'fill="$titleBackground"/>',
)
..write(
'<rect x="38" y="12" width="7" height="44" rx="3" fill="$accent"/>',
)
..write(
'<text x="62" y="41" font-size="23" font-weight="bold" '
'fill="$titleColor">${_esc(title)}</text>',
);
}
final plotTop = spec.title.isNotEmpty ? 68.0 : 20.0;
switch (spec.type) {
case ChartType.bar:
_barSvg(b, spec, plotTop, theme);
case ChartType.line:
_lineSvg(b, spec, plotTop, theme);
case ChartType.pie:
final legendRows = (spec.x.length / 6).ceil().clamp(1, 3);
_pieSvg(b, spec, plotTop, theme, bottom: 398 - (legendRows - 1) * 28);
case ChartType.radar:
_radarSvg(b, spec, plotTop, theme, textColor);
}
if (spec.type == ChartType.pie) {
_pieLegendSvg(b, spec, textColor);
} else {
_legendSvg(b, spec, theme, textColor);
}
b.write('</svg>');
return b.toString();
}
static void _legendSvg(
StringBuffer b,
ChartSpec spec,
ThemeProfile? theme,
String textColor,
) {
final count = math.min(spec.series.length, 6);
final cellWidth = 720.0 / count;
for (var i = 0; i < count; i++) {
final rawName = spec.series[i].name.isEmpty
? 'Reeks ${i + 1}'
: spec.series[i].name;
final name = rawName.length > 12
? '${rawName.substring(0, 11)}'
: rawName;
final x = 40 + i * cellWidth;
b
..write(
'<rect x="$x" y="414" width="${cellWidth - 8}" height="24" rx="12" '
'fill="$textColor" fill-opacity=".05"/>',
)
..write(
'<circle cx="${x + 13}" cy="426" r="5" '
'fill="${_color(spec, i, theme)}"/>',
)
..write(
'<text x="${x + 24}" y="431" font-size="13" font-weight="600" '
'fill="$textColor">${_esc(name)}</text>',
);
}
}
static void _pieLegendSvg(StringBuffer b, ChartSpec spec, String textColor) {
const maxColumns = 6;
final columns = math.min(spec.x.length, maxColumns);
final rows = (spec.x.length / maxColumns).ceil().clamp(1, 3);
final cellWidth = 720.0 / columns;
final startY = 414.0 - (rows - 1) * 28;
for (var i = 0; i < spec.x.length; i++) {
final row = i ~/ maxColumns;
if (row >= rows) break;
final column = i % maxColumns;
final x = 40 + column * cellWidth;
final y = startY + row * 28;
final label = spec.x[i].length > 12
? '${spec.x[i].substring(0, 11)}'
: spec.x[i];
b
..write(
'<rect x="$x" y="$y" width="${cellWidth - 8}" height="24" rx="12" '
'fill="$textColor" fill-opacity=".05"/>',
)
..write(
'<circle cx="${x + 13}" cy="${y + 12}" r="5" '
'fill="${chartRowColor(spec, i)}"/>',
)
..write(
'<text x="${x + 24}" y="${y + 17}" font-size="13" font-weight="600" '
'fill="$textColor">${_esc(label)}</text>',
);
}
}
static double _maxY(ChartSpec spec) {
var m = 0.0;
for (final s in spec.series) {
for (final v in s.data) {
if (v > m) m = v;
}
}
if (spec.supportsBounds) {
for (final b in [spec.minBound, spec.maxBound]) {
if (b != null && b > m) m = b;
}
}
return m <= 0 ? 1 : m * 1.15;
}
/// Draw the optional min/max threshold lines (bar/line only) as dashed rules.
static void _boundLinesSvg(
StringBuffer b,
ChartSpec spec,
double left,
double top,
double right,
double bottom,
double maxY,
) {
if (!spec.supportsBoundLines) return;
void draw(double? value, String color, String prefix) {
if (value == null || value < 0 || value > maxY) return;
final y = bottom - (bottom - top) * (value / maxY);
b
..write(
'<line x1="$left" y1="$y" x2="$right" y2="$y" stroke="$color" '
'stroke-width="2.5" stroke-dasharray="8 5"/>',
)
..write(
'<text x="${right - 4}" y="${y - 5}" text-anchor="end" '
'font-size="14" font-weight="700" fill="$color">'
'$prefix ${_num(value)}</text>',
);
}
draw(spec.minBound, '#F59E0B', 'min');
draw(spec.maxBound, '#EF4444', 'max');
}
static String _num(double v) =>
v == v.roundToDouble() ? v.toInt().toString() : v.toStringAsFixed(1);
static void _axes(
StringBuffer b,
ChartSpec spec,
double left,
double top,
double right,
double bottom,
double maxY,
) {
// Horizontal gridlines + y labels.
for (var i = 0; i <= 4; i++) {
final y = bottom - (bottom - top) * i / 4;
final val = maxY * i / 4;
b
..write(
'<line x1="$left" y1="$y" x2="$right" y2="$y" stroke="#e2e8f0" stroke-width="1"/>',
)
..write(
'<text x="${left - 8}" y="${y + 5}" text-anchor="end" font-size="14" fill="#64748b">${_num(val)}</text>',
);
}
// X labels.
final n = spec.x.length;
final step = math.max(1, (n / 8).ceil());
for (var i = 0; i < n; i++) {
if (i != n - 1 && i % step != 0) continue;
final x = left + (right - left) * (i + 0.5) / n;
final label = spec.x[i].length > 10
? '${spec.x[i].substring(0, 9)}'
: spec.x[i];
b.write(
'<text x="$x" y="${bottom + 20}" text-anchor="middle" '
'font-size="13" fill="#334155">${_esc(label)}</text>',
);
}
}
static void _barSvg(
StringBuffer b,
ChartSpec spec,
double top,
ThemeProfile? theme,
) {
const left = 60.0, right = 770.0, bottom = 382.0;
final maxY = _maxY(spec);
_axes(b, spec, left, top, right, bottom, maxY);
final n = spec.x.length;
final groupW = (right - left) / n;
final sCount = spec.series.length;
final barW = (groupW * 0.7) / sCount;
for (var xi = 0; xi < n; xi++) {
final gx = left + groupW * xi + groupW * 0.15;
for (var si = 0; si < sCount; si++) {
if (xi >= spec.series[si].data.length) continue;
final v = spec.series[si].data[xi];
final h = (bottom - top) * (v / maxY);
final x = gx + barW * si;
b.write(
'<rect x="$x" y="${bottom - h}" width="${barW * 0.86}" height="$h" '
'rx="5" fill="${_color(spec, si, theme)}"/>',
);
}
}
_boundLinesSvg(b, spec, left, top, right, bottom, maxY);
}
static void _lineSvg(
StringBuffer b,
ChartSpec spec,
double top,
ThemeProfile? theme,
) {
const left = 60.0, right = 770.0, bottom = 382.0;
final maxY = _maxY(spec);
_axes(b, spec, left, top, right, bottom, maxY);
final n = spec.x.length;
double px(int i) => left + (right - left) * (i + 0.5) / n;
double py(double v) => bottom - (bottom - top) * (v / maxY);
for (var si = 0; si < spec.series.length; si++) {
final data = spec.series[si].data;
final pts = [
for (var i = 0; i < data.length; i++) '${px(i)},${py(data[i])}',
].join(' ');
b.write(
'<polyline points="$pts" fill="none" '
'stroke="${_color(spec, si, theme)}" stroke-width="4" '
'stroke-linecap="round" stroke-linejoin="round"/>',
);
for (var i = 0; i < data.length; i++) {
b.write(
'<circle cx="${px(i)}" cy="${py(data[i])}" r="5" '
'fill="${_color(spec, si, theme)}" stroke="white" stroke-width="2"/>',
);
}
}
_boundLinesSvg(b, spec, left, top, right, bottom, maxY);
}
static void _pieSvg(
StringBuffer b,
ChartSpec spec,
double top,
ThemeProfile? theme, {
required double bottom,
}) {
final count = math.min(spec.series.length, 2);
final columns = count;
final rows = (count / columns).ceil();
final cellWidth = 720.0 / columns;
final cellHeight = (bottom - top) / rows;
final radius = math.min(cellWidth * 0.25, cellHeight * 0.42);
for (var xi = 0; xi < count; xi++) {
final col = xi % columns;
final row = xi ~/ columns;
final cellLeft = 40 + cellWidth * col;
final cx = cellLeft + cellWidth * 0.36;
final cy = top + cellHeight * (row + 0.5);
final series = spec.series[xi];
final values = [
for (var labelIndex = 0; labelIndex < spec.x.length; labelIndex++)
labelIndex < series.data.length && series.data[labelIndex] > 0
? series.data[labelIndex]
: 0.0,
];
final total = values.fold<double>(0, (a, v) => a + v);
var angle = -90.0;
for (var labelIndex = 0; labelIndex < values.length; labelIndex++) {
final frac = total > 0 ? values[labelIndex] / total : 0;
final sweep = frac * 360;
if (sweep <= 0) continue;
final a0 = angle * math.pi / 180;
final a1 = (angle + sweep) * math.pi / 180;
final x0 = cx + radius * math.cos(a0);
final y0 = cy + radius * math.sin(a0);
final x1 = cx + radius * math.cos(a1);
final y1 = cy + radius * math.sin(a1);
final large = sweep > 180 ? 1 : 0;
b.write(
'<path d="M$cx,$cy L$x0,$y0 A$radius,$radius 0 $large,1 '
'$x1,$y1 Z" '
'fill="${chartRowColor(spec, labelIndex)}" '
'stroke="white" '
'stroke-width="2"/>',
);
angle += sweep;
}
b
..write('<circle cx="$cx" cy="$cy" r="${radius * 0.43}" fill="white"/>')
..write(
'<text x="${cellLeft + cellWidth * 0.66}" y="${cy + 5}" '
'font-size="14" font-weight="700">'
'${_esc(_shortChartLabel(series.name.isEmpty ? 'Reeks ${xi + 1}' : series.name))}</text>',
);
}
}
static void _radarSvg(
StringBuffer b,
ChartSpec spec,
double top,
ThemeProfile? theme,
String textColor,
) {
final n = spec.x.length;
if (n < 3 || spec.series.isEmpty) return;
const bottom = 382.0;
const cx = 400.0;
final cy = (top + bottom) / 2;
final radius = math.min(170.0, (bottom - top) / 2 - 34);
final (lo, hi, ticks) = _radarScale(spec);
final span = (hi - lo) == 0 ? 1.0 : (hi - lo);
double angle(int i) => -math.pi / 2 + 2 * math.pi * i / n;
// Concentric grid rings, evenly spaced across the [lo, hi] scale.
for (var ring = 1; ring <= ticks; ring++) {
final rr = radius * ring / ticks;
final pts = [
for (var i = 0; i < n; i++)
'${cx + rr * math.cos(angle(i))},${cy + rr * math.sin(angle(i))}',
].join(' ');
b.write(
'<polygon points="$pts" fill="none" stroke="#e2e8f0" '
'stroke-width="1"/>',
);
}
// Scale legend on the right: hi at the top down to lo at the bottom, so the
// figure itself stays clean.
final legendX = cx + radius + 30;
for (var k = ticks; k >= 0; k--) {
final value = lo + span * k / ticks;
final y = (cy - radius) + (2 * radius) * (ticks - k) / ticks;
b
..write(
'<line x1="$legendX" y1="$y" x2="${legendX + 8}" y2="$y" '
'stroke="#cbd5e1" stroke-width="1"/>',
)
..write(
'<text x="${legendX + 12}" y="${y + 4}" font-size="12" '
'fill="#94a3b8">${_num(value)}</text>',
);
}
// Spokes and axis labels.
for (var i = 0; i < n; i++) {
final c = math.cos(angle(i));
final s = math.sin(angle(i));
b.write(
'<line x1="$cx" y1="$cy" x2="${cx + radius * c}" '
'y2="${cy + radius * s}" stroke="#e2e8f0" stroke-width="1"/>',
);
final anchor = c > 0.3 ? 'start' : (c < -0.3 ? 'end' : 'middle');
final label = spec.x[i].length > 12
? '${spec.x[i].substring(0, 11)}'
: spec.x[i];
b.write(
'<text x="${cx + (radius + 18) * c}" y="${cy + (radius + 18) * s + 4}" '
'text-anchor="$anchor" font-size="13" fill="$textColor">'
'${_esc(label)}</text>',
);
}
// One filled polygon per series.
for (var si = 0; si < spec.series.length; si++) {
final data = spec.series[si].data;
final pts = [
for (var i = 0; i < n; i++)
() {
final v = i < data.length ? data[i] : 0.0;
final rr = radius * ((v - lo) / span).clamp(0.0, 1.0);
return '${cx + rr * math.cos(angle(i))},'
'${cy + rr * math.sin(angle(i))}';
}(),
].join(' ');
final color = _color(spec, si, theme);
b.write(
'<polygon points="$pts" fill="$color" fill-opacity="0.16" '
'stroke="$color" stroke-width="3" stroke-linejoin="round"/>',
);
}
}
/// Radar scale shared with the live preview: honour optional min/max bounds,
/// otherwise round the data range to a tidy scale with an even tick count.
static (double, double, int) _radarScale(ChartSpec spec) {
var dataMin = 0.0;
var dataMax = 0.0;
var seen = false;
for (final s in spec.series) {
for (final v in s.data) {
if (!seen) {
dataMin = v;
dataMax = v;
seen = true;
} else {
if (v < dataMin) dataMin = v;
if (v > dataMax) dataMax = v;
}
}
}
if (!seen) {
dataMin = 0;
dataMax = 1;
}
final rawLo = spec.minBound ?? (dataMin < 0 ? dataMin : 0);
final rawHi = spec.maxBound ?? dataMax;
final range = (rawHi - rawLo).abs();
final r = range <= 0 ? 1.0 : range;
final rawStep = r / 4;
final mag = math
.pow(10, (math.log(rawStep) / math.ln10).floor())
.toDouble();
final norm = rawStep / mag;
final niceNorm = norm < 1.5
? 1.0
: norm < 3
? 2.0
: norm < 7
? 5.0
: 10.0;
final step = niceNorm * mag;
final lo = spec.minBound ?? (rawLo / step).floorToDouble() * step;
var hi = spec.maxBound ?? (rawHi / step).ceilToDouble() * step;
if (hi <= lo) hi = lo + step;
final ticks = math.max(2, ((hi - lo) / step).round());
return (lo, hi, ticks);
}
static String _shortChartLabel(String value) =>
value.length > 13 ? '${value.substring(0, 12)}' : value;
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/// CSS that mirrors the deck's [ThemeProfile]: slide background, text and
/// accent colours, table colours and font. The EB Garamond font is embedded
/// (base64) so it renders offline; other fonts resolve to system families.
Future<String> _themedCss(ThemeProfile t) async {
final fontFace = await _ebGaramondFontFace(t.fontFamily);
final family = _cssFontStack(t.fontFamily);
final codePrefix = t.codeFontFamily == 'monospace'
? ''
: "'${t.codeFontFamily}',";
final codeFamily =
'${codePrefix}SFMono-Regular,Consolas,"Liberation Mono",monospace';
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return '$fontFace\n'
'*{box-sizing:border-box}'
'html,body{margin:0;padding:0}'
'body{background:#1e1e1e;font-family:$family;color:${t.textColor}}'
'.slide{position:relative;width:1280px;min-height:720px;margin:24px auto;'
'background:${t.slideBackgroundColor};color:${t.textColor};padding:60px;'
'overflow:hidden;box-shadow:0 4px 24px rgba(0,0,0,.4);border-radius:4px;'
'font-family:$family}'
'.slide h1{font-size:48px;margin:.15em 0;color:${t.textColor}}'
'.slide h2{font-size:34px;margin:.15em 0;color:${t.accentColor}}'
'.slide a{color:${t.accentColor}}'
'.slide p,.slide li{font-size:24px;line-height:1.45}'
'.slide pre{background:${t.codeBackgroundColor};color:${t.codeTextColor};'
'border:1px solid ${t.codeTextColor}38;border-radius:6px;'
'padding:16px;overflow:auto;font-size:18px;font-family:$codeFamily}'
'.slide pre code{color:${t.codeTextColor};background:transparent}'
'.slide code{font-family:$codeFamily}'
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'.slide pre.mermaid{background:transparent;border:0;text-align:center}'
'.slide img{max-width:100%}'
'.slide blockquote{border-left:4px solid ${t.accentColor};margin:.5em 0;'
'padding-left:16px;opacity:.85}'
'.slide table{border-collapse:collapse}'
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'.slide th{background:${t.tableHeaderBackgroundColor};color:${t.tableHeaderTextColor};'
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'border:1px solid #ccc;padding:6px 12px;font-size:20px}'
'.slide td{color:${t.tableTextColor};border:1px solid #ccc;padding:6px 12px;font-size:20px}'
'@media print{body{background:#fff}.slide{margin:0;box-shadow:none;'
'border-radius:0;page-break-after:always;width:100%;min-height:100vh}}';
}
String _cssFontStack(String font) {
if (font == 'EB Garamond') return "'EB Garamond', Georgia, serif";
const serif = {'Georgia', 'Times New Roman'};
final generic = serif.contains(font) ? 'serif' : 'sans-serif';
return "'$font', $generic";
}
/// Embed the bundled EB Garamond variable font as base64 so it works offline.
/// Returns an empty string for any other (system) font.
Future<String> _ebGaramondFontFace(String font) async {
if (font != 'EB Garamond') return '';
try {
final bytes = await loadBytes('assets/fonts/EBGaramond-Variable.ttf');
final b64 = base64Encode(bytes);
return "@font-face{font-family:'EB Garamond';font-weight:400 800;"
"font-style:normal;src:url(data:font/ttf;base64,$b64) "
"format('truetype');}";
} catch (e) {
logWarning('MarpHtmlService._ebGaramondFontFace: load font asset', e);
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return ''; // Fall back to the CSS font stack if the asset is missing.
}
}
static const _mathjaxConfig =
r'''window.MathJax={tex:{inlineMath:[['$','$']],displayMath:[['$$','$$']]},svg:{fontCache:'global'},startup:{typeset:false}};''';
static const _baseCss = r'''
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{background:#1e1e1e;font-family:-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:#1a1a1a}
.slide{position:relative;width:1280px;min-height:720px;margin:24px auto;background:#fff;padding:60px;overflow:hidden;box-shadow:0 4px 24px rgba(0,0,0,.4);border-radius:4px}
.slide h1{font-size:48px;margin:.15em 0}
.slide h2{font-size:34px;margin:.15em 0}
.slide p,.slide li{font-size:24px;line-height:1.45}
.slide pre{background:#f6f8fa;border:1px solid #e1e4e8;border-radius:6px;padding:16px;overflow:auto;font-size:18px}
.slide code{font-family:SFMono-Regular,Consolas,"Liberation Mono",monospace}
.slide pre.mermaid{background:transparent;border:0;text-align:center}
.slide img{max-width:100%}
.slide blockquote{border-left:4px solid #ccc;margin:.5em 0;padding-left:16px;color:#555}
.slide table{border-collapse:collapse}.slide th,.slide td{border:1px solid #ccc;padding:6px 12px;font-size:20px}
@media print{body{background:#fff}.slide{margin:0;box-shadow:none;border-radius:0;page-break-after:always;width:100%;min-height:100vh}}
''';
static const _renderScript = r'''
(function(){
if(window.marked&&marked.setOptions){marked.setOptions({gfm:true,breaks:false});}
document.querySelectorAll('section.slide').forEach(function(sec){
var holder=sec.querySelector('script[type="text/markdown"]');
var src=holder?holder.textContent:'';
var div=document.createElement('div');div.className='content';
var html=window.marked?marked.parse(src):src;
// Sanitise rendered Markdown before it touches the DOM: a deck must not be
// able to run script/onerror/javascript: payloads when the export is opened.
// If the sanitiser somehow isn't present, fail closed to plain text.
if(window.DOMPurify){div.innerHTML=DOMPurify.sanitize(html);}else{div.textContent=src;}
sec.innerHTML='';sec.appendChild(div);
});
document.querySelectorAll('code.language-mermaid').forEach(function(code){
var pre=code.closest('pre');if(!pre)return;
var holder=document.createElement('pre');holder.className='mermaid';
holder.textContent=code.textContent;pre.replaceWith(holder);
});
if(window.hljs){document.querySelectorAll('pre code').forEach(function(el){try{hljs.highlightElement(el);}catch(e){}});}
if(window.mermaid){try{mermaid.initialize({startOnLoad:false});mermaid.run();}catch(e){}}
if(window.MathJax&&MathJax.typesetPromise){MathJax.typesetPromise();}
})();
''';
}