voyagehandbook/lib/util/render.dart
2023-03-28 18:08:26 +02:00

317 lines
8.7 KiB
Dart

import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';
import 'package:html/parser.dart';
import 'package:html/dom.dart' as dom;
import 'package:url_launcher/url_launcher.dart';
import 'package:voyagehandbook/api/classes.dart';
import 'package:voyagehandbook/util/styles.dart';
import 'package:voyagehandbook/util/widgets/warning.dart';
import 'package:html_unescape/html_unescape_small.dart';
/*
Voyage Handbook - The open-source WikiVoyage reader
Copyright (C) 2023 Matyáš Caras
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
final _ignoredTags = ["style", "script"];
/// Used to create Widgets from raw HTML from WM API
ListView renderFromPageHTML(RawPage page, double height, double width) {
var out = <Widget>[
const SizedBox(
height: 10,
),
Text(
page.title,
textAlign: TextAlign.center,
style: PageStyles.h1,
),
const SizedBox(
height: 10,
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
const Text("From"),
const SizedBox(
width: 5,
),
GestureDetector(
onTap: () => launchUrl(
Uri.parse("https://en.wikivoyage.org/wiki/${page.key}"),
mode: LaunchMode.externalApplication),
child: const Text(
"WikiVoyage",
style: TextStyle(
decoration: TextDecoration.underline,
fontWeight: FontWeight.bold,
),
),
),
],
),
Row(
children: [
const Text("under"),
const SizedBox(
width: 5,
),
GestureDetector(
onTap: () => launchUrl(Uri.parse(page.license.url),
mode: LaunchMode.externalApplication),
child: Text(
page.license.title,
style: const TextStyle(
decoration: TextDecoration.underline,
),
),
)
],
)
];
var document = parse(page.html);
var sections = document.body!.getElementsByTagName("section");
for (var sec in sections) {
if (sec.localName == "section") {
out.addAll(_renderSection(sec, height, width));
}
}
var l = ListView.builder(
padding: EdgeInsets.zero,
itemBuilder: (c, i) => out[i],
itemCount: out.length,
);
return l;
}
List<Widget> _renderSection(dom.Element sec, double height, double width) {
var out = <Widget>[];
// Get Section Title
var headings = sec.children
.where((element) => ["h2", "h3", "h4", "h5"].contains(element.localName));
var sectionTitle = (headings.isNotEmpty) ? headings.first : null;
if (sectionTitle != null) {
switch (sectionTitle.localName) {
case "h2":
out.add(
const SizedBox(
height: 10,
),
);
out.add(Text(
sectionTitle.text,
style: PageStyles.h2,
textAlign: TextAlign.center,
));
break;
case "h3":
out.add(
Align(
alignment: Alignment.centerLeft,
child: Text(
sectionTitle.text,
style: PageStyles.h3,
),
),
);
break;
case "h4":
out.add(
Align(
alignment: Alignment.centerLeft,
child: Text(sectionTitle.text, style: PageStyles.h4),
),
);
break;
case "h5":
out.add(
Align(
alignment: Alignment.centerLeft,
child: Text(sectionTitle.text, style: PageStyles.h5),
),
);
break;
default:
out.add(
Align(
alignment: Alignment.centerLeft,
child: Text(sectionTitle.text),
),
);
break;
}
// out.add(
// const SizedBox(
// height: 5,
// ),
// );
}
// create TextSpans from text content
for (var element in sec.children) {
// Go through all section's children
for (var t in _ignoredTags) {
var ignored = element.getElementsByTagName(t);
if (ignored.isNotEmpty) {
// Remove ignored tags
for (var element in ignored) {
element.remove();
}
}
}
switch (element.localName) {
case "p":
case "link":
out.add(
RichText(
text: TextSpan(children: _renderText(element.innerHtml)),
textAlign: TextAlign.justify,
),
); // add paragraph spans as single rich text
out.add(
const SizedBox(
height: 5,
),
); // space paragraphs
break;
case "figure":
/// Image figure
var imgs = element.getElementsByTagName("img");
if (imgs.isEmpty) break;
var img = imgs.first; // get image element
if (img.attributes["src"] == null) break;
var figcap = element.getElementsByTagName("figcaption"); // get caption
String? caption;
if (figcap.isNotEmpty) {
caption = figcap.first.text; // TODO: handle links
}
out.add(const SizedBox(
height: 10,
));
out.add(
Container(
// TODO: add tap detector to open wikimedia page?
width: width * 0.8,
height: height * 0.3,
foregroundDecoration: BoxDecoration(
image: DecorationImage(
fit: BoxFit.fitHeight,
image: CachedNetworkImageProvider(
img.attributes["src"]!.replaceAll("//", "https://"),
),
),
),
//height: height * 0.3,
),
); // load image
if (caption != null) {
// Add caption when available
out.add(
const SizedBox(
height: 3,
),
);
out.add(Text(
caption,
textAlign: TextAlign.center,
));
}
out.add(
const SizedBox(
height: 10,
),
);
break;
case "section":
out.addAll(_renderSection(element, height, width));
break;
case "div":
if (element.attributes["class"] != null &&
element.attributes["class"] == "pp_cautionbox") {
out.add(_renderWarning(element));
out.add(
const SizedBox(
height: 10,
),
);
}
break;
default:
break;
}
element.remove();
}
out.add(
const SizedBox(
height: 5,
),
);
return out;
}
// used to render warning box
Widget _renderWarning(dom.Element element) {
var content = <TextSpan>[];
for (var tr in element
.getElementsByTagName("table")
.first
.getElementsByTagName("tbody")
.first
.getElementsByTagName("tr")) {
for (var e in tr.getElementsByTagName("td")) {
// Get to table data
content.addAll(
_renderText(
e.innerHtml.replaceAll(RegExp(r'<img.+?\/?>'), ""),
),
);
}
}
return Warning(content: content);
}
/// Used to render basic text with bold and italic formatting
List<TextSpan> _renderText(String innerHtml) {
var unescape = HtmlUnescape();
innerHtml = unescape.convert(innerHtml);
var content = <TextSpan>[];
var input = innerHtml
.replaceAll(RegExp(r"<(?!(?:\/b)|(?:\/i)|b|i).+?>", dotAll: true), "")
.replaceAll("\\n", "\r");
var noFormatting =
input.split(RegExp(r"(?:<b.*?>.+?<\/b>)|<i.*?>.+?<\/i>", dotAll: true));
var needToFormat = RegExp(r"(?:<b.*?>.+?<\/b>)|<i.*?>.+?<\/i>", dotAll: true)
.allMatches(input)
.toList();
for (var s in needToFormat) {
content.add(TextSpan(
text: noFormatting[needToFormat.indexOf(s)])); // add text before styled
var raw = s.group(0)!;
content.add(
TextSpan(
text: RegExp(r">(?!<)(.+?)<").firstMatch(raw)!.group(1),
style: TextStyle(
fontWeight: (raw.contains("<b")) ? FontWeight.bold : null,
fontStyle: (raw.contains("<i")) ? FontStyle.italic : null,
),
),
); // add styled
}
content.add(TextSpan(text: noFormatting.last)); // add last
return content;
}