ttffont.dart
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/*
* Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// ignore_for_file: omit_local_variable_types
part of pdf;
class PdfTtfFont extends PdfFont {
/// Constructs a [PdfTtfFont]
PdfTtfFont(PdfDocument pdfDocument, ByteData bytes, {bool protect = false})
: font = TtfParser(bytes),
super._create(pdfDocument, subtype: '/TrueType') {
file = PdfObjectStream(pdfDocument, isBinary: true);
unicodeCMap = PdfUnicodeCmap(pdfDocument, protect);
descriptor = PdfFontDescriptor(this, file);
widthsObject = PdfArrayObject(pdfDocument, PdfArray());
}
@override
String get subtype => font.unicode ? '/Type0' : super.subtype;
PdfUnicodeCmap unicodeCMap;
PdfFontDescriptor descriptor;
PdfObjectStream file;
PdfArrayObject widthsObject;
final TtfParser font;
@override
String get fontName => font.fontName;
@override
double get ascent => font.ascent.toDouble() / font.unitsPerEm;
@override
double get descent => font.descent.toDouble() / font.unitsPerEm;
@override
PdfFontMetrics glyphMetrics(int charCode) {
final int g = font.charToGlyphIndexMap[charCode];
if (g == null) {
return PdfFontMetrics.zero;
}
if (PdfArabic._isArabicDiacriticValue(charCode)) {
final PdfFontMetrics metric = font.glyphInfoMap[g] ?? PdfFontMetrics.zero;
return metric.copyWith(advanceWidth: 0);
}
return font.glyphInfoMap[g] ?? PdfFontMetrics.zero;
}
void _buildTrueType(PdfDict params) {
int charMin;
int charMax;
file.buf.putBytes(font.bytes.buffer.asUint8List());
file.params['/Length1'] = PdfNum(font.bytes.lengthInBytes);
params['/BaseFont'] = PdfName('/' + fontName);
params['/FontDescriptor'] = descriptor.ref();
charMin = 32;
charMax = 255;
for (int i = charMin; i <= charMax; i++) {
widthsObject.array
.add(PdfNum((glyphMetrics(i).advanceWidth * 1000.0).toInt()));
}
params['/FirstChar'] = PdfNum(charMin);
params['/LastChar'] = PdfNum(charMax);
params['/Widths'] = widthsObject.ref();
}
void _buildType0(PdfDict params) {
int charMin;
int charMax;
final TtfWriter ttfWriter = TtfWriter(font);
final Uint8List data = ttfWriter.withChars(unicodeCMap.cmap);
file.buf.putBytes(data);
file.params['/Length1'] = PdfNum(data.length);
final PdfDict descendantFont = PdfDict(<String, PdfDataType>{
'/Type': const PdfName('/Font'),
'/BaseFont': PdfName('/' + fontName),
'/FontFile2': file.ref(),
'/FontDescriptor': descriptor.ref(),
'/W': PdfArray(<PdfDataType>[
const PdfNum(0),
widthsObject.ref(),
]),
'/CIDToGIDMap': const PdfName('/Identity'),
'/DW': const PdfNum(1000),
'/Subtype': const PdfName('/CIDFontType2'),
'/CIDSystemInfo': PdfDict(<String, PdfDataType>{
'/Supplement': const PdfNum(0),
'/Registry': PdfSecString.fromString(this, 'Adobe'),
'/Ordering': PdfSecString.fromString(this, 'Identity-H'),
})
});
params['/BaseFont'] = PdfName('/' + fontName);
params['/Encoding'] = const PdfName('/Identity-H');
params['/DescendantFonts'] = PdfArray(<PdfDataType>[descendantFont]);
params['/ToUnicode'] = unicodeCMap.ref();
charMin = 0;
charMax = unicodeCMap.cmap.length - 1;
for (int i = charMin; i <= charMax; i++) {
widthsObject.array.add(PdfNum(
(glyphMetrics(unicodeCMap.cmap[i]).advanceWidth * 1000.0).toInt()));
}
}
@override
void _prepare() {
super._prepare();
if (font.unicode) {
_buildType0(params);
} else {
_buildTrueType(params);
}
}
@override
void putText(PdfStream stream, String text) {
if (!font.unicode) {
super.putText(stream, text);
}
final Runes runes = text.runes;
stream.putByte(0x3c);
for (int rune in runes) {
int char = unicodeCMap.cmap.indexOf(rune);
if (char == -1) {
char = unicodeCMap.cmap.length;
unicodeCMap.cmap.add(rune);
}
stream.putBytes(latin1.encode(char.toRadixString(16).padLeft(4, '0')));
}
stream.putByte(0x3e);
}
@override
PdfFontMetrics stringMetrics(String s, {double letterSpacing = 0}) {
if (s.isEmpty || !font.unicode) {
return super.stringMetrics(s, letterSpacing: letterSpacing);
}
final Runes runes = s.runes;
final List<int> bytes = <int>[];
runes.forEach(bytes.add);
final Iterable<PdfFontMetrics> metrics = bytes.map(glyphMetrics);
return PdfFontMetrics.append(metrics, letterSpacing: letterSpacing);
}
}