Add support for Icon Fonts

@@ -15,7 +15,7 @@
  DART_SRC=$(shell find . -name '*.dart')
  CLNG_SRC=$(shell find printing/ios printing/macos printing/windows printing/android -name '*.cpp' -o -name '*.m' -o -name '*.h' -o -name '*.java')
  SWFT_SRC=$(shell find printing/ios printing/macos -name '*.swift')
- FONTS=pdf/open-sans.ttf pdf/open-sans-bold.ttf pdf/roboto.ttf pdf/noto-sans.ttf pdf/genyomintw.ttf demo/assets/roboto1.ttf demo/assets/roboto2.ttf demo/assets/roboto3.ttf demo/assets/open-sans.ttf demo/assets/open-sans-bold.ttf pdf/hacen-tunisia.ttf
+ FONTS=pdf/open-sans.ttf pdf/open-sans-bold.ttf pdf/roboto.ttf pdf/noto-sans.ttf pdf/genyomintw.ttf demo/assets/roboto1.ttf demo/assets/roboto2.ttf demo/assets/roboto3.ttf demo/assets/open-sans.ttf demo/assets/open-sans-bold.ttf pdf/hacen-tunisia.ttf pdf/material.ttf
  COV_PORT=9292
 
 all: $(FONTS) demo/assets/logo.png demo/assets/profile.jpg format printing/example/.metadata get
@@ -42,6 +42,9 @@ pdf/noto-sans.ttf:
 pdf/genyomintw.ttf:
 	curl -L "https://github.com/ButTaiwan/genyo-font/raw/bc2fa246196fefc1ef9e9843bc8cdba22523a39d/TW/GenYoMinTW-Heavy.ttf" > $@
 
+pdf/material.ttf:
+	curl -L "https://github.com/google/material-design-icons/raw/master/font/MaterialIcons-Regular.ttf" > $@
+
 demo/assets/roboto1.ttf:
 	curl -L "https://fonts.gstatic.com/s/roboto/v20/KFOlCnqEu92Fr1MmSU5vAw.ttf" > $@
 

@@ -9,6 +9,7 @@
 - Fix the line cap and joint enums
 - Fix PdfOutlineMode enum
 - Improve API documentation
+- Add support for Icon Fonts (MaterialIcons)
 
 ## 1.12.0
 

@@ -138,6 +138,9 @@ See https://github.com/DavBfr/dart_pdf/wiki/Fonts-Management
   /// Default width of a glyph
   static const double defaultGlyphWidth = 0.600;
 
+  /// Internal units per
+  int get unitsPerEm;
+
   @override
   void _prepare() {
     super._prepare();

@@ -20,17 +20,19 @@ part of pdf;
 @immutable
 class PdfFontMetrics {
   /// Create a PdfFontMetrics object
-  const PdfFontMetrics(
-      {@required this.left,
-      @required this.top,
-      @required this.right,
-      @required this.bottom,
-      double ascent,
-      double descent,
-      double advanceWidth})
-      : ascent = ascent ?? bottom,
+  const PdfFontMetrics({
+    @required this.left,
+    @required this.top,
+    @required this.right,
+    @required this.bottom,
+    double ascent,
+    double descent,
+    double advanceWidth,
+    double leftBearing,
+  })  : ascent = ascent ?? bottom,
         descent = descent ?? top,
         advanceWidth = advanceWidth ?? right - left,
+        leftBearing = leftBearing ?? left,
         assert(left != null),
         assert(top != null),
         assert(right != null),
@@ -55,9 +57,11 @@ class PdfFontMetrics {
     double ascent;
     double descent;
     double lastBearing;
+    double firstBearing;
     double spacing;
 
     for (var metric in metrics) {
+      firstBearing ??= metric.leftBearing;
       left ??= metric.left;
       spacing = metric.advanceWidth > 0 ? letterSpacing : 0.0;
       right += metric.advanceWidth + spacing;
@@ -70,13 +74,15 @@ class PdfFontMetrics {
     }
 
     return PdfFontMetrics(
-        left: left,
-        top: top,
-        right: right - lastBearing - spacing,
-        bottom: bottom,
-        ascent: ascent,
-        descent: descent,
-        advanceWidth: right - spacing);
+      left: left,
+      top: top,
+      right: right - lastBearing - spacing,
+      bottom: bottom,
+      ascent: ascent,
+      descent: descent,
+      advanceWidth: right - spacing,
+      leftBearing: firstBearing,
+    );
   }
 
   /// Zero-sized dimensions
@@ -122,32 +128,36 @@ class PdfFontMetrics {
   double get effectiveLeft => math.min(leftBearing, 0);
 
   /// Starting point
-  double get leftBearing => left;
+  final double leftBearing;
 
   /// Ending point
   double get rightBearing => advanceWidth - right;
 
   @override
   String toString() =>
-      'PdfFontMetrics(left:$left, top:$top, right:$right, bottom:$bottom, ascent:$ascent, descent:$descent, advanceWidth:$advanceWidth)';
+      'PdfFontMetrics(left:$left, top:$top, right:$right, bottom:$bottom, ascent:$ascent, descent:$descent, advanceWidth:$advanceWidth, leftBearing:$leftBearing, rightBearing:$rightBearing)';
 
   /// Make a copy of this object
-  PdfFontMetrics copyWith(
-      {double left,
-      double top,
-      double right,
-      double bottom,
-      double ascent,
-      double descent,
-      double advanceWidth}) {
+  PdfFontMetrics copyWith({
+    double left,
+    double top,
+    double right,
+    double bottom,
+    double ascent,
+    double descent,
+    double advanceWidth,
+    double leftBearing,
+  }) {
     return PdfFontMetrics(
-        left: left ?? this.left,
-        top: top ?? this.top,
-        right: right ?? this.right,
-        bottom: bottom ?? this.bottom,
-        ascent: ascent ?? this.ascent,
-        descent: descent ?? this.descent,
-        advanceWidth: advanceWidth ?? this.advanceWidth);
+      left: left ?? this.left,
+      top: top ?? this.top,
+      right: right ?? this.right,
+      bottom: bottom ?? this.bottom,
+      ascent: ascent ?? this.ascent,
+      descent: descent ?? this.descent,
+      advanceWidth: advanceWidth ?? this.advanceWidth,
+      leftBearing: leftBearing ?? this.leftBearing,
+    );
   }
 
   /// Multiply this metrics object with a font size
@@ -160,6 +170,7 @@ class PdfFontMetrics {
       ascent: ascent * factor,
       descent: descent * factor,
       advanceWidth: advanceWidth * factor,
+      leftBearing: leftBearing * factor,
     );
   }
 

@@ -253,6 +253,9 @@ class TtfParser {
     final baseOffset = tableOffsets[glyf_table];
     final hmtxOffset = tableOffsets[hmtx_table];
     final unitsPerEm = this.unitsPerEm;
+    final numOfLongHorMetrics = this.numOfLongHorMetrics;
+    final defaultadvanceWidth =
+        bytes.getUint16(hmtxOffset + (numOfLongHorMetrics - 1) * 4);
     var glyphIndex = 0;
     for (var offset in glyphOffsets) {
       final xMin = bytes.getInt16(baseOffset + offset + 2); // 2
@@ -260,16 +263,23 @@ class TtfParser {
       final xMax = bytes.getInt16(baseOffset + offset + 6); // 6
       final yMax = bytes.getInt16(baseOffset + offset + 8); // 8
       final advanceWidth = glyphIndex < numOfLongHorMetrics
-          ? bytes.getInt16(hmtxOffset + glyphIndex * 4).toDouble() / unitsPerEm
-          : null;
+          ? bytes.getUint16(hmtxOffset + glyphIndex * 4)
+          : defaultadvanceWidth;
+      final leftBearing = glyphIndex < numOfLongHorMetrics
+          ? bytes.getInt16(hmtxOffset + glyphIndex * 4 + 2)
+          : bytes.getInt16(hmtxOffset +
+              numOfLongHorMetrics * 4 +
+              (glyphIndex - numOfLongHorMetrics) * 2);
       glyphInfoMap[glyphIndex] = PdfFontMetrics(
-          left: xMin.toDouble() / unitsPerEm,
-          top: yMin.toDouble() / unitsPerEm,
-          right: xMax.toDouble() / unitsPerEm,
-          bottom: yMax.toDouble() / unitsPerEm,
-          ascent: ascent.toDouble() / unitsPerEm,
-          descent: descent.toDouble() / unitsPerEm,
-          advanceWidth: advanceWidth);
+        left: xMin.toDouble() / unitsPerEm,
+        top: yMin.toDouble() / unitsPerEm,
+        right: xMax.toDouble() / unitsPerEm,
+        bottom: yMax.toDouble() / unitsPerEm,
+        ascent: ascent.toDouble() / unitsPerEm,
+        descent: descent.toDouble() / unitsPerEm,
+        advanceWidth: advanceWidth.toDouble() / unitsPerEm,
+        leftBearing: leftBearing.toDouble() / unitsPerEm,
+      );
       glyphIndex++;
     }
   }

@@ -187,10 +187,21 @@ class TtfWriter {
       final hmtx = Uint8List(_wordAlign(len, 4));
       final hmtxOffset = ttf.tableOffsets[TtfParser.hmtx_table];
       final hmtxData = hmtx.buffer.asByteData();
+      final numOfLongHorMetrics = ttf.numOfLongHorMetrics;
+      final defaultadvanceWidth =
+          ttf.bytes.getUint16(hmtxOffset + (numOfLongHorMetrics - 1) * 4);
       var index = 0;
       for (var glyph in glyphsInfo) {
-        hmtxData.setUint32(
-            index, ttf.bytes.getInt32(hmtxOffset + glyph.index * 4));
+        final advanceWidth = glyph.index < numOfLongHorMetrics
+            ? ttf.bytes.getUint16(hmtxOffset + glyph.index * 4)
+            : defaultadvanceWidth;
+        final leftBearing = glyph.index < numOfLongHorMetrics
+            ? ttf.bytes.getInt16(hmtxOffset + glyph.index * 4 + 2)
+            : ttf.bytes.getInt16(hmtxOffset +
+                numOfLongHorMetrics * 4 +
+                (glyph.index - numOfLongHorMetrics) * 2);
+        hmtxData.setUint16(index, advanceWidth);
+        hmtxData.setInt16(index + 2, leftBearing);
         index += 4;
       }
       tables[TtfParser.hmtx_table] = hmtx;

@@ -50,6 +50,9 @@ class PdfTtfFont extends PdfFont {
   double get descent => font.descent.toDouble() / font.unitsPerEm;
 
   @override
+  int get unitsPerEm => font.unitsPerEm;
+
+  @override
   PdfFontMetrics glyphMetrics(int charCode) {
     final g = font.charToGlyphIndexMap[charCode];
 

@@ -44,6 +44,9 @@ class PdfType1Font extends PdfFont {
   @override
   final double descent;
 
+  @override
+  int get unitsPerEm => 1000;
+
   /// Width of each glyph
   final List<double> widths;
 

@@ -20,9 +20,9 @@ import 'dart:collection';
 import 'dart:convert';
 import 'dart:math' as math;
 import 'dart:typed_data';
-import 'package:image/image.dart' as im;
 
 import 'package:barcode/barcode.dart';
+import 'package:image/image.dart' as im;
 import 'package:meta/meta.dart';
 import 'package:pdf/pdf.dart';
 import 'package:vector_math/vector_math_64.dart';
@@ -48,6 +48,7 @@ part 'widgets/font.dart';
 part 'widgets/forms.dart';
 part 'widgets/geometry.dart';
 part 'widgets/grid_view.dart';
+part 'widgets/icon.dart';
 part 'widgets/image.dart';
 part 'widgets/multi_page.dart';
 part 'widgets/page.dart';

@@ -565,12 +565,12 @@ class AspectRatio extends SingleChildWidget {
 typedef CustomPainter = Function(PdfGraphics canvas, PdfPoint size);
 
 class CustomPaint extends SingleChildWidget {
-  CustomPaint(
-      {this.painter,
-      this.foregroundPainter,
-      this.size = PdfPoint.zero,
-      Widget child})
-      : super(child: child);
+  CustomPaint({
+    this.painter,
+    this.foregroundPainter,
+    this.size = PdfPoint.zero,
+    Widget child,
+  }) : super(child: child);
 
   final CustomPainter painter;
   final CustomPainter foregroundPainter;

+/*
+ * 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.
+ */
+
+part of widget;
+
+/// A description of an icon fulfilled by a font glyph.
+@immutable
+class IconData {
+  /// Creates icon data.
+  const IconData(
+    this.codePoint, {
+    this.matchTextDirection = false,
+  });
+
+  /// The Unicode code point at which this icon is stored in the icon font.
+  final int codePoint;
+
+  /// Whether this icon should be automatically mirrored in right-to-left
+  /// environments.
+  final bool matchTextDirection;
+}
+
+/// Defines the color, opacity, and size of icons.
+@immutable
+class IconThemeData {
+  /// Creates an icon theme data.
+  const IconThemeData({this.color, this.opacity, this.size, this.font});
+
+  /// Creates an icon them with some reasonable default values.
+  const IconThemeData.fallback(this.font)
+      : color = PdfColors.black,
+        opacity = 1.0,
+        size = 24.0;
+
+  /// Creates a copy of this icon theme but with the given fields replaced with
+  /// the new values.
+  IconThemeData copyWith(
+      {PdfColor color, double opacity, double size, Font font}) {
+    return IconThemeData(
+      color: color ?? this.color,
+      opacity: opacity ?? this.opacity,
+      size: size ?? this.size,
+      font: font ?? this.font,
+    );
+  }
+
+  /// The default color for icons.
+  final PdfColor color;
+
+  /// An opacity to apply to both explicit and default icon colors.
+  final double opacity;
+
+  /// The default size for icons.
+  final double size;
+
+  /// The font to use
+  final Font font;
+}
+
+/// A graphical icon widget drawn with a glyph from a font described in
+/// an [IconData] such as material's predefined [IconData]s in [Icons].
+class Icon extends StatelessWidget {
+  /// Creates an icon.
+  Icon(
+    this.icon, {
+    this.size,
+    this.color,
+    this.textDirection,
+    this.font,
+  })  : assert(icon != null),
+        super();
+
+  /// The icon to display. The available icons are described in [Icons].
+  final IconData icon;
+
+  /// The size of the icon in logical pixels.
+  final double size;
+
+  /// The color to use when drawing the icon.
+  final PdfColor color;
+
+  /// The text direction to use for rendering the icon.
+  final TextDirection textDirection;
+
+  /// Font to use to draw the icon
+  final Font font;
+
+  @override
+  Widget build(Context context) {
+    final textDirection = this.textDirection ?? Directionality.of(context);
+    final iconTheme = Theme.of(context).iconTheme;
+    final iconSize = size ?? iconTheme.size;
+    final iconColor = color ?? iconTheme.color;
+    final iconOpacity = iconColor.alpha;
+    final iconFont = font ?? iconTheme.font;
+
+    Widget iconWidget = RichText(
+      textDirection: textDirection,
+      text: TextSpan(
+        text: String.fromCharCode(icon.codePoint),
+        style: TextStyle.defaultStyle().copyWith(
+          color: iconColor,
+          fontSize: iconSize,
+          fontNormal: iconFont,
+        ),
+      ),
+    );
+
+    if (icon.matchTextDirection) {
+      switch (textDirection) {
+        case TextDirection.rtl:
+          iconWidget = Transform(
+            transform: Matrix4.identity()..scale(-1.0, 1.0, 1.0),
+            alignment: Alignment.center,
+            child: iconWidget,
+          );
+          break;
+        case TextDirection.ltr:
+          break;
+      }
+    }
+
+    if (iconOpacity < 1.0) {
+      iconWidget = Opacity(
+        opacity: iconOpacity,
+        child: iconWidget,
+      );
+    }
+    return iconWidget;
+  }
+}

@@ -33,6 +33,7 @@ class ThemeData extends Inherited {
     bool softWrap,
     TextAlign textAlign,
     int maxLines,
+    IconThemeData iconTheme,
   }) {
     final base = ThemeData.base();
     return base.copyWith(
@@ -50,6 +51,7 @@ class ThemeData extends Inherited {
       softWrap: softWrap,
       textAlign: textAlign,
       maxLines: maxLines,
+      iconTheme: iconTheme,
     );
   }
 
@@ -67,6 +69,7 @@ class ThemeData extends Inherited {
     @required this.tableCell,
     @required this.softWrap,
     @required this.textAlign,
+    @required this.iconTheme,
     this.maxLines,
   })  : assert(defaultTextStyle.inherit == false),
         assert(paragraphStyle.inherit == false),
@@ -80,16 +83,23 @@ class ThemeData extends Inherited {
         assert(tableHeader.inherit == false),
         assert(tableCell.inherit == false),
         assert(softWrap != null),
-        assert(maxLines == null || maxLines > 0);
+        assert(maxLines == null || maxLines > 0),
+        assert(iconTheme != null);
 
-  factory ThemeData.withFont(
-      {Font base, Font bold, Font italic, Font boldItalic}) {
+  factory ThemeData.withFont({
+    Font base,
+    Font bold,
+    Font italic,
+    Font boldItalic,
+    Font icons,
+  }) {
     final defaultStyle = TextStyle.defaultStyle().copyWith(
-        font: base,
-        fontNormal: base,
-        fontBold: bold,
-        fontItalic: italic,
-        fontBoldItalic: boldItalic);
+      font: base,
+      fontNormal: base,
+      fontBold: bold,
+      fontItalic: italic,
+      fontBoldItalic: boldItalic,
+    );
     final fontSize = defaultStyle.fontSize;
 
     return ThemeData._(
@@ -107,6 +117,7 @@ class ThemeData extends Inherited {
       tableCell: defaultStyle.copyWith(fontSize: fontSize * 0.8),
       softWrap: true,
       textAlign: TextAlign.left,
+      iconTheme: IconThemeData.fallback(icons),
     );
   }
 
@@ -127,6 +138,7 @@ class ThemeData extends Inherited {
     bool softWrap,
     TextAlign textAlign,
     int maxLines,
+    IconThemeData iconTheme,
   }) =>
       ThemeData._(
         defaultTextStyle: this.defaultTextStyle.merge(defaultTextStyle),
@@ -143,6 +155,7 @@ class ThemeData extends Inherited {
         softWrap: softWrap ?? this.softWrap,
         textAlign: textAlign ?? this.textAlign,
         maxLines: maxLines ?? this.maxLines,
+        iconTheme: iconTheme ?? this.iconTheme,
       );
 
   final TextStyle defaultTextStyle;
@@ -165,6 +178,8 @@ class ThemeData extends Inherited {
   final TextAlign textAlign;
   final bool softWrap;
   final int maxLines;
+
+  final IconThemeData iconTheme;
 }
 
 class Theme extends StatelessWidget {

@@ -38,6 +38,7 @@ import 'widget_container_test.dart' as widget_container;
 import 'widget_flex_test.dart' as widget_flex;
 import 'widget_form_test.dart' as widget_form;
 import 'widget_grid_view_test.dart' as widget_grid_view;
+import 'widget_icon_test.dart' as widget_icon;
 import 'widget_multipage_test.dart' as widget_multipage;
 import 'widget_opacity_test.dart' as widget_opacity;
 import 'widget_outline_test.dart' as widget_outline;
@@ -72,6 +73,7 @@ void main() {
   widget_flex.main();
   widget_form.main();
   widget_grid_view.main();
+  widget_icon.main();
   widget_multipage.main();
   widget_opacity.main();
   widget_outline.main();

@@ -22,50 +22,94 @@ import 'package:pdf/widgets.dart';
 import 'package:test/test.dart';
 
 void printMetrics(
-    PdfGraphics canvas, String text, PdfFont font, PdfPoint size) {
-  final metricsUnscales = font.stringMetrics(text);
-  final fontSizeW = size.x / metricsUnscales.maxWidth;
-  final fontSizeH = size.y / metricsUnscales.maxHeight;
+  PdfGraphics canvas,
+  int codeUnit,
+  PdfFont font,
+  PdfPoint size,
+) {
+  final metricsUnscaled = font.glyphMetrics(codeUnit);
+  final fontSizeW = size.x / metricsUnscaled.maxWidth;
+  final fontSizeH = size.y / metricsUnscaled.maxHeight;
   final fontSize = min(fontSizeW, fontSizeH);
-  final metrics = metricsUnscales * fontSize;
+  final metrics = metricsUnscaled * fontSize;
+  final m = metricsUnscaled * font.unitsPerEm.toDouble();
 
   const deb = 20;
+  const s = 5.0;
 
   final x = (size.x - metrics.maxWidth) / 2.0;
   final y = (size.y - metrics.maxHeight) / 2.0 - metrics.descent;
 
+  int index;
+  if (font is PdfTtfFont) {
+    index = font.font.charToGlyphIndexMap[codeUnit];
+  }
+
   canvas
     ..setLineWidth(0.5)
+    // Glyph maximum size
     ..drawRect(x, y + metrics.descent, metrics.advanceWidth, metrics.maxHeight)
     ..setStrokeColor(PdfColors.green)
     ..strokePath()
+    // Glyph bounding box
     ..drawRect(x + metrics.left, y + metrics.top, metrics.width, metrics.height)
     ..setStrokeColor(PdfColors.amber)
     ..strokePath()
+    // Glyph baseline
     ..drawLine(x + metrics.effectiveLeft - deb, y,
         x + metrics.maxWidth + metrics.effectiveLeft + deb, y)
     ..setColor(PdfColors.blue)
     ..strokePath()
+    // Drawing Start
     ..drawEllipse(x, y, 5, 5)
     ..setFillColor(PdfColors.black)
     ..fillPath()
+    // Next glyph
     ..drawEllipse(x + metrics.advanceWidth, y, 5, 5)
     ..setFillColor(PdfColors.red)
     ..fillPath()
+    // Left Bearing
+    ..saveContext()
+    ..setGraphicState(const PdfGraphicState(opacity: 0.5))
+    ..drawEllipse(x + metrics.leftBearing, y, 5, 5)
+    ..setFillColor(PdfColors.purple)
+    ..fillPath()
+    ..restoreContext()
+    // The glyph
     ..setFillColor(PdfColors.grey)
-    ..drawString(font, fontSize, text, x, y);
+    ..drawString(font, fontSize, String.fromCharCode(codeUnit), x, y)
+    // Metrics information
+    ..setFillColor(PdfColors.black)
+    ..drawString(canvas.defaultFont, s,
+        'unicode: 0x${codeUnit.toRadixString(16)}', 10, size.y - 20 - s * 0)
+    ..drawString(canvas.defaultFont, s, 'index: 0x${index.toRadixString(16)}',
+        10, size.y - 20 - s * 1)
+    ..drawString(canvas.defaultFont, s, 'left: ${m.left.toInt()}', 10,
+        size.y - 20 - s * 2)
+    ..drawString(canvas.defaultFont, s, 'right: ${m.right.toInt()}', 10,
+        size.y - 20 - s * 3)
+    ..drawString(
+        canvas.defaultFont, s, 'top: ${m.top.toInt()}', 10, size.y - 20 - s * 4)
+    ..drawString(canvas.defaultFont, s, 'bottom: ${m.bottom.toInt()}', 10,
+        size.y - 20 - s * 5)
+    ..drawString(canvas.defaultFont, s,
+        'advanceWidth: ${m.advanceWidth.toInt()}', 10, size.y - 20 - s * 6)
+    ..drawString(canvas.defaultFont, s, 'leftBearing: ${m.leftBearing.toInt()}',
+        10, size.y - 20 - s * 7);
 }
 
 void main() {
   test('Pdf Font Metrics', () {
     final pdf = Document();
 
+    PdfFont.courier(pdf.document);
     final ttfFont = File('open-sans.ttf');
     final fontData = ttfFont.readAsBytesSync();
     final font = PdfTtfFont(pdf.document, fontData.buffer.asByteData());
 
-    for (var letter
-        in 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz&%!?0123456789'
+    for (var letter in
+        //font.font.charToGlyphIndexMap.keys
+        'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz&%!?0123456789'
             .codeUnits) {
       pdf.addPage(Page(
           pageFormat: const PdfPageFormat(500, 500, marginAll: 20),
@@ -76,8 +120,7 @@ void main() {
                     child: CustomPaint(
                         size: const PdfPoint(200, 200),
                         painter: (PdfGraphics canvas, PdfPoint size) {
-                          printMetrics(
-                              canvas, String.fromCharCode(letter), font, size);
+                          printMetrics(canvas, letter, font, size);
                         })));
           }));
     }

@@ -81,3 +81,55 @@ Font loadFont(String filename) {
   final data = File(filename).readAsBytesSync();
   return Font.ttf(data.buffer.asByteData());
 }
+
+void hexDump(
+  ByteData bytes,
+  int offset,
+  int length, [
+  int highlight,
+  int highlightLength,
+]) {
+  const reset = '\x1B[0m';
+  const red = '\x1B[1;31m';
+  var s = '';
+  var t = '';
+  var n = 0;
+  var hl = false;
+  for (var i = 0; i < length; i++) {
+    final b = bytes.getUint8(offset + i);
+    if (highlight != null && highlightLength != null) {
+      if (offset + i >= highlight && offset + i < highlight + highlightLength) {
+        if (!hl) {
+          hl = true;
+          s += red;
+          t += red;
+        }
+      } else {
+        if (hl) {
+          hl = false;
+          s += reset;
+          t += reset;
+        }
+      }
+    }
+    s += b.toRadixString(16).padLeft(2, '0') + ' ';
+    if (b > 31 && b < 128) {
+      t += String.fromCharCode(b);
+    } else {
+      t += '.';
+    }
+
+    n++;
+    if (n % 16 == 0) {
+      if (hl) {
+        s += reset;
+        t += reset;
+        hl = false;
+      }
+      print('$s   $t');
+      s = '';
+      t = '';
+    }
+  }
+  print('$s   $t');
+}

+/*
+ * 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.
+ */
+
+import 'dart:io';
+
+import 'package:pdf/pdf.dart';
+import 'package:pdf/widgets.dart';
+import 'package:test/test.dart';
+
+import 'utils.dart';
+
+Document pdf;
+Font icons;
+
+void main() {
+  setUpAll(() {
+    Document.debug = true;
+    pdf = Document();
+    icons = loadFont('material.ttf');
+  });
+
+  test('Icon Widgets', () {
+    pdf.addPage(
+      MultiPage(
+        theme: ThemeData.withFont(icons: icons),
+        build: (Context context) {
+          final iconList = List<IconData>();
+          final pdfFont = icons.getFont(context);
+          if (pdfFont is PdfTtfFont) {
+            iconList.addAll(
+              pdfFont.font.charToGlyphIndexMap.keys
+                  .where((e) => e > 0x7f && e < 0xe05d)
+                  .map((e) => IconData(e)),
+            );
+          }
+
+          return <Widget>[
+            Wrap(
+              spacing: 10,
+              runSpacing: 10,
+              children: <Widget>[
+                ...iconList.map<Widget>(
+                  (e) => Column(children: [
+                    Icon(e, size: 50, color: PdfColors.blueGrey),
+                    Text('0x${e.codePoint.toRadixString(16)}'),
+                  ]),
+                ),
+              ],
+            ),
+          ];
+        },
+      ),
+    );
+  });
+
+  tearDownAll(() {
+    final file = File('widgets-icons.pdf');
+    file.writeAsBytesSync(pdf.save());
+  });
+}