migrate to null-safety, fix #7

Author: robert-virkus

README.md

@@ -20,7 +20,8 @@ import 'package:enough_ascii_art/enough_ascii_art.dart' as art;
 import 'package:image/image.dart' as img;
 
 void main() async {
-  var image = img.decodeImage(File('./example/enough.jpg').readAsBytesSync());
+  final bytes = await File('./example/enough.jpg').readAsBytes();
+  final image = img.decodeImage(bytes)!;
   var asciiImage = art.convertImage(image, maxWidth: 40, invert: true);
   print('');
   print(asciiImage);

example/enough_ascii_art_example.dart

@@ -3,7 +3,8 @@ import 'package:enough_ascii_art/enough_ascii_art.dart' as art;
 import 'package:image/image.dart' as img;
 
 void main() async {
-  var image = img.decodeImage(File('./example/enough.jpg').readAsBytesSync());
+  final bytes = await File('./example/enough.jpg').readAsBytes();
+  final image = img.decodeImage(bytes)!;
   var asciiImage = art.convertImage(image, maxWidth: 40, invert: true);
   print('');
   print(asciiImage);

lib/enough_ascii_art.dart

@@ -31,7 +31,7 @@ const String _asciiGrayScaleCharacters = '#@%=+*:-. ';
 /// [fontHeightCompensationFactor] the optional factor between 0 and 1 that is used to adjust the height of the image. Most fonts have a greater height than width, so this factor allows to compensate this. Defaults to 0.6.
 String convertImage(Image image,
     {int maxWidth = 80,
-    int maxHeight,
+    int? maxHeight,
     String charset = _asciiGrayScaleCharacters,
     bool invert = false,
     double fontHeightCompensationFactor = 0.6}) {

lib/src/emoticon_converter.dart

@@ -63,7 +63,7 @@ class EmoticonConverter {
   /// [style] the optional emoticon style
   static String convertEmoticons(String text,
       [EmoticonStyle style = EmoticonStyle.western]) {
-    if (text == null || text.isEmpty) {
+    if (text.isEmpty) {
       return text;
     }
     switch (style) {
@@ -75,7 +75,7 @@ class EmoticonConverter {
 
   static String _convert(String text, Map<String, String> emoticons) {
     for (var key in emoticons.keys) {
-      text = text.replaceAll(key, emoticons[key]);
+      text = text.replaceAll(key, emoticons[key]!);
     }
     return text;
   }

lib/src/figlet/figlet.dart

@@ -1,5 +1,3 @@
-import 'dart:io';
-import 'package:enough_ascii_art/src/figlet/parser.dart';
 import 'package:enough_ascii_art/src/figlet/renderer.dart';
 
 import 'font.dart';

lib/src/figlet/font.dart

@@ -72,19 +72,19 @@ enum VerticalLayout {
 ///
 /// Since a FIGfont file is a text file, it can be created with any text editing program on any platform. The filename of a FIGfont file must end with ".flf", which stands for "FIGLettering Font".
 class Font {
-  int hardblank;
-  int height;
-  int baseLine;
-  int maxCharacterLength;
-  PrintDirection printDirection;
-  List<HorizontalLayout> horizontalLayouts;
+  int? hardblank;
+  late int height;
+  int? baseLine;
+  int? maxCharacterLength;
+  PrintDirection? printDirection;
+  List<HorizontalLayout>? horizontalLayouts;
   bool get isFullWidthLayout =>
       horizontalLayouts == null ||
-      (horizontalLayouts.length == 1 &&
-          horizontalLayouts.first == HorizontalLayout.fullWidth);
+      (horizontalLayouts!.length == 1 &&
+          horizontalLayouts!.first == HorizontalLayout.fullWidth);
 
-  Character _zeroCharacter;
-  final Map<int, Character> _charactersByRuneCode = <int, Character>{};
+  Character? _zeroCharacter;
+  final _charactersByRuneCode = <int, Character>{};
 
   void addCharacter(
       int runeCode, int characterWidth, List<String> characterLines) {
@@ -95,16 +95,15 @@ class Font {
     }
   }
 
-  Character getCharacter(int rune) {
+  Character? getCharacter(int rune) {
     var character = _charactersByRuneCode[rune];
-    character ??= _zeroCharacter;
-    return character;
+    return character ?? _zeroCharacter;
   }
 
   static Future<Font> network(String src) async {
     final response = await HttpHelper.httpGet(src);
     if (response.statusCode == 200) {
-      return text(response.text);
+      return text(response.text!);
     }
     throw StateError(
         'Unable to resolve url "$src": got response code ${response.statusCode}');

lib/src/figlet/parser.dart

@@ -45,22 +45,19 @@ class Parser {
     var baseLine = int.tryParse(baseDefinitionElements[2]);
     var maxCharacterLength = int.tryParse(baseDefinitionElements[3]);
     var oldLayoutInt = int.tryParse(baseDefinitionElements[4]);
-    var numberOfCommentLines = int.tryParse(baseDefinitionElements[5]);
+    var numberOfCommentLines = int.tryParse(baseDefinitionElements[5]) ?? 0;
     var textDirectionInt = 0;
-    int fullLayoutInt;
+    int? fullLayoutInt;
     if (baseDefinitionElements.length > 7) {
-      var tempDirectionInt = int.tryParse(baseDefinitionElements[6]);
-      if (tempDirectionInt != null) {
-        textDirectionInt = tempDirectionInt;
-      }
+      textDirectionInt = int.tryParse(baseDefinitionElements[6]) ?? 0;
       fullLayoutInt = int.tryParse(baseDefinitionElements[7]);
     }
     var font = Font()
       ..hardblank = hardblank
       ..height = height
       ..baseLine = baseLine
       ..maxCharacterLength = maxCharacterLength
-      ..printDirection = (textDirectionInt == 0 || textDirectionInt == null)
+      ..printDirection = (textDirectionInt == 0)
           ? PrintDirection.leftToRight
           : PrintDirection.rightToLeft
       ..horizontalLayouts = _getHorizontalLayouts(oldLayoutInt, fullLayoutInt);
@@ -121,23 +118,24 @@ class Parser {
     var lineIndex = 1 + numberOfCommentLines;
     var runeCode = 32;
     var parsePhase = _ParsePhase.ascii;
-    var umlauts = [196, 214, 220, 228, 246, 252, 223];
+    final umlauts = [196, 214, 220, 228, 246, 252, 223];
     var germanUmlautIndex = 0;
     while (lineIndex < lines.length) {
       if (parsePhase == _ParsePhase.utf8) {
         // read code unit in first line of character definition:
         var codeUnitLine = lines[lineIndex];
         lineIndex++;
-        var spaceIndex = codeUnitLine.indexOf(' ');
+        final spaceIndex = codeUnitLine.indexOf(' ');
         if (spaceIndex != -1) {
           codeUnitLine = codeUnitLine.substring(0, spaceIndex);
         }
         if (codeUnitLine.isEmpty) continue;
-        runeCode = int.tryParse(codeUnitLine);
-        if (runeCode == null) {
+        final intValue = int.tryParse(codeUnitLine);
+        if (intValue == null) {
           throw FormatException(
               'Invalid font definition at line [$lineIndex]: [$codeUnitLine] contains invalid code unit at beginning.');
         }
+        runeCode = intValue;
       }
       var firstCharacterLine = lines[lineIndex];
       var characterWidth = firstCharacterLine.length - 1;
@@ -174,9 +172,10 @@ class Parser {
     return font;
   }
 
-  List<HorizontalLayout> _getHorizontalLayouts(int oldLayout, int fullLayout) {
+  List<HorizontalLayout> _getHorizontalLayouts(
+      int? oldLayout, int? fullLayout) {
     var layouts = <HorizontalLayout>[];
-    var compatibleLayout = fullLayout ?? oldLayout;
+    var compatibleLayout = fullLayout ?? oldLayout!;
     if (compatibleLayout & horizontalEqualCharacterSmushing ==
         horizontalEqualCharacterSmushing) {
       layouts.add(HorizontalLayout.equalCharacterSmushing);

lib/src/figlet/renderer.dart

@@ -1,5 +1,4 @@
 import 'figlet.dart';
-import 'figlet.dart';
 import 'font.dart';
 
 enum RenderOptions { none }
@@ -17,13 +16,13 @@ class Renderer {
     String text,
     Font font,
     FigletRenderDirection direction, {
-    int maxLineWidth,
-    List<HorizontalLayout> horizontalLayouts,
-    List<VerticalLayout> verticalLayouts,
+    int? maxLineWidth,
+    List<HorizontalLayout>? horizontalLayouts,
+    List<VerticalLayout>? verticalLayouts,
   }) {
     horizontalLayouts ??= font.horizontalLayouts;
     if (direction == FigletRenderDirection.LeftToRight) {
-      return _renderLR(text, font, horizontalLayouts);
+      return _renderLR(text, font, horizontalLayouts!);
     } else {
       return _renderTB(text, font);
     }
@@ -33,9 +32,9 @@ class Renderer {
     _RenderLine renderLine,
     int rune,
     Font font,
-    List<HorizontalLayout> horizontalLayouts,
+    List<HorizontalLayout>? horizontalLayouts,
   ) {
-    var character = font.getCharacter(rune);
+    final character = font.getCharacter(rune);
     if (character != null) {
       renderLine.addCharacterToRight(character, horizontalLayouts);
       //TODO observe line width and wrap text when reaching maximum width
@@ -49,20 +48,20 @@ class Renderer {
     List<HorizontalLayout> horizontalLayouts,
   ) {
     var renderLine = _RenderLine(font);
-    var runes = text.runes;
+    final runes = text.runes;
     for (var rune in runes) {
       _processRune(renderLine, rune, font, horizontalLayouts);
     }
-    var result = renderLine.render();
+    final result = renderLine.render();
     return result;
   }
 
   String _renderTB(String text, Font font) {
-    var runes = text.runes;
-    var result = <String>[];
+    final runes = text.runes;
+    final result = <String>[];
 
     for (var rune in runes) {
-      var renderLine = _RenderLine(font);
+      final renderLine = _RenderLine(font);
       _processRune(renderLine, rune, font, font.horizontalLayouts);
       result.add(renderLine.render());
     }
@@ -88,7 +87,7 @@ class _RenderLine {
 
   // Underscore smushing: An underscore ("_") will be replaced by any of: "|", "/", "\", "[", "]", "{", "}", "(", ")", "<" or ">".
   // Hierarchy smushing: A hierarchy of six classes is used: "|", "/\", "[]", "{}", "()", and "<>".
-  static const List<int> _underscoreOrHierarchyReplacementsRunes = [
+  static const List<int?> _underscoreOrHierarchyReplacementsRunes = [
     _runeVerticalBar,
     _runeForwardSlash,
     _runeBackwardSlash,
@@ -108,7 +107,8 @@ class _RenderLine {
 
   _RenderLine(this._font);
 
-  int addCharacterToRight(Character character, List<HorizontalLayout> layouts) {
+  int addCharacterToRight(
+      Character character, List<HorizontalLayout>? layouts) {
     var isFullWidthLayout = layouts == null ||
         layouts.isEmpty ||
         (layouts.length == 1 && layouts[0] == HorizontalLayout.fullWidth);
@@ -141,7 +141,7 @@ class _RenderLine {
   }
 
   void _layoutLeftToRight(_RenderCharacter left, _RenderCharacter right,
-      List<HorizontalLayout> layouts) {
+      List<HorizontalLayout>? layouts) {
     var originalRightCharacter =
         right.character; // used to restore in case smushing needs to be aborted
     var hardblank = _font.hardblank;
@@ -171,7 +171,7 @@ class _RenderLine {
       var isLayoutRuleAppliedForLine = false;
       var leftRune = leftPos.rune;
       var rightRune = rightPos.rune;
-      for (var layout in layouts) {
+      for (var layout in layouts!) {
         switch (layout) {
           // Moves FIGcharacters closer together until they touch.
           // Typographers use the term "kerning" for this phenomenon when applied to the horizontal axis.
@@ -205,7 +205,7 @@ class _RenderLine {
               } else if ((rightIndex < leftIndex) &&
                   (leftIndex & 1 == 1 || rightIndex < leftIndex - 1)) {
                 isLayoutRuleAppliedForLine = true;
-                replace(right, row, rightPos, String.fromCharCode(leftRune));
+                replace(right, row, rightPos, String.fromCharCode(leftRune!));
               }
             }
             break;
@@ -300,7 +300,7 @@ class _RenderLine {
     } else {
       copyLine = copyLine.substring(0, pos) +
           replacement +
-          copyLine.substring(pos + 1);
+          copyLine.substring(pos! + 1);
     }
     copy.lines[row] = copyLine;
     //print('replaced ${renderCharacter.character.lines[row]} with $copyLine');
@@ -332,11 +332,10 @@ class _RenderLine {
   }
 
   String render() {
-    var runeHardblank = _font.hardblank;
-    var buffer = StringBuffer();
+    final runeHardblank = _font.hardblank;
+    final buffer = StringBuffer();
     for (var row = 0; row < _font.height; row++) {
-      //var lineOfRunes = List<int>(width);
-      var lineOfRunes = List<int>(_width);
+      final lineOfRunes = List.filled(_width, 32);
       var charIndex = 0;
       for (var char in _characters) {
         charIndex += char.relativeX;
@@ -348,8 +347,7 @@ class _RenderLine {
           if (rune == runeHardblank) {
             rune = _runeSpace;
           }
-          if (charIndex >= 0 &&
-              (rune != _runeSpace || lineOfRunes[charIndex] == null)) {
+          if (charIndex >= 0 && (rune != _runeSpace)) {
             lineOfRunes[charIndex] = rune;
           }
           charIndex++;
@@ -365,13 +363,13 @@ class _RenderLine {
 
 class _RenderCharacter {
   Character character;
-  int relativeX;
+  late int relativeX;
   _RenderCharacter(this.character);
 }
 
 class _RunePos {
-  final int rune;
-  final int pos;
+  final int? rune;
+  final int? pos;
   final int steps;
   _RunePos(this.rune, this.pos, this.steps);
 }

lib/src/image_converter.dart

@@ -8,13 +8,13 @@ class ImageConverter {
   ///
   /// [image] the image to be converted
   /// [maxWidth] the optional maximum width of the image in characters, defaults to 80
-  /// [maxHeight] the optional maximum height of th eimage in characters, defaults to null, so the image is caled linearily
+  /// [maxHeight] the optional maximum height of the image in characters, defaults to null, so the image is scaled linearily
   /// [charSet] the optional charset from darkest to lightest character, defaults to '#@%=+*:-. '
   /// [invert] allows to invert pixels, so that a dark pixel gets a bright characater and vise versa. This is useful when printing bight text on a dark background (console). Defaults to false.
   /// [fontHeightCompensationFactor] the optional factor between 0 and 1 that is used to adjust the height of the image. Most fonts have a greater height than width, so this factor allows to compensate this. Defaults to 0.6.
   static String convertImage(Image image,
       {int maxWidth = 80,
-      int maxHeight,
+      int? maxHeight,
       String charset = _asciiGrayScaleCharacters,
       bool invert = false,
       double fontHeightCompensationFactor = 0.6}) {

lib/src/unicode_font_converter.dart

@@ -26,8 +26,8 @@ enum UnicodeFont {
 class UnicodeFontConverter {
   static String encode(final String text, final UnicodeFont font) {
     final buffer = StringBuffer();
-    final from = _fonts[UnicodeFont.normal];
-    final to = _fonts[font];
+    final from = _fonts[UnicodeFont.normal]!;
+    final to = _fonts[font]!;
     for (var i = 0; i < text.length; i++) {
       final c = text[i];
       final index = from.indexOf(c);