Implement ColoredTextPrintStrategy

README.md

@@ -34,6 +34,47 @@ void setupLogger(bool debugMode) {
 }
 ```
 
+### Using `ColoredTextPrintStrategy`
+
+To enable log level-based text coloring in console output, consider using
+[ColoredTextPrintStrategy]. Note that this strategy may not function
+correctly depending on the output terminal and target device.
+
+For optimal results, test this print strategy in your chosen IDE and
+output device combination. Consider enabling this feature conditionally,
+for example, using dart defines.
+
+1. Prepare code setup
+
+```dart
+// ...
+void setupLogger(bool debugMode) {
+  if (debugMode) {
+    // During debugging, you'll usually want to log everything
+    Logger.root.level = Level.ALL;
+
+    const useColoredText = bool.fromEnvironment("USE_COLORED_TEXT_LOGGING");
+
+    LoggingBugfenderListener(
+      config.bugfenderKey,
+      consolePrintStrategy: useColoredText
+          ? const ColoredTextPrintStrategy()
+          : const PlainTextPrintStrategy(),
+    ).listen(Logger.root);
+  } else {
+    // ...
+  }
+}
+```
+
+2. Pass the flag using `--dart-define`
+
+```
+flutter run --dart-define="USE_COLORED_TEXT_LOGGING=true"
+```
+
+Note: You can also use --dart-define-from-file which is introduced in Flutter 3.7.
+
 ### Custom data
 
 You can also add and remove custom data.

lib/src/logging_bugfender.dart

@@ -42,6 +42,7 @@ class LoggingBugfenderListener {
     int? maximumLocalStorageSize,
     this.consolePrintStrategy = const NeverPrintStrategy(),
     this.bugfenderPrintStrategy = const PlainTextPrintStrategy(),
+    this.consoleLoggingMethod = ConsoleLoggingMethod.print,
     bool enableUIEventLogging = true,
     bool enableCrashReporting = true,
     bool enableAndroidLogcatLogging = true,
@@ -63,16 +64,26 @@ class LoggingBugfenderListener {
   /// Defines if and how logs should be created and printed to the console.
   final PrintStrategy consolePrintStrategy;
 
+  /// Defines the preferred method for printing logs to the console. By using
+  /// the `log` function, additional information can be included in the console
+  /// output. Depending on the output console type, this approach may also help
+  /// display colored text correctly when using [ColoredTextPrintStrategy].
+  final ConsoleLoggingMethod consoleLoggingMethod;
+
   /// Defines if and how logs should be created and sent to Bugfender.
   final PrintStrategy bugfenderPrintStrategy;
 
   /// Starts listening to logs emitted by [logger].
   StreamSubscription<LogRecord> listen(Logger logger) {
     return logger.onRecord.listen((logRecord) {
-      final consoleLog = consolePrintStrategy.print(logRecord);
-      if (consoleLog != null) {
-        // ignore: avoid_print
-        print(consoleLog);
+      if (consoleLoggingMethod == ConsoleLoggingMethod.log) {
+        consolePrintStrategy.log(logRecord);
+      } else {
+        final consoleLog = consolePrintStrategy.print(logRecord);
+        if (consoleLog != null) {
+          // ignore: avoid_print
+          print(consoleLog);
+        }
       }
 
       final bugfenderLog = bugfenderPrintStrategy.print(logRecord);
@@ -109,3 +120,12 @@ class LoggingBugfenderListener {
   Future<void> removeCustomData(String key) =>
       FlutterBugfender.removeDeviceKey(key);
 }
+
+/// Defines prefered method of printing the logs to the console
+enum ConsoleLoggingMethod {
+  /// Logs will be printed using the `print` function
+  print,
+
+  /// Logs will be printed using the `log` function from `dart:developer`
+  log,
+}

lib/src/print_strategy.dart

@@ -1,3 +1,5 @@
+import 'dart:developer' as dev;
+
 import 'package:logging/logging.dart';
 import 'package:logging_bugfender/src/logging_bugfender.dart';
 
@@ -8,6 +10,11 @@ abstract class PrintStrategy {
 
   /// Creates a log message.
   String? print(LogRecord record);
+
+  /// Creates a log message and prints it using the `log` function from
+  /// `dart:developer`.
+
+  void log(LogRecord record);
 }
 
 /// Instructs [LoggingBugfenderListener] to never print.
@@ -17,6 +24,9 @@ class NeverPrintStrategy extends PrintStrategy {
 
   @override
   String? print(LogRecord record) => null;
+
+  @override
+  void log(LogRecord record) {}
 }
 
 /// Instructs [LoggingBugfenderListener] to print plain text.
@@ -26,7 +36,7 @@ class PlainTextPrintStrategy extends PrintStrategy {
 
   @override
   String print(LogRecord record) {
-    final log = StringBuffer()
+    final logMessage = StringBuffer()
       ..writeAll(
         <String>[
           '[${record.level.name}]',
@@ -37,12 +47,93 @@ class PlainTextPrintStrategy extends PrintStrategy {
       );
 
     if (record.error != null) {
-      log.write('\n${record.error}');
+      logMessage.write('\n${record.error}');
     }
     if (record.stackTrace != null) {
-      log.write('\n${record.stackTrace}');
+      logMessage.write('\n${record.stackTrace}');
     }
 
-    return log.toString();
+    return logMessage.toString();
+  }
+
+  @override
+  void log(LogRecord record) {
+    final logMessage = '[${record.level.name}] ${record.message}';
+
+    dev.log(
+      logMessage,
+      name: record.loggerName,
+      error: record.error,
+      stackTrace: record.stackTrace,
+      level: record.level.value,
+      time: record.time,
+      sequenceNumber: record.sequenceNumber,
+      zone: record.zone,
+    );
+  }
+}
+
+/// Instructs [LoggingBugfenderListener] to print color-coded text based
+/// on log levels. Color display depends on the terminal’s support for ANSI
+/// escape sequences, which theoretically can be verified using
+/// `io.stdout.supportsAnsiEscapes`. However, this check often fails to return
+/// `true` even when ANSI escapes are supported by the terminal.
+///
+/// For optimal results, test this print strategy in your chosen
+/// IDE and output device combination. Consider enabling this feature
+/// conditionally, such as through an environment variable.
+
+class ColoredTextPrintStrategy extends PlainTextPrintStrategy {
+  /// Creates a strategy that prints colored plain text.
+  const ColoredTextPrintStrategy();
+
+  static final _levelColors = <Level, String?>{
+    Level.FINEST: '8',
+    Level.FINER: '8',
+    Level.FINE: '8',
+    Level.CONFIG: null,
+    Level.INFO: '12',
+    Level.WARNING: '208',
+    Level.SEVERE: '196',
+    Level.SHOUT: '199',
+  };
+
+  /// ANSI Control Sequence Introducer, signals the terminal for new settings.
+  static const ansiEsc = '\x1B[';
+
+  /// Reset all colors and options to terminal defaults.
+  static const ansiDefault = '${ansiEsc}0m';
+
+  @override
+  String print(LogRecord record) {
+    final logMessage = super.print(record);
+
+    return _encodeColor(logMessage, record.level);
+  }
+
+  @override
+  void log(LogRecord record) {
+    final logMessage = '[${record.level.name}] ${record.message}';
+
+    dev.log(
+      _encodeColor(logMessage.toString(), record.level),
+      name: record.loggerName,
+      error: record.error,
+      stackTrace: record.stackTrace,
+      level: record.level.value,
+      time: record.time,
+      sequenceNumber: record.sequenceNumber,
+      zone: record.zone,
+    );
+  }
+
+  String _encodeColor(String text, Level level) {
+    final color = _levelColors[level];
+
+    if (color != null) {
+      return '${ansiEsc}38;5;${color}m$text$ansiDefault';
+    } else {
+      return text;
+    }
   }
 }