hex_config›Classes

HexConfig

class HexConfig

Configuration for hex viewer display and behavior.

This class controls all visual and interactive aspects of the HexViewer widget, including layout, colors, and enabled features.

Example:

const config = HexConfig(
  bytesPerLine: 16,
  groupSize: 8,
  showOffset: true,
  showAscii: true,
  enableSelection: true,
  enableCopy: true,
  colorScheme: ByteColorScheme.fromTheme(theme),
);

See also:

• HexViewer which uses this configuration
• ByteColorScheme for color customization

Constructors

HexConfig() const

const HexConfig({
  int bytesPerLine = 16,
  int groupSize = 8,
  bool showOffset = true,
  bool showAscii = true,
  bool enableSelection = true,
  bool enableCopy = true,
  ByteColorScheme colorScheme = const ByteColorScheme.standard(),
})

Creates a hex viewer configuration.

All parameters are optional with sensible defaults suitable for most use cases.

Throws AssertionError if:

• bytesPerLine is not positive
• groupSize is negative
• groupSize exceeds bytesPerLine

Implementation

const HexConfig({
  this.bytesPerLine = 16,
  this.groupSize = 8,
  this.showOffset = true,
  this.showAscii = true,
  this.enableSelection = true,
  this.enableCopy = true,
  this.colorScheme = const ByteColorScheme.standard(),
}) : assert(bytesPerLine > 0, 'bytesPerLine must be positive'),
     assert(groupSize >= 0, 'groupSize must be non-negative'),
     assert(
       groupSize == 0 || groupSize <= bytesPerLine,
       'groupSize cannot exceed bytesPerLine',
     );

Properties

bytesPerLine final

final int bytesPerLine

Number of bytes displayed per line.

Common values:

• 8: Compact view for narrow screens
• 16: Standard hex editor layout (default)
• 32: Wide view for large displays

Must be positive. Defaults to 16.

Implementation

final int bytesPerLine;

colorScheme final

final ByteColorScheme colorScheme

Color scheme for different byte types.

Controls the visual appearance of:

• Null bytes (0x00)
• Printable ASCII (0x20-0x7E)
• Control characters (0x01-0x1F)
• Extended ASCII (0x80+)

Use ByteColorScheme.fromTheme to automatically adapt to the app theme. Defaults to ByteColorScheme.standard.

Implementation

final ByteColorScheme colorScheme;

enableCopy final

final bool enableCopy

Whether to enable copy to clipboard functionality.

When true, users can copy selected bytes in:

• Hex format (48 65 6C 6C 6F)
• Text format (Hello)
• Binary format (raw bytes)

Requires enableSelection to be true. Defaults to true.

Implementation

final bool enableCopy;

enableSelection final

final bool enableSelection

Whether to enable interactive byte selection.

When true, users can:

• Click bytes to select them
• Shift+click to extend selection
• See selection info in status bar

Defaults to true.

Implementation

final bool enableSelection;

groupSize final

final int groupSize

Size of byte groups for visual separation.

Controls how bytes are grouped with separators:

• 0: No grouping (48 65 6C 6C 6F)
• 4: Four-byte groups (48656C6C | 6F20576F)
• 8: Eight-byte groups (default, 48 65 6C 6C 6F 20 57 6F | 72 6C 64)

Must be 0 or less than bytesPerLine. Defaults to 8.

Example with groupSize=4 and bytesPerLine=16:

48656C6C | 6F20576F | 726C6421 | 0A000000

Implementation

final int groupSize;

hashCode no setter override

int get hashCode

The hash code for this object.

A hash code is a single integer which represents the state of the object that affects operator == comparisons.

All objects have hash codes. The default hash code implemented by Object represents only the identity of the object, the same way as the default operator == implementation only considers objects equal if they are identical (see identityHashCode).

If operator == is overridden to use the object state instead, the hash code must also be changed to represent that state, otherwise the object cannot be used in hash based data structures like the default Set and Map implementations.

Hash codes must be the same for objects that are equal to each other according to operator ==. The hash code of an object should only change if the object changes in a way that affects equality. There are no further requirements for the hash codes. They need not be consistent between executions of the same program and there are no distribution guarantees.

Objects that are not equal are allowed to have the same hash code. It is even technically allowed that all instances have the same hash code, but if clashes happen too often, it may reduce the efficiency of hash-based data structures like HashSet or HashMap.

If a subclass overrides hashCode, it should override the operator == operator as well to maintain consistency.

Implementation

@override
int get hashCode {
  return Object.hash(
    bytesPerLine,
    groupSize,
    showOffset,
    showAscii,
    enableSelection,
    enableCopy,
    colorScheme,
  );
}

runtimeType no setter inherited

Type get runtimeType

A representation of the runtime type of the object.

Inherited from Object.

Implementation

external Type get runtimeType;

showAscii final

final bool showAscii

Whether to display the ASCII column on the right.

When true, shows ASCII representation of bytes (printable characters or · for non-printable). Defaults to true.

Implementation

final bool showAscii;

showOffset final

final bool showOffset

Whether to display the offset column on the left.

When true, shows addresses like 00000000, 00000010, etc. Defaults to true.

Implementation

final bool showOffset;

Methods

copyWith()

HexConfig copyWith({
  int? bytesPerLine,
  int? groupSize,
  bool? showOffset,
  bool? showAscii,
  bool? enableSelection,
  bool? enableCopy,
  ByteColorScheme? colorScheme,
})

Creates a copy of this configuration with the given fields replaced.

Example:

final newConfig = config.copyWith(
  bytesPerLine: 32,
  groupSize: 16,
);

Implementation

HexConfig copyWith({
  int? bytesPerLine,
  int? groupSize,
  bool? showOffset,
  bool? showAscii,
  bool? enableSelection,
  bool? enableCopy,
  ByteColorScheme? colorScheme,
}) {
  return HexConfig(
    bytesPerLine: bytesPerLine ?? this.bytesPerLine,
    groupSize: groupSize ?? this.groupSize,
    showOffset: showOffset ?? this.showOffset,
    showAscii: showAscii ?? this.showAscii,
    enableSelection: enableSelection ?? this.enableSelection,
    enableCopy: enableCopy ?? this.enableCopy,
    colorScheme: colorScheme ?? this.colorScheme,
  );
}

noSuchMethod() inherited

dynamic noSuchMethod(Invocation invocation)

Invoked when a nonexistent method or property is accessed.

A dynamic member invocation can attempt to call a member which doesn't exist on the receiving object. Example:

dynamic object = 1;
object.add(42); // Statically allowed, run-time error

This invalid code will invoke the noSuchMethod method of the integer 1 with an Invocation representing the .add(42) call and arguments (which then throws).

Classes can override noSuchMethod to provide custom behavior for such invalid dynamic invocations.

A class with a non-default noSuchMethod invocation can also omit implementations for members of its interface. Example:

class MockList<T> implements List<T> {
  noSuchMethod(Invocation invocation) {
    log(invocation);
    super.noSuchMethod(invocation); // Will throw.
  }
}
void main() {
  MockList().add(42);
}

This code has no compile-time warnings or errors even though the MockList class has no concrete implementation of any of the List interface methods. Calls to List methods are forwarded to noSuchMethod, so this code will log an invocation similar to Invocation.method(#add, [42]) and then throw.

If a value is returned from noSuchMethod, it becomes the result of the original invocation. If the value is not of a type that can be returned by the original invocation, a type error occurs at the invocation.

The default behavior is to throw a NoSuchMethodError.

Inherited from Object.

Implementation

@pragma("vm:entry-point")
@pragma("wasm:entry-point")
external dynamic noSuchMethod(Invocation invocation);

toString() inherited

String toString()

A string representation of this object.

Some classes have a default textual representation, often paired with a static parse function (like int.parse). These classes will provide the textual representation as their string representation.

Other classes have no meaningful textual representation that a program will care about. Such classes will typically override toString to provide useful information when inspecting the object, mainly for debugging or logging.

Inherited from Object.

Implementation

external String toString();

Operators

operator ==() override

bool operator ==(Object other)

The equality operator.

The default behavior for all Objects is to return true if and only if this object and other are the same object.

Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:

• Total: It must return a boolean for all arguments. It should never throw.

• Reflexive: For all objects o, o == o must be true.

• Symmetric: For all objects o1 and o2, o1 == o2 and o2 == o1 must either both be true, or both be false.

• Transitive: For all objects o1, o2, and o3, if o1 == o2 and o2 == o3 are true, then o1 == o3 must be true.

The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.

If a subclass overrides the equality operator, it should override the hashCode method as well to maintain consistency.

Implementation

@override
bool operator ==(Object other) {
  if (identical(this, other)) return true;
  return other is HexConfig &&
      other.bytesPerLine == bytesPerLine &&
      other.groupSize == groupSize &&
      other.showOffset == showOffset &&
      other.showAscii == showAscii &&
      other.enableSelection == enableSelection &&
      other.enableCopy == enableCopy &&
      other.colorScheme == colorScheme;
}