Text Area

The textarea example demonstrates a simple Bubble Tea application using a textarea bubble.

Preview

Code

pkgs/artisanal/example/tui/examples/textarea/main.dart

/// Textarea example ported from Bubble Tea.
library;

import 'package:artisanal/bubbles.dart'
    as tui
    hide
        CodeBlockCommentDelimiters,
        CodeLanguageProfile,
        Column,
        CommonKeyBindings,
        EditBuffer,
        EditHistoryCoalescePredicate,
        EditHistoryController,
        EditHistoryMarkerBuilder,
        EditHistoryStateEquals,
        EditorCoreConfig,
        EditorState,
        GraphemePredicate,
        GraphemeReader,
        Help,
        KeyBinding,
        KeyMap,
        PasteMsg,
        Row,
        Spinner,
        SpinnerModel,
        SpinnerTickMsg,
        Spinners,
        Text,
        TextCommandResult,
        TextCursorCommandResult,
        TextDecorationLayerKey,
        TextDecorationRange,
        TextDiagnosticRange,
        TextDiagnosticSeverity,
        TextDocument,
        TextDocumentChange,
        TextDocumentEditResult,
        TextEditResult,
        TextExtmark,
        TextExtmarkOptions,
        TextExtmarkPositionRange,
        TextExtmarksController,
        TextHighlightRange,
        TextHitResult,
        TextLineCommandResult,
        TextLineDecoration,
        TextLineStateCommandExtensions,
        TextLineStateSnapshot,
        TextOffsetStateCommandExtensions,
        TextOffsetStateDocumentEditingExtensions,
        TextOffsetStateSnapshot,
        TextPasteChunk,
        TextPasteChunkStep,
        TextPasteController,
        TextPasteMode,
        TextPastePlan,
        TextPasteReference,
        TextPasteReferenceStore,
        TextPasteSession,
        TextPatternDiagnosticRule,
        TextPosition,
        TextPositionDiagnosticRange,
        TextSelection,
        TextSyntaxBuildResult,
        TextSyntaxChangeWindow,
        TextSyntaxDecorationPatch,
        TextSyntaxLineWindow,
        TextSyntaxProvider,
        TextSyntaxSession,
        TextSyntaxSnapshot,
        TextView,
        TextViewLine,
        TextViewport,
        TextVisualCursorPosition,
        UndoCommandDecoder,
        UndoCommandJournalEntry,
        UndoManager,
        UndoableCommand;

import 'package:artisanal/artisanal.dart' show Style, AnsiColor;
import 'package:artisanal/tui.dart' as tui;

class TextareaModel implements tui.Model {
  TextareaModel({required this.textarea, this.error, this.initCmd});

  factory TextareaModel.initial() {
    // #region textarea_usage
    final ta = tui.TextAreaModel(placeholder: 'Once upon a time...');
    final focusCmd = ta.focus();
    // #endregion
    return TextareaModel(textarea: ta, initCmd: focusCmd);
  }

  final tui.TextAreaModel textarea;
  final Object? error;
  final tui.Cmd? initCmd;

  @override
  tui.Cmd? init() => initCmd;

  @override
  (tui.Model, tui.Cmd?) update(tui.Msg msg) {
    final cmds = <tui.Cmd>[];

    if (msg is tui.KeyMsg) {
      final key = msg.key;
      if (key.type == tui.KeyType.escape) {
        textarea.blur();
        return (copyWith(textarea: textarea), null);
      }
      if (key.ctrl && key.runes.isNotEmpty && key.runes.first == 0x63) {
        return (this, tui.Cmd.quit());
      }
      if (!textarea.focused) {
        final focusCmd = textarea.focus();
        if (focusCmd != null) cmds.add(focusCmd);
      }
    }

    final (newTa, cmd) = textarea.update(msg);
    if (cmd != null) cmds.add(cmd);

    return (copyWith(textarea: newTa), _batch(cmds));
  }

  tui.Cmd? _batch(List<tui.Cmd> cmds) =>
      cmds.isEmpty ? null : tui.Cmd.batch(cmds);

  TextareaModel copyWith({
    tui.TextAreaModel? textarea,
    Object? error,
    tui.Cmd? initCmd,
  }) {
    return TextareaModel(
      textarea: textarea ?? this.textarea,
      error: error ?? this.error,
      initCmd: initCmd ?? this.initCmd,
    );
  }

  @override
  String view() {
    final errLine = error == null
        ? ''
        : '${Style().foreground(const AnsiColor(196)).render('$error')}\n\n';
    return 'Tell me a story.\n\n${textarea.view()}\n\n$errLine(ctrl+c to quit)\n\n';
  }
}

Future<void> main() async {
  await tui.runProgram(
    TextareaModel.initial(),
    options: const tui.ProgramOptions(altScreen: false, hideCursor: false),
  );
}

Run it

dart run pkgs/artisanal/example/tui/examples/textarea/main.dart