scientific_input

A Flutter package for parsing, validating, formatting, and displaying scientific notation such as 1.2e-3 and 1.2 × 10⁻³.

Example overview

Why this package?

scientific_input gives you a clean scientific-notation workflow without having to stitch together parsing, controller state, validation, formatting, and display widgets yourself.

  • Accept standard scientific input like 1.2e-3
  • Accept pasted readable input like 1.2 × 10⁻³
  • Keep written input or format on edit completion
  • Show readable × 10 previews with optional tooltips
  • Reuse the same formatting logic in editable and display-only widgets

This is particularly useful for applications that rely on precise magnitude handling, such as Life Cycle Assessment tools, sustainability platforms, environmental impact models, laboratory systems, and scientific dashboards, where values often span many orders of magnitude and must remain both readable and mathematically reliable.

What it accepts

  • Standard scientific notation like 1.2e-3 or 1.2E-3
  • Readable scientific notation like 1.2 × 10⁻³
  • Plain decimals like 12 when allowPlainDecimal is enabled

Installation

dependencies:
  scientific_input: ^1.0.0

Quick start

import 'package:scientific_input/scientific_input.dart';

final controller = ScientificNumberController(text: '1.2e-3');

ScientificNumberInputField(
  controller: controller,
  labelText: 'Value',
  hintText: 'e.g. -3.5e6',
  previewTooltipBuilder: (data) => data.value.toString(),
  onChanged: (value) {
    debugPrint('Parsed value: $value');
  },
);

Choose a setup

Use a controller when you need state

This is the best fit when you want parsed values, validation errors, or both the raw and readable forms of the input.

final controller = ScientificNumberController(text: '1.2e-3');

ScientificNumberInputField(
  controller: controller,
);

Let the field manage its own controller

This keeps simple forms lightweight. Pass validation and parsing options directly to the widget.

ScientificNumberInputField(
  labelText: 'Scientific value',
  minExponent: -12,
  maxExponent: 12,
);

Input modes

Keep written input

This is the default behavior. The field keeps the user's typed scientific text and shows a readable preview underneath.

ScientificNumberInputField(
  controller: ScientificNumberController(text: '1.2e-3'),
  labelText: 'Scientific value',
);

Format on finish

Opt in when you want the field itself to switch to the readable × 10 form after blur or submit.

final controller = ScientificNumberController(
  text: '3.4e5',
  formatOnEditingComplete: true,
);

ScientificNumberInputField(
  controller: controller,
  formatOnEditingComplete: true,
  showFormattedPreview: false,
);

Display-only text

Use ScientificNumberText anywhere you want formatted output without a text field.

ScientificNumberText(
  '1.2e4',
  selectable: true,
  tooltipBuilder: (data) => data.value.toString(),
);

Tooltips and full-value display

Both the input preview and the display-only widget support optional tooltips.

ScientificNumberInputField(
  previewTooltipBuilder: (data) => data.value.toString(),
);

ScientificNumberText(
  '5e6',
  tooltipBuilder: (data) => data.value.toString(),
);

Tooltip demo

Controller state

ScientificNumberController keeps the typed text, parsed value, normalized scientific string, and validation state together.

final controller = ScientificNumberController(
  text: '1.2 × 10⁻³',
  minExponent: -12,
  maxExponent: 12,
);

final double? value = controller.doubleValue; // 0.0012
final String? error = controller.errorText; // null when valid
final String? raw = controller.rawScientificText; // 1.2e-3
final String? pretty = controller.readableText; // 1.2 × 10⁻³

Validation and constraints

Validation can live on the controller or be passed directly to ScientificNumberInputField when it creates its own internal controller.

If you supply your own ScientificNumberController, put the validation options on the controller itself. If you do not supply a controller, pass them directly to ScientificNumberInputField.

ScientificNumberInputField(
  allowPlainDecimal: false,
  minValue: 1e-6,
  maxValue: 1e6,
  minExponent: -12,
  maxExponent: 12,
  validator: (details) {
    if (details.scientificText == '0e0') {
      return 'Zero is not allowed.';
    }
    return null;
  },
);

Preview customization

Use the preview hooks to change rendering, tooltips, semantics, or spacing.

ScientificNumberInputField(
  previewSpacing: 12,
  previewTooltipBuilder: (data) => data.value.toString(),
  previewSemanticsLabelBuilder: (data) => 'Parsed value ${data.value}',
  previewBuilder: (context, data) {
    return Text('Preview: ${data.formattedText}');
  },
);

Utilities

final strict = ScientificNumberParser.parse('1.2e-3'); // 0.0012
final permissive = ScientificNumberParser.tryParse('1.2 × 10⁻³'); // 0.0012
final components = ScientificNumberParser.tryParseComponents('-3.5e6');
final normalized = ScientificNumberParser.normalizeScientificString('1.2 × 10⁻³'); // 1.2e-3
final formatted = ScientificNumberFormatter.format('5e6'); // 5 × 10⁶
final readable = ScientificNumberFormatter.formatReadable('12'); // 12

Example app

The bundled example app includes dedicated demos for:

  • keeping written input
  • text-only display
  • tooltip and full-value display

Run it with:

cd example
flutter run

Or launch it on the web with:

cd example
flutter run -d chrome

Preview:

Animated demo

Libraries

scientific_input