super_text_layout 0.1.15

Configurable, composable, extensible text display for Flutter.

example/lib/main.dart

import 'package:example/typing_robot.dart';
import 'package:flutter/material.dart';
import 'package:super_text_layout/super_text_layout.dart';
import 'package:super_text_layout/super_text_layout_logging.dart';

import 'rainbow_builder.dart';
import 'rainbow_character_supertext.dart';
import 'user_label_layer.dart';

void main() {
  initLoggers(
    Level.WARNING,
    {
      buildsLog,
      robotLog,
    },
  );

  runApp(const SuperTextExampleApp());
}

class SuperTextExampleApp extends StatelessWidget {
  const SuperTextExampleApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: 'Super Text Example',
      home: SuperTextExampleScreen(),
      debugShowCheckedModeBanner: false,
    );
  }
}

class SuperTextExampleScreen extends StatefulWidget {
  const SuperTextExampleScreen({Key? key}) : super(key: key);

  @override
  State<SuperTextExampleScreen> createState() => _SuperTextExampleScreenState();
}

class _SuperTextExampleScreenState extends State<SuperTextExampleScreen> with TickerProviderStateMixin {
  static const _text = TextSpan(
    text: _textMessage,
    style: _textStyle,
  );

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SingleChildScrollView(
        child: Center(
          child: ConstrainedBox(
            constraints: const BoxConstraints(maxWidth: 500),
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                _buildHeader("Welcome to super_text_layout"),
                // SuperTextWithSelection examples
                _buildSubHeader("SuperTextWithSelection Widget"),
                _buildDescription(
                    "SuperTextWithSelection is a product-level widget that renders text with traditional user selections. If you want to build a custom text decoration experience, see SuperText."),
                _buildSuperTextWithSelectionStaticSingle(),
                _buildSuperTextWithSelectionRobot(),
                _buildSuperTextWithSelectionStaticMulti(),
                const SizedBox(height: 48),
                // SuperText examples
                _buildSubHeader("SuperText Widget"),
                _buildDescription(
                    "SuperText is a platform, upon which you can build various text experiences. A SuperText widget allows you to build an arbitrary UI beneath the text, and above the text."),
                _buildCharacterRainbow(),
                _buildSingleCaret(),
                _buildSingleSelectionHighlight(),
                _buildSingleSelectionHighlightRainbow(),
                _buildComposingRegionUnderline(),
                _buildMultiUserSelections(),
                _buildEmptySelection(),
                const SizedBox(height: 48),
              ],
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildHeader(String text) {
    return Padding(
      padding: const EdgeInsets.only(top: 24, bottom: 8.0),
      child: Text(
        text,
        style: const TextStyle(
          color: Color(0xFF444444),
          fontSize: 24,
          fontWeight: FontWeight.bold,
        ),
      ),
    );
  }

  Widget _buildSubHeader(String text) {
    return Padding(
      padding: const EdgeInsets.only(top: 12, bottom: 8.0),
      child: Text(
        text,
        style: const TextStyle(
          color: Color(0xFF444444),
          fontSize: 18,
          fontWeight: FontWeight.bold,
        ),
      ),
    );
  }

  Widget _buildDescription(String text) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 16.0),
      child: Text(
        text,
        style: const TextStyle(
          color: Color(0xFF444444),
          fontSize: 14,
          height: 1.4,
        ),
      ),
    );
  }

  Widget _buildSuperTextWithSelectionRobot() {
    return _buildExampleContainer(
      child: const _TypingRobotExample(),
    );
  }

  Widget _buildSuperTextWithSelectionStaticSingle() {
    return _buildExampleContainer(
      child: SuperTextWithSelection.single(
        richText: _text,
        userSelection: const UserSelection(
          highlightStyle: _primaryHighlightStyle,
          caretStyle: _primaryCaretStyle,
          selection: TextSelection(baseOffset: 11, extentOffset: 21),
        ),
      ),
    );
  }

  Widget _buildSuperTextWithSelectionStaticMulti() {
    return _buildExampleContainer(
      child: SuperTextWithSelection.multi(
        richText: _text,
        userSelections: [
          const UserSelection(
            highlightStyle: _primaryHighlightStyle,
            caretStyle: _primaryCaretStyle,
            selection: TextSelection(baseOffset: 11, extentOffset: 21),
          ),
          UserSelection(
            highlightStyle: _johnHighlightStyle,
            caretStyle: _johnCaretStyle,
            selection: const TextSelection(baseOffset: 58, extentOffset: 65),
          ),
          UserSelection(
            highlightStyle: _sallyHighlightStyle,
            caretStyle: _sallyCaretStyle,
            selection: const TextSelection(baseOffset: 79, extentOffset: 120),
          ),
        ],
      ),
    );
  }

  Widget _buildCharacterRainbow() {
    return _buildExampleContainer(
      child: const CharacterRainbowSuperText(
        text: _text,
      ),
    );
  }

  Widget _buildSingleCaret() {
    return _buildExampleContainer(
      child: SuperText(
        richText: _text,
        layerAboveBuilder: (context, textLayout) {
          return Stack(
            children: [
              TextLayoutCaret(
                textLayout: textLayout,
                style: _primaryCaretStyle,
                position: const TextPosition(offset: 21),
              ),
            ],
          );
        },
      ),
    );
  }

  Widget _buildSingleSelectionHighlight() {
    return _buildExampleContainer(
      child: SuperText(
        richText: _text,
        layerAboveBuilder: (context, textLayout) {
          return Stack(
            children: [
              TextLayoutCaret(
                textLayout: textLayout,
                style: _primaryCaretStyle,
                position: const TextPosition(offset: 21),
              ),
            ],
          );
        },
        layerBeneathBuilder: (context, textLayout) {
          return Stack(
            children: [
              TextLayoutSelectionHighlight(
                textLayout: textLayout,
                style: _primaryHighlightStyle,
                selection: const TextSelection(baseOffset: 11, extentOffset: 21),
              ),
            ],
          );
        },
      ),
    );
  }

  Widget _buildSingleSelectionHighlightRainbow() {
    return _buildExampleContainer(
      child: SuperText(
        richText: _text,
        layerAboveBuilder: (context, textLayout) {
          return Stack(
            children: [
              RainbowBuilder(builder: (context, color) {
                return TextLayoutCaret(
                  textLayout: textLayout,
                  style: _primaryCaretStyle.copyWith(color: color),
                  position: const TextPosition(offset: 21),
                );
              }),
            ],
          );
        },
        layerBeneathBuilder: (context, textLayout) {
          return Stack(
            children: [
              RainbowBuilder(builder: (context, color) {
                return TextLayoutSelectionHighlight(
                  textLayout: textLayout,
                  style: _primaryHighlightStyle.copyWith(color: color.withOpacity(0.2)),
                  selection: const TextSelection(baseOffset: 11, extentOffset: 21),
                );
              }),
            ],
          );
        },
      ),
    );
  }

  Widget _buildComposingRegionUnderline() {
    return _buildExampleContainer(
      child: SuperText(
        richText: const TextSpan(
          text: "Can display underlines like the composing reg",
          style: _textStyle,
        ),
        layerBeneathBuilder: (context, textLayout) {
          return TextUnderlineLayer(
            textLayout: textLayout,
            style: const StraightUnderlineStyle(color: Colors.black),
            underlines: const [
              TextLayoutUnderline(
                range: TextSelection(baseOffset: 42, extentOffset: 45),
              ),
            ],
          );
        },
      ),
    );
  }

  Widget _buildMultiUserSelections() {
    return _buildExampleContainer(
      child: SuperText(
        richText: _text,
        layerAboveBuilder: (context, getTextLayout) {
          return MultiLayerBuilder([
            (context, textLayout) {
              return Stack(
                children: [
                  TextLayoutCaret(
                    textLayout: textLayout,
                    style: _primaryCaretStyle,
                    position: const TextPosition(offset: 21),
                  ),
                  TextLayoutCaret(
                    textLayout: textLayout,
                    style: _johnCaretStyle,
                    position: const TextPosition(offset: 65),
                  ),
                  TextLayoutCaret(
                    textLayout: textLayout,
                    style: _sallyCaretStyle,
                    position: const TextPosition(offset: 120),
                  ),
                ],
              );
            },
            (context, textLayout) {
              return Stack(
                children: [
                  TextLayoutUserLabel(
                    textLayout: textLayout,
                    style: _johnUserLabelStyle,
                    label: "John",
                    position: const TextPosition(offset: 65),
                  ),
                  TextLayoutUserLabel(
                    textLayout: textLayout,
                    style: _sallyUserLabelStyle,
                    label: "Sally",
                    position: const TextPosition(offset: 120),
                  ),
                ],
              );
            },
          ]).build(context, getTextLayout);
        },
        layerBeneathBuilder: (context, textLayout) {
          return Stack(
            children: [
              TextLayoutSelectionHighlight(
                textLayout: textLayout,
                style: _primaryHighlightStyle,
                selection: const TextSelection(baseOffset: 11, extentOffset: 21),
              ),
              TextLayoutSelectionHighlight(
                textLayout: textLayout,
                style: _johnHighlightStyle,
                selection: const TextSelection(baseOffset: 58, extentOffset: 65),
              ),
              TextLayoutSelectionHighlight(
                textLayout: textLayout,
                style: _sallyHighlightStyle,
                selection: const TextSelection(baseOffset: 79, extentOffset: 120),
              ),
            ],
          );
        },
      ),
    );
  }

  Widget _buildEmptySelection() {
    return _buildExampleContainer(
      child: SuperText(
        richText: const TextSpan(text: "", style: _textStyle),
        layerAboveBuilder: (context, textLayout) {
          return TextLayoutEmptyHighlight(
            textLayout: textLayout,
            style: _primaryHighlightStyle,
          );
        },
      ),
    );
  }

  Widget _buildExampleContainer({
    required Widget child,
  }) {
    return Container(
      margin: const EdgeInsets.only(top: 30.0, left: 24),
      padding: const EdgeInsets.only(top: 20.0, bottom: 20.0, left: 16.0),
      decoration: const BoxDecoration(
        border: Border(left: BorderSide(width: 5, color: Color(0xFFDDDDDD))),
      ),
      child: child,
    );
  }
}

class _TypingRobotExample extends StatefulWidget {
  const _TypingRobotExample({Key? key}) : super(key: key);

  @override
  _TypingRobotExampleState createState() => _TypingRobotExampleState();
}

class _TypingRobotExampleState extends State<_TypingRobotExample> {
  final _caretLink = LayerLink();
  late TextEditingController _controller;
  String _plainText = "";
  TextSpan _richText = const TextSpan(text: "", style: _textStyle);

  late TypingRobot _robot;

  @override
  void initState() {
    super.initState();
    _controller = TextEditingController()
      ..addListener(() {
        if (_controller.text != _plainText && mounted) {
          setState(() {
            _plainText = _controller.text;
            _richText = TextSpan(text: _plainText, style: _textStyle);
          });
        }
      });

    _robot = TypingRobot(
      textEditingController: _controller,
    )
      ..placeCaret(const TextPosition(offset: 0))
      ..typeText(_textMessage)
      ..start();
  }

  @override
  void dispose() {
    _robot.dispose();
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        SuperTextWithSelection.single(
          richText: _richText,
          userSelection: UserSelection(
            highlightStyle: _primaryHighlightStyle,
            caretStyle: _primaryCaretStyle,
            selection: _controller.selection,
            caretFollower: _caretLink,
          ),
        ),
        CompositedTransformFollower(
          link: _caretLink,
          followerAnchor: Alignment.centerLeft,
          targetAnchor: Alignment.centerRight,
          showWhenUnlinked: false,
          child: const UserLabel(
            label: "iRobot",
            style: UserLabelStyle(
              color: Colors.red,
            ),
          ),
        ),
      ],
    );
  }
}

const defaultSelectionColor = Color(0xFFACCEF7);

const _textMessage =
    "Welcome to super_text_layout, which provides a selection of text widgets that support custom carets, selection, and decoration.";

const _textStyle = TextStyle(
  color: Color(0xFF444444),
  fontFamily: 'Roboto',
  fontSize: 20,
  height: 1.4,
);

const _primaryCaretStyle = CaretStyle(
  width: 2.0,
  color: Colors.black,
);
const _primaryHighlightStyle = SelectionHighlightStyle(
  color: defaultSelectionColor,
);
const _johnCaretStyle = CaretStyle(
  width: 1.0,
  color: Colors.red,
);
final _johnHighlightStyle = SelectionHighlightStyle(
  color: Colors.red.withOpacity(0.5),
);
const _johnUserLabelStyle = UserLabelStyle(
  color: Colors.red,
  shape: RoundedRectangleBorder(
    borderRadius: BorderRadius.only(
      topLeft: Radius.circular(4),
      topRight: Radius.circular(16),
      bottomLeft: Radius.circular(16),
      bottomRight: Radius.circular(16),
    ),
  ),
);
const _sallyCaretStyle = CaretStyle(
  width: 2.0,
  color: Colors.purpleAccent,
);
final _sallyHighlightStyle = SelectionHighlightStyle(
  color: Colors.purpleAccent.withOpacity(0.5),
);
const _sallyUserLabelStyle = UserLabelStyle(
  color: Colors.purpleAccent,
  shape: RoundedRectangleBorder(
    borderRadius: BorderRadius.only(
      topLeft: Radius.circular(4),
      topRight: Radius.circular(16),
      bottomLeft: Radius.circular(16),
      bottomRight: Radius.circular(16),
    ),
  ),
);