update

Bouncing animation added

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.0.2
+
+* Bouncing animation added
+
 ## 0.0.1
 
 * Initial release.

example/lib/main.dart

@@ -1,4 +1,4 @@
-import 'package:auto_scroll_text/auto_scroll_text.dart';
+import 'package:auto_scroll_text/auto_scroll_text_impl.dart';
 import 'package:flutter/material.dart';
 
 //  Created by Bomsamdi on 2022
@@ -49,6 +49,12 @@ class _MyHomePageState extends State<MyHomePage> {
             ElevatedButton(
                 onPressed: _openVertical,
                 child: const Text("Open VERTICAL example")),
+            ElevatedButton(
+                onPressed: _openBouncingHorizontal,
+                child: const Text("Open BOUNCING HORIZONTAL example")),
+            ElevatedButton(
+                onPressed: _openBouncingVertical,
+                child: const Text("Open BOUNCING VERTICAL example")),
           ],
         ),
       ),
@@ -66,6 +72,18 @@ class _MyHomePageState extends State<MyHomePage> {
       builder: (context) => const VerticalExample(),
     ));
   }
+
+  void _openBouncingHorizontal() {
+    Navigator.of(context).push(MaterialPageRoute(
+      builder: (context) => const BouncingHorizontalExample(),
+    ));
+  }
+
+  void _openBouncingVertical() {
+    Navigator.of(context).push(MaterialPageRoute(
+      builder: (context) => const BouncingVerticalExample(),
+    ));
+  }
 }
 
 class HorizontalExample extends StatefulWidget {
@@ -88,9 +106,8 @@ class _HorizontalExampleState extends State<HorizontalExample> {
           crossAxisAlignment: CrossAxisAlignment.stretch,
           children: const <Widget>[
             AutoScrollText(
-              text:
+              "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.",
-                  "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.",
+              style: TextStyle(fontSize: 24),
-              textStyle: TextStyle(fontSize: 24),
             ),
           ],
         ),
@@ -119,10 +136,74 @@ class _VerticalExampleState extends State<VerticalExample> {
           crossAxisAlignment: CrossAxisAlignment.stretch,
           children: const <Widget>[
             AutoScrollText(
-              text:
+              "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.",
-                  "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.",
+              style: TextStyle(fontSize: 24),
-              textStyle: TextStyle(fontSize: 24),
+              scrollDirection: Axis.vertical,
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class BouncingHorizontalExample extends StatefulWidget {
+  const BouncingHorizontalExample({Key? key}) : super(key: key);
+
+  @override
+  State<BouncingHorizontalExample> createState() =>
+      _BouncingHorizontalExampleState();
+}
+
+class _BouncingHorizontalExampleState extends State<BouncingHorizontalExample> {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text("Bouncing Horizontal Example"),
+      ),
+      body: Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: const <Widget>[
+            AutoScrollText(
+              "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.",
+              style: TextStyle(fontSize: 24),
+              mode: AutoScrollTextMode.bouncing,
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class BouncingVerticalExample extends StatefulWidget {
+  const BouncingVerticalExample({Key? key}) : super(key: key);
+
+  @override
+  State<BouncingVerticalExample> createState() =>
+      _BouncingVerticalExampleState();
+}
+
+class _BouncingVerticalExampleState extends State<BouncingVerticalExample> {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text("Bouncing Vertical Example"),
+      ),
+      body: Center(
+        child: Row(
+          mainAxisAlignment: MainAxisAlignment.center,
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: const <Widget>[
+            AutoScrollText(
+              "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.",
+              style: TextStyle(fontSize: 24),
               scrollDirection: Axis.vertical,
+              mode: AutoScrollTextMode.bouncing,
             ),
           ],
         ),

example/pubspec.lock

@@ -14,7 +14,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "0.0.1"
+    version: "0.0.2"
   boolean_selector:
     dependency: transitive
     description:

lib/after_layout_mixin.dart

@@ -1,18 +0,0 @@
-import 'dart:async';
-//  Created by Bomsamdi on 2022
-//  Copyright © 2022 Bomsamdi. All rights reserved.
-import 'package:flutter/widgets.dart';
-
-mixin AfterLayoutMixin<T extends StatefulWidget> on State<T> {
-  @override
-  void initState() {
-    super.initState();
-    WidgetsBinding.instance.endOfFrame.then(
-      (_) {
-        if (mounted) afterFirstLayout(context);
-      },
-    );
-  }
-
-  FutureOr<void> afterFirstLayout(BuildContext context);
-}

lib/auto_scroll_text.dart

@@ -1,148 +1,429 @@
-library auto_scroll_text;
-
 //  Created by Bomsamdi on 2022
 //  Copyright © 2022 Bomsamdi. All rights reserved.
 import 'dart:async';
+
+import 'package:auto_scroll_text/auto_scroll_text_mode.dart';
 import 'package:flutter/material.dart';
-import 'after_layout_mixin.dart';
 
-/// [AutoScrollText] is a solution when you need
+/// AutoScrollText widget automatically scrolls provided [text]
-/// text widget for long texts without overlaping or overflow.elipsis
+///
-/// [AutoScrollText] supports both directions [Axis.horizontal] and [Axis.vertical]
+/// ### Example:
+///
+/// ```dart
+/// AutoScrollText(
+///     "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.",
+///     mode: AutoScrollTextMode.bouncing,
+///     velocity: Velocity(pixelsPerSecond: Offset(150, 0)),
+///     delayBefore: Duration(milliseconds: 500),
+///     numberOfReps: 5,
+///     pauseBetween: Duration(milliseconds: 50),
+///     style: TextStyle(color: Colors.green),
+///     textAlign: TextAlign.right,
+///     selectable: true,
+///     scrollDirection: Axis.horizontal,
+///     curve: Curves.linear,
+/// )
+/// ```
 class AutoScrollText extends StatefulWidget {
-  /// [Text.text] of [AutoScrollText]
+  const AutoScrollText(
+    this.text, {
+    Key? key,
+    this.style,
+    this.textAlign,
+    this.textDirection = TextDirection.ltr,
+    this.numberOfReps,
+    this.delayBefore,
+    this.pauseBetween,
+    this.mode = AutoScrollTextMode.endless,
+    this.velocity = const Velocity(pixelsPerSecond: Offset(80, 0)),
+    this.selectable = false,
+    this.intervalSpaces,
+    this.scrollDirection = Axis.horizontal,
+    this.curve = Curves.linear,
+  }) : super(key: key);
+
+  /// The text string, that would be scrolled.
+  /// In case text does fit into allocated space, it wouldn't be scrolled
+  /// and would be shown as is.
+  ///
+  /// ### Example:
+  ///
+  /// ```dart
+  /// AutoScrollText('A sample text for AutoScrollText widget.')
+  /// ```
   final String text;
 
-  /// [TextStyle] of [Text]
+  /// Provides [TextAlign] alignment if text string is not long enough to be scrolled.
-  final TextStyle? textStyle;
+  ///
+  /// ### Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'Short text',
+  ///   textAlign: TextAlign.right,
+  /// )
+  /// ```
+  final TextAlign? textAlign;
 
-  /// [SingleChildScrollView.scrollDirection] default value [Axis.horizontal]
+  /// Provides [TextDirection] - a direction in which text flows.
-  final Axis scrollDirection;
+  /// Default is [TextDirection.ltr].
+  /// Default scrolling direction would be opposite to [textDirection],
+  /// e.g. for [TextDirection.rtl] scrolling would be from left to right
+  ///
+  /// ### Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'This is a RTL text. This is a RTL text. This is a RTL text. This is a RTL text. ',
+  ///   textDirection: TextDirection.rtl,
+  /// )
+  /// ```
+  final TextDirection textDirection;
 
-  /// [Curve] of scroll animation
+  /// Allows to apply custom [TextStyle] to [text].
-  final Curve curve;
+  ///
+  /// `null` by default.
+  ///
+  /// ### Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'Text with TextStyle',
+  ///   style: TextStyle(
+  ///     color: Colors.white,
+  ///   ),
+  /// )
+  /// ```
+  final TextStyle? style;
 
-  /// Distance per tick
+  /// Limits number of scroll animation rounds.
-  final double moveDistance;
+  ///
+  /// Default is [infinity].
+  ///
+  /// ### Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'Limit scroll rounds to 10',
+  ///   numberOfReps: 10,
+  /// )
+  /// ```
+  final int? numberOfReps;
 
-  /// Reset timer
+  /// Delay before first animation round.
-  final int timerRest;
+  ///
+  /// Default is [Duration.zero].
+  ///
+  /// ### Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'Start animation after 1 sec delay',
+  ///   delayBefore: Duration(seconds: 1),
+  /// )
+  /// ```
+  final Duration? delayBefore;
 
-  const AutoScrollText({
+  /// Determines pause interval between animation rounds.
-    super.key,
+  ///
-    required this.text,
+  /// Only allowed if [mode] is set to [AutoScrollTextMode.bouncing].
-    this.textStyle,
+  ///
-    this.scrollDirection = Axis.horizontal,
+  /// Default is [Duration.zero].
-    this.curve = Curves.linear,
+  ///
-    this.moveDistance = 3.0,
+  /// ### Example:
-    this.timerRest = 100,
+  ///
-  });
+  /// ```dart
+  /// AutoScrollText(
+  ///   'Text with pause between animations',
+  ///   mode: AutoScrollTextMode.bouncing,
+  ///   pauseBetween: Duration(milliseconds: 300),
+  /// )
+  /// ```
+  final Duration? pauseBetween;
 
-  @override
+  /// Sets one of two different types of scrolling behavior.
-  State<StatefulWidget> createState() {
+  /// [AutoScrollTextMode.endless] - default, scrolls text in one direction endlessly.
-    return AutoScrollTextState();
+  /// [AutoScrollTextMode.bouncing] - when [text] string is scrolled to its end,
-  }
+  /// starts animation to opposite direction.
-}
+  ///
-
+  /// ### Example:
-class AutoScrollTextState extends State<AutoScrollText>
+  ///
-    with SingleTickerProviderStateMixin, AfterLayoutMixin {
+  /// ```dart
-  /// Final text for scrolling
+  /// AutoScrollText(
-  String textToScroll = "";
+  ///   'Animate text string back and forth',
+  ///   mode: AutoScrollTextMode.bouncing,
+  /// )
+  /// ```
+  final AutoScrollTextMode mode;
 
-  /// SingleChildScrollView controller
+  /// Allows to customize animation speed.
-  final ScrollController _scrollController = ScrollController();
+  ///
+  /// Default is `Velocity(pixelsPerSecond: Offset(80, 0))`
+  ///
+  /// ### Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'Text with animation of 100px per second',
+  ///   velocity: Velocity(pixelsPerSecond: Offset(100, 0)),
+  /// )
+  final Velocity velocity;
 
-  /// Actual position of scroll
+  /// Allows users to select provided [text], copy it to clipboard etc.
-  double position = 0.0;
+  ///
+  /// Default is `false`.
+  ///
+  /// Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'This text is has possibility to select and copy it to clipboard',
+  ///   selectable: true,
+  /// )
+  /// ```
+  final bool selectable;
 
-  /// Repeatable timer
+  /// Adds blank spaces between two nearby text sentences
-  Timer? timer;
+  /// in case of [AutoScrollTextMode.endless]
+  ///
+  /// Default is `1`.
+  ///
+  /// Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'This is the sample text for AutoScrollText widget. ',
+  ///   blankSpaces: 10,
+  /// )
+  /// ```
+  final int? intervalSpaces;
 
-  /// if text is to long for axis, define auto scroll action
+  /// Allows users to define scrollDirection of [AutoScrollText]
-  bool _isScrollable = false;
+  ///
+  /// Default is [Axis.horizontal].
+  ///
+  /// Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'Text with vertical scroll direction',
+  ///   scrollDirection: Axis.vertical,
+  /// )
+  /// ```
+  final Axis scrollDirection;
 
-  /// SingleChildScrollView key
+  /// [Curve] of scroll animation
-  final GlobalKey _scrollKey = GlobalKey();
+  /// Allows users to define [Curve] of animation for [AutoScrollText]
+  ///
+  /// Default is [Curves.linear].
+  ///
+  /// Example:
+  ///
+  /// ```dart
+  /// AutoScrollText(
+  ///   'Text with linear animation,
+  ///   curve: Curves.linear,
+  /// )
+  /// ```
+  final Curve curve;
 
-  /// Default [TextStyle] if [widget.textStyle] is null
+  @override
-  TextStyle get defaultTextStyle => const TextStyle();
+  State<AutoScrollText> createState() => _AutoScrollTextState();
+}
 
+class _AutoScrollTextState extends State<AutoScrollText> {
+  final _scrollController = ScrollController();
+  String _text = "";
+  String? _endlessText;
+  double? _originalTextWidth;
+  Timer? _timer;
+  bool _running = false;
+  int _counter = 0;
   @override
   void initState() {
-    textToScroll = widget.text;
     super.initState();
-  }
+    if (widget.scrollDirection == Axis.vertical) {
-
+      String newString = widget.text.split("").join("\n");
-  /// Timer for animation
+      _text = newString;
-  void _startTimer() {
+    } else {
-    if (_scrollKey.currentContext != null) {
+      _text = widget.text;
-      timer = Timer.periodic(Duration(milliseconds: widget.timerRest), (timer) {
-        double maxScrollExtent = _scrollController.position.maxScrollExtent;
-        double pixels = _scrollController.position.pixels;
-        if (pixels + widget.moveDistance >= maxScrollExtent) {
-          position = 0;
-          _scrollController.jumpTo(position);
-        }
-        position += widget.moveDistance;
-        _scrollController.animateTo(position,
-            duration: Duration(milliseconds: widget.timerRest),
-            curve: widget.curve);
-      });
     }
+    final WidgetsBinding binding = WidgetsBinding.instance;
+    binding.addPostFrameCallback(_initScroll);
   }
 
-  /// Check if autoscroll animation is needed
+  @override
-  void _checkIsAutoScrollNeeded() {
+  void didUpdateWidget(covariant AutoScrollText oldWidget) {
-    setState(() {
+    _onUpdate(oldWidget);
-      _isScrollable = _scrollController.position.maxScrollExtent > 0;
+    super.didUpdateWidget(oldWidget);
-    });
-  }
-
-  /// Text builder
-  Widget _text() {
-    if (widget.scrollDirection == Axis.vertical) {
-      String newString = textToScroll.split("").join("\n");
-      return Text(
-        newString,
-        style: widget.textStyle ?? defaultTextStyle,
-        textAlign: TextAlign.center,
-      );
-    }
-    return Text(
-      textToScroll,
-      style: widget.textStyle ?? defaultTextStyle,
-      textAlign: TextAlign.justify,
-    );
   }
 
   @override
   void dispose() {
+    _timer?.cancel();
     super.dispose();
-    // dispose timer when needed
-    timer?.cancel();
   }
 
   @override
   Widget build(BuildContext context) {
-    return SingleChildScrollView(
+    assert(
-      key: _scrollKey,
+        widget.pauseBetween == null ||
-      scrollDirection: widget.scrollDirection,
+            widget.mode == AutoScrollTextMode.bouncing,
-      controller: _scrollController,
+        'pauseBetween is only available in AutoScrollTextMode.bouncing mode');
-      physics: _isScrollable
+    assert(
-          ? const AlwaysScrollableScrollPhysics()
+        widget.intervalSpaces == null ||
-          : const NeverScrollableScrollPhysics(),
+            widget.mode == AutoScrollTextMode.endless,
-      child: _text(),
+        'intervalSpaces is only available in AutoScrollTextMode.endless mode');
+    return Directionality(
+      textDirection: widget.textDirection,
+      child: Scrollbar(
+        controller: _scrollController,
+        thickness: 0,
+        child: SingleChildScrollView(
+          controller: _scrollController,
+          scrollDirection: widget.scrollDirection,
+          child: widget.selectable
+              ? SelectableText(
+                  _endlessText ?? _text,
+                  style: widget.style,
+                  textAlign: widget.textAlign,
+                )
+              : Text(
+                  _endlessText ?? _text,
+                  style: widget.style,
+                  textAlign: widget.textAlign,
+                ),
+        ),
+      ),
     );
   }
 
-  @override
+  Future<void> _initScroll(_) async {
-  FutureOr<void> afterFirstLayout(BuildContext context) {
+    await _delayBeforeStartAnimation();
-    _checkIsAutoScrollNeeded();
+    _timer = Timer.periodic(const Duration(milliseconds: 50), (timer) {
-    if (_isScrollable) {
+      if (!_available) {
+        timer.cancel();
+        return;
+      }
+      final int? maxReps = widget.numberOfReps;
+      if (maxReps != null && _counter >= maxReps) {
+        timer.cancel();
+        return;
+      }
+      if (!_running) _runAnimation();
+    });
+  }
+
+  Future<void> _runAnimation() async {
+    _running = true;
+    final int? maxReps = widget.numberOfReps;
+    if (maxReps == null || _counter < maxReps) {
+      _counter++;
+      switch (widget.mode) {
+        case AutoScrollTextMode.bouncing:
+          {
+            await _animateBouncing();
+            break;
+          }
+        default:
+          {
+            await _animateEndless();
+          }
+      }
+    }
+    _running = false;
+  }
+
+  Future<void> _animateEndless() async {
+    if (!_available) return;
+    final ScrollPosition position = _scrollController.position;
+    final bool needsScrolling = position.maxScrollExtent > 0;
+    if (!needsScrolling) {
+      if (_endlessText != null) setState(() => _endlessText = null);
+      return;
+    }
+    if (_endlessText == null || _originalTextWidth == null) {
       setState(() {
-        textToScroll = "     $textToScroll     ";
+        _originalTextWidth =
+            position.maxScrollExtent + position.viewportDimension;
+        _endlessText = _text + _getSpaces(widget.intervalSpaces ?? 1) + _text;
       });
-      _startTimer();
+      return;
+    }
+    final double endlessTextWidth =
+        position.maxScrollExtent + position.viewportDimension;
+    final double singleRoundExtent = endlessTextWidth - _originalTextWidth!;
+    final Duration duration = _getDuration(singleRoundExtent);
+    if (duration == Duration.zero) return;
+    if (!_available) return;
+    await _scrollController.animateTo(
+      singleRoundExtent,
+      duration: duration,
+      curve: widget.curve,
+    );
+    if (!_available) return;
+    _scrollController.jumpTo(position.minScrollExtent);
+  }
+
+  Future<void> _animateBouncing() async {
+    final double maxExtent = _scrollController.position.maxScrollExtent;
+    final double minExtent = _scrollController.position.minScrollExtent;
+    final double extent = maxExtent - minExtent;
+    final Duration duration = _getDuration(extent);
+    if (duration == Duration.zero) return;
+    if (!_available) return;
+    await _scrollController.animateTo(
+      maxExtent,
+      duration: duration,
+      curve: widget.curve,
+    );
+    if (!_available) return;
+    await _scrollController.animateTo(
+      minExtent,
+      duration: duration,
+      curve: widget.curve,
+    );
+    if (!_available) return;
+    if (widget.pauseBetween != null) {
+      await Future<dynamic>.delayed(widget.pauseBetween!);
     }
   }
+
+  Future<void> _delayBeforeStartAnimation() async {
+    final Duration? delayBefore = widget.delayBefore;
+    if (delayBefore == null) return;
+    await Future<dynamic>.delayed(delayBefore);
+  }
+
+  Duration _getDuration(double extent) {
+    final int milliseconds =
+        (extent * 1000 / widget.velocity.pixelsPerSecond.dx).round();
+    return Duration(milliseconds: milliseconds);
+  }
+
+  void _onUpdate(AutoScrollText oldWidget) {
+    if (widget.text != oldWidget.text && _endlessText != null) {
+      setState(() {
+        _endlessText = null;
+        _originalTextWidth = null;
+        if (widget.scrollDirection == Axis.vertical) {
+          String newString = widget.text.split("").join("\n");
+          _text = newString;
+        } else {
+          _text = widget.text;
+        }
+      });
+      _scrollController.jumpTo(_scrollController.position.minScrollExtent);
+    }
+  }
+
+  String _getSpaces(int number) {
+    String spaces = '';
+    for (int i = 0; i < number; i++) {
+      spaces += '\u{00A0}';
+    }
+    return spaces;
+  }
+
+  bool get _available => mounted && _scrollController.hasClients;
 }

lib/auto_scroll_text_impl.dart

@@ -0,0 +1,4 @@
+library auto_scroll_text;
+
+export 'package:auto_scroll_text/auto_scroll_text.dart';
+export 'package:auto_scroll_text/auto_scroll_text_mode.dart';

lib/auto_scroll_text_mode.dart

@@ -0,0 +1,11 @@
+//  Created by Bomsamdi on 2022
+//  Copyright © 2022 Bomsamdi. All rights reserved.
+
+/// Animation types for [AutoScrollText] widget.
+/// [endless] - scrolls text in one direction endlessly.
+/// [bouncing] - when text is scrolled to its end,
+/// starts animation to opposite direction.
+enum AutoScrollTextMode {
+  bouncing,
+  endless,
+}

pubspec.yaml

@@ -1,6 +1,6 @@
 name: auto_scroll_text
 description: AutoScrollText is package for users which need a single line text widget without overlaping or TextOverflow.elipsis for long texts.
-version: 0.0.1
+version: 0.0.2
 homepage: https://github.com/Bomsamdi/auto_scroll_text
 
 environment: