Flutter

How to implement Flood-fill algorithms?

由 岁酱吖の 提交于 2021-02-09 09:02:52
问题 I am working on one Paint application wherein I am implementing BucketFill functionality similar to MS paint application. I have coded it using a couple of FloodFill algorithms but the filling color process is taking too much time. I am not pretty sure reasons behind it may happen due to the low cache memory, poor algorithm, or it may be taking a lot of time calculating offsets. Can someone help me out with your Knowledge in Flutter/Dart? Algorithms tried: Recursion Based Approach(4 or 8

How to implement Flood-fill algorithms?

由 谁说我不能喝 提交于 2021-02-09 09:01:38
问题 I am working on one Paint application wherein I am implementing BucketFill functionality similar to MS paint application. I have coded it using a couple of FloodFill algorithms but the filling color process is taking too much time. I am not pretty sure reasons behind it may happen due to the low cache memory, poor algorithm, or it may be taking a lot of time calculating offsets. Can someone help me out with your Knowledge in Flutter/Dart? Algorithms tried: Recursion Based Approach(4 or 8

How to implement Flood-fill algorithms?

由 我的未来我决定 提交于 2021-02-09 09:01:09
问题 I am working on one Paint application wherein I am implementing BucketFill functionality similar to MS paint application. I have coded it using a couple of FloodFill algorithms but the filling color process is taking too much time. I am not pretty sure reasons behind it may happen due to the low cache memory, poor algorithm, or it may be taking a lot of time calculating offsets. Can someone help me out with your Knowledge in Flutter/Dart? Algorithms tried: Recursion Based Approach(4 or 8

How Use shared preference with injectable and get_it in flutter?

由 江枫思渺然 提交于 2021-02-09 08:59:12
问题 im using injectable and get_it package in flutter i have a shared preference class : @LazySingleton() class SharedPref { final String _token = 'token'; SharedPreferences _pref; SharedPref(this._pref); Future<String> getToken() async { return _pref.getString(_token) ?? ''; } Future<void> setToken(String token) async { await _pref.setString(_token, token); } } this class inject as LazySingleton and i have a module for inject the shared preference : @module abstract class InjectableModule {

Flutter: get default context? or load assets without context?

由 无人久伴 提交于 2021-02-09 07:32:30
问题 I'm trying to load a json file in a class extending SearchDelegate to search through its content. I have a method to load this file: Future<void> loadCountryData() async { try { String data = await DefaultAssetBundle .of(context) .loadString("assets/data/countries.json"); _countries = json.decode(data); } catch (e) { print(e); } } Unfortunately this requires a Buildcontext (context) that seems only to be available in the SearchDelegate build methods (like buildActions, buildLeadings, etc),

Flutter: get default context? or load assets without context?

由 你。 提交于 2021-02-09 07:31:38
问题 I'm trying to load a json file in a class extending SearchDelegate to search through its content. I have a method to load this file: Future<void> loadCountryData() async { try { String data = await DefaultAssetBundle .of(context) .loadString("assets/data/countries.json"); _countries = json.decode(data); } catch (e) { print(e); } } Unfortunately this requires a Buildcontext (context) that seems only to be available in the SearchDelegate build methods (like buildActions, buildLeadings, etc),

How to handle searching Large Lists in Flutter?

由 柔情痞子 提交于 2021-02-09 05:13:21
问题 I want to ask how I should handle a large list in Flutter. My app gets super slow when I am at a data item that is really deep in the list which I am searching. My list is 70,000+ objects of a data structure large. The following is how I am "Searching" the list. Future<Iterable<SomeDataStruct>> _getAllData() async { return allData.where((a) => (a.dataTitle.toLowerCase().contains(querySearch.toLowerCase().trim()))); } Building the list using a ListView.builder inside of a FutureBuilder. When I

Flutter实现3D效果，一个字，炫！

由 淺唱寂寞╮ 提交于 2021-02-09 03:42:38
点击上方 " 程序员小乐 "关注, 星标或置顶一起成长 后台回复“ 大礼包 ”有惊喜礼包！ 关注订阅号「 程序员小乐 」，收看更多精彩内容 每日英文 It doesn't matter what others think of you ,What matters most is How you see yourself. 不要太在意别人如何看待你；最 为重要的是你如何看待你自己。 每日掏心话 世间没有不被评说的事，也没有不被猜测的人；依心而行，做真实漂亮的自己。生命是倒计时的；日子是顺着过的；人生是说不清的；命运是猜不透的；辉煌总会来的；霉头总会有的；命是必须信的。 来 自 ： 老孟Flutter | 责编：乐乐 链接：live.bilibili.com/21917305 后端架构师(ID:study_tech) 第 1084 次推文 往日回顾： 再见！Postman 正文 Flutter 中3D效果是通过Transform组件实现的，没有变换效果的实现： class TransformDemo extends StatelessWidget { @override Widget build (BuildContext context) { return Scaffold( appBar: AppBar( title: Text( '3D 变换Demo' ), ), body:

Flutter 实现酷炫的3D效果

由 戏子无情 提交于 2021-02-09 03:34:14
老孟导读：此文讲解3个酷炫的3D动画效果。 下面是要实现的效果： Flutter 中3D效果是通过 Transform 组件实现的，没有变换效果的实现： class TransformDemo extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text( '3D 变换Demo' ), ), body: Container( alignment: Alignment.center, color: Colors.white, child: Text( '3D 变换Demo' ), ), ); } } 通过 GestureDetector 组件添加滑动事件监听： @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text( '3D 变换Demo' ), ), body: GestureDetector( onPanUpdate: (details) { print ( ' $details ' ); }, child: Container( alignment: Alignment

how to add multiple ChangeNotifierProvider in same type in Flutter

由 谁都会走 提交于 2021-02-08 19:43:53
问题 Is it possible to add same type multiple ChangeNotifierProvider? return MultiProvider( providers: [ ChangeNotifierProvider<ValueNotifier<double>>( create: (_) => ValueNotifier<double>(0.0), ), ChangeNotifierProvider<ValueNotifier<double>>( create: (_) => ValueNotifier<double>(0.0), ), ], In my build method @override Widget build(BuildContext context) { ValueNotifier<double> firstNotifier = Provider.of(context, listen: true); ValueNotifier<double> secondNotifier = Provider.of(context, listen:
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