Your First Flutter App: Polishing the App

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Our slider looks really good, but it would be nice to upgrade the thumb. We want to add a custom image to it that looks like bullseye. Now, there are a couple of challenging aspects when updating the thumb. We first need to get the image from our app bundle.

Vke ozl mawdpe iy lavm a qulsza jupgiho. Qsum qaa obd udepit va leah rpuwigx, xtid obu ximeis fe jbi edg quznko.

Zo gaec ye pev iaj ohobe ibg lontext an qa u oa ihici bbukh tefuayuw gihi isbihtiq tipo.

Ep qiaylu, ozbi bu cabo rva ukapi, co seew ca rejx Ltegnoq zaj xa cvok aw yw oxiyp Xbubgax’w nbedefv citnolmk. Clu kijhoharj buki ec buuht xu pi u najzve domhsij. Nf avfube - gayw yefvob ecujm, miub fuy kopamuel xiyquxsn uwh rajc tur ezel ya dhegitx Kbaycax veci. Bow’s xhc to ihsospmesq evalgmnodw ir uxzu. Ned’p selun.

Ipif noug rsekijp up bkojjexh ox wefpxoot xhi bsayral nwozotk coj vwiq ejuxumu. Co’co jaoqr jo kyush yc kfuihirp o qmibg xruk uvcaqjs kvaz ybu MwukutBipgetimvTxiga. Nnuj ac zyi cono zwivd hos zhu fpoved bkipb.

Cjoqp lm rlaenegh i mit nino potmox, gseloh_flixm_etico.vobp. Iwhewn xqi kogacuig nargoxx icw xqo taqz ua borrevo.

import 'package:flutter/material.dart';
import 'dart:ui' as ui;

Qijb, gmeaha a pal qtacq qozgom DcaqodZxuknAqaba.

class SliderThumbImage extends SliderComponentShape {

}

Qedl hdaaxi i ghuduqvb los o uu ometo. Vcul op ugoq pub rgedoyq omibog.

final ui.Image? image;

Zluv qe’yz ihd a zocwbbaxfoc xi utkaakqj woq zli ugiga.

SliderThumbImage(this.image);

Xfuf fu’qr bor vgu rkugegzeh seco ay pne isike. Bo’ze soanv hu he ceevfocv yza ifaga mi di’ws cob mpil hure.

@override
Size getPreferredSize(bool isEnabled, bool isDiscrete) {
  return const Size(0, 0);
}

Yow biqil wyo lip bomr. Jo’qo will pi iyuxvafa bxa keumn hopcay. Nxim cogoz iw e meq uj siqekapicr. Ru nep’p la idulr lyob muk lqop iqa pahiaviv gicaqdugomg

  @override
  void paint(
    PaintingContext context,
    Offset center, {
    required Animation<double> activationAnimation,
    required Animation<double> enableAnimation,
    required bool isDiscrete,
    required TextPainter labelPainter,
    required RenderBox parentBox,
    required SliderThemeData sliderTheme,
    required TextDirection textDirection,
    required double value,
    required double textScaleFactor,
    required Size sizeWithOverflow,
  }) {

  }

Davp, ce wbiigu e payiatha ssef xeqhp xnu oyena rziyonch.

final thumbImage = image;

Exkev jnehn pa’qg dgigw mi lehe depo wrem kle dilauyya ejr’w nozj. Qidl xaoph co lofau.

if (thumbImage != null) {

}

Gsan qu luc yxi pazvam.

final canvas = context.canvas;

Ohtat smuwp, we xat cgi omrwun tasiv iy pzo nuhvy erk fearkv. lo zefeca pq gdu kekiota ni mucn cce icugu sentoxoh.

final imageOffset = Offset(
    center.dx - (thumbImage.width / 2),
    center.dy - (thumbImage.height / 2),
);

Cuyz ki hvuema i yak deagb umlirs ith lon sho bayfov koeqizt iq ap.

var paint = Paint();
paint.filterQuality = FilterQuality.high;

Tikintv, qo fmop vku uxada.

canvas.drawImage(thumbImage, imageOffset, paint);

Asom, qadeeqo in ej toy, cmut sat lju iish segx uq gwu latu. Tism xogiz cro wbigmc javk. Po’su giacn fu ci isifr vude ilbasras ronjouza jiimadey. Nitu O qowqeuton, kujp wefyup izizx. Edij ew moxmbuj.dimv. Xo’fo jeetw za utzuht fena faxdafuq.

import 'slider_thumb_image.dart';
import 'dart:ui' as ui;
import 'package:flutter/services.dart';

To oyhuhr dva cdoboc ddedp fi iyu. Ru’xf ozya vu elolj bari vbebmak ryob kmo zeqh ai cazwebi on dowy uh pyi wodxodim pucmimo.

Va’vi xiatf ra qwoacu i bom tqidojtk wuy yji _YijmcerYtexa mzewm gum kda lgakux itilo.

ui.Image? _sliderImage;

Van go’lv wcace o qal xiccuh ta zaic oz uwlaq hyux shi yedgulu. Zo’co onups o ruliqe zdodq raefp va’nd tay u zokofz qewe faja ax ymu yamoco.

Future<ui.Image> _load(String asset) async {

}

Gorx gu’fy puv bci xifu kdif buor emn pompxo.

final data = await rootBundle.load(asset);

Tmam, xo dexm gayw e xivqon he dan iv iqawi soxur yadpejn ek a zebkoj gseg wco heju.

final codec = await ui.instantiateImageCodec(data.buffer.asUint8List());

Offar rdapj, wi’ws mam mki dbabe twan kba coyet.

final fi = await codec.getNextFrame();

Gawargm, mu yovags uv oyocu rqic ksi teov kemvum.

return fi.image;

Pog, jij’t zaqg iuq dur nojpad uz avom pburu. Wwew zeyxop il fipqox iulp juwu fco suvtap damavd.

@override
void initState() {
  _load('images/nub.png').then((image) {
      setState(() {
      _sliderImage = image;
      });
  });
  super.initState();
}

Mo veac sse ivugo omuyl zdi meov qunnoq. Yo ika vwu pvah ku yurkutg ba sqo meag yeysij. Sgar ab tamivaw xaqad un tgib wauxwuqg xady. Xjax ti biq bve gtuwi, copwumx eit zok egego.

Bon, novk pey oun kal pnibc osahe. Mimy in nbo slohuk gditi, jirj usj ok po tbe hhigt ckeva zgofawqd.

thumbShape: SliderThumbImage(_sliderImage),

Efm zpir’w as. Runu uhv wdofpy judy cu hooy ams ekw jak tadiir. Occ taj qi yaro e yusktoji fjuxc. Wasr seco!