flutter/examples/stocks/lib/stock_data.dart
Eric Seidel 6b3840e384 Move image loading out of C++ into Dart
We already know how to talk to the network_service from Dart
via fetch.dart.  Might as well use that for Image loading
as well insetad of having ImageLoader do it.

As part of this I've renamed *ImageLoader to *ImageDecoder
and moved all the image loading logic into Dart.  This required
me to teach the idl system about mojo handles so that I could
pass the resulting MojoHandle from fetch.dart up through to
ImageDecoder.

R=abarth@chromium.org, jackson@google.com, hansmuller@google.com

Review URL: https://codereview.chromium.org/1173703002.
2015-06-09 12:14:13 -07:00

73 lines
1.8 KiB
Dart

// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'dart:convert';
import 'dart:math';
import 'package:sky/framework/net/fetch.dart';
// Snapshot from http://www.nasdaq.com/screening/company-list.aspx
// Fetched 2/23/2014.
// "Symbol","Name","LastSale","MarketCap","IPOyear","Sector","industry","Summary Quote",
// Data in stock_data.json
final Random _rng = new Random();
class Stock {
String symbol;
String name;
double lastSale;
String marketCap;
double percentChange;
Stock(this.symbol, this.name, this.lastSale, this.marketCap, this.percentChange);
Stock.fromFields(List<String> fields) {
// FIXME: This class should only have static data, not lastSale, etc.
// "Symbol","Name","LastSale","MarketCap","IPOyear","Sector","industry","Summary Quote",
lastSale = 0.0;
try{
lastSale = double.parse(fields[2]);
} catch(_) {}
symbol = fields[0];
name = fields[1];
marketCap = fields[4];
percentChange = (_rng.nextDouble() * 20) - 10;
}
}
class StockData {
List<List<String>> _data;
StockData(this._data);
void appendTo(List<Stock> stocks) {
for (List<String> fields in _data)
stocks.add(new Stock.fromFields(fields));
}
}
typedef void StockDataCallback(StockData data);
const _kChunkCount = 30;
class StockDataFetcher {
int _currentChunk = 0;
final StockDataCallback callback;
StockDataFetcher(this.callback) {
_fetchNextChunk();
}
void _fetchNextChunk() {
fetchBody('data/stock_data_${_currentChunk++}.json').then((Response response) {
String json = response.bodyAsString();
JsonDecoder decoder = new JsonDecoder();
callback(new StockData(decoder.convert(json)));
if (_currentChunk < _kChunkCount)
_fetchNextChunk();
});
}
}