The mapviewer project is a Dart web application with an index.html entry point that kicks off the application on main.dart:
main() async {
quakeMap = new MapDisplay(querySelector('#mapview'), width, height);
await quakeMap.loadImage();
featPlotter = new FeaturePlotter(width, height, quakeMap.mapCtx);
quakeMap.showPopup = showPopup;
quakeUpdate();
querySelector('#zoombtn').onClick.listen(zoomMap);
querySelector('#locatebtn').onClick.listen(locateUser);
querySelector('#sortbtn').onClick.listen(sortFeatures);
new Timer.periodic(new Duration(seconds: 60), quakeUpdate);
new Timer.periodic(new Duration(milliseconds: 100), animationUpdate);
}The MapDisplay class sets up the map on the web page (on the div element with the ID mapview) and the image is loaded in. Then, quakeUpdate() is called to ensure the initial display of the map and data on the page.
Once the initial display is handled, the Zoom button is connected to the zoomMap function. Then the two...