Leaflet featureGroup with tracks fitbounds invalid - javascript

Is there a better way???
I am adding several tracks to a map (using leaflet-gpx plugin) and want to fit the maps to the bounds of all the added tracks.
By using a featureGroup layer to contain the tracks it is possible to used the fitBounds() method using the feature group.
However the featureGroup does not have a loaded event to trigger the fitBounds() and the map also doesn't seem to have a suitable trigger.
Calling fitBounds() directly on the map after it is rendered fails with 'invalid bounds' error. However delaying the call for about a second allows it to execute correctly.
I presume what is happening is that it takes time for all of the gpx layers in the group to be loaded and until that is complete the group can't return a valid set of bounds.
So using a setTimeout to delay the fitBounds() works, but causes some annoying flashing as the map re-renders itself. Is there a better way?
This works:
// mapname has been created and tracks have already been loaded into their individual layers
var tracksLayer = L.featureGroup([track1,track2,track3]);
tracksLayer.addTo(mapname);
//this works, with more and complex tracks you might need a longer timeout
setTimeout(function(){ mapname.fitBounds(tracksLayer.getBounds()); }, 1000);
// this however does not work
// mapname.on('load', function() { mapname.fitBounds(tracksLayer.getBounds());});
//nor does this despite the fact that by this stage the map has been created and the featureGroup added
// mapname.fitBounds(tracksLayer.getBounds());

Related

How Can I animate Bing map pushpins based on a live GPS feed

I have looked over the bing maps documentation trying to find an answer to my question. I would prefer to do everything using the bing maps api and not have to add a third party library if possible.
Question: How can I animate a pushpin to make a smooth transition from one set of gps coordinate(longitude/latitude) to another in order to simulate smooth movement of a Pushpin on Bing maps?
Question: can deleting an entire object out of the map.entities array waste enough resources to cause performance issues? If so how can I change the pushpin latitude and longitude properties without deleting the entire object?
Sample code of trying to change the pushpins properties without deleting the object out of the array. This code does not work… I am unsure why it is not working?
map.entities.get(theIndexOfThePushPin)._location.latitude = newLat;
map.entities.get(theIndexOfThePushPin)._location.longitude = newLon;
I create a pushpin like so - This works fine
map.entities.push(new Microsoft.Maps.Pushpin(new Microsoft.Maps.Location(lat, lon), {
text: text,
visible: true,
textOffset: new Microsoft.Maps.Point(0, 5)
}));
Pseudo code for my recursive angular $http call
function BusMoveGPSRefresh() {
$http.get(resourceURL)
.then(function (data) {
if ('if pushpins have not been created') {
//create pushpins...
}
} else {
//delete pushpins out of the array and then recreate them
//with updated lon/lat. Or just update existing objects lon/lat properties if possible?
}
}
BusMoveGPSRefresh();//after everything is done then go get more info and start again. recursion...
}, function (reason) {// if fail than do
console.log(reason);
console.log("This Is not Working!!! Dang!!");
});
}
Any insight into the problem would be greatly appreciated! Thanks!
I could not find a simple answer for adding animation. I did find a site that gave a step by step tutorial on a more in-depth answer on how to animate pushpins.
Answer: 1 -- tutorial on how to animate bing map pushpins
https://blogs.bing.com/maps/2014/08/07/bring-your-maps-to-life-creating-animations-with-bing-maps-javascript/
Answer: 2 -- this is how to update the pushpin location without deleting the pushpin object out of the entities array.
Instead of deleting the entire pushpin object find the pushpin index and then use the property "setLocation()" and then add a new location.
//check to make sure that the lat and lon have
//changed if it is still the same location do nothing. else update
if (map.entities.get(indexOfPushpin).getLocation().latitude != lat
|| map.entities.get(indexOfPushpin).getLocation().longitude != lon) {
map.entities.get(indexOfPushpin).setLocation(new Microsoft.Maps.Location(lat, lon));
}

How to get max zoom for maptype in location

On Google Maps' JS API reference page, it says that the method getMaxZoomAtLatLng:
Returns the maximum zoom level available at a particular LatLng for
the Satellite map type.
For some reason, the terrain maptype bottoms out at level 15 in Calgary (for example) but the Satellite maptype can go all the way to zoom 19. I have two map services running simulataneously, and I want the maps to be in sync, but they can't sync up if they can't reach the same zoom level.
So, basically I want to know when the terrain map (or any maptype) can't cope, and trigger some special case functions.
Is there a method, or an alternative, for getting the maximum zoom for a location for a specific map type (since the above mentioned method only works for Satellite)?
Well, one solution I've decided to go with in the meantime is to attach a zoom-end handler to my ArcGIS map (could easily do this with Leaflet as well) and a maptypeid_changed handler to the Google map.
So, for the ArcGIS map (eMap) I did this:
eMap.on('zoom-end', function (e) {
// map zooms are synced
gMap.setCenter(esri.geometry.webMercatorToGeographic(e.extent.getCenter()));
gMap.setZoom(e.level);
// if the google map couldn't do it, reset eMap
if (gMap.getZoom() !== e.level) {
eMap.setZoom(gMap.getZoom());
// runs the handler again
}
});
And if the google map was set to Satellite, then changed, it also needed to trigger the same check, so I forced it to execute another zoomEnd handler:
google.maps.event.addListener(gMap, 'maptypeid_changed', function () {
// for some reason, ESRI has issues setting zoom to current zoom
// so it has to run an initial check before calling zoomEnd
if (gMap.getZoom() !== eMap.getZoom()) {
eMap.setZoom(gMap.getZoom());
}
});
Hope this helps someone, but really, I'm looking forward to seeing a better solution than this. Seems like an awfully complicated approach to merely firing a function if Google's maptype can't reach a certain zoom level.

Openlayers initial extent

According to the OpenLayers documentation, the constructor, OpenLayers.Map(), allows for an additional property extent which is "The initial extent of the map" (see here).
However, I cannot get it to have any effect. I know I can set an initial extent by calling .zoomToExtent() after constructing the map. But I would like to use this extent property because I set a zoomend event in the eventListeners property but don't want it to trigger with an initial call to .zoomToExtent(). Does anyone have a clue how to use this extent property?
This is the code that isn't working
map = new OpenLayers.Map('map',{
extent: bounds,
layers: [osmLayer,vectorLayer],
projection: "EPSG:900913",
eventListeners: {
zoomend: function() {
//..zoomend event listener code
}
}
});
In the above example:
bounds is a valid OpenLayers.Bounds object
osmLayer and vectorLayer are valid OpenLayers.Layer objects of which osmLayer is the base layer.
What happens with above code is that the map is completely zoomed out (in fact you can't actually see anything) and any attempts to pan results in errors being thrown. To get to map into a correct state the user has to zoom in and then panning works again and you can see the map.
I'm afraid I'm not sure off-handedly how to make the code you listed work, however the following alternative has worked for me:
map = new OpenLayers.Map('map',{projection: new OpenLayers.Projection("EPSG:4326")});
//ADD A BUNCH OF LAYERS AND SUCH HERE
//Set map center to this location at this zoom level
map.setCenter(new OpenLayers.LonLat(-93.9196,45.7326),5);
As a last resort, you could put a line at the beginning of your zoom function:
if(!map_ready) return;
And then set the variable map_ready to true at the appropriate time.
I ran into the same problem.
The "extent" option mentioned in the documentation is there probably by mistake. It does not exist. I checked the source code and could not see any code handling such option. I contacted the author and he already created a pull request for the removal of this option from the documentation.

Bing Maps API v7 limit by bounds

So I'm trying to use the Search Module of the Bing Maps AJAX API (v7), and I've noticed that in the Interactive SDK for it you can pass in a property called bounds which you give a bounding box to search within. The example simply uses the map's current bounding box so theoretically, if you zoom in, a new search should simply show you results within your zoomed in area, right?
Well here's the issue: Add the following code at the end of the example code in the Interactive SDK:
Microsoft.Maps.Events.addHandler(map, 'viewchange', searchRequest);
What this should do is every time you move around the map or zoom in or out, it should fire a new search with the new bounding area of the map... I say this because of the line that looks like this: bounds: map.getBounds(),. What actually happens is that it bounces back to where it was initially before zooming.
Call me crazy, but is the bounds property just being completely ignored? Does anyone know how to limit the search results to the currently visible map area?
Lastly: Is it just me, or are the API docs for V7 rather incomplete? I've managed to find a few things by inspecting stuff in the Chrome console that doesn't appear in the API docs.
Update: This is what my call to the search function looks like:
searchManager.search({
bounds: map.getBounds(),
callback: searchSuccess,
count: 20,
entityType:"Business",
errorCallback: searchFail,
startIndex: 0,
userData: userData,
what: what,
where: search
});
I have not personally used on view changed as I'm not sure that was available when I migrated from 6.0.
I'll share an alternative route I went that gets the trick done.
My search functionality also puts a Microsoft.Maps.Pushpin exactly where the user searched ("You are here!").
I then I create a boundary from the pushpin:
var viewBoundaries = Microsoft.Maps.LocationRect.fromLocations(pushpin.getLocation());
Then set the Map.setView properties for bounds. (Aswell as zoom in my case)
map.setView({ bounds: viewBoundaries });
map.setView({ zoom: 10 });
If you are not using a pushpin, you can simply create the view boundary from the location class.
MSDN Location Class

Google Maps ClusterManager on API V3 not working on reload / initial load

I am trying to use the Google Maps V3 API ClusterManager from http://cm.qfox.nl/ to cluster together markers on a map, but I'm hitting the same error in my code as in the original web site - an error when the page is loaded the first time, or reloaded:
Uncaught TypeError: Cannot call method 'fromLatLngToPoint' of undefined ClusterManager_v3.js:586
ClusterManager.latlngToPoint ClusterManager_v3.js:586
ClusterManager._getMarkerBounds ClusterManager_v3.js:645
ClusterManager._cacheMarkerIcon ClusterManager_v3.js:580
ClusterManager.update ClusterManager_v3.js:345
(anonymous function) ClusterManager_v3.js:91
It works fine after the initial load, so I'm fairly sure it's because of a timing issue - e.g., the map or marker isn't initialized before it being used. Unfortunately, I can't figure out a way to wait for everything to initialize because Javascript isn't my first language. Any help or pointers would be most welcome. The source from the web site is the code I'm using almost exactly.
UPDATE:
If found that changing the line:
cm._requestUpdate(50);
to
cm._requestUpdate(250);
Prevented the error. Changing it to 150 resulted in the error occurring 3/10 times. I'm not entirely sure this is a fix, but it maybe so I'm leaving this posted just in case anyone else has a better solution or wants to know mine.
For using Projection methods , it must be initialized. Map will trigger "projection_changed" event, when Projection will be created.Only after that you can use map.getProjection(). So my suggestion is, to add "projection_changed" event's listener, and initialize ClusterManager when it is called:
google.maps.event.addListenerOnce(map, 'projection_changed', function(){
var cm = window.cm = new ClusterManager(
map,
{
objClusterIcon: new google.maps.MarkerImage('markers/cluster.png', false, false, false, new google.maps.Size(20,20)),
objClusterImageSize: new google.maps.Size(20,20)
}
);
// now json contains a list of marker positions. lets add them.
for (var i = 0; i < json.length; ++i) {
.....
}
cm._requestUpdate(50);
});

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