No setBounds function for Leaflet imageOverlay - leaflet

I'm reading an imageOverlay URL from an ArcGIS webserver that uses the leaflet getBound() coordinates as part of the URL (we have large maps that are filtered for the current window 'extent'). Apologies for not including the actual path (I'm working with sensitive client data). Eg:
http://myarcgiswebserver.com/MapServer/export/dpi=96&format=png32&bbox=27.119750976562504%2C-31.194007509998823%2C32.39044189453126%2C-29.692824739380754&size=1719%2C434
[bbox] = current imageBounds
When dragging my map the imageOverlay url is updated correctly but my leaflet window is no longer aligned to the imageBound values that were set when first adding the imageOverlay which results in a skewed output (this is my assumption):
The only workaround is to remove the existing imageOverlay and add a new one (which ruins the user experience as the map disappears then reappears each time the window is dragged or zoomed).
Am i approaching this problem incorrectly or would the introduction of a function to update the current imageBounds resolve this? Perhaps not a new function but the expansion of setUrl with additional parameters...?
Many thanks for any feedback...

As #ghybs pointed out, your use case might be better served by using the WMS
interface of your ArcGIS server.
Anyway, you say
The only workaround is to remove the existing imageOverlay and add a new one (which ruins the user experience as the map disappears then reappears each time the window is dragged or zoomed).
Well, that glitch is due to you probably doing something like:
Remove old overlay
Add new overlay
Wait until the image is received from the network
Wait one frame so the new overlay is shown
and instead you should be doing something like:
Add new overlay
Wait until the image is received from the network
Remove old overlay
Wait one frame so the new overlay is shown
The problem is just the async wait and the possible race conditions there, but should be easy to hack together, e.g.:
var activeOverlay = null;
var overlayInRequest = null;
map.on('moveend zoomend', {
// If we are already requesting a new overlay, ignore it.
// This might need some additional debouncing logic to prevent
// lots of concurrent requests
if (overlayInRequest) {
overlayInRequest.off('load', showOverlay);
}
overlayInRequest = L.imageOverlay( computeUrl( map.getBounds() ), myOverlayOptions );
overlayInRequest.on('load', showOverlay);
});
function showOverlay(ev) {
activeOverlay.remove();
activeOverlay = overlayInRequest;
activeOverlay.addTo(map);
overlayInRequest = undefined;
}

If you use an ImageOverlay but change its url dynamically, with a new image that reflects a new bounding box, then indeed that is the reason for the behaviour you describe: you display an image that has been generated using a new bbox, but positioned in the initial bbox, since the image overlay remains at the same geographical position on the map.
Instead, it sounds to me that you should use a TileLayer.WMS.
It would automatically manage the bounding box update for you. You may need to find the correct options to fit your service provider required URL syntax, though.
Example: http://playground-leaflet.rhcloud.com/yel/1/edit?html,output

Related

Changing DOM content of konva container causes crash?

I try to save the content of my last konva stage object in a Map in window object. My original aim is to minimize the loading time when I want to open the same page that has been drawn. Things are going well within my own frame. However, when I load my frame which has Konva content in another window (which becomes the parent of my Konva frame), the konva frame crashes and the console does not show any errors.
My code snipplet looks like this:
var xjGraph = cachedGraphObject; //Konva graph that already drawn, loaded from a js Map in parent window
var containerDOM = document.getElementById(oldId);
var konvaJsContent = xjGraph.getStage().content; //get the div of "konvajs-content" class
var oldChild = containerDOM.firstChild;
oldChild.remove();
containerDOM.appendChild(konvaJsContent); //remove the old div of "konvajs-content" and replace it with the one that I want to show; I could use replaceChild() here, but I get the same result
PS: If there is another way to save a stage in browser and load it when I need it for later use, please kindly help. Very much appreciated!

Update leaflet baselayer properties with GoogleMutant

I have a google layer (baselayer) GoogleMutant and want to update its options. I try to
map.remove(google.layer)
//update the POI visibility
google.layer.options.styles.forEach(i=>i.stylers[0].visibility = "off")
map.addLayer(google.layer)
this updates the layer options but the Points of interest are still on the map. Is there any way to update the options and apply them to the baselayer?
Thanks
Here is an example with google mutant https://jsfiddle.net/benderlio/2m4c01w6/10/
There is a button "remove POI", and I want to remove all poi from current layer with leaflet API
Leaflet doesn't work changing settings on the fly. You have to remove the whole object and create a substitute.
Like if you need to change a layer, you have to remove it like:
roadMutant.removeFrom(map); // or
map.removeLayer(roadMutant);
And then create and add the new one:
roadMutant.addTo(map);
I created a fiddle to help the change based on yours. It still have bugs and somewhere to grow, but it's a base...

Leaflet markercluster group and layer control not working

I'm trying to add clustering and layer control to filter markers on my map. After reading older posts on this issue, the code that was marked as the right answer looks like this. However, no matter how I change it, it does not work on my map.
var parent= new L.MarkerClusterGroup().addTo(map);
var overlay={}
overlay["Markers A"]=L.featureGroup.subGroup(parent,aPoints).addTo(map);
overlay["Markers B"]=L.featureGroup.subGroup(parent,bPoints).addTo(map);
control = L.control.layers(null, overlay, {collapsed: false });
control.addTo(map);
What am I doing wrong?
The issue that I was having was that L.featureGroup.subGroup takes in an array of markers as it's second parameters therefore, aPoints needed to be [aPoints].

Click-through markers and polylines in Leaflet

In Leaflet, is it possible to define a marker or polyline with {clickable:false}, so that a click is passed through to whatever lies beneath - be it the map or a clickable geometry object?
At the moment I solve this problem by making the marker/polyline clickable and passing the event onwards myself. But this leads to the mouse cursor always showing as the hand symbol. Ideally, the mouse cursor should look like the normal pointer or the hand, depending on whether what is beneath the marker/polyline is clickable.
This may not be the answer you are looking for, but you can use featureGroups to have all of your clickable polylines come to the front so that the actions are surfaced.
var lg_noclick = new L.FeatureGroup().addTo(map);
var lg_click = new L.FeatureGroup().addTo(map);
// Add lines
lg_click.bringToFront();
updated fiddle
Also if you can afford to know your lines before hand, correct ordering of when you add the lines it will work as well.
I know this is not ideal but it suited my situation just fine, so it might be good for you as well.
This hides the icon and brings it back after a second using mouseenter and mouseleave events:
$('.leaflet-marker-icon').mouseenter(function() {
$(this).hide();
});
$('.leaflet-marker-icon').mouseleave(function() {
$(this).delay(1000).show(0);
});

How do I center and show an infobox in bing maps?

My code does a .pantolatlong then a .showinfobox
The info box does not appear, unless I remove the pantolatlong. I guess it is stopping it. I tried adding it to the endpan event but that did not work.
What is the simplest way to pan to a pushpin and display the infobox for it?
I was using setcenter, but I discovered that sometimes setcenter pans, and this breaks it.
After some insane googling, I came up with the solution, and I'll share it here so that others can hopefully not have the grief I went through.
I created and power my bing map using pure javascript, no sdk or iframe solutions. In my code, I generate the javascript to add all of the pins I want to the map, and inject it using an asp.net label.
If you call the setCenter() method on your Bing Map, it is supposed to instantly set the map, surprise surprise, to the coordinates you specify. And it does... most of the time. Occasionally though, it decides to pan between points. If you do a SetCenter, followed by a ShowInfoBox, it will work great, unless it decides to pan.
The solution? Being great programmers we are, we dive into the sdk, and it reveals there are events we can hook into to deal with these. There is an onendpan event, which is triggered after a pan is completed. There is also an onchangeview event, which triggers when the map jumps.
So we hook into these events, and try to display the infobox for our pushpin shape... but nothing happens. Why not?
You have to give it a few milliseconds to catch its breath, for unknown reasons, when the event is called. Using a setTimeout with 10 milliseconds seems to be fine. Your box will appear great after this.
The next problem is, you only want it to appear when it pans via whatever you used to make it flick between your pushpins (in my case, a table with onclick methods). I create/destroy the event handlers on the fly, although there are other options such as using a global variable to track if the user is panning, or if the system is panning in response to a click.
Finally, you have the one bug that comes from this. If you click a place in your list, and it jumps/pans to that location, the infobox will display fine. If the user dismisses it though, then clicks again on the list item, the map does not move, and therefore no events are triggered.
My solution to this is to detect if the map moved or not, by recording its long/lat, and using another setTimeout method, detecting if they changed 100ms later. If they did not, display the infobox.
There are other things you need to keep track of, as there is no way I can see to pass parameters to the eventhandlers so I use global javascript variables for this - you have to know which pushpin shape you are displaying, and also keep track of the previous mapcoordinates before checking to see if they changed.
It took me a while to piece all this together, but it seems to work. Here is my code, some sections are removed:
// An array of our pins to allow panning to them
var myPushPins = [];
// Used by the eventhandler
var eventPinIndex;
var oldMapCenter;
// Zoom in and center on a pin, then show its information box
function ShowPushPin(pinIndex) {
eventPinIndex = pinIndex;
oldMapCenter = map.GetCenter();
map.AttachEvent("onendpan", EndPanHandler);
map.AttachEvent("onchangeview", ChangeViewHandler);
setTimeout("DetectNoMapChange();", 200);
map.SetZoomLevel(9);
map.SetCenter(myPushPins[pinIndex].GetPoints()[0]);
}
function EndPanHandler(e) {
map.DetachEvent("onendpan", EndPanHandler);
setTimeout("map.ShowInfoBox(myPushPins[eventPinIndex]);", 10);
}
function ChangeViewHandler(e) {
map.DetachEvent("onchangeview", ChangeViewHandler);
setTimeout("map.ShowInfoBox(myPushPins[eventPinIndex]);", 10);
}
function DetectNoMapChange(centerofmap) {
if (map.GetCenter().Latitude == oldMapCenter.Latitude && map.GetCenter().Longitude == oldMapCenter.Longitude) {
map.ShowInfoBox(myPushPins[eventPinIndex]);
}
}
Here is another way:
function addPushpin(lat,lon,pinNumber) {
var pinLocation = new Microsoft.Maps.Location(lat, lon);
var pin = new Microsoft.Maps.Pushpin(map.getCenter(), { text: pinNumber.toString() });
pinInfobox = new Microsoft.Maps.Infobox(pinLocation,
{ title: 'Details',
description: 'Latitude: ' + lat.toString() + ' Longitude: ' + lon.toString(),
offset: new Microsoft.Maps.Point(0, 15)
});
map.entities.push(pinInfobox);
map.entities.push(pin);
pin.setLocation(pinLocation);
map.setView({ center: pinLocation});
}