[GIS] OpenLayers zoom to Boundingbox depends on lat/lon positions

openlayers-2

I'll try to explain my application and the problem.

My application gets a position for a zip code and receives a Lat/Long position, then I'm looking for all points around this position and show them.(This works fine)

Now I want to try to show a user his zipcode position at the center of the map, but I also want to specify the correct zoom level, so that the user can see all points around this point. (it's not limited by the distance)

Is this possible?

My minLat,maxLat,minLng,maxLng looks like this :

Array ( [minLng] => 8.381 [maxLng] => 9.15259 [minLat] => 49.5103735 [maxLat] => 50.06762 )

Edit:

-HTML:

map.setCenter(new OpenLayers.LonLat(center.lon,center.lat) // Center of the map
            .transform(
                new OpenLayers.Projection("EPSG:4326"), // transform from WGS 1984
                new OpenLayers.Projection("EPSG:900913") // to Spherical Mercator Projection
                ), config.zoom // Zoom level
            );
    map.zoomToExtent(new OpenLayers.Bounds(config.bounds.minLng,config.bounds.minLat,config.bounds.maxLng,config.bounds.maxLat).transform(epsg4326));

I have added the html of the function.

Best Answer

You can use openlayers bounds to set extent and then zoom your map to extent using map.zoomToExtent() or map.zoomToMaxExtent()

Here's an example:

map.zoomToExtent(new OpenLayers.Bounds(minLng,minLat,maxLng,maxLat).transform("EPSG:4326", "EPSG:900913"))

Related Solutions

[GIS] Problems with features, popups and strategy with OpenLayers

you can catch your opened(active) popup with this way:

map.popups[a]

you can change so update its content:

map.popups[a].contentHTML = 'Test Content';
map.popups[a].redraw();

or

map.popups[a].setContentHTML = 'Test Content'

you can show or hide your popup:

map.popups[a].show();
map.popups[a].hide();

you can update position of your popup:

map.popups[a].lonlat.lon = 10;
map.popups[a].lonlat.lat = 10;
map.popups[a].updatePosition();

for openlayers cluster you should check out Cluster Strategy Example here. Only one thing you should do is that define fillColor or externalGraphic for your cluster.

          var style = new OpenLayers.Style({
                pointRadius: "${radius}",
                fillColor: "${getColor}",
                fillOpacity: 0.8,
                strokeColor: "#cc6633",
                strokeWidth: 2,
                strokeOpacity: 0.8
            }, {
                context: {
                    radius: function(feature) {
                        return Math.min(feature.attributes.count, 7) + 3;
                    },
                    getColor: function(feature) {
                        return // Your color selection logic;
                    }
                }
            });

As the last question, i dont understand very well what you want? but try to use removeFeatures instead of destroyFeatures....

i hope it helps you...

[GIS] OpenLayers with a small, discrete set of XYZ tiles

Kromey, try this:

All tiles in OpenLayers is by default 256x256, so you don't need to explicitly declare it.
The bounds you want is in pixels, because you are dealing with an image. So the image that was split up (your original .png at 8138x5034) needs to be a perfect multiple of 256x256. Your intuition about the size being rounded up is a good one, so use that. But also, you can set your bounds higher, but you might end up pulling in status codes of 404 when OpenLayers tries to pull in tiles that are beyond your map's size.
What you are missing is resolution: 16
The magical part about maxResolution: 16 is that the map knows about it's layer via tiling -- it has no spacial reference, so resolution helps determine how big your map will be. Why 16? I don't know. I do know that resolution and maxResolution is supposed to represent units/pixel.

So, how does the code below help you?

var map; //The map
var day, night; //The layers, one for a "day" map and one for a "night" map

function init(){
  map = new OpenLayers.Map('map', {
    maxExtent: new OpenLayers.Bounds(0,0,8192,8192), //Size of the raw .png image, rounded up to a multiple of 256
    maxResolution: 16,
    resolution: 16,
    numZoomLevels: 6,

    eventListeners: {
        "zoomend": mapEvent,
        "moveend": mapEvent
    }
  });

  //Add the "day" layer
  day = new OpenLayers.Layer.XYZ("Day", "./tiles/x${x}y${y}z${z}.png");
  map.addLayer(day);

  map.zoomToMaxExtent();
}

Cheers!

Best Answer

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[GIS] Problems with features, popups and strategy with OpenLayers

[GIS] OpenLayers with a small, discrete set of XYZ tiles

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