[GIS] Popup overlays on draw (measure) with OpenLayers 3

openlayers

Using the OpenLayers Measure exemple (http://openlayers.org/en/v3.10.1/examples/measure.html), I'm trying to have only a single measure active at a time.

http://jsfiddle.net/Sinnel/yfdejpre/1/

However, the static measure results appear in a overlay and I have not been able to limit/delete old measures from staying on the map. I have tried different approaches for quite some time, the one giving the "best" results being :

if (map.getOverlays().getArray().length >= 2) {
map.getOverlays().clear()};

However, the result is quite inconsistent…
How should I approach this?

Best Answer

source_mesure.clear(); should be fired on drawstart and not on drawend.
I have used $( ".tooltip" ).remove(); in order to clear the tooltips. Maybe you should find something more elgant for that.
You had a firebug error (draw is undifined). That was because you asign the listener before initialising the interaction. So I put the listener asignments imediate after initialising the interaction.

check this fiddle. click Its your fiddle with slight mods to do your job.

Related Solutions

[GIS] Draw square with OpenLayers 3

You can easily recreate the functionality with ol.interaction.DragBox. The interaction has a boxend event, which propagates an object with a getGeometry() function.

The geometry can be added to a new feature, which can be added to the vector source. The geometry can be logged directly from the boxend event handler, but the source object also has an addfeature event.

To create a dragbox interaction, you have to define the condition on which the interaction activates (I think it is shiftKey by default), and the style of the box.

var interaction = new ol.interaction.DragBox({
    condition: ol.events.condition.noModifierKeys,
    style: new ol.style.Style({
        stroke: new ol.style.Stroke({
            color: [0, 0, 255, 1]
        })
    })
});

The geometry of the last dragged box then gets extracted by the event handler, and added to the vector source.

interaction.on('boxend', function(evt){
    var geom = evt.target.getGeometry();
    console.log(geom);
    var feat = new ol.Feature({geometry: geom});
    source.addFeature(feat);
});

See how it works in this fiddle.

[GIS] OpenLayers 3 – Modify Feature – Delete vertex on keypress

I think there is a problem with freehandCondition in Draw interaction, which is ShiftKeyOnly by default. When I changed it to ol.events.condition.never I can delete vertex without creating new feature. This solution deactivates freehand drawing. Example:

draw = new ol.interaction.Draw({
features:features,
type: ('Polygon'),
freehandCondition: function(event){
return ol.events.condition.never(event);
}

Best Answer

Related Solutions

[GIS] Draw square with OpenLayers 3

[GIS] OpenLayers 3 – Modify Feature – Delete vertex on keypress

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