[GIS] Openlayers drawing interaction geometryFunction

draw-interactiongeometrymap-drawingopenlayers

Can anyone help me to convert this function so that it is not dependant on the ol3-debug file as I don't know quite what is replaced upon build. The function works but only in debug mode.

It is in reference to this question: Sketch event in Openlayers 3 drawing interaction

The intention is that it will allow me to display each features co-ords as they are drawn on-screen.

geometryFunction: function (c, g) {
        if (goog.isDef(g)) {
            g.setCoordinates(c);
        } else {
            g = new ol.geom.LineString(c);
        }
        if (c[0].length > ct) {
            console.log('click coord : ' + c[0][c[0].length - 1]);
            ct = c[0].length;
        } else {
            console.log('move coord : ' + c[0][c[0].length - 1]);
        }

        return g;
    }

Best Answer

You can use:

var draw = new ol.interaction.Draw({
    source: vectorSource,
    type: "LineString",
    geometryFunction: function(coords, geom) {
        if (!geom) {
            geom = new ol.geom.LineString(null);
        }
        console.info(coords);
        geom.setCoordinates(coords);
        return geom;
    }
});
map.addInteraction(draw);

See https://gis.stackexchange.com/a/152646/50718

http://jsfiddle.net/jonataswalker/8b322285/

Related Solutions

OpenLayers – Sketch Event in Drawing Interaction

OpenLayers v3.5.0 does not easily support the feature you're looking for, but there is a feature currently in development that you can use.

On ol.interaction.Draw, you can specify an ol.interaction.DrawGeometryFunctionType function to handle updates to the current geometry.

An example I've written up is shown below:

var geometryFunction = function (c, g) {
  if (goog.isDef(g)) {
    g.setCoordinates(c);
  } else {
    g = new ol.geom.Polygon(c);
  }

  if (c[0].length > ct) {
    console.log('mouse click coord : ' + c[0][c[0].length - 1]);
    ct = c[0].length;
  } else {
    console.log('mouse move coord : ' + c[0][c[0].length - 1]);
  }

  return g;
}

This is pretty much what the default geometryFunction function does, without the new point identification and console logging.

A fully functional example is here: http://jsfiddle.net/1a948faa/2/

Note the following caveats:

You will have to implement a separate function, or case for different geometry types.
The code is currently still in development and is thus not stable. In addition it is subject to change at any time.

[GIS] Problem in remove interaction after draw end in openlayers-3

The proper way to handle this is something like:

// Find the double click interaction that is on the map.
var dblclickzoom;
map.getInteractions().forEach(function (interaction) {
   if (interaction instanceof ol.interaction.DoubleClickZoom) {
       dblclickzoom=interaction;
   }
});

// Remove the interaction from the map.
if (dblclickzoom) { map.removeInteraction(dblclickzoom); }

/* Add your draw interaction here */
var drawinteraction=new ol.interaction.Draw(...);

// I like to stick the listener on the source's change event rather than
// the interaction's drawend, but I think either should work...
drawinteraction.on('drawend', function () {
   map.removeInteraction(drawinteraction);
   // Do this in a timeout so it doesn't get triggered by the potential
   // double click that caused the drawing to end.
   if (dblclickzoom) {
       setTimeout(function () {
          map.addInteraction(dblclickzoom);
       });
   }
});
// Start the draw interaction...
map.addInteraction(drawinteraction);

Best Answer

Related Solutions

OpenLayers – Sketch Event in Drawing Interaction

[GIS] Problem in remove interaction after draw end in openlayers-3

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