OpenLayers measure tool - instant measurement

Question

I need to use measure tool to measure distances (instant measurement!) in my application. Instant measurement example can be found here. But the main problem is that when I use instant measurement tool and try to measure distance, it sums all the pieces and shows sum. So the question: how can I instantly show only the current piece distance (I mean not to sum up all pieces distances)?

Answer 1

Here is copy-paste from one of my old applications. EDIT: I modified getCustomLength, so it should work with different coordinate systems. Fiddle: http://jsfiddle.net/A78Zu/

measureControl = new OpenLayers.Control.Measure(
    OpenLayers.Handler.Path,
    {
        immediate: true,
        persist: true
    }
);  

measureControl.getCustomLength = function(evt, onlySum) {
    var idx = evt.geometry.components.length;

    if (idx < 2)
        return '';  

    var geom = new OpenLayers.Geometry.LineString([
        evt.geometry.components[idx - 2],
        evt.geometry.components[idx - 1]
    ]);

    var lastLengthArr = this.getBestLength(geom);

    var str = '';

    if (idx > 2 || onlySum)
        str += 'Total: ' + (evt.units === 'km' ? evt.measure.toFixed(3) : evt.measure.toFixed(1)) + ' ' + evt.units + '&nbsp;&nbsp;&nbsp;';

    if (!onlySum)
        str += 'Last segment: ' + (lastLengthArr[1] === 'km' ?  lastLengthArr[0].toFixed(3) : lastLengthArr[0].toFixed(1)) + ' ' + lastLengthArr[1];

    return str;
}

map.addControl(measureControl); 

// Update content in .foo div   
measureControl.events.on({
    'measure': function(evt) {
        $('.foo').html(measureControl.getCustomLength(evt, true));
    },
    'measurepartial': function(evt) {
        $('.foo').html(measureControl.getCustomLength(evt, false));
    }
});