[OpenLayers-Dev] ScaleLine on IE

[Andrea Battisti]

Hi All,


there is a small glitch on the ScaleLine Control:
http://dev.openlayers.org/releases/OpenLayers-2.7/lib/OpenLayers/Control/ScaleLine.js

The "update" function computes the width of the scale element without
checking if the element is visible.


/* works */
scaleControl = new OpenLayers.Control.ScaleLine();

/* triggers a runtime error on IE (tried on IE 6, 7 and 8) */
scaleControl = new OpenLayers.Control.ScaleLine( { bottomOutUnits: "",
bottomInUnits: "" } );



A simple workaround would be to compute the top and bottom elements
width only if they are visible:

        topPx = 0; bottomPx = 0;
       
        if ( this.eTop.style.visibility == "visible" )
        {
            var topMax = maxSizeData / inches[topUnits];               
                    // and to map units units
            var topRounded = this.getBarLen(topMax);                   
                    // now trim this down to useful block length
            topMax = topRounded / inches[curMapUnits] *
inches[topUnits];                    // and back to display units
            topPx = topMax / res;                                       
                    // and to pixel units
        }
       
        if ( this.eBottom.style.visibility == "visible" )
        {
            var bottomMax = maxSizeData / inches[bottomUnits];       
                        // and to map units units
            var bottomRounded = this.getBarLen(bottomMax);           
                        // now trim this down to useful block length
            bottomMax = bottomRounded / inches[curMapUnits] *
inches[bottomUnits];            // and back to display units
            bottomPx = bottomMax / res;                               
                        // and to pixel units
        }



Best Regards,

-- 
Andrea Battisti
Applied Coherent Technology Corp.