topic Re: remove highlight flashes on hover in ArcGIS JavaScript Maps SDK Questions

remove highlight flashes on hover

LeidavanHees — Tue, 20 Dec 2022 14:11:40 GMT

Hello!

I'd like to know how to check if a feature is already highlighted.

I added a highlight for features on mousehover. But the highlight keeps flashing off and on if you move the mouse within a feature.

I think this is because I remove the highlight on every mouse move, without checking if a feature is already highlighted first. I've tried to build in a check for this, but it doesn't work yet. Which is why I'd like to know how to check for this.

Any help would be much appreciated!

Code (V4.24):

view.when(() => { let highlight = null; view.on("pointer-move", evt => { view.hitTest(evt).then(response => { if (response.results.length > 0) { if (highlight) { highlight.remove(); } let graphic = response.results[0].graphic; view.whenLayerView(graphic.layer).then(function(layerView){ highlight = layerView.highlight(graphic); }); } else{ if (highlight) { highlight.remove(); } } }); }); });

Re: remove highlight flashes on hover

UndralBatsukh — Tue, 20 Dec 2022 16:04:12 GMT

Hi there,

This sample https://developers.arcgis.com/javascript/latest/sample-code/sandbox/?sample=view-hittest shows you how to do this. Namely take a look at the getGraphics function where we are checking if the some attributes of the graphic returned from hottest matches the attributes of the already highlighted graphic like so:

const graphic = response.results[0].graphic; const attributes = graphic.attributes; const category = attributes.CAT; const wind = attributes.WIND_KTS; const name = attributes.NAME; const year = attributes.YEAR; const id = attributes.OBJECTID; if (highlight && (currentName !== name || currentYear !== year)) { highlight.remove(); highlight = null; return; } if (highlight) { return; }

Re: remove highlight flashes on hover

LeidavanHees — Wed, 21 Dec 2022 08:53:09 GMT

Thank you! I thought I couldn't use this because I have different layers with different attributes. But I looked at it again and am now using the OBJECTID, which works like a charm.