Styjun

After clicking on a button I overwrite the default behaviour of map.on('dblclick') which is zoom in.

I would like to retrieve this behavior in other part of code.

How can I do that?

EDIT: For better explanation. I have a button which when I click I override the behavior on map dblclick

$('#RemoveArea').on('click', function()
 map.getInteractions().pop()
 map.on('dblclick', function(evt) 
 evt.preventDefault();
 evt.map.forEachFeatureAtPixel(evt.pixel, function(feature,layer) 
 featureId = feature.getId()
 areaFeature = feature.getGeometry().getArea()/ 10000;
 totalSelectedArea -= parseFloat(areaFeature.toFixed(2));
 )
 ); 
)

How to on click on other btn again make the map behave the same as before, it is zoom in the map

 $('#OtherBtn').on('click', function()
 //... 
 )

Is it possible?

You can disable the interaction when you create the map

var map = new ol.Map(
 layers [myLayer],
 target: 'map',
 interactions: ol.interaction.defaults(doubleClickZoom: false),
 view: new ol.View(
 center: [x, y],
 zoom: z
 )
);

To be able to switch an interaction on/off you need to assign it to a variable instead of creating it with the defaults:

var dcz = new ol.interaction.DoubleClickZoom();

var map = new ol.Map(
 layers [myLayer],
 target: 'map',
 interactions: ol.interaction.defaults(doubleClickZoom: false).extend([dcz]),
 view: new ol.View(
 center: [x, y],
 zoom: z
 )
);

to switch off and on :

dcz.setActive(false);

dcz.setActive(true);

 var layer = new ol.layer.Tile(
 source: new ol.source.OSM()
 );

 var dcz = new ol.interaction.DoubleClickZoom();

 var map1 = new ol.Map(
 target: 'map',
 layers: [layer],
 interactions: ol.interaction.defaults(doubleClickZoom: false).extend([dcz]),
 view: new ol.View(
 center: [0, 0],
 zoom: 1
 )
 );

 function dczOnOff() 
 dcz.setActive(document.getElementsByName('dcz')[1].checked);
 

html, body 
 margin: 0;
 padding: 0;
 width: 100%;
 height: 100%;

.map 
 width: 100%;
 height: 80%;

<link href="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/css/ol.css" rel="stylesheet" />
<script src="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/build/ol.js"></script>
<div id="map" class="map"></div>
<div style="padding-left: 50px;">
<input type="radio" name="dcz" value="0" size="16" onchange="dczOnOff()"> DCZ OFF</br>
<input type="radio" name="dcz" value="1" size="16" onchange="dczOnOff()" checked> DCZ ON</br>

Either keep your double click listener permanently active and let it test whether your buttons have turned on or off the double click zoom:

map.on('dblclick', function(evt) 
 if (!dcz.getActive()) 
 evt.map.forEachFeatureAtPixel(evt.pixel, function(feature,layer) 
 featureId = feature.getId()
 areaFeature = feature.getGeometry().getArea()/ 10000;
 totalSelectedArea -= parseFloat(areaFeature.toFixed(2));
 )
 
); 

$('#RemoveArea').on('click', function()
 dcz.setActive(false);
)

$('#OtherBtn').on('click', function()
 dcz.setActive(true);
)

or you need to store the key of the double click listener so you can unset it later

$('#RemoveArea').on('click', function()
 key = map.on('dblclick', function(evt) 
 evt.preventDefault();
 evt.map.forEachFeatureAtPixel(evt.pixel, function(feature,layer) 
 featureId = feature.getId()
 areaFeature = feature.getGeometry().getArea()/ 10000;
 totalSelectedArea -= parseFloat(areaFeature.toFixed(2));
 )
 ); 
)

$('#OtherBtn').on('click', function()
 ol.Observable.unByKey(key) 
)

So I didnt find a way to retrieve zoom on dblclick, but I am able to prevent the behavior that I override before. So, after clickin OtherBtn

I added this

 map.on('dblclick', function(evt) 
 evt.preventDefault();
 )

So as I said, It does not zoom in but also does not do other things.

EDIT: I found the function in which is un and it is opposite of on. So in OtherBtn I set

map.un('dblclick', doubleClickCallback);

where doubleClickCallback is just a function with all the things I was doing after dblclick, and comes back to the deafualt behavior