https://www.focusmyanmar.net/lib/leaflet_plugins/leaflet-NavBar-1.0.1/src/Leaflet.NavBar.min.js

1/*
2*  Simple navigation control that allows back and forward navigation through map's view history
3*/
4(function(){L.Control.NavBar=L.Control.extend({options:{position:'topleft',forwardTitle:'Go forward in map view history',backTitle:'Go back in map view history',homeTitle:'Go to home map view'},onAdd:function(map){if(!this.options.center){this.options.center=map.getCenter()}if(!this.options.zoom){this.options.zoom=map.getZoom()}var options=this.options;var controlName='leaflet-control-navbar',container=L.DomUtil.create('div',controlName+' leaflet-bar');this._homeButton=this._createButton(options.homeTitle,controlName+'-home',container,this._goHome);this._fwdButton=this._createButton(options.forwardTitle,controlName+'-fwd',container,this._goFwd);this._backButton=this._createButton(options.backTitle,controlName+'-back',container,this._goBack);this._viewHistory=[{center:this.options.center,zoom:this.options.zoom}];this._curIndx=0;this._updateDisabled();map.once('moveend',function(){this._map.on('moveend',this._updateHistory,this)},this);map.setView(options.center,options.zoom);return container},onRemove:function(map){map.off('moveend',this._updateHistory,this)},_goHome:function(){if(this.options.bbox){try{this._map.fitBounds(this.options.bbox)}

4catch(err){this._map.setView(this.options.center,this.options.zoom);}}this._map.setView(this.options.center,this.options.zoom)},_goBack:function(){if(this._curIndx!==0){this._map.off('moveend',this._updateHistory,this);this._map.once('moveend',function(){this._map.on('moveend',this._updateHistory,this)},this);this._curIndx-=1;this._updateDisabled();var view=this._viewHistory[this._curIndx];this._map.setView(view.center,view.zoom)}},_goFwd:function(){if(this._curIndx!=this._viewHistory.length-1){this._map.off('moveend',this._updateHistory,this);this._map.once('moveend',function(){this._map.on('moveend',this._updateHistory,this)},this);this._curIndx+=1;this._updateDisabled();var view=this._viewHistory[this._curIndx];this._map.setView(view.center,view.zoom)}},_createButton:function(title,className,container,fn){var link=L.DomUtil.create('a',className,container);link.href='#';link.title=title;L.DomEvent.on(link,'mousedown dblclick',L.DomEvent.stopPropagation).on(link,'click',L.DomEvent.stop).on(link,'click',fn,this).on(link,'click',this._refocusOnMap,this);return link},_updateHistory:function(){var newView={center:this._map.getCenter(),zoom:this._map.getZoom()};var insertIndx=this._curIndx+1;this._viewHistory.splice(insertIndx,this._viewHistory.length-insertIndx,newView);this._curIndx+=1;this._updateDisabled()},_setFwdEnabled:function(enabled){var leafletDisabled='leaflet-disabled';var fwdDisabled='leaflet-control-navbar-fwd-disabled';if(enabled===true){L.DomUtil.removeClass(this._fwdButton,fwdDisabled);L.DomUtil.removeClass(this._fwdButton,leafletDisabled)}else{L.DomUtil.addClass(this._fwdButton,fwdDisabled);L.DomUtil.addClass(this._fwdButton,leafletDisabled)}},_setBackEnabled:function(enabled){var leafletDisabled='leaflet-disabled';var backDisabled='leaflet-control-navbar-back-disabled';if(enabled===true){L.DomUtil.removeClass(this._backButton,backDisabled);L.DomUtil.removeClass(this._backButton,leafletDisabled)}else{L.DomUtil.addClass(this._backButton,backDisabled);L.DomUtil.addClass(this._backButton,leafletDisabled)}},_updateDisabled:function(){if(this._curIndx==(this._viewHistory.length-1)){this._setFwdEnabled(false)}else{this._setFwdEnabled(true)}if(this._curIndx<=0){this._setBackEnabled(false)}else{this._setBackEnabled(true)}}});L.control.navbar=function(options){return new L.Control.NavBar(options)}})();