openseadragonzoomlevels.js

!function(e){"use strict";function o(o){e.isArray(o)&&o.sort(function(e,o){return e-o})}if(!e.version||e.version.major<2)throw new Error("This version of OpenSeadragonZoomLevels requires OpenSeadragon version 2.0.0+");e.Viewer.prototype.zoomLevels=function(o){return(!this.zoomLevelsInstance||o)&&(o=o||{},o.viewer=this,this.zoomLevelsInstance=new e.ZoomLevels(o)),this.zoomLevelsInstance},e.ZoomLevels=function(r){var t=this;e.extend(!0,t,{viewer:null,levels:[]},r),o(r.levels);var i,s=t.viewer.viewport;t.viewer.addHandler("zoom",function(e){i!==e.zoom&&(i=e.zoom,i!==s.getHomeZoom()&&(i<s.zoomSpring.current.value?i=t.getLowerZoomLevel(i):i>s.zoomSpring.current.value&&(i=t.getUpperZoomLevel(i))),i!==e.zoom&&(e.zoom=i,s.zoomTo(i,e.refPoint,e.immediately)))})},e.extend(e.ZoomLevels.prototype,{getUpperZoomLevel:function(o){if(e.isArray(this.levels)&&this.levels.length){var r=this.viewer.viewport,t=r.viewportToImageZoom(o);o=r.imageToViewportZoom(this.levels[this.levels.length-1]);for(var i=0;i<this.levels.length;i++)if(this.levels[i]>t){o=r.imageToViewportZoom(this.levels[i]);break}return Math.min(o,r.getMaxZoom())}return o},getLowerZoomLevel:function(o){if(e.isArray(this.levels)&&this.levels.length){var r=this.viewer.viewport,t=r.viewportToImageZoom(o);o=r.imageToViewportZoom(this.levels[0]);for(var i=this.levels.length-1;i>=0;i--)if(this.levels[i]<t){o=r.imageToViewportZoom(this.levels[i]);break}return Math.max(o,r.getMinZoom())}return o}})}(OpenSeadragon);