MediaWiki:Gadget-artTab.js

function artTabSwitch(evt, artTabName) {
    var i, tabcontent, tablinks;
    tabcontent = document.getElementsByClassName("artTabContent");
    for (i = 0; i < tabcontent.length; i++) {
        tabcontent[i].style.display = "none";
    }
    tablinks = document.getElementsByClassName("artTabLinks");
    for (i = 0; i < tablinks.length; i++) {
        tablinks[i].className = tablinks[i].className.replace(" active", "");
    }
    document.getElementById(artTabName).style.display = "block";
    evt.currentTarget.className += " active";
}

$(document).ready(function() {
        console.log(document.getElementById("artTab"));    
        if (document.getElementById("artTab") !=== null) {
        
	var artTabDiv = document.getElementById("artTab");
	buttonsStr =   '<div style="position:absolute;top:0;left:0">' +
                       '<button class="artTabLinks" id="defaultArtTab" onclick="artTabSwitch(event, \'fullart\')">Normal</button>' +
                       '<button class="artTabLinks" onclick="artTabSwitch(event, \'fullart_D\')">Damaged</button>' +
                    '</div>'
        if (document.getElementById ("defaultArtTab") === null)  { 
	    	artTabDiv.insertAdjacentHTML( 'afterbegin', buttonsStr);
        }

	document.getElementById("defaultArtTab").click();
    }
});