scrolltotop.js

/**
 * JS file of the Responsive jQuery ScrollToTop Arrow by Fabian Lins
 * https://github.com/FabianLins/scrolltotop_arrow_jquery
 */

$(document).ready(function() {

    /*Change this variable to adjust the speed of the scrolling.*/
    scrolltotop_scroll_speed=400;

    /*Change this variable to adjust the speed of the fading.*/
    scrolltotop_animation_speed=500;

    /*Change this variable to adjust the start position of the fade in.*/
    scrolltotop_fadein_start_position=200;

    /*True means you have a circle, false means you have a rectangle with round corners.*/
    scrolltotop_circle_mode=true;

    /*Make the rectangle a circle or give it round corners.*/
    if(scrolltotop_circle_mode==true){
        $("#scrolltotop_parent").addClass("circle");
    }
    else{
        $("#scrolltotop_parent").addClass("square");
    }

    /*Scrolls to the top of the page.*/
    $("#scrolltotop_parent").on(
        "click keypress", function () {
        $("html, body").animate({
             scrollTop: 0		
        }, scrolltotop_scroll_speed);
        document.activeElement.blur();  
    });

    /*Fades the scrolltotop box in and out while scrolling.*/
    $(window).scroll(function () {
        if (window.pageYOffset >= scrolltotop_fadein_start_position) {
            $("#scrolltotop_parent").fadeIn(scrolltotop_animation_speed);
        }
        else {
            $("#scrolltotop_parent").fadeOut(scrolltotop_animation_speed);
        }
    });

	/* Keyboard accessibility */
    $(document).keydown(function(e) {
		var key_pressed = e.keykey_pressed || e.which;
		/* Esc Key */
		if (key_pressed == "27") {
			if($("#scrolltotop_arrow").is(":focus")) {
			    document.activeElement.blur();	
		    }
        }
    });
});