search.js

$(document).ready(function() {
    $("#searchForm").hover(
        function() {
            $(".hover-block").show();
        },
        function() {
            $(".hover-block").hide();
        });

    $("#searchForm").mousemove(function(event) {
        $(".hover-block").css("top", event.pageY + 10 + "px");
        $(".hover-block").css("left", event.pageX + 10 + "px");
    });

    /* Search providers list */
    regexSearchProviders = [
        "Google",
        "Steam",
        "Wikipedia",
        "YouTube"
    ];

    regexSearchPatterns = [
        "!g",   // Google
        "!s",   // Steam
        "!w",   // Wikipedia
        "!y",   // YouTube
    ];

    providerCurrent = "none";
	providerInit = 0;

    // Initialize
    changeProvider("Google");

    // Build regex string
    var i = 0;
    while (i < regexSearchPatterns.length) {
        if (i == 0)
            regexString = "(" + regexSearchPatterns[i] + ")";

        if (i > 0)
            regexString = regexString.concat("|(" + regexSearchPatterns[i] + ")");

        i += 1;
    }

    $("#searchInput").keypress(function() {
        var str = $(this).val();
        var regexPattern = new RegExp(regexString);

        if (regexPattern.test(str)) {
            keyword = regexPattern.exec(str);
            if (keyword != null) {
                var i = 0;
                while (i < regexSearchPatterns.length) {
                    if (keyword[0] == regexSearchPatterns[i])
                        changeProvider(regexSearchProviders[i]);

                    i += 1;
                }
            }
        } else {
            changeProvider("Google");
        }
    });

    // On submit form
    $("#searchForm").submit(function(e) {
        e.preventDefault();

        var str = $("#searchInput").val();
        var regexPattern = new RegExp(regexString, "g");

        if (regexPattern.test(str)) {
            newstring = str.replace(regexPattern, "");
            newstring = newstring.replace(/^(\s)/, "");
        } else {
            newstring = str;
        }

        $("#searchSubmit").attr("value", newstring);
        $("#searchForm")[0].submit();
    });

});

function changeProvider(providerNew) {
    if (providerNew != providerCurrent) {
        providerCurrent = providerNew;
		if (providerInit == 0) {fadeTime = 0; providerInit = 1;} else {fadeTime = 450;}
        $("#searchIcon").fadeOut(fadeTime, function() {
            $("#searchIcon").attr("src", "images/" + providerCurrent + ".ico");
            $("#searchIcon").fadeIn(fadeTime);
        });

        /* Providers */
        switch(providerCurrent) {
            case "Google":
                $("#searchForm").attr("action", "http://google.com/search");
                $("#searchSubmit").attr("name", "q");
                break;
			case "Steam":
                $("#searchForm").attr("action", "http://store.steampowered.com/search");
                $("#searchSubmit").attr("name", "term");
				break;
            case "Wikipedia":
                $("#searchForm").attr("action", "http://en.wikipedia.org/w/index.php");
                $("#searchSubmit").attr("name", "search");
                break;
            case "YouTube":
                $("#searchForm").attr("action", "http://youtube.com/results");
                $("#searchSubmit").attr("name", "search_query");
                break;
        }
    }
}