Spinning Disc Image Viewer for WSH panel mod

// ================================================== //
// @name "Spinning Disc Image Viewer  (Jan 23, 2013)"
// @author "eXtremeHunter"
// ================================================== //

window.DlgCode = 0x0001; // arrow keys for DUI
var vinylImage = gdi.Image(fb.FoobarPath + "images\\vinyl.jpg");
var margin = window.GetProperty("Margin", 50);
var zoomStep = window.GetProperty("Zoom Step", 30);
var angle = 0;
var minSize = 20;

function on_paint(gr) {

    gr.DrawImage(resizedVinylImage, vinylX, vinylY, vinylW, vinylH, 0, 0, resizedVinylImage.Width, resizedVinylImage.Height, angle);

}

function on_mouse_wheel(step) {

    if (utils.IsKeyPressed(16)) {

        if (step == -1 && vinylW <= minSize) return;

        var s = step * zoomStep;
        margin = margin -= s;
        window.SetProperty("Margin", margin);
        on_size();

        window.Repaint();

    }

}

function on_key_down(vkey) {

    if (vkey == 38) on_mouse_wheel(1) //UP ARROW
    if (vkey == 40) on_mouse_wheel(-1); //DOWN ARROW

}

function on_size() {

    ww = window.Width;
    wh = window.Height;

    vinylW = Math.max(minSize, ww - margin);
    vinylH = Math.max(minSize, wh - margin);

    if (vinylH < vinylW) vinylW = vinylH;
    else if (vinylW < vinylH) vinylH = vinylW;

    vinylX = ww / 2 - vinylW / 2;
    vinylY = wh / 2 - vinylH / 2;

    resizedVinylImage = vinylImage.resize(vinylW, vinylH);

}

var rotationInterval = 50;
var rotationTimer;
var rotationTimerStarted = false;

(function onRotationTimer() {

    if (!rotationTimerStarted) {

        rotationTimer = window.SetInterval(function () {

            if (angle >= 360) angle = 0;
            angle += 10;
            (vinylW >= ww || vinylH >= wh) ? window.Repaint() : window.RepaintRect(vinylX, vinylY, vinylW, vinylH);

        }, rotationInterval);

        rotationTimerStarted = true;
    }

})();

function stopRotationTimer() {

    window.ClearInterval(rotationTimer);
    rotationTimerStarted = false;

}

function on_playback_stop(reason) {

    if (reason != 2) {

        stopRotationTimer();

    }

}

function on_playback_pause(state) {

    state ? stopRotationTimer() : onRotationTimer();

}

function on_playback_new_track() {

    onRotationTimer();

}