Spinning Disc Image Viewer (for pre 1.5 wsh)

// ================================================== //
// @name "Spinning Disc Image Viewer (for pre 1.5 WSH) (08.08.2013)"
// @author "eXtremeHunter"
// ================================================== //

function RGB(r, g, b) {
    return (0xff000000 | (r << 16) | (g << 8) | (b));
}
window.DlgCode = 0x0001; // arrow keys for DUI

var defaultDisc = gdi.Image(fb.FoobarPath + "images\\disc.jpg");
var margin = window.GetProperty("Margin", 50);
var zoomStep = window.GetProperty("Zoom Step", 30);
var useDiscMask = window.GetProperty("Use Disc Mask", true);

var angle = 0;
var minSize = 20;
var disc = defaultDisc;
var rotationInterval = 50;
var rotationTimer;
var rotationTimerStarted = false;
// ============================== //

function on_paint(gr) {

    gr.FillGradRect(0, 0, ww, wh, 65, RGB(50, 50, 50), RGB(105, 105, 105), 0.5);

    disc && gr.DrawImage(resizedDisc, discX, discY, discW, discH, 0, 0, resizedDisc.Width, resizedDisc.Height, angle);

}
// ============================== //

function on_mouse_wheel(step) {

    if (utils.IsKeyPressed(16)) {

        if (step == -1 && discW <= 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;

    discW = Math.max(minSize, ww - margin);
    discH = Math.max(minSize, wh - margin);

    if (discH < discW) discW = discH;
    else if (discW < discH) discH = discW;

    discX = ww / 2 - discW / 2;
    discY = wh / 2 - discH / 2;

    resizedDisc = disc.resize(discW, discH);

    if (useDiscMask) {

        var discMask = gdi.CreateImage(discW, discH);
        var g = discMask.GetGraphics();
        g.FillSolidRect(0, 0, discW, discH, 0xffffffff);
        g.SetSmoothingMode(2);
        g.FillEllipse(1, 1, discW - 2, discH - 2, 0xff000000);
        discMask.ReleaseGraphics(g);
        resizedDisc.ApplyMask(discMask);
        discMask.Dispose();

    }

}
// ============================== //
(function onRotationTimer() {

    getDiscImage();

    if (!fb.IsPlaying || fb.IsPaused) {
        return;
    }

    if (!rotationTimerStarted) {

        rotationTimer = window.CreateTimerInterval(rotationInterval);
        rotationTimerStarted = true;
    }

})();
// ============================== //

function stopRotationTimer() {

    window.KillTimer(rotationTimer);
    rotationTimerStarted = false;

}
// ============================== //

function on_timer(id) {

    if (rotationTimer && id == rotationTimer.ID) {

        if (angle >= 360) angle = 0;
        angle += 10;
        (discW >= ww || discH >= wh) ? window.Repaint() : window.RepaintRect(discX, discY, discW, discH);

    }

}
// ============================== //

function on_playback_stop(reason) {

    if (reason != 2) {
        stopRotationTimer();
        getDiscImage();
    }
}
// ============================== //

function on_playback_pause(state) {

    state ? stopRotationTimer() : onRotationTimer();

}
// ============================== //

function on_playback_new_track() {

    onRotationTimer();

}
// ============================== //
var tempAlbum;

function getDiscImage() {

    var nowPlayingDisc;

    var metadb = fb.IsPlaying ? fb.GetNowPlaying() : fb.GetFocusItem();

    if (!metadb) return;

    var currentAlbum = fb.TitleFormat("%album%").EvalWithMetadb(metadb);

    if (currentAlbum == tempAlbum) return;

    nowPlayingDisc = utils.GetAlbumArtV2(metadb, 2);

    nowPlayingDisc ? disc = nowPlayingDisc : disc = defaultDisc;

    tempAlbum = currentAlbum;

    on_size();
    window.Repaint();

}
// ============================== //

function on_selection_changed(metadb) {
    if (!fb.IsPlaying) getDiscImage();
}
// ============================== //

function on_playlist_items_removed() {

    if (!plman.PlaylistItemCount(plman.ActivePlaylist)) disc = defaultDisc;
    on_size();
    window.Repaint();

}