WSH seekbar

// vi:set ft=javascript ff=dos ts=4 sts=4 sw=4 et:

// This is just a demo so is buggy.
var g_theme = window.CreateThemeManager("PROGRESS");
var g_bar_height = 15;
var g_cycles = 0;
var ww = 0,
    wh = 0;
var top = 0;
var g_pos = 0;
var g_drag = false;
var g_length = 1;

function clamp(x, l, h) {
    return (x < l) ? l : ((x > h) ? h : x);
}


function on_size() {
    ww = window.Width;
    wh = window.Height;
    top = (wh - g_bar_height) >> 1;
}

function on_paint(gr) {
    g_theme.SetPartAndStateID(1, 0);
    g_theme.DrawThemeBackground(gr, 0, top, ww, g_bar_height);

    if (fb.IsPlaying && g_length > 0) {
        g_theme.SetPartAndStateID(5, fb.IsPaused ? 3 : 1);
        g_theme.DrawThemeBackground(gr, 0, top, g_pos, g_bar_height);
    }
}

function on_mouse_lbtn_down(x, y) {
    if (g_length > 0) {
        g_drag = true;
        on_mouse_move(x, y);
    }
}

function on_mouse_lbtn_up(x, y) {
    if (g_length > 0 && g_drag) {
        g_drag = false;
        fb.PlaybackTime = g_length * g_pos / ww;
        on_mouse_move(x, y);
    }
}

function on_mouse_move(x, y) {
    if (g_drag) {
        g_pos = clamp(x, 0, ww);
        window.Repaint();
    }
}

function on_mouse_wheel(delta) {
    fb.PlaybackTime = fb.PlaybackTime + delta * 2;
}

function on_playback_time(time) {
    if (!g_drag) {
        if (g_length > 0) g_pos = ww * time / g_length;
        window.Repaint();
    }
}

function on_playback_seek() {
    if (!g_drag && g_length > 0) window.Repaint();
}

function on_playback_pause() {
    window.Repaint();
}

function on_playback_stop() {
    g_length = 0;
    g_pos = 0;
    g_drag = false;
    window.Repaint();
}

function on_playback_new_track() {
    g_length = fb.PlaybackLength;
    g_pos = 0;
    g_drag = false;
    window.Repaint();
}

if (fb.IsPlaying) on_playback_new_track();