var DT_CENTER = 0x00000001;
var DT_VCENTER = 0x00000004;
var DT_SINGLELINE = 0x00000020;
var g_tooltip = window.CreateTooltip();
var g_trackingMouse = false;
var v, old_v;

function RGB(r, g, b) {
    return (0xff000000 | (r << 16) | (g << 8) | (b));
}

var g_font = gdi.Font("Tahoma", 12, 0);
var g_drag = 0;

function on_paint(gr) {
    var ww = window.Width;
    var wh = window.Height;
    var volume = fb.Volume;
    var pos = window.Width * ((100 + volume) / 100);
    var txt = (Math.ceil(volume)) + "dB";
    gr.FillGradRect(0, 0, pos, wh, 90, RGB(240, 240, 240), RGB(100, 230, 100));
    gr.FillGradRect(pos, 0, ww - pos, wh, 90, RGB(240, 240, 240), RGB(190, 190, 190));
    gr.GdiDrawText(txt, g_font, RGB(64, 64, 128), 0, 0, ww, wh, DT_CENTER | DT_VCENTER | DT_SINGLELINE);
    gr.DrawRect(0, 0, ww - 1, wh - 1, 1.0, RGB(150, 150, 150));
}

function on_mouse_lbtn_down(x, y) {
    g_drag = 1;
}

function on_mouse_lbtn_up(x, y) {
    on_mouse_move(x, y);
    g_drag = 0;
}

function on_mouse_move(x, y) {
    if (!g_trackingMouse) {
        g_tooltip.Activate();
        g_tooltip.TrackActivate = true;
        g_trackingMouse = true;
    }
    var v = x / window.Width;
    v = (v < 0) ? 0 : (v < 1) ? v : 1;
    v = -100 * (1 - v);
    if (old_v != v) {
        g_tooltip.Text = Math.ceil(v) + "dB";
        g_tooltip.TrackPosition(x, y - 20);
        old_v = v;
    }
    if (g_drag && fb.Volume != v) fb.Volume = v;
}

function on_mouse_leave() {
    g_trackingMouse = false;
    g_tooltip.TrackActivate = false;
}

function on_mouse_wheel(delta) {
    if (delta > 0) fb.VolumeUp();
    else fb.VolumeDown();
}

function on_volume_change(val) {
    window.Repaint();
}