function SliderWidget(elmt, options) {
    this._elmt = elmt;
    this._options = options || {};
    
    this._range = {
        min: 0,
        max: 1,
        step: 1,
        from: 0,
        to: 0
    };
    this._drag = null;
    
    var self = this;
    this._mouseMoveHandler = function(evt) {
        return self._onMouseMove(evt);
    };
    this._mouseUpHandler = function(evt) {
        return self._onMouseUp(evt);
    };
    
    this._initializeUI();
    this._update();
}

SliderWidget.prototype.update = function(min, max, step, from, to) {
    if (step <= 0) {
        step = 1;
    }
    max = Math.max(max, min + step);
    from = Math.max(min, from);
    to = Math.min(max, to);
    
    this._range = {
        min: min,
        max: max,
        step: step,
        from: from,
        to: to
    };
    this._update();
};

SliderWidget.prototype._initializeUI = function() {
    this._elmt.addClass("slider-widget");
    
    this._leftTintedRect = $("<div>").addClass("slider-widget-tint left").appendTo(this._elmt);
    this._rightTintedRect = $("<div>").addClass("slider-widget-tint right").appendTo(this._elmt);
    this._highlightRect = $("<div>").addClass("slider-widget-highlight slider-widget-draggable").attr("part", "highlight").appendTo(this._elmt);
    this._leftBracket = $("<div>").addClass("slider-widget-bracket slider-widget-draggable left").attr("part", "left").appendTo(this._elmt);
    this._rightBracket = $("<div>").addClass("slider-widget-bracket slider-widget-draggable right").attr("part", "right").appendTo(this._elmt);
    
    var self = this;
    this._elmt.find(".slider-widget-draggable")
        .mousedown(function(evt) {
            return self._onMouseDown(evt, this.getAttribute("part"));
        });
    
    this._highlightRect.dblclick(function(evt) {
        if (self._range.from > self._range.min || self._range.to < self._range.max) {
            self._range.from = self._range.min;
            self._range.to = self._range.max;
            self._update();
            self._trigger("stop");
        }
    });
        
    this._elmt
        .mousemove(function(evt) {
            return self._onMouseMove(evt);
        })
        .mouseup(function(evt) {
            return self._onMouseUp(evt);
        });
};

SliderWidget.prototype._onMouseDown = function(evt, part) {
    if (this._drag) {
        return;
    }
    
    $(document).mousemove(this._mouseMoveHandler);
    $(document).mouseup(this._mouseUpHandler);
    
    this._drag = {
        sureDrag: false,
        overlay: $('<div>').addClass("slider-widget-overlay").appendTo(document.body)
    };
    if ("highlight" == part) {
        this._drag.elmt = this._highlightRect;
        this._drag.value = this._range.from;
        $(this._drag.overlay).css("cursor", "move");
    } else if ("left" == part) {
        this._drag.elmt = this._leftBracket;
        $(this._drag.overlay).css("cursor", "e-resize");
    } else if ("right" == part) {
        this._drag.elmt = this._rightBracket;
        $(this._drag.overlay).css("cursor", "w-resize");
    }
    this._drag.what = part;
    this._drag.from = this._range.from;
    this._drag.to = this._range.to;
    this._drag.down = {
        x: evt.pageX,
        y: evt.pageY
    };
};

SliderWidget.prototype._onMouseUp = function(evt) {
    if (!(this._drag)) {
        return;
    }
    
    $(document).unbind("mousemove", this._mouseMoveHandler);
    $(document).unbind("mouseup", this._mouseUpHandler);
    
    if (this._drag.sureDrag) {
        this._update();
        this._trigger("stop");
    }
    this._drag.overlay.remove();
    this._drag = null;
};

SliderWidget.prototype._trigger = function(eventName) {
    this._elmt.trigger(eventName, [{ from: this._range.from, to: this._range.to }]);
};

SliderWidget.prototype._onMouseMove = function(evt) {
    if (!(this._drag)) {
        return;
    }
    
    var drag = this._drag;
    var range = this._range;
    
    var offset = this._elmt.offset();
    var xDiff = evt.pageX - drag.down.x;
    var yDiff = evt.pageX - drag.down.y;
    
    if (Math.abs(xDiff) >= 2) {
        drag.sureDrag = true;
    }
    
    var pixelWidth = this._elmt.width();
    var scale = pixelWidth / (range.max - range.min);
    var vDiff = xDiff / scale;
    
    var adjustFrom = function() {
        range.from = drag.from + Math.floor(vDiff / range.step) * range.step;
        range.from = Math.max(Math.min(range.from, range.max), range.min);
    };
    var adjustTo = function() {
        range.to = drag.to + Math.floor(vDiff / range.step) * range.step;
        range.to = Math.max(Math.min(range.to, range.max), range.min);
    };
    
    if (drag.what == "left") {
        adjustFrom();
        range.to = Math.min(Math.max(range.to, range.from + range.step), range.max);
    } else if (drag.what == "right") {
        adjustTo();
        range.from = Math.max(Math.min(range.from, range.to - range.step), range.min);
    } else {
        adjustFrom();
        adjustTo();
    }
    
    this._update();
    this._trigger("slide");
    
    evt.preventDefault();
    return false;
};

SliderWidget.prototype._update = function() {
    var range = this._range;
    
    var pixelWidth = this._elmt.width();
    var scale = pixelWidth / (range.max - range.min);
    var valueToPixel = function(x) {
        return (x - range.min) * scale;
    };
    
    var fromPixel = Math.floor(valueToPixel(range.from));
    var toPixel = Math.floor(valueToPixel(range.to));
    
    if (range.from == range.min && range.to == range.max) {
        this._leftTintedRect.hide();
        this._rightTintedRect.hide();
    } else {
        this._leftTintedRect.show().width(fromPixel);
        this._rightTintedRect.show().width(pixelWidth - toPixel);
    }
    
    this._highlightRect.css("left", (fromPixel - 1) + "px").width(toPixel - fromPixel);
    this._leftBracket.css("left", fromPixel + "px");
    this._rightBracket.css("left", toPixel + "px");
};