source: Dev/branches/jQueryUI/js/jquery/ui/jquery.ui.mouse.js @ 244

/*!
 * jQuery UI Mouse 1.8.17
 *
 * Copyright 2011, AUTHORS.txt (http://jqueryui.com/about)
 * Dual licensed under the MIT or GPL Version 2 licenses.
 * http://jquery.org/license
 *
 * http://docs.jquery.com/UI/Mouse
 *
 * Depends:
 *      jquery.ui.widget.js
 */
(function( $, undefined ) {

var mouseHandled = false;
$( document ).mouseup( function( e ) {
        mouseHandled = false;
});

$.widget("ui.mouse", {
        options: {
                cancel: ':input,option',
                distance: 1,
                delay: 0
        },
        _mouseInit: function() {
                var self = this;

                this.element
                        .bind('mousedown.'+this.widgetName, function(event) {
                                return self._mouseDown(event);
                        })
                        .bind('click.'+this.widgetName, function(event) {
                                if (true === $.data(event.target, self.widgetName + '.preventClickEvent')) {
                                    $.removeData(event.target, self.widgetName + '.preventClickEvent');
                                        event.stopImmediatePropagation();
                                        return false;
                                }
                        });

                this.started = false;
        },

        // TODO: make sure destroying one instance of mouse doesn't mess with
        // other instances of mouse
        _mouseDestroy: function() {
                this.element.unbind('.'+this.widgetName);
        },

        _mouseDown: function(event) {
                // don't let more than one widget handle mouseStart
                if( mouseHandled ) { return };

                // we may have missed mouseup (out of window)
                (this._mouseStarted && this._mouseUp(event));

                this._mouseDownEvent = event;

                var self = this,
                        btnIsLeft = (event.which == 1),
                        // event.target.nodeName works around a bug in IE 8 with
                        // disabled inputs (#7620)
                        elIsCancel = (typeof this.options.cancel == "string" && event.target.nodeName ? $(event.target).closest(this.options.cancel).length : false);
                if (!btnIsLeft || elIsCancel || !this._mouseCapture(event)) {
                        return true;
                }

                this.mouseDelayMet = !this.options.delay;
                if (!this.mouseDelayMet) {
                        this._mouseDelayTimer = setTimeout(function() {
                                self.mouseDelayMet = true;
                        }, this.options.delay);
                }

                if (this._mouseDistanceMet(event) && this._mouseDelayMet(event)) {
                        this._mouseStarted = (this._mouseStart(event) !== false);
                        if (!this._mouseStarted) {
                                event.preventDefault();
                                return true;
                        }
                }

                // Click event may never have fired (Gecko & Opera)
                if (true === $.data(event.target, this.widgetName + '.preventClickEvent')) {
                        $.removeData(event.target, this.widgetName + '.preventClickEvent');
                }

                // these delegates are required to keep context
                this._mouseMoveDelegate = function(event) {
                        return self._mouseMove(event);
                };
                this._mouseUpDelegate = function(event) {
                        return self._mouseUp(event);
                };
                $(document)
                        .bind('mousemove.'+this.widgetName, this._mouseMoveDelegate)
                        .bind('mouseup.'+this.widgetName, this._mouseUpDelegate);

                event.preventDefault();
                
                mouseHandled = true;
                return true;
        },

        _mouseMove: function(event) {
                // IE mouseup check - mouseup happened when mouse was out of window
                if ($.browser.msie && !(document.documentMode >= 9) && !event.button) {
                        return this._mouseUp(event);
                }

                if (this._mouseStarted) {
                        this._mouseDrag(event);
                        return event.preventDefault();
                }

                if (this._mouseDistanceMet(event) && this._mouseDelayMet(event)) {
                        this._mouseStarted =
                                (this._mouseStart(this._mouseDownEvent, event) !== false);
                        (this._mouseStarted ? this._mouseDrag(event) : this._mouseUp(event));
                }

                return !this._mouseStarted;
        },

        _mouseUp: function(event) {
                $(document)
                        .unbind('mousemove.'+this.widgetName, this._mouseMoveDelegate)
                        .unbind('mouseup.'+this.widgetName, this._mouseUpDelegate);

                if (this._mouseStarted) {
                        this._mouseStarted = false;

                        if (event.target == this._mouseDownEvent.target) {
                            $.data(event.target, this.widgetName + '.preventClickEvent', true);
                        }

                        this._mouseStop(event);
                }

                return false;
        },

        _mouseDistanceMet: function(event) {
                return (Math.max(
                                Math.abs(this._mouseDownEvent.pageX - event.pageX),
                                Math.abs(this._mouseDownEvent.pageY - event.pageY)
                        ) >= this.options.distance
                );
        },

        _mouseDelayMet: function(event) {
                return this.mouseDelayMet;
        },

        // These are placeholder methods, to be overriden by extending plugin
        _mouseStart: function(event) {},
        _mouseDrag: function(event) {},
        _mouseStop: function(event) {},
        _mouseCapture: function(event) { return true; }
});

})(jQuery);