jquery.tablednd.js

news新闻系统. news新闻系统 news新闻系统

/**
 * TableDnD plug-in for JQuery, allows you to drag and drop table rows
 * You can set up various options to control how the system will work
 * Copyright (c) Denis Howlett <[e-mail]>
 * Licensed like jQuery, see http://docs.jquery.com/License.
 *
 * Configuration options:
 * 
 * onDragStyle
 *     This is the style that is assigned to the row during drag. There are limitations to the styles that can be
 *     associated with a row (such as you can't assign a border--well you can, but it won't be
 *     displayed). (So instead consider using onDragClass.) The CSS style to apply is specified as
 *     a map (as used in the jQuery css(...) function).
 * onDropStyle
 *     This is the style that is assigned to the row when it is dropped. As for onDragStyle, there are limitations
 *     to what you can do. Also this replaces the original style, so again consider using onDragClass which
 *     is simply added and then removed on drop.
 * onDragClass
 *     This class is added for the duration of the drag and then removed when the row is dropped. It is more
 *     flexible than using onDragStyle since it can be inherited by the row cells and other content. The default
 *     is class is tDnD_whileDrag. So to use the default, simply customise this CSS class in your
 *     stylesheet.
 * onDrop
 *     Pass a function that will be called when the row is dropped. The function takes 2 parameters: the table
 *     and the row that was dropped. You can work out the new order of the rows by using
 *     table.rows.
 * onDragStart
 *     Pass a function that will be called when the user starts dragging. The function takes 2 parameters: the
 *     table and the row which the user has started to drag.
 * onAllowDrop
 *     Pass a function that will be called as a row is over another row. If the function returns true, allow 
 *     dropping on that row, otherwise not. The function takes 2 parameters: the dragged row and the row under
 *     the cursor. It returns a boolean: true allows the drop, false doesn't allow it.
 * scrollAmount
 *     This is the number of pixels to scroll if the user moves the mouse cursor to the top or bottom of the
 *     window. The page should automatically scroll up or down as appropriate (tested in IE6, IE7, Safari, FF2,
 *     FF3 beta
 * dragHandle
 *     This is the name of a class that you assign to one or more cells in each row that is draggable. If you
 *     specify this class, then you are responsible for setting cursor: move in the CSS and only these cells
 *     will have the drag behaviour. If you do not specify a dragHandle, then you get the old behaviour where
 *     the whole row is draggable.
 * 
 * Other ways to control behaviour:
 *
 * Add class="nodrop" to any rows for which you don't want to allow dropping, and class="nodrag" to any rows
 * that you don't want to be draggable.
 *
 * Inside the onDrop method you can also call $.tableDnD.serialize() this returns a string of the form
 * <tableID>[]=<rowID1>&<tableID>[]=<rowID2> so that you can send this back to the server. The table must have
 * an ID as must all the rows.
 *
 * Other methods:
 *
 * $("...").tableDnDUpdate() 
 * Will update all the matching tables, that is it will reapply the mousedown method to the rows (or handle cells).
 * This is useful if you have updated the table rows using Ajax and you want to make the table draggable again.
 * The table maintains the original configuration (so you don't have to specify it again).
 *
 * $("...").tableDnDSerialize()
 * Will serialize and return the serialized string as above, but for each of the matching tables--so it can be
 * called from anywhere and isn't dependent on the currentTable being set up correctly before calling
 *
 * Known problems:
 * - Auto-scoll has some problems with IE7  (it scrolls even when it shouldn't), work-around: set scrollAmount to 0
 * 
 * Version 0.2: 2008-02-20 First public version
 * Version 0.3: 2008-02-07 Added onDragStart option
 *                         Made the scroll amount configurable (default is 5 as before)
 * Version 0.4: 2008-03-15 Changed the noDrag/noDrop attributes to nodrag/nodrop classes
 *                         Added onAllowDrop to control dropping
 *                         Fixed a bug which meant that you couldn't set the scroll amount in both directions
 *                         Added serialize method
 * Version 0.5: 2008-05-16 Changed so that if you specify a dragHandle class it doesn't make the whole row
 *                         draggable
 *                         Improved the serialize method to use a default (and settable) regular expression.
 *                         Added tableDnDupate() and tableDnDSerialize() to be called when you are outside the table
 */
jQuery.tableDnD = {
    /** Keep hold of the current table being dragged */
    currentTable : null,
    /** Keep hold of the current drag object if any */
    dragObject: null,
    /** The current mouse offset */
    mouseOffset: null,
    /** Remember the old value of Y so that we don't do too much processing */
    oldY: 0,

    /** Actually build the structure */
    build: function(options) {
        // Set up the defaults if any

        this.each(function() {
            // This is bound to each matching table, set up the defaults and override with user options
            this.tableDnDConfig = jQuery.extend({
                onDragStyle: null,
                onDropStyle: null,
				// Add in the default class for whileDragging
				onDragClass: "tDnD_whileDrag",
                onDrop: null,
                onDragStart: null,
                scrollAmount: 5,
				serializeRegexp: /[^\-]*$/, // The regular expression to use to trim row IDs
				serializeParamName: null, // If you want to specify another parameter name instead of the table ID
                dragHandle: null // If you give the name of a class here, then only Cells with this class will be draggable
            }, options || {});
            // Now make the rows draggable
            jQuery.tableDnD.makeDraggable(this);
        });

        // Now we need to capture the mouse up and mouse move event
        // We can use bind so that we don't interfere with other event handlers
        jQuery(document)
            .bind('mousemove', jQuery.tableDnD.mousemove)
            .bind('mouseup', jQuery.tableDnD.mouseup);

        // Don't break the chain
        return this;
    },

    /** This function makes all the rows on the table draggable apart from those marked as "NoDrag" */
    makeDraggable: function(table) {
        var config = table.tableDnDConfig;
		if (table.tableDnDConfig.dragHandle) {
			// We only need to add the event to the specified cells
			var cells = jQuery("td."+table.tableDnDConfig.dragHandle, table);
			cells.each(function() {
				// The cell is bound to "this"
                jQuery(this).mousedown(function(ev) {
                    jQuery.tableDnD.dragObject = this.parentNode;
                    jQuery.tableDnD.currentTable = table;
                    jQuery.tableDnD.mouseOffset = jQuery.tableDnD.getMouseOffset(this, ev);
                    if (config.onDragStart) {
                        // Call the onDrop method if there is one
                        config.onDragStart(table, this);
                    }
                    return false;
                });
			})
		} else {
			// For backwards compatibility, we add the event to the whole row
	        var rows = jQuery("tr", table); // get all the rows as a wrapped set
	        rows.each(function() {
				// Iterate through each row, the row is bound to "this"
				var row = jQuery(this);
				if (! row.hasClass("nodrag")) {
	                row.mousedown(function(ev) {
	                    if (ev.target.tagName == "TD") {
	                        jQuery.tableDnD.dragObject = this;
	                        jQuery.tableDnD.currentTable = table;
	                        jQuery.tableDnD.mouseOffset = jQuery.tableDnD.getMouseOffset(this, ev);
	                        if (config.onDragStart) {
	                            // Call the onDrop method if there is one
	                            config.onDragStart(table, this);
	                        }
	                        return false;
	                    }
	                }).css("cursor", "move"); // Store the tableDnD object
				}
			});
		}
	},

	updateTables: function() {
		this.each(function() {
			// this is now bound to each matching table
			if (this.tableDnDConfig) {
				jQuery.tableDnD.makeDraggable(this);
			}
		})
	},

    /** Get the mouse coordinates from the event (allowing for browser differences) */
    mouseCoords: function(ev){
        if(ev.pageX || ev.pageY){
            return {x:ev.pageX, y:ev.pageY};
        }
        return {
            x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
            y:ev.clientY + document.body.scrollTop  - document.body.clientTop
        };
    },

    /** Given a target element and a mouse event, get the mouse offset from that element.
        To do this we need the element's position and the mouse position */
    getMouseOffset: function(target, ev) {
        ev = ev || window.event;

        var docPos    = this.getPosition(target);
        var mousePos  = this.mouseCoords(ev);
        return {x:mousePos.x - docPos.x, y:mousePos.y - docPos.y};
    },