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) {
// Make sure options exists
options = options || {};
// Set up the defaults if any
this.each(function() {
// Remember the options
this.tableDnDConfig = {
onDragStyle: options.onDragStyle,
onDropStyle: options.onDropStyle,
// Add in the default class for whileDragging
onDragClass: options.onDragClass ? options.onDragClass : "dragged",
onDrop: options.onDrop,
onDragStart: options.onDragStart,
scrollAmount: options.scrollAmount ? options.scrollAmount : 5
};
// 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) {
// Now initialise the rows
var rows = table.rows; //getElementsByTagName("tr")
var config = table.tableDnDConfig;
for (var i=0; i<rows.length; i++) {
// To make non-draggable rows, add the nodrag class (eg for Category and Header rows)
// inspired by John Tarr and Famic
var nodrag = $(rows[i]).hasClass("nodrag");
if (! nodrag) { //There is no NoDnD attribute on rows I want to drag
jQuery(rows[i]).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
}
}
},
/** 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};
},
/** Get the position of an element by going up the DOM tree and adding up all the offsets */
getPosition: function(e){
var left = 0;
var top = 0;
/** Safari fix -- thanks to Luis Chato for this! */
if (e.offsetHeight == 0) {
/** Safari 2 doesn't correctly grab the offsetTop of a table row
this is detailed here:
http://jacob.peargrove.com/blog/2006/technical/table-row-offsettop-bug-in-safari/
the solution is likewise noted there, grab the offset of a table cell in the row - the firstChild.
note that firefox will return a text node as a first child, so designing a more thorough
solution may need to take that into account, for now this seems to work in firefox, safari, ie */
e = e.firstChild; // a table cell
}
while (e.offsetParent){
left += e.offsetLeft;
top += e.offsetTop;
e = e.offsetParent;
}
left += e.offsetLeft;
top += e.offsetTop;
return {x:left, y:top};
},
mousemove: function(ev) {
if (jQuery.tableDnD.dragObject == null) {
return;
}
var dragObj = jQuery(jQuery.tableDnD.dragObject);
var config = jQuery.tableDnD.currentTable.tableDnDConfig;
var mousePos = jQuery.tableDnD.mouseCoords(ev);
var y = mousePos.y - jQuery.tableDnD.mouseOffset.y;
//auto scroll the window
var yOffset = window.pageYOffset;
if (document.all) {
// Windows version
//yOffset=document.body.scrollTop;
if (typeof document.compatMode != 'undefined' &&
document.compatMode != 'BackCompat') {
yOffset = document.documentElement.scrollTop;
}
else if (typeof document.body != 'undefined') {
yOffset=document.body.scrollTop;
}
}
if (mousePos.y-yOffset < config.scrollAmount) {
window.scrollBy(0, -config.scrollAmount);
} else {
var windowHeight = window.innerHeight ? window.innerHeight
: document.documentElement.clientHeight ? document.documentElement.clientHeight : document.body.clientHeight;
if (windowHeight-(mousePos.y-yOffset) < config.scrollAmount) {
window.scrollBy(0, config.scrollAmount);
}
}
if (y != jQuery.tableDnD.oldY) {
// work out if we're going up or down...
var movingDown = y > jQuery.tableDnD.oldY;
// update the old value
jQuery.tableDnD.oldY = y;
// update the style to show we're dragging
if (config.onDragClass) {
dragObj.addClass(config.onDragClass);
} else {
dragObj.css(config.onDragStyle);
}
// If we're over a row then move the dragged row to there so that the user sees the
// effect dynamically
var currentRow = jQuery.tableDnD.findDropTargetRow(dragObj, y);
if (currentRow) {
// TODO worry about what happens when there are multiple TBODIES
if (movingDown && jQuery.tableDnD.dragObject != currentRow) {
jQuery.tableDnD.dragObject.parentNode.insertBefore(jQuery.tableDnD.dragObject, currentRow.nextSibling);
} else if (! movingDown && jQuery.tableDnD.dragObject != currentRow) {
jQuery.tableDnD.dragObject.parentNode.insertBefore(jQuery.tableDnD.dragObject, currentRow);
}
}
}
return false;
},
/** We're only worried about the y position really, because we can only move rows up and down */
findDropTargetRow: function(draggedRow, y) {
var rows = jQuery.tableDnD.currentTable.rows;
for (var i=0; i<rows.length; i++) {
var row = rows[i];
var rowY = this.getPosition(row).y;
var rowHeight = parseInt(row.offsetHeight)/2;
if (row.offsetHeight == 0) {
rowY = this.getPosition(row.firstChild).y;
rowHeight = parseInt(row.firstChild.offsetHeight)/2;
}
// Because we always have to insert before, we need to offset the height a bit
if ((y > rowY - rowHeight) && (y < (rowY + rowHeight))) {
// that's the row we're over
// If it's the same as the current row, ignore it
if (row == draggedRow) {return null;}
var config = jQuery.tableDnD.currentTable.tableDnDConfig;
if (config.onAllowDrop) {
if (config.onAllowDrop(draggedRow, row)) {
return row;
} else {
return null;
}
} else {
// If a row has nodrop class, then don't allow dropping (inspired by John Tarr and Famic)
var nodrop = $(row).hasClass("nodrop");
if (! nodrop) {
return row;
} else {
return null;
}
}
return row;
}
}
return null;
},
mouseup: function(e) {
if (jQuery.tableDnD.currentTable && jQuery.tableDnD.dragObject) {
var droppedRow = jQuery.tableDnD.dragObject;
var config = jQuery.tableDnD.currentTable.tableDnDConfig;
// If we have a dragObject, then we need to release it,
// The row will already have been moved to the right place so we just reset stuff
if (config.onDragClass) {
jQuery(droppedRow).removeClass(config.onDragClass);
} else {
jQuery(droppedRow).css(config.onDropStyle);
}
jQuery.tableDnD.dragObject = null;
if (config.onDrop) {
// Call the onDrop method if there is one
config.onDrop(jQuery.tableDnD.currentTable, droppedRow);
}
jQuery.tableDnD.currentTable = null; // let go of the table too
}
},
serialize: function() {
if (jQuery.tableDnD.currentTable) {
var result = "";
var tableId = jQuery.tableDnD.currentTable.id;
var rows = jQuery.tableDnD.currentTable.rows;
for (var i=0; i<rows.length; i++) {
if (result.length > 0) result += "&";
result += tableId + '[]=' + rows[i].id;
}
return result;
} else {
return "Error: No Table id set, you need to set an id on your table and every row";
}
}
}
jQuery.fn.extend(
{
tableDnD : jQuery.tableDnD.build
}
);