comparison misc/tabledrag.js @ 0:ff03f76ab3fe

initial version

+(function ($) {
+
+/**
+ * Drag and drop table rows with field manipulation.
+ *
+ * Using the drupal_add_tabledrag() function, any table with weights or parent
+ * relationships may be made into draggable tables. Columns containing a field
+ * may optionally be hidden, providing a better user experience.
+ *
+ * Created tableDrag instances may be modified with custom behaviors by
+ * overriding the .onDrag, .onDrop, .row.onSwap, and .row.onIndent methods.
+ * See blocks.js for an example of adding additional functionality to tableDrag.
+ */
+Drupal.behaviors.tableDrag = {
+  attach: function (context, settings) {
+    for (var base in settings.tableDrag) {
+      $('#' + base, context).once('tabledrag', function () {
+        // Create the new tableDrag instance. Save in the Drupal variable
+        // to allow other scripts access to the object.
+        Drupal.tableDrag[base] = new Drupal.tableDrag(this, settings.tableDrag[base]);
+      });
+    }
+  }
+};
+
+/**
+ * Constructor for the tableDrag object. Provides table and field manipulation.
+ *
+ * @param table
+ *   DOM object for the table to be made draggable.
+ * @param tableSettings
+ *   Settings for the table added via drupal_add_dragtable().
+ */
+Drupal.tableDrag = function (table, tableSettings) {
+  var self = this;
+
+  // Required object variables.
+  this.table = table;
+  this.tableSettings = tableSettings;
+  this.dragObject = null; // Used to hold information about a current drag operation.
+  this.rowObject = null; // Provides operations for row manipulation.
+  this.oldRowElement = null; // Remember the previous element.
+  this.oldY = 0; // Used to determine up or down direction from last mouse move.
+  this.changed = false; // Whether anything in the entire table has changed.
+  this.maxDepth = 0; // Maximum amount of allowed parenting.
+  this.rtl = $(this.table).css('direction') == 'rtl' ? -1 : 1; // Direction of the table.
+
+  // Configure the scroll settings.
+  this.scrollSettings = { amount: 4, interval: 50, trigger: 70 };
+  this.scrollInterval = null;
+  this.scrollY = 0;
+  this.windowHeight = 0;
+
+  // Check this table's settings to see if there are parent relationships in
+  // this table. For efficiency, large sections of code can be skipped if we
+  // don't need to track horizontal movement and indentations.
+  this.indentEnabled = false;
+  for (var group in tableSettings) {
+    for (var n in tableSettings[group]) {
+      if (tableSettings[group][n].relationship == 'parent') {
+        this.indentEnabled = true;
+      }
+      if (tableSettings[group][n].limit > 0) {
+        this.maxDepth = tableSettings[group][n].limit;
+      }
+    }
+  }
+  if (this.indentEnabled) {
+    this.indentCount = 1; // Total width of indents, set in makeDraggable.
+    // Find the width of indentations to measure mouse movements against.
+    // Because the table doesn't need to start with any indentations, we
+    // manually append 2 indentations in the first draggable row, measure
+    // the offset, then remove.
+    var indent = Drupal.theme('tableDragIndentation');
+    var testRow = $('<tr/>').addClass('draggable').appendTo(table);
+    var testCell = $('<td/>').appendTo(testRow).prepend(indent).prepend(indent);
+    this.indentAmount = $('.indentation', testCell).get(1).offsetLeft - $('.indentation', testCell).get(0).offsetLeft;
+    testRow.remove();
+  }
+
+  // Make each applicable row draggable.
+  // Match immediate children of the parent element to allow nesting.
+  $('> tr.draggable, > tbody > tr.draggable', table).each(function () { self.makeDraggable(this); });
+
+  // Add a link before the table for users to show or hide weight columns.
+  $(table).before($('<a href="#" class="tabledrag-toggle-weight"></a>')
+    .attr('title', Drupal.t('Re-order rows by numerical weight instead of dragging.'))
+    .click(function () {
+      if ($.cookie('Drupal.tableDrag.showWeight') == 1) {
+        self.hideColumns();
+      }
+      else {
+        self.showColumns();
+      }
+      return false;
+    })
+    .wrap('<div class="tabledrag-toggle-weight-wrapper"></div>')
+    .parent()
+  );
+
+  // Initialize the specified columns (for example, weight or parent columns)
+  // to show or hide according to user preference. This aids accessibility
+  // so that, e.g., screen reader users can choose to enter weight values and
+  // manipulate form elements directly, rather than using drag-and-drop..
+  self.initColumns();
+
+  // Add mouse bindings to the document. The self variable is passed along
+  // as event handlers do not have direct access to the tableDrag object.
+  $(document).bind('mousemove', function (event) { return self.dragRow(event, self); });
+  $(document).bind('mouseup', function (event) { return self.dropRow(event, self); });
+};
+
+/**
+ * Initialize columns containing form elements to be hidden by default,
+ * according to the settings for this tableDrag instance.
+ *
+ * Identify and mark each cell with a CSS class so we can easily toggle
+ * show/hide it. Finally, hide columns if user does not have a
+ * 'Drupal.tableDrag.showWeight' cookie.
+ */
+Drupal.tableDrag.prototype.initColumns = function () {
+  for (var group in this.tableSettings) {
+    // Find the first field in this group.
+    for (var d in this.tableSettings[group]) {
+      var field = $('.' + this.tableSettings[group][d].target + ':first', this.table);
+      if (field.length && this.tableSettings[group][d].hidden) {
+        var hidden = this.tableSettings[group][d].hidden;
+        var cell = field.closest('td');
+        break;
+      }
+    }
+
+    // Mark the column containing this field so it can be hidden.
+    if (hidden && cell[0]) {
+      // Add 1 to our indexes. The nth-child selector is 1 based, not 0 based.
+      // Match immediate children of the parent element to allow nesting.
+      var columnIndex = $('> td', cell.parent()).index(cell.get(0)) + 1;
+      $('> thead > tr, > tbody > tr, > tr', this.table).each(function () {
+        // Get the columnIndex and adjust for any colspans in this row.
+        var index = columnIndex;
+        var cells = $(this).children();
+        cells.each(function (n) {
+          if (n < index && this.colSpan && this.colSpan > 1) {
+            index -= this.colSpan - 1;
+          }
+        });
+        if (index > 0) {
+          cell = cells.filter(':nth-child(' + index + ')');
+          if (cell[0].colSpan && cell[0].colSpan > 1) {
+            // If this cell has a colspan, mark it so we can reduce the colspan.
+            cell.addClass('tabledrag-has-colspan');
+          }
+          else {
+            // Mark this cell so we can hide it.
+            cell.addClass('tabledrag-hide');
+          }
+        }
+      });
+    }
+  }
+
+  // Now hide cells and reduce colspans unless cookie indicates previous choice.
+  // Set a cookie if it is not already present.
+  if ($.cookie('Drupal.tableDrag.showWeight') === null) {
+    $.cookie('Drupal.tableDrag.showWeight', 0, {
+      path: Drupal.settings.basePath,
+      // The cookie expires in one year.
+      expires: 365
+    });
+    this.hideColumns();
+  }
+  // Check cookie value and show/hide weight columns accordingly.
+  else {
+    if ($.cookie('Drupal.tableDrag.showWeight') == 1) {
+      this.showColumns();
+    }
+    else {
+      this.hideColumns();
+    }
+  }
+};
+
+/**
+ * Hide the columns containing weight/parent form elements.
+ * Undo showColumns().
+ */
+Drupal.tableDrag.prototype.hideColumns = function () {
+  // Hide weight/parent cells and headers.
+  $('.tabledrag-hide', 'table.tabledrag-processed').css('display', 'none');
+  // Show TableDrag handles.
+  $('.tabledrag-handle', 'table.tabledrag-processed').css('display', '');
+  // Reduce the colspan of any effected multi-span columns.
+  $('.tabledrag-has-colspan', 'table.tabledrag-processed').each(function () {
+    this.colSpan = this.colSpan - 1;
+  });
+  // Change link text.
+  $('.tabledrag-toggle-weight').text(Drupal.t('Show row weights'));
+  // Change cookie.
+  $.cookie('Drupal.tableDrag.showWeight', 0, {
+    path: Drupal.settings.basePath,
+    // The cookie expires in one year.
+    expires: 365
+  });
+  // Trigger an event to allow other scripts to react to this display change.
+  $('table.tabledrag-processed').trigger('columnschange', 'hide');
+};
+
+/**
+ * Show the columns containing weight/parent form elements
+ * Undo hideColumns().
+ */
+Drupal.tableDrag.prototype.showColumns = function () {
+  // Show weight/parent cells and headers.
+  $('.tabledrag-hide', 'table.tabledrag-processed').css('display', '');
+  // Hide TableDrag handles.
+  $('.tabledrag-handle', 'table.tabledrag-processed').css('display', 'none');
+  // Increase the colspan for any columns where it was previously reduced.
+  $('.tabledrag-has-colspan', 'table.tabledrag-processed').each(function () {
+    this.colSpan = this.colSpan + 1;
+  });
+  // Change link text.
+  $('.tabledrag-toggle-weight').text(Drupal.t('Hide row weights'));
+  // Change cookie.
+  $.cookie('Drupal.tableDrag.showWeight', 1, {
+    path: Drupal.settings.basePath,
+    // The cookie expires in one year.
+    expires: 365
+  });
+  // Trigger an event to allow other scripts to react to this display change.
+  $('table.tabledrag-processed').trigger('columnschange', 'show');
+};
+
+/**
+ * Find the target used within a particular row and group.
+ */
+Drupal.tableDrag.prototype.rowSettings = function (group, row) {
+  var field = $('.' + group, row);
+  for (var delta in this.tableSettings[group]) {
+    var targetClass = this.tableSettings[group][delta].target;
+    if (field.is('.' + targetClass)) {
+      // Return a copy of the row settings.
+      var rowSettings = {};
+      for (var n in this.tableSettings[group][delta]) {
+        rowSettings[n] = this.tableSettings[group][delta][n];
+      }
+      return rowSettings;
+    }
+  }
+};
+
+/**
+ * Take an item and add event handlers to make it become draggable.
+ */
+Drupal.tableDrag.prototype.makeDraggable = function (item) {
+  var self = this;
+
+  // Create the handle.
+  var handle = $('<a href="#" class="tabledrag-handle"><div class="handle">&nbsp;</div></a>').attr('title', Drupal.t('Drag to re-order'));
+  // Insert the handle after indentations (if any).
+  if ($('td:first .indentation:last', item).length) {
+    $('td:first .indentation:last', item).after(handle);
+    // Update the total width of indentation in this entire table.
+    self.indentCount = Math.max($('.indentation', item).length, self.indentCount);
+  }
+  else {
+    $('td:first', item).prepend(handle);
+  }
+
+  // Add hover action for the handle.
+  handle.hover(function () {
+    self.dragObject == null ? $(this).addClass('tabledrag-handle-hover') : null;
+  }, function () {
+    self.dragObject == null ? $(this).removeClass('tabledrag-handle-hover') : null;
+  });
+
+  // Add the mousedown action for the handle.
+  handle.mousedown(function (event) {
+    // Create a new dragObject recording the event information.
+    self.dragObject = {};
+    self.dragObject.initMouseOffset = self.getMouseOffset(item, event);
+    self.dragObject.initMouseCoords = self.mouseCoords(event);
+    if (self.indentEnabled) {
+      self.dragObject.indentMousePos = self.dragObject.initMouseCoords;
+    }
+
+    // If there's a lingering row object from the keyboard, remove its focus.
+    if (self.rowObject) {
+      $('a.tabledrag-handle', self.rowObject.element).blur();
+    }
+
+    // Create a new rowObject for manipulation of this row.
+    self.rowObject = new self.row(item, 'mouse', self.indentEnabled, self.maxDepth, true);
+
+    // Save the position of the table.
+    self.table.topY = $(self.table).offset().top;
+    self.table.bottomY = self.table.topY + self.table.offsetHeight;
+
+    // Add classes to the handle and row.
+    $(this).addClass('tabledrag-handle-hover');
+    $(item).addClass('drag');
+
+    // Set the document to use the move cursor during drag.
+    $('body').addClass('drag');
+    if (self.oldRowElement) {
+      $(self.oldRowElement).removeClass('drag-previous');
+    }
+
+    // Hack for IE6 that flickers uncontrollably if select lists are moved.
+    if (navigator.userAgent.indexOf('MSIE 6.') != -1) {
+      $('select', this.table).css('display', 'none');
+    }
+
+    // Hack for Konqueror, prevent the blur handler from firing.
+    // Konqueror always gives links focus, even after returning false on mousedown.
+    self.safeBlur = false;
+
+    // Call optional placeholder function.
+    self.onDrag();
+    return false;
+  });
+
+  // Prevent the anchor tag from jumping us to the top of the page.
+  handle.click(function () {
+    return false;
+  });
+
+  // Similar to the hover event, add a class when the handle is focused.
+  handle.focus(function () {
+    $(this).addClass('tabledrag-handle-hover');
+    self.safeBlur = true;
+  });
+
+  // Remove the handle class on blur and fire the same function as a mouseup.
+  handle.blur(function (event) {
+    $(this).removeClass('tabledrag-handle-hover');
+    if (self.rowObject && self.safeBlur) {
+      self.dropRow(event, self);
+    }
+  });
+
+  // Add arrow-key support to the handle.
+  handle.keydown(function (event) {
+    // If a rowObject doesn't yet exist and this isn't the tab key.
+    if (event.keyCode != 9 && !self.rowObject) {
+      self.rowObject = new self.row(item, 'keyboard', self.indentEnabled, self.maxDepth, true);
+    }
+
+    var keyChange = false;
+    switch (event.keyCode) {
+      case 37: // Left arrow.
+      case 63234: // Safari left arrow.
+        keyChange = true;
+        self.rowObject.indent(-1 * self.rtl);
+        break;
+      case 38: // Up arrow.
+      case 63232: // Safari up arrow.
+        var previousRow = $(self.rowObject.element).prev('tr').get(0);
+        while (previousRow && $(previousRow).is(':hidden')) {
+          previousRow = $(previousRow).prev('tr').get(0);
+        }
+        if (previousRow) {
+          self.safeBlur = false; // Do not allow the onBlur cleanup.
+          self.rowObject.direction = 'up';
+          keyChange = true;
+
+          if ($(item).is('.tabledrag-root')) {
+            // Swap with the previous top-level row.
+            var groupHeight = 0;
+            while (previousRow && $('.indentation', previousRow).length) {
+              previousRow = $(previousRow).prev('tr').get(0);
+              groupHeight += $(previousRow).is(':hidden') ? 0 : previousRow.offsetHeight;
+            }
+            if (previousRow) {
+              self.rowObject.swap('before', previousRow);
+              // No need to check for indentation, 0 is the only valid one.
+              window.scrollBy(0, -groupHeight);
+            }
+          }
+          else if (self.table.tBodies[0].rows[0] != previousRow || $(previousRow).is('.draggable')) {
+            // Swap with the previous row (unless previous row is the first one
+            // and undraggable).
+            self.rowObject.swap('before', previousRow);
+            self.rowObject.interval = null;
+            self.rowObject.indent(0);
+            window.scrollBy(0, -parseInt(item.offsetHeight, 10));
+          }
+          handle.get(0).focus(); // Regain focus after the DOM manipulation.
+        }
+        break;
+      case 39: // Right arrow.
+      case 63235: // Safari right arrow.
+        keyChange = true;
+        self.rowObject.indent(1 * self.rtl);
+        break;
+      case 40: // Down arrow.
+      case 63233: // Safari down arrow.
+        var nextRow = $(self.rowObject.group).filter(':last').next('tr').get(0);
+        while (nextRow && $(nextRow).is(':hidden')) {
+          nextRow = $(nextRow).next('tr').get(0);
+        }
+        if (nextRow) {
+          self.safeBlur = false; // Do not allow the onBlur cleanup.
+          self.rowObject.direction = 'down';
+          keyChange = true;
+
+          if ($(item).is('.tabledrag-root')) {
+            // Swap with the next group (necessarily a top-level one).
+            var groupHeight = 0;
+            var nextGroup = new self.row(nextRow, 'keyboard', self.indentEnabled, self.maxDepth, false);
+            if (nextGroup) {
+              $(nextGroup.group).each(function () {
+                groupHeight += $(this).is(':hidden') ? 0 : this.offsetHeight;
+              });
+              var nextGroupRow = $(nextGroup.group).filter(':last').get(0);
+              self.rowObject.swap('after', nextGroupRow);
+              // No need to check for indentation, 0 is the only valid one.
+              window.scrollBy(0, parseInt(groupHeight, 10));
+            }
+          }
+          else {
+            // Swap with the next row.
+            self.rowObject.swap('after', nextRow);
+            self.rowObject.interval = null;
+            self.rowObject.indent(0);
+            window.scrollBy(0, parseInt(item.offsetHeight, 10));
+          }
+          handle.get(0).focus(); // Regain focus after the DOM manipulation.
+        }
+        break;
+    }
+
+    if (self.rowObject && self.rowObject.changed == true) {
+      $(item).addClass('drag');
+      if (self.oldRowElement) {
+        $(self.oldRowElement).removeClass('drag-previous');
+      }
+      self.oldRowElement = item;
+      self.restripeTable();
+      self.onDrag();
+    }
+
+    // Returning false if we have an arrow key to prevent scrolling.
+    if (keyChange) {
+      return false;
+    }
+  });
+
+  // Compatibility addition, return false on keypress to prevent unwanted scrolling.
+  // IE and Safari will suppress scrolling on keydown, but all other browsers
+  // need to return false on keypress. http://www.quirksmode.org/js/keys.html
+  handle.keypress(function (event) {
+    switch (event.keyCode) {
+      case 37: // Left arrow.
+      case 38: // Up arrow.
+      case 39: // Right arrow.
+      case 40: // Down arrow.
+        return false;
+    }
+  });
+};
+
+/**
+ * Mousemove event handler, bound to document.
+ */
+Drupal.tableDrag.prototype.dragRow = function (event, self) {
+  if (self.dragObject) {
+    self.currentMouseCoords = self.mouseCoords(event);
+
+    var y = self.currentMouseCoords.y - self.dragObject.initMouseOffset.y;
+    var x = self.currentMouseCoords.x - self.dragObject.initMouseOffset.x;
+
+    // Check for row swapping and vertical scrolling.
+    if (y != self.oldY) {
+      self.rowObject.direction = y > self.oldY ? 'down' : 'up';
+      self.oldY = y; // Update the old value.
+
+      // Check if the window should be scrolled (and how fast).
+      var scrollAmount = self.checkScroll(self.currentMouseCoords.y);
+      // Stop any current scrolling.
+      clearInterval(self.scrollInterval);
+      // Continue scrolling if the mouse has moved in the scroll direction.
+      if (scrollAmount > 0 && self.rowObject.direction == 'down' || scrollAmount < 0 && self.rowObject.direction == 'up') {
+        self.setScroll(scrollAmount);
+      }
+
+      // If we have a valid target, perform the swap and restripe the table.
+      var currentRow = self.findDropTargetRow(x, y);
+      if (currentRow) {
+        if (self.rowObject.direction == 'down') {
+          self.rowObject.swap('after', currentRow, self);
+        }
+        else {
+          self.rowObject.swap('before', currentRow, self);
+        }
+        self.restripeTable();
+      }
+    }
+
+    // Similar to row swapping, handle indentations.
+    if (self.indentEnabled) {
+      var xDiff = self.currentMouseCoords.x - self.dragObject.indentMousePos.x;
+      // Set the number of indentations the mouse has been moved left or right.
+      var indentDiff = Math.round(xDiff / self.indentAmount * self.rtl);
+      // Indent the row with our estimated diff, which may be further
+      // restricted according to the rows around this row.
+      var indentChange = self.rowObject.indent(indentDiff);
+      // Update table and mouse indentations.
+      self.dragObject.indentMousePos.x += self.indentAmount * indentChange * self.rtl;
+      self.indentCount = Math.max(self.indentCount, self.rowObject.indents);
+    }
+
+    return false;
+  }
+};
+
+/**
+ * Mouseup event handler, bound to document.
+ * Blur event handler, bound to drag handle for keyboard support.
+ */
+Drupal.tableDrag.prototype.dropRow = function (event, self) {
+  // Drop row functionality shared between mouseup and blur events.
+  if (self.rowObject != null) {
+    var droppedRow = self.rowObject.element;
+    // The row is already in the right place so we just release it.
+    if (self.rowObject.changed == true) {
+      // Update the fields in the dropped row.
+      self.updateFields(droppedRow);
+
+      // If a setting exists for affecting the entire group, update all the
+      // fields in the entire dragged group.
+      for (var group in self.tableSettings) {
+        var rowSettings = self.rowSettings(group, droppedRow);
+        if (rowSettings.relationship == 'group') {
+          for (var n in self.rowObject.children) {
+            self.updateField(self.rowObject.children[n], group);
+          }
+        }
+      }
+
+      self.rowObject.markChanged();
+      if (self.changed == false) {
+        $(Drupal.theme('tableDragChangedWarning')).insertBefore(self.table).hide().fadeIn('slow');
+        self.changed = true;
+      }
+    }
+
+    if (self.indentEnabled) {
+      self.rowObject.removeIndentClasses();
+    }
+    if (self.oldRowElement) {
+      $(self.oldRowElement).removeClass('drag-previous');
+    }
+    $(droppedRow).removeClass('drag').addClass('drag-previous');
+    self.oldRowElement = droppedRow;
+    self.onDrop();
+    self.rowObject = null;
+  }
+
+  // Functionality specific only to mouseup event.
+  if (self.dragObject != null) {
+    $('.tabledrag-handle', droppedRow).removeClass('tabledrag-handle-hover');
+
+    self.dragObject = null;
+    $('body').removeClass('drag');
+    clearInterval(self.scrollInterval);
+
+    // Hack for IE6 that flickers uncontrollably if select lists are moved.
+    if (navigator.userAgent.indexOf('MSIE 6.') != -1) {
+      $('select', this.table).css('display', 'block');
+    }
+  }
+};
+
+/**
+ * Get the mouse coordinates from the event (allowing for browser differences).
+ */
+Drupal.tableDrag.prototype.mouseCoords = function (event) {
+  if (event.pageX || event.pageY) {
+    return { x: event.pageX, y: event.pageY };
+  }
+  return {
+    x: event.clientX + document.body.scrollLeft - document.body.clientLeft,
+    y: event.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.
+ */
+Drupal.tableDrag.prototype.getMouseOffset = function (target, event) {
+  var docPos   = $(target).offset();
+  var mousePos = this.mouseCoords(event);
+  return { x: mousePos.x - docPos.left, y: mousePos.y - docPos.top };
+};
+
+/**
+ * Find the row the mouse is currently over. This row is then taken and swapped
+ * with the one being dragged.
+ *
+ * @param x
+ *   The x coordinate of the mouse on the page (not the screen).
+ * @param y
+ *   The y coordinate of the mouse on the page (not the screen).
+ */
+Drupal.tableDrag.prototype.findDropTargetRow = function (x, y) {
+  var rows = $(this.table.tBodies[0].rows).not(':hidden');
+  for (var n = 0; n < rows.length; n++) {
+    var row = rows[n];
+    var indentDiff = 0;
+    var rowY = $(row).offset().top;
+    // Because Safari does not report offsetHeight on table rows, but does on
+    // table cells, grab the firstChild of the row and use that instead.
+    // http://jacob.peargrove.com/blog/2006/technical/table-row-offsettop-bug-in-safari.
+    if (row.offsetHeight == 0) {
+      var rowHeight = parseInt(row.firstChild.offsetHeight, 10) / 2;
+    }
+    // Other browsers.
+    else {
+      var rowHeight = parseInt(row.offsetHeight, 10) / 2;
+    }
+
+    // Because we always insert before, we need to offset the height a bit.
+    if ((y > (rowY - rowHeight)) && (y < (rowY + rowHeight))) {
+      if (this.indentEnabled) {
+        // Check that this row is not a child of the row being dragged.
+        for (var n in this.rowObject.group) {
+          if (this.rowObject.group[n] == row) {
+            return null;
+          }
+        }
+      }
+      else {
+        // Do not allow a row to be swapped with itself.
+        if (row == this.rowObject.element) {
+          return null;
+        }
+      }
+
+      // Check that swapping with this row is allowed.
+      if (!this.rowObject.isValidSwap(row)) {
+        return null;
+      }
+
+      // We may have found the row the mouse just passed over, but it doesn't
+      // take into account hidden rows. Skip backwards until we find a draggable
+      // row.
+      while ($(row).is(':hidden') && $(row).prev('tr').is(':hidden')) {
+        row = $(row).prev('tr').get(0);
+      }
+      return row;
+    }
+  }
+  return null;
+};
+
+/**
+ * After the row is dropped, update the table fields according to the settings
+ * set for this table.
+ *
+ * @param changedRow
+ *   DOM object for the row that was just dropped.
+ */
+Drupal.tableDrag.prototype.updateFields = function (changedRow) {
+  for (var group in this.tableSettings) {
+    // Each group may have a different setting for relationship, so we find
+    // the source rows for each separately.
+    this.updateField(changedRow, group);
+  }
+};
+
+/**
+ * After the row is dropped, update a single table field according to specific
+ * settings.
+ *
+ * @param changedRow
+ *   DOM object for the row that was just dropped.
+ * @param group
+ *   The settings group on which field updates will occur.
+ */
+Drupal.tableDrag.prototype.updateField = function (changedRow, group) {
+  var rowSettings = this.rowSettings(group, changedRow);
+
+  // Set the row as its own target.
+  if (rowSettings.relationship == 'self' || rowSettings.relationship == 'group') {
+    var sourceRow = changedRow;
+  }
+  // Siblings are easy, check previous and next rows.
+  else if (rowSettings.relationship == 'sibling') {
+    var previousRow = $(changedRow).prev('tr').get(0);
+    var nextRow = $(changedRow).next('tr').get(0);
+    var sourceRow = changedRow;
+    if ($(previousRow).is('.draggable') && $('.' + group, previousRow).length) {
+      if (this.indentEnabled) {
+        if ($('.indentations', previousRow).length == $('.indentations', changedRow)) {
+          sourceRow = previousRow;
+        }
+      }
+      else {
+        sourceRow = previousRow;
+      }
+    }
+    else if ($(nextRow).is('.draggable') && $('.' + group, nextRow).length) {
+      if (this.indentEnabled) {
+        if ($('.indentations', nextRow).length == $('.indentations', changedRow)) {
+          sourceRow = nextRow;
+        }
+      }
+      else {
+        sourceRow = nextRow;
+      }
+    }
+  }
+  // Parents, look up the tree until we find a field not in this group.
+  // Go up as many parents as indentations in the changed row.
+  else if (rowSettings.relationship == 'parent') {
+    var previousRow = $(changedRow).prev('tr');
+    while (previousRow.length && $('.indentation', previousRow).length >= this.rowObject.indents) {
+      previousRow = previousRow.prev('tr');
+    }
+    // If we found a row.
+    if (previousRow.length) {
+      sourceRow = previousRow[0];
+    }
+    // Otherwise we went all the way to the left of the table without finding
+    // a parent, meaning this item has been placed at the root level.
+    else {
+      // Use the first row in the table as source, because it's guaranteed to
+      // be at the root level. Find the first item, then compare this row
+      // against it as a sibling.
+      sourceRow = $(this.table).find('tr.draggable:first').get(0);
+      if (sourceRow == this.rowObject.element) {
+        sourceRow = $(this.rowObject.group[this.rowObject.group.length - 1]).next('tr.draggable').get(0);
+      }
+      var useSibling = true;
+    }
+  }
+
+  // Because we may have moved the row from one category to another,
+  // take a look at our sibling and borrow its sources and targets.
+  this.copyDragClasses(sourceRow, changedRow, group);
+  rowSettings = this.rowSettings(group, changedRow);
+
+  // In the case that we're looking for a parent, but the row is at the top
+  // of the tree, copy our sibling's values.
+  if (useSibling) {
+    rowSettings.relationship = 'sibling';
+    rowSettings.source = rowSettings.target;
+  }
+
+  var targetClass = '.' + rowSettings.target;
+  var targetElement = $(targetClass, changedRow).get(0);
+
+  // Check if a target element exists in this row.
+  if (targetElement) {
+    var sourceClass = '.' + rowSettings.source;
+    var sourceElement = $(sourceClass, sourceRow).get(0);
+    switch (rowSettings.action) {
+      case 'depth':
+        // Get the depth of the target row.
+        targetElement.value = $('.indentation', $(sourceElement).closest('tr')).length;
+        break;
+      case 'match':
+        // Update the value.
+        targetElement.value = sourceElement.value;
+        break;
+      case 'order':
+        var siblings = this.rowObject.findSiblings(rowSettings);
+        if ($(targetElement).is('select')) {
+          // Get a list of acceptable values.
+          var values = [];
+          $('option', targetElement).each(function () {
+            values.push(this.value);
+          });
+          var maxVal = values[values.length - 1];
+          // Populate the values in the siblings.
+          $(targetClass, siblings).each(function () {
+            // If there are more items than possible values, assign the maximum value to the row.
+            if (values.length > 0) {
+              this.value = values.shift();
+            }
+            else {
+              this.value = maxVal;
+            }
+          });
+        }
+        else {
+          // Assume a numeric input field.
+          var weight = parseInt($(targetClass, siblings[0]).val(), 10) || 0;
+          $(targetClass, siblings).each(function () {
+            this.value = weight;
+            weight++;
+          });
+        }
+        break;
+    }
+  }
+};
+
+/**
+ * Copy all special tableDrag classes from one row's form elements to a
+ * different one, removing any special classes that the destination row
+ * may have had.
+ */
+Drupal.tableDrag.prototype.copyDragClasses = function (sourceRow, targetRow, group) {
+  var sourceElement = $('.' + group, sourceRow);
+  var targetElement = $('.' + group, targetRow);
+  if (sourceElement.length && targetElement.length) {
+    targetElement[0].className = sourceElement[0].className;
+  }
+};
+
+Drupal.tableDrag.prototype.checkScroll = function (cursorY) {
+  var de  = document.documentElement;
+  var b  = document.body;
+
+  var windowHeight = this.windowHeight = window.innerHeight || (de.clientHeight && de.clientWidth != 0 ? de.clientHeight : b.offsetHeight);
+  var scrollY = this.scrollY = (document.all ? (!de.scrollTop ? b.scrollTop : de.scrollTop) : (window.pageYOffset ? window.pageYOffset : window.scrollY));
+  var trigger = this.scrollSettings.trigger;
+  var delta = 0;
+
+  // Return a scroll speed relative to the edge of the screen.
+  if (cursorY - scrollY > windowHeight - trigger) {
+    delta = trigger / (windowHeight + scrollY - cursorY);
+    delta = (delta > 0 && delta < trigger) ? delta : trigger;
+    return delta * this.scrollSettings.amount;
+  }
+  else if (cursorY - scrollY < trigger) {
+    delta = trigger / (cursorY - scrollY);
+    delta = (delta > 0 && delta < trigger) ? delta : trigger;
+    return -delta * this.scrollSettings.amount;
+  }
+};
+
+Drupal.tableDrag.prototype.setScroll = function (scrollAmount) {
+  var self = this;
+
+  this.scrollInterval = setInterval(function () {
+    // Update the scroll values stored in the object.
+    self.checkScroll(self.currentMouseCoords.y);
+    var aboveTable = self.scrollY > self.table.topY;
+    var belowTable = self.scrollY + self.windowHeight < self.table.bottomY;
+    if (scrollAmount > 0 && belowTable || scrollAmount < 0 && aboveTable) {
+      window.scrollBy(0, scrollAmount);
+    }
+  }, this.scrollSettings.interval);
+};
+
+Drupal.tableDrag.prototype.restripeTable = function () {
+  // :even and :odd are reversed because jQuery counts from 0 and
+  // we count from 1, so we're out of sync.
+  // Match immediate children of the parent element to allow nesting.
+  $('> tbody > tr.draggable:visible, > tr.draggable:visible', this.table)
+    .removeClass('odd even')
+    .filter(':odd').addClass('even').end()
+    .filter(':even').addClass('odd');
+};
+
+/**
+ * Stub function. Allows a custom handler when a row begins dragging.
+ */
+Drupal.tableDrag.prototype.onDrag = function () {
+  return null;
+};
+
+/**
+ * Stub function. Allows a custom handler when a row is dropped.
+ */
+Drupal.tableDrag.prototype.onDrop = function () {
+  return null;
+};
+
+/**
+ * Constructor to make a new object to manipulate a table row.
+ *
+ * @param tableRow
+ *   The DOM element for the table row we will be manipulating.
+ * @param method
+ *   The method in which this row is being moved. Either 'keyboard' or 'mouse'.
+ * @param indentEnabled
+ *   Whether the containing table uses indentations. Used for optimizations.
+ * @param maxDepth
+ *   The maximum amount of indentations this row may contain.
+ * @param addClasses
+ *   Whether we want to add classes to this row to indicate child relationships.
+ */
+Drupal.tableDrag.prototype.row = function (tableRow, method, indentEnabled, maxDepth, addClasses) {
+  this.element = tableRow;
+  this.method = method;
+  this.group = [tableRow];
+  this.groupDepth = $('.indentation', tableRow).length;
+  this.changed = false;
+  this.table = $(tableRow).closest('table').get(0);
+  this.indentEnabled = indentEnabled;
+  this.maxDepth = maxDepth;
+  this.direction = ''; // Direction the row is being moved.
+
+  if (this.indentEnabled) {
+    this.indents = $('.indentation', tableRow).length;
+    this.children = this.findChildren(addClasses);
+    this.group = $.merge(this.group, this.children);
+    // Find the depth of this entire group.
+    for (var n = 0; n < this.group.length; n++) {
+      this.groupDepth = Math.max($('.indentation', this.group[n]).length, this.groupDepth);
+    }
+  }
+};
+
+/**
+ * Find all children of rowObject by indentation.
+ *
+ * @param addClasses
+ *   Whether we want to add classes to this row to indicate child relationships.
+ */
+Drupal.tableDrag.prototype.row.prototype.findChildren = function (addClasses) {
+  var parentIndentation = this.indents;
+  var currentRow = $(this.element, this.table).next('tr.draggable');
+  var rows = [];
+  var child = 0;
+  while (currentRow.length) {
+    var rowIndentation = $('.indentation', currentRow).length;
+    // A greater indentation indicates this is a child.
+    if (rowIndentation > parentIndentation) {
+      child++;
+      rows.push(currentRow[0]);
+      if (addClasses) {
+        $('.indentation', currentRow).each(function (indentNum) {
+          if (child == 1 && (indentNum == parentIndentation)) {
+            $(this).addClass('tree-child-first');
+          }
+          if (indentNum == parentIndentation) {
+            $(this).addClass('tree-child');
+          }
+          else if (indentNum > parentIndentation) {
+            $(this).addClass('tree-child-horizontal');
+          }
+        });
+      }
+    }
+    else {
+      break;
+    }
+    currentRow = currentRow.next('tr.draggable');
+  }
+  if (addClasses && rows.length) {
+    $('.indentation:nth-child(' + (parentIndentation + 1) + ')', rows[rows.length - 1]).addClass('tree-child-last');
+  }
+  return rows;
+};
+
+/**
+ * Ensure that two rows are allowed to be swapped.
+ *
+ * @param row
+ *   DOM object for the row being considered for swapping.
+ */
+Drupal.tableDrag.prototype.row.prototype.isValidSwap = function (row) {
+  if (this.indentEnabled) {
+    var prevRow, nextRow;
+    if (this.direction == 'down') {
+      prevRow = row;
+      nextRow = $(row).next('tr').get(0);
+    }
+    else {
+      prevRow = $(row).prev('tr').get(0);
+      nextRow = row;
+    }
+    this.interval = this.validIndentInterval(prevRow, nextRow);
+
+    // We have an invalid swap if the valid indentations interval is empty.
+    if (this.interval.min > this.interval.max) {
+      return false;
+    }
+  }
+
+  // Do not let an un-draggable first row have anything put before it.
+  if (this.table.tBodies[0].rows[0] == row && $(row).is(':not(.draggable)')) {
+    return false;
+  }
+
+  return true;
+};
+
+/**
+ * Perform the swap between two rows.
+ *
+ * @param position
+ *   Whether the swap will occur 'before' or 'after' the given row.
+ * @param row
+ *   DOM element what will be swapped with the row group.
+ */
+Drupal.tableDrag.prototype.row.prototype.swap = function (position, row) {
+  Drupal.detachBehaviors(this.group, Drupal.settings, 'move');
+  $(row)[position](this.group);
+  Drupal.attachBehaviors(this.group, Drupal.settings);
+  this.changed = true;
+  this.onSwap(row);
+};
+
+/**
+ * Determine the valid indentations interval for the row at a given position
+ * in the table.
+ *
+ * @param prevRow
+ *   DOM object for the row before the tested position
+ *   (or null for first position in the table).
+ * @param nextRow
+ *   DOM object for the row after the tested position
+ *   (or null for last position in the table).
+ */
+Drupal.tableDrag.prototype.row.prototype.validIndentInterval = function (prevRow, nextRow) {
+  var minIndent, maxIndent;
+
+  // Minimum indentation:
+  // Do not orphan the next row.
+  minIndent = nextRow ? $('.indentation', nextRow).length : 0;
+
+  // Maximum indentation:
+  if (!prevRow || $(prevRow).is(':not(.draggable)') || $(this.element).is('.tabledrag-root')) {
+    // Do not indent:
+    // - the first row in the table,
+    // - rows dragged below a non-draggable row,
+    // - 'root' rows.
+    maxIndent = 0;
+  }
+  else {
+    // Do not go deeper than as a child of the previous row.
+    maxIndent = $('.indentation', prevRow).length + ($(prevRow).is('.tabledrag-leaf') ? 0 : 1);
+    // Limit by the maximum allowed depth for the table.
+    if (this.maxDepth) {
+      maxIndent = Math.min(maxIndent, this.maxDepth - (this.groupDepth - this.indents));
+    }
+  }
+
+  return { 'min': minIndent, 'max': maxIndent };
+};
+
+/**
+ * Indent a row within the legal bounds of the table.
+ *
+ * @param indentDiff
+ *   The number of additional indentations proposed for the row (can be
+ *   positive or negative). This number will be adjusted to nearest valid
+ *   indentation level for the row.
+ */
+Drupal.tableDrag.prototype.row.prototype.indent = function (indentDiff) {
+  // Determine the valid indentations interval if not available yet.
+  if (!this.interval) {
+    var prevRow = $(this.element).prev('tr').get(0);
+    var nextRow = $(this.group).filter(':last').next('tr').get(0);
+    this.interval = this.validIndentInterval(prevRow, nextRow);
+  }
+
+  // Adjust to the nearest valid indentation.
+  var indent = this.indents + indentDiff;
+  indent = Math.max(indent, this.interval.min);
+  indent = Math.min(indent, this.interval.max);
+  indentDiff = indent - this.indents;
+
+  for (var n = 1; n <= Math.abs(indentDiff); n++) {
+    // Add or remove indentations.
+    if (indentDiff < 0) {
+      $('.indentation:first', this.group).remove();
+      this.indents--;
+    }
+    else {
+      $('td:first', this.group).prepend(Drupal.theme('tableDragIndentation'));
+      this.indents++;
+    }
+  }
+  if (indentDiff) {
+    // Update indentation for this row.
+    this.changed = true;
+    this.groupDepth += indentDiff;
+    this.onIndent();
+  }
+
+  return indentDiff;
+};
+
+/**
+ * Find all siblings for a row, either according to its subgroup or indentation.
+ * Note that the passed-in row is included in the list of siblings.
+ *
+ * @param settings
+ *   The field settings we're using to identify what constitutes a sibling.
+ */
+Drupal.tableDrag.prototype.row.prototype.findSiblings = function (rowSettings) {
+  var siblings = [];
+  var directions = ['prev', 'next'];
+  var rowIndentation = this.indents;
+  for (var d = 0; d < directions.length; d++) {
+    var checkRow = $(this.element)[directions[d]]();
+    while (checkRow.length) {
+      // Check that the sibling contains a similar target field.
+      if ($('.' + rowSettings.target, checkRow)) {
+        // Either add immediately if this is a flat table, or check to ensure
+        // that this row has the same level of indentation.
+        if (this.indentEnabled) {
+          var checkRowIndentation = $('.indentation', checkRow).length;
+        }
+
+        if (!(this.indentEnabled) || (checkRowIndentation == rowIndentation)) {
+          siblings.push(checkRow[0]);
+        }
+        else if (checkRowIndentation < rowIndentation) {
+          // No need to keep looking for siblings when we get to a parent.
+          break;
+        }
+      }
+      else {
+        break;
+      }
+      checkRow = $(checkRow)[directions[d]]();
+    }
+    // Since siblings are added in reverse order for previous, reverse the
+    // completed list of previous siblings. Add the current row and continue.
+    if (directions[d] == 'prev') {
+      siblings.reverse();
+      siblings.push(this.element);
+    }
+  }
+  return siblings;
+};
+
+/**
+ * Remove indentation helper classes from the current row group.
+ */
+Drupal.tableDrag.prototype.row.prototype.removeIndentClasses = function () {
+  for (var n in this.children) {
+    $('.indentation', this.children[n])
+      .removeClass('tree-child')
+      .removeClass('tree-child-first')
+      .removeClass('tree-child-last')
+      .removeClass('tree-child-horizontal');
+  }
+};
+
+/**
+ * Add an asterisk or other marker to the changed row.
+ */
+Drupal.tableDrag.prototype.row.prototype.markChanged = function () {
+  var marker = Drupal.theme('tableDragChangedMarker');
+  var cell = $('td:first', this.element);
+  if ($('span.tabledrag-changed', cell).length == 0) {
+    cell.append(marker);
+  }
+};
+
+/**
+ * Stub function. Allows a custom handler when a row is indented.
+ */
+Drupal.tableDrag.prototype.row.prototype.onIndent = function () {
+  return null;
+};
+
+/**
+ * Stub function. Allows a custom handler when a row is swapped.
+ */
+Drupal.tableDrag.prototype.row.prototype.onSwap = function (swappedRow) {
+  return null;
+};
+
+Drupal.theme.prototype.tableDragChangedMarker = function () {
+  return '<span class="warning tabledrag-changed">*</span>';
+};
+
+Drupal.theme.prototype.tableDragIndentation = function () {
+  return '<div class="indentation">&nbsp;</div>';
+};
+
+Drupal.theme.prototype.tableDragChangedWarning = function () {
+  return '<div class="tabledrag-changed-warning messages warning">' + Drupal.theme('tableDragChangedMarker') + ' ' + Drupal.t('Changes made in this table will not be saved until the form is submitted.') + '</div>';
+};
+
+})(jQuery);