Squashed commit of the following:

Draggable:
 Fixed when cssPosition is being set.
 Scrolling handles non-doc overflow.
 _handleScrolling handles scrolling up and left now
 Made window, doc, and window part of base widget
 All parts of drag may be stopped via stopPropagation
 User can now override position of draggable on start, drag, and stop
 Whitespace fix
 Moved overflowWidth and overflowHeight into overflow.width and overflow.height

ui/jquery.ui.draggable.js

@@ -24,20 +24,16 @@ $.widget( "ui.draggable", {
 	},
 
 	// dragEl: element being dragged (original or helper)
-	// position: CSS position of dragEl
+	// position: final CSS position of dragEl
 	// offset: offset of dragEl
 	// startCoords: clientX/Y of the mousedown (offset of pointer)
 	// startPosition: CSS position prior to drag start
 	// startOffset: offset prior to drag start
+	// tempPosition: overridable CSS position of dragEl
 	// overflowOffset: offset of scroll parent
-	// overflowHeight: height of scroll parent
+	// overflow: object containing width and height keys of scroll parent
-	// overflowWidth: width of scroll parent
 
 	_create: function() {
-		// TODO: add these to the base widget
-		this.doc = $( this.element[0].ownerDocument );
-		this.win = $( this.doc[0].defaultView );
-
 		this.scrollParent = this.element.scrollParent();
 
 		// Static position elements can't be moved with top/left
@@ -79,13 +75,62 @@ $.widget( "ui.draggable", {
 		};
 	},
 
+	_handleScrolling: function( event ) {
+		// TODO: what is expected behavior of absolute/fixed draggable inside a div having overflow:scroll?
+		var scrollTop = this.scrollParent.scrollTop(),
+			scrollLeft = this.scrollParent.scrollLeft();
+	
+		// overflowOffset is only set when scrollParent is not doc/html
+		if ( !this.overflowOffset ) {
+	
+			// Handle vertical scrolling
+			if ( ( ( this.overflow.height + scrollTop ) - event.pageY ) < this.options.scrollSensitivity ) {
+				this.scrollParent.scrollTop( scrollTop + this.options.scrollSpeed );
+			}
+			else if ( event.pageY < ( scrollTop + this.options.scrollSensitivity ) ) {
+				this.scrollParent.scrollTop( scrollTop - this.options.scrollSpeed );
+			}
+			
+			// Handle horizontal scrolling
+			if ( ( ( this.overflow.width + scrollLeft ) - event.pageX ) < this.options.scrollSensitivity ) {
+				this.scrollParent.scrollLeft( scrollLeft + this.options.scrollSpeed );
+			}
+			else if ( event.pageX < ( scrollLeft + this.options.scrollSensitivity ) ) {
+				this.scrollParent.scrollLeft( scrollLeft - this.options.scrollSpeed );
+			}
+		
+		} else {
+			
+			
+			// Handle vertical scrolling
+			if ( ( event.pageY + this.options.scrollSensitivity ) > ( this.overflow.height + this.overflowOffset.top ) ) {
+				this.scrollParent.scrollTop( scrollTop + this.options.scrollSpeed );
+			}
+			else if ( ( event.pageY - this.options.scrollSensitivity ) < this.overflowOffset.top ) {
+				this.scrollParent.scrollTop( scrollTop - this.options.scrollSpeed );
+			}
+			
+			// Handle horizontal scrolling
+			if ( ( event.pageX + this.options.scrollSensitivity ) > ( this.overflow.width + this.overflowOffset.left ) ) {
+				this.scrollParent.scrollLeft( scrollLeft + this.options.scrollSpeed );
+			}
+			else if ( ( event.pageX - this.options.scrollSensitivity ) < this.overflowOffset.left ) {
+				this.scrollParent.scrollLeft( scrollLeft - this.options.scrollSpeed );
+			}
+		
+		
+		}
+		
+	},
+
 	_mouseDown: function( event ) {
+		var newLeft, newTop;
+
 		// Prevent text selection, among other things
 		event.preventDefault();
 
 		// The actual dragging element, should always be a jQuery object
 		this.dragEl = this.element;
-		this.cssPosition = this.dragEl.css( "position" );
 
 		// Helper required
 		if ( this.options.helper ) {
@@ -108,6 +153,8 @@ $.widget( "ui.draggable", {
 				.offset( this.element.offset() );
 		}
 		
+		this.cssPosition = this.dragEl.css( "position" );
+
 		// Cache starting absolute and relative positions
 		this.startPosition = this._getPosition();
 		this.startOffset = this.dragEl.offset();
@@ -121,17 +168,32 @@ $.widget( "ui.draggable", {
 			top: event.clientY
 		};
 
-		// Cache the offset of scrollParent
+		// Cache the offset of scrollParent, if required for _handleScrolling
-		// TODO: store overflow height/width in a hash instead of separate properties
+		if ( this.scrollParent[0] != this.doc[0] && this.scrollParent[0].tagName != 'HTML') {
 			this.overflowOffset = this.scrollParent.offset();
-		this.overflowHeight = ( this.scrollParent[0] === this.doc[0] ) ?
+		}
+
+		this.overflow = {};
+
+		this.overflow.height = ( this.scrollParent[0] === this.doc[0] ) ?
 			this.win.height() : this.scrollParent.height();
-		this.overflowWidth = ( this.scrollParent[0] === this.doc[0] ) ?
+
+		this.overflow.width = ( this.scrollParent[0] === this.doc[0] ) ?
 			this.win.width() : this.scrollParent.width();
 
-		// TODO: allow modifying position, just like during drag
+		this._preparePosition( event );
+
 		this._trigger( "start", event, this._uiHash() );
 		
+		// TODO: should user be able to change position of draggable, if event stopped?
+		// If user stops propagation, leave helper there ( if there's one ), disallow any CSS changes
+		if ( event.cancelBubble === true ) {
+			this.doc.unbind( "." + this.widgetName );
+			return;
+		}
+
+		this._setCss( event );
+
 		this._bind( this.doc, {
 			mousemove: "_mouseMove",
 			mouseup: "_mouseUp"
@@ -139,24 +201,76 @@ $.widget( "ui.draggable", {
 	},
 
 	_mouseMove: function( event ) {
+		var newLeft, newTop;
+
+		this._preparePosition( event );
+
+		this._trigger( "drag", event, this._uiHash() );
+
+		// TODO: should user be able to change position of draggable, if event stopped?
+		// If user stops propagation, leave helper there ( if there's one ), disallow any CSS changes
+		if ( event.cancelBubble === true ) {
+			this.doc.unbind( "." + this.widgetName );
+			return;
+		}
+
+		this._setCss( event );
+
+		// Scroll the scrollParent, if needed
+		this._handleScrolling( event );
+	},
+
+	_mouseUp: function( event ) {
+
+		this._preparePosition( event );
+
+		this._trigger( "stop", event, this._uiHash() );
+
+		// TODO: should user be able to change position of draggable, if event stopped?
+		// If user stops propagation, leave helper there, disallow any CSS changes
+		if ( event.cancelBubble !== true ) {
+
+			this._setCss( event );
+
+			if ( this.options.helper ) {
+				this.dragEl.remove();
+			}
+
+		}
+
+		this.doc.unbind( "." + this.widgetName );
+	},
+
+	// Uses event to determine new position of draggable, before any override from callbacks
+	_preparePosition: function( event ) {
 		var leftDiff = event.clientX - this.startCoords.left,
 			topDiff = event.clientY - this.startCoords.top,
 			newLeft = leftDiff + this.startPosition.left,
 			newTop = topDiff + this.startPosition.top;
 
+		// Save off new values for .css() in various callbacks using this function
 		this.position = {
 			left: newLeft,
 			top: newTop
 		};
 
+		// Save off values to compare user override against automatic coordinates
+		this.tempPosition = {
+			left: newLeft,
+			top: newTop
+		}
+
 		// Refresh offset cache with new positions
 		this.offset.left = this.startOffset.left + newLeft;
 		this.offset.top = this.startOffset.top + newTop;
+	},
 
-		this._trigger( "drag", event, this._uiHash() );
+	// Places draggable where mouse or user from callback indicates
+	_setCss: function( event ) {
+		var newLeft, newTop;
 
 		// User overriding left/top so shortcut math is no longer valid
-		if ( newLeft !== this.position.left || newTop !== this.position.top ) {
+		if ( this.tempPosition.left !== this.position.left || this.tempPosition.top !== this.position.top ) {
 			// TODO: can we just store the previous offset values
 			// and not go through .offset()?
 			// refresh offset using slower functions
@@ -176,34 +290,6 @@ $.widget( "ui.draggable", {
 			left: newLeft + "px",
 			top: newTop + "px"
 		});
-
-		// Scroll the scrollParent, if needed
-		this._handleScrolling( event );
-	},
-
-	_handleScrolling: function( event ) {
-		var scrollTop = this.doc.scrollTop(),
-			scrollLeft = this.doc.scrollLeft();
-
-		// Handle vertical scrolling
-		if ( ( ( this.overflowHeight + scrollTop ) - event.pageY ) < this.options.scrollSensitivity ) {
-			this.doc.scrollTop( scrollTop + this.options.scrollSpeed );
-		}
-
-		// Handle horizontal scrolling
-		if ( ( ( this.overflowWidth + scrollLeft ) - event.pageX ) < this.options.scrollSensitivity ) {
-			this.doc.scrollLeft( scrollLeft + this.options.scrollSpeed );
-		}
-	},
-
-	_mouseUp: function( event ) {
-		this._trigger( "stop", event, this._uiHash() );
-
-		if ( this.options.helper ) {
-			this.dragEl.remove();
-		}
-
-		this.doc.unbind( "." + this.widgetName );
 	},
 
 	_uiHash: function( event ) {

ui/jquery.ui.widget.js

@@ -183,6 +183,9 @@ $.Widget.prototype = {
 	_createWidget: function( options, element ) {
 		element = $( element || this.defaultElement || this )[ 0 ];
 		this.element = $( element );
+		this.doc = $( this.element[0].ownerDocument );
+		this.win = $( this.doc[0].defaultView );
+		this.body = this.doc.body;
 		this.options = $.widget.extend( {},
 			this.options,
 			this._getCreateOptions(),