Draggable: containment now updates dynamically to handle scrolling co…

…ntainer. Fixed #4445 containment ignored when scrolling in overflow div

(cherry picked from commit d620749)

ui/jquery.ui.draggable.js

@@ -342,16 +342,19 @@ $.widget("ui.draggable", $.ui.mouse, {
 		];
 
 		if(!(/^(document|window|parent)$/).test(o.containment) && o.containment.constructor != Array) {
-			var ce = $(o.containment)[0]; if(!ce) return;
-			var co = $(o.containment).offset();
+		        var c = $(o.containment);
+			var ce = c[0]; if(!ce) return;
+			var co = c.offset();
 			var over = ($(ce).css("overflow") != 'hidden');
 
 			this.containment = [
-				co.left + (parseInt($(ce).css("borderLeftWidth"),10) || 0) + (parseInt($(ce).css("paddingLeft"),10) || 0),
-				co.top + (parseInt($(ce).css("borderTopWidth"),10) || 0) + (parseInt($(ce).css("paddingTop"),10) || 0),
-				co.left+(over ? Math.max(ce.scrollWidth,ce.offsetWidth) : ce.offsetWidth) - (parseInt($(ce).css("borderLeftWidth"),10) || 0) - (parseInt($(ce).css("paddingRight"),10) || 0) - this.helperProportions.width - this.margins.left - this.margins.right,
-				co.top+(over ? Math.max(ce.scrollHeight,ce.offsetHeight) : ce.offsetHeight) - (parseInt($(ce).css("borderTopWidth"),10) || 0) - (parseInt($(ce).css("paddingBottom"),10) || 0) - this.helperProportions.height - this.margins.top  - this.margins.bottom
+				(parseInt($(ce).css("borderLeftWidth"),10) || 0) + (parseInt($(ce).css("paddingLeft"),10) || 0),
+				(parseInt($(ce).css("borderTopWidth"),10) || 0) + (parseInt($(ce).css("paddingTop"),10) || 0),
+				(over ? Math.max(ce.scrollWidth,ce.offsetWidth) : ce.offsetWidth) - (parseInt($(ce).css("borderLeftWidth"),10) || 0) - (parseInt($(ce).css("paddingRight"),10) || 0) - this.helperProportions.width - this.margins.left - this.margins.right,
+				(over ? Math.max(ce.scrollHeight,ce.offsetHeight) : ce.offsetHeight) - (parseInt($(ce).css("borderTopWidth"),10) || 0) - (parseInt($(ce).css("paddingBottom"),10) || 0) - this.helperProportions.height - this.margins.top  - this.margins.bottom
 			];
+			this.relative_container = c;
+
 		} else if(o.containment.constructor == Array) {
 			this.containment = o.containment;
 		}
@@ -393,20 +396,31 @@ $.widget("ui.draggable", $.ui.mouse, {
 		 */
 
 		if(this.originalPosition) { //If we are not dragging yet, we won't check for options
-
-			if(this.containment) {
-				if(event.pageX - this.offset.click.left < this.containment[0]) pageX = this.containment[0] + this.offset.click.left;
-				if(event.pageY - this.offset.click.top < this.containment[1]) pageY = this.containment[1] + this.offset.click.top;
-				if(event.pageX - this.offset.click.left > this.containment[2]) pageX = this.containment[2] + this.offset.click.left;
-				if(event.pageY - this.offset.click.top > this.containment[3]) pageY = this.containment[3] + this.offset.click.top;
+		         var containment;
+		         if(this.containment) {
+				 if (this.relative_container){
+				     var co = this.relative_container.offset();
+				     containment = [ this.containment[0] + co.left,
+						     this.containment[1] + co.top,
+						     this.containment[2] + co.left,
+						     this.containment[3] + co.top ];
+				 }
+				 else {
+				     containment = this.containment;
+				 }
+
+				if(event.pageX - this.offset.click.left < containment[0]) pageX = containment[0] + this.offset.click.left;
+				if(event.pageY - this.offset.click.top < containment[1]) pageY = containment[1] + this.offset.click.top;
+				if(event.pageX - this.offset.click.left > containment[2]) pageX = containment[2] + this.offset.click.left;
+				if(event.pageY - this.offset.click.top > containment[3]) pageY = containment[3] + this.offset.click.top;
 			}
 
 			if(o.grid) {
 				var top = this.originalPageY + Math.round((pageY - this.originalPageY) / o.grid[1]) * o.grid[1];
-				pageY = this.containment ? (!(top - this.offset.click.top < this.containment[1] || top - this.offset.click.top > this.containment[3]) ? top : (!(top - this.offset.click.top < this.containment[1]) ? top - o.grid[1] : top + o.grid[1])) : top;
+				pageY = containment ? (!(top - this.offset.click.top < containment[1] || top - this.offset.click.top > containment[3]) ? top : (!(top - this.offset.click.top < containment[1]) ? top - o.grid[1] : top + o.grid[1])) : top;
 
 				var left = this.originalPageX + Math.round((pageX - this.originalPageX) / o.grid[0]) * o.grid[0];
-				pageX = this.containment ? (!(left - this.offset.click.left < this.containment[0] || left - this.offset.click.left > this.containment[2]) ? left : (!(left - this.offset.click.left < this.containment[0]) ? left - o.grid[0] : left + o.grid[0])) : left;
+				pageX = containment ? (!(left - this.offset.click.left < containment[0] || left - this.offset.click.left > containment[2]) ? left : (!(left - this.offset.click.left < containment[0]) ? left - o.grid[0] : left + o.grid[0])) : left;
 			}
 
 		}