Dragging nested fields 78614 (#54)

* Drag-Drop: add a negative margin (as a positive) to the marginBoxWidth to correct the width when using a drag/drop helper element. See #78614

---------

Co-authored-by: Stefanie Hein <stefanie.hein@the-elements.de>

Author: novaxpro

public/cui.js

@@ -25750,7 +25750,7 @@ CUI.Draggable = (function(superClass) {
   };
 
   Draggable.prototype.init_helper = function(ev, $target, diff) {
-    var clone_source, dim, helper, hn, offset, set_dim, start;
+    var cloneMarginBoxWidth, clone_source, dim, helper, hn, offset, set_dim, start;
     helper = this.get_helper(ev, CUI.globalDrag, diff);
     if (!helper) {
       return;
@@ -25779,8 +25779,12 @@ CUI.Draggable = (function(superClass) {
     CUI.dom.setStyle(hn, start);
     if (helper === "clone") {
       set_dim = CUI.dom.getDimensions(clone_source);
+      cloneMarginBoxWidth = set_dim.marginBoxWidth;
+      if (set_dim.marginLeft < 0) {
+        cloneMarginBoxWidth = set_dim.marginBoxWidth + (-1 * set_dim.marginLeft);
+      }
       CUI.dom.setDimensions(hn, {
-        marginBoxWidth: set_dim.marginBoxWidth,
+        marginBoxWidth: cloneMarginBoxWidth,
         marginBoxHeight: set_dim.marginBoxHeight
       });
     }

public/cui.min.js

@@ -629,8 +629,13 @@ class CUI.Draggable extends CUI.DragDropSelect
 
 			# console.error "measureing clone", set_dim.marginBoxWidth, CUI.globalDrag.$source, dim
 
+			# if element has a negative margin we need to add that (as a positive) to the marginBoxWidth, so the width is correct
+			cloneMarginBoxWidth = set_dim.marginBoxWidth
+			if set_dim.marginLeft < 0
+				cloneMarginBoxWidth = set_dim.marginBoxWidth + (-1 * set_dim.marginLeft)
+
 			CUI.dom.setDimensions hn,
-				marginBoxWidth: set_dim.marginBoxWidth
+				marginBoxWidth: cloneMarginBoxWidth
 				marginBoxHeight: set_dim.marginBoxHeight