auto-scroll doc fix

Author: adumesny

doc/CHANGES.md

@@ -49,6 +49,7 @@ Change log
 - fix [1540](https://github.com/gridstack/gridstack.js/issues/1540) Safari H5 drag&drop fixed
 - fix [1545](https://github.com/gridstack/gridstack.js/issues/1545) `disableMove()` correctly prevents drag later (remove events and draggable attribute)
 - fix [1546](https://github.com/gridstack/gridstack.js/issues/1546) resize no longer delayed, which caused race conditions errors
+- fix [1001](https://github.com/gridstack/gridstack.js/issues/1001) resizing near bottom/top needs to auto-scroll/. thanks [@hbcarlos](https://github.com/hbcarlos)!
 
 ## 3.1.2 (2020-12-7)
 

src/utils.ts

@@ -328,14 +328,12 @@ export class Utils {
     }
   }
 
-  /** 
-   * @internal
-   * 
-   * Function used to scroll the page.
-   * 
+  /**
+   * @internal Function used to scroll the page.
+   *
    * @param event `MouseEvent` that triggers the resize
    * @param el `HTMLElement` that's being resized
-   * @param distance Distance to scroll
+   * @param distance Distance from the V edges to start scrolling
    */
   static updateScrollResize(event: MouseEvent, el: HTMLElement, distance: number): void {
     const scrollEl = this.getScrollParent(el);
@@ -348,7 +346,6 @@ export class Utils {
       // This also can be done with a timeout to keep scrolling while the mouse is
       // in the scrolling zone. (will have smoother behavior)
       scrollEl.scrollBy({ behavior: 'smooth', top: event.clientY - distance});
-
     } else if (bottom) {
       scrollEl.scrollBy({ behavior: 'smooth', top: distance - (height - event.clientY)});
     }