Drag and resize element in grid.
基本拖动 | Basic drag
拖动区域扩展 | Drag area expansion
拖动目标判断 | Drag target judgment
Basic resize
调整区域扩展 | Resize area expansion
从外部拖入（设置了默认占用空间）| Drag in from outside (default space is set)
拖入区域扩展 | Drop in area expansion
跨嵌套拖入 | Drop in cross group
跨嵌套拖出 | Drop out cross group
层层嵌套 | Group
躲避选中 | Avoid selection
间隙不足偏移 | Offset without gap enough
仓库 | Repository
欢迎大家来看看 | Articles：