feature: tooltip in the checkbox

feature: add GridColumn.getElement
feature: column property of `contentWrap` and `maxLines`
change: line height from 24px to 18px
fix: adapt enabled after cell changed
fix: wrap issue of filter panel

lib/ui/grid/column.js

@@ -73,6 +73,15 @@ export class GridColumn {
      * @virtual
      */
 
+    /**
+     * 获取用于判断文本大小的元素
+     * @method
+     * @name GridColumn.getElement
+     * @param {HTMLElement} element - 单元格主内容元素
+     * @returns {HTMLElement} 返回文本元素
+     * @virtual
+     */
+
     /**
      * 获取编辑状态单元格值时调用的方法
      * @method
@@ -153,7 +162,7 @@ export class GridColumn {
     /**
      * @ignore
      */
-    static toString() { return '[object Column]' }
+    static toString() { return 'GridCommon' }
 
     /**
      * @ignore
@@ -234,6 +243,11 @@ export class GridInputColumn extends GridColumn {
         super.setEnabled(element, enabled);
         element.disabled = enabled === false;
     }
+
+    /**
+     * @ignore
+     */
+    static toString() { return 'GridInput' }
 }
 
 /**
@@ -280,6 +294,11 @@ export class GridTextColumn extends GridInputColumn {
             // TODO: bad performance
         }
     }
+
+    /**
+     * @ignore
+     */
+    static toString() { return 'GridText' }
 }
 
 const SymbolDropdown = Symbol.for('ui-dropdown');
@@ -477,6 +496,11 @@ export class GridDropdownColumn extends GridColumn {
             drop.onCollapsed();
         }
     }
+
+    /**
+     * @ignore
+     */
+    static toString() { return 'GridDropdown' }
 }
 
 /**
@@ -538,6 +562,11 @@ export class GridCheckboxColumn extends GridColumn {
         super.setEnabled(element, enabled);
         element.querySelector('input').disabled = enabled === false;
     }
+
+    /**
+     * @ignore
+     */
+    static toString() { return 'GridCheckbox' }
 }
 
 /**
@@ -609,6 +638,11 @@ export class GridIconColumn extends GridColumn {
             element.classList.remove('disabled');
         }
     }
+
+    /**
+     * @ignore
+     */
+    static toString() { return 'GridIcon' }
 }
 
 /**
@@ -700,4 +734,9 @@ export class GridDateColumn extends GridColumn {
     static formatDate(date) {
         return formatDate(date);
     }
+
+    /**
+     * @ignore
+     */
+    static toString() { return 'GridDate' }
 }