fix: 表头高度属性不生效

由于表头使用了动态计算，可能会导致不会按照参数预期高度展示，会取 `可能的最小值` 与 `给定参数值` 的最大值作为最终展示值。

fix #127

src/composables/useElement.ts

@@ -1,32 +1,36 @@
 import Variables from '@/constants/vars';
 import useStore from '@/store';
 import useParam from './useParam';
+import useStyle from './useStyle';
 
 export default () => {
   const { $param } = useParam();
+  const { $styleBox } = useStyle();
   const { tableHeaderRef, ganttHeaderRef, ganttBodyRef, ganttRef } = useStore();
 
   function getMaxHeaderHeight() {
     return Math.max(
       tableHeaderRef.value?.clientHeight ?? 0,
       ganttHeaderRef.value?.clientHeight ?? 0,
-      Variables.default.headerHeight
+      Variables.size.minHeaderHeight
     );
   }
 
   function updateHeaderHeight() {
-    if (!$param.headerHeight) return;
-
     // 删除 ref 中 style 的 height 属性，以便获取真实高度
     tableHeaderRef.value?.style.removeProperty('height');
     ganttHeaderRef.value?.style.removeProperty('height');
 
-    const maxHeight = getMaxHeaderHeight();
+    let maxHeight = getMaxHeaderHeight();
     if ($param.headerHeight !== maxHeight) {
       $param.headerHeight = maxHeight;
     }
 
     // 重新设置高度
+    if ($styleBox.headerHeight) {
+      maxHeight = Math.max($styleBox.headerHeight, maxHeight);
+    }
+
     tableHeaderRef.value &&
       (tableHeaderRef.value.style.height = `${maxHeight}px`);
     ganttHeaderRef.value &&

src/composables/useStyle.ts

@@ -50,6 +50,7 @@ export default () => {
       store.$styleBox.draggable = props.draggable;
       store.$styleBox.holidays = props.holidays;
       store.$styleBox.formatGanttHeader = props.formatGanttHeader;
+      store.$styleBox.headerHeight = props.headerHeight;
     };
 
     fn();

src/models/param/styles.ts

@@ -54,6 +54,19 @@ export default class StyleBox {
     }
   }
 
+  private _headerHeight: number | undefined;
+  public get headerHeight(): number | undefined {
+    return this._headerHeight;
+  }
+
+  public set headerHeight(v: number | string) {
+    if (typeof v === 'string') {
+      this._headerHeight = parseInt(v);
+    } else {
+      this._headerHeight = v;
+    }
+  }
+
   private _showCheckbox: boolean = false;
   public get showCheckbox(): boolean {
     return this._showCheckbox;