fix: adjust `useWatermark` logic (#4896)

packages/effects/hooks/src/use-watermark.ts

@@ -1,8 +1,11 @@
 import type { Watermark, WatermarkOptions } from 'watermark-js-plus';
 
-import { nextTick, onUnmounted, ref } from 'vue';
+import { nextTick, onUnmounted, readonly, ref } from 'vue';
+
+import { updatePreferences } from '@vben/preferences';
 
 const watermark = ref<Watermark>();
+const unmountedHooked = ref<boolean>(false);
 const cachedOptions = ref<Partial<WatermarkOptions>>({
   advancedStyle: {
     colorStops: [
@@ -45,7 +48,7 @@ export function useWatermark() {
       ...options,
     };
     watermark.value = new Watermark(cachedOptions.value);
-
+    updatePreferences({ app: { watermark: true } });
     await watermark.value?.create();
   }
 
@@ -62,16 +65,24 @@ export function useWatermark() {
   }
 
   function destroyWatermark() {
-    watermark.value?.destroy();
+    if (watermark.value) {
+      watermark.value.destroy();
+      watermark.value = undefined;
+    }
+    updatePreferences({ app: { watermark: false } });
   }
 
+  // 只在第一次调用时注册卸载钩子，防止重复注册以致于在路由切换时销毁了水印
+  if (!unmountedHooked.value) {
+    unmountedHooked.value = true;
     onUnmounted(() => {
       destroyWatermark();
     });
+  }
 
   return {
     destroyWatermark,
     updateWatermark,
-    watermark,
+    watermark: readonly(watermark),
   };
 }

playground/src/views/demos/features/watermark/index.vue

@@ -4,7 +4,12 @@ import { useWatermark } from '@vben/hooks';
 
 import { Button, Card } from 'ant-design-vue';
 
-const { destroyWatermark, updateWatermark } = useWatermark();
+const { destroyWatermark, updateWatermark, watermark } = useWatermark();
+
+async function recreateWaterMark() {
+  destroyWatermark();
+  await updateWatermark({});
+}
 
 async function createWaterMark() {
   await updateWatermark({
@@ -21,7 +26,7 @@ async function createWaterMark() {
       ],
       type: 'linear',
     },
-    content: 'hello my watermark',
+    content: `hello my watermark\n${new Date().toLocaleString()}`,
     globalAlpha: 0.5,
     gridLayoutOptions: {
       cols: 2,
@@ -57,10 +62,25 @@ async function createWaterMark() {
     </template>
 
     <Card title="使用">
-      <Button class="mr-2" type="primary" @click="createWaterMark()">
+      <Button
+        :disabled="!!watermark"
+        class="mr-2"
+        type="primary"
+        @click="recreateWaterMark"
+      >
         创建水印
       </Button>
-      <Button danger @click="destroyWatermark">移除水印</Button>
+      <Button
+        :disabled="!watermark"
+        class="mr-2"
+        type="primary"
+        @click="createWaterMark"
+      >
+        更新水印
+      </Button>
+      <Button :disabled="!watermark" danger @click="destroyWatermark">
+        移除水印
+      </Button>
     </Card>
   </Page>
 </template>