imp ui dag button tooltip.

dolphinscheduler-ui/src/js/conf/home/pages/dag/_source/dag.vue

@@ -70,12 +70,15 @@
                :id="item.code"
                :key="$index"
                @click="_ckOperation(item,$event)">
-              <el-button type="text" class="operBtn" data-container="body" :icon="item.icon" v-tooltip.light="item.desc"></el-button>
+              <el-tooltip :content="item.desc" placement="top" :enterable="false">
+                <span><el-button type="text" class="operBtn" data-container="body" :icon="item.icon"></el-button></span>
+              </el-tooltip>
             </a>
           </div>
+          <el-tooltip :content="$t('Format DAG')" placement="top" :enterable="false">
+            <span>
               <el-button
                 type="primary"
-            v-tooltip.light="$t('Format DAG')"
                 icon="el-icon-caret-right"
                 size="mini"
                 data-container="body"
@@ -83,9 +86,11 @@
                 style="vertical-align: middle;"
                 @click="dagAutomaticLayout">
               </el-button>
+            </span>
+          </el-tooltip>
+          <el-tooltip :content="$t('Refresh DAG status')" placement="top" :enterable="false">
             <span>
               <el-button
-              v-tooltip.light="$t('Refresh DAG status')"
                 data-container="body"
                 style="vertical-align: middle;"
                 icon="el-icon-refresh"
@@ -96,6 +101,7 @@
                 size="mini" >
               </el-button>
             </span>
+          </el-tooltip>
           <el-button
                   v-if="isRtTasks"
                   style="vertical-align: middle;"
@@ -108,7 +114,6 @@
           <span>
             <el-button
               type="primary"
-              v-tooltip.light="$t('Close')"
               icon="el-icon-switch-button"
               size="mini"
               data-container="body"