float-add-btn 悬浮球支持屏幕内自由拖动与位置记忆

uniapp/youjiala/src/components/float-add-btn/float-add-btn.vue

@@ -1,10 +1,14 @@
 <script setup lang="ts">
 /**
- * 悬浮操作按钮：右下角圆形蓝色渐变「+」，固定在底部导航之上。
+ * 悬浮操作按钮：蓝色渐变「+」，可在屏幕内自由拖动，松手后位置写入 Storage 下次启动恢复。
  * 只做外观与点击上报；新建/上传等动作语义由页面处理。
+ * 拖动实现：touch 事件（真机/App）+ mouse 事件（H5 桌面调试）双轨；
+ * 位移小于阈值视为轻点（emit click），超过阈值才算拖动（touch 后屏蔽 mouse 兼容事件防双触发）。
  */
-defineProps({
+import { computed, onMounted, ref } from "vue";
-  /** 额外底部偏移（rpx 数值），供不同页面避开各自的底部元素 */
+
+const props = defineProps({
+  /** 初始底部偏移（rpx 数值，仅首次无存储记录时生效），供不同页面避开各自的底部元素 */
   bottomOffset: {
     type: Number,
     default: 0,
@@ -14,10 +18,132 @@ defineProps({
 const emit = defineEmits<{
   (e: "click"): void;
 }>();
+
+const STORAGE_KEY = "float-add-btn-pos";
+
+/** 位移阈值（px）：低于它按轻点处理 */
+const TAP_THRESHOLD = 6;
+
+const pos = ref({ x: 0, y: 0 });
+
+/** 位置定妥前隐藏，避免默认位置 → 恢复位置的一帧闪跳 */
+const ready = ref(false);
+
+let dragging = false;
+let moved = false;
+let startPoint = { x: 0, y: 0 };
+let originPos = { x: 0, y: 0 };
+/** touch 已处理标记：移动端浏览器会在 touch 后补发 mouse 兼容事件，防双触发 */
+let touchHandled = false;
+
+function sizePx(): number {
+  return uni.upx2px(112);
+}
+
+/** 夹在屏幕可视区内，四边留 8px 呼吸位 */
+function clampPos(x: number, y: number): { x: number; y: number } {
+  const { windowWidth, windowHeight } = uni.getSystemInfoSync();
+  const size = sizePx();
+  return {
+    x: Math.min(Math.max(8, x), windowWidth - size - 8),
+    y: Math.min(Math.max(8, y), windowHeight - size - 8),
+  };
+}
+
+onMounted(() => {
+  const { windowWidth, windowHeight } = uni.getSystemInfoSync();
+  const size = sizePx();
+  let x = windowWidth - size - 20;
+  let y = windowHeight - size - uni.upx2px(180 + props.bottomOffset);
+  const saved = uni.getStorageSync(STORAGE_KEY) as { x?: number; y?: number } | "";
+  if (saved && typeof saved.x === "number" && typeof saved.y === "number") {
+    x = saved.x;
+    y = saved.y;
+  }
+  pos.value = clampPos(x, y);
+  ready.value = true;
+});
+
+const posStyle = computed(() => ({
+  left: `${pos.value.x}px`,
+  top: `${pos.value.y}px`,
+  visibility: ready.value ? "visible" : "hidden",
+}));
+
+function onDragStart(x: number, y: number): void {
+  dragging = true;
+  moved = false;
+  startPoint = { x, y };
+  originPos = { ...pos.value };
+}
+
+function onDragMove(x: number, y: number): void {
+  if (!dragging) {
+    return;
+  }
+  const dx = x - startPoint.x;
+  const dy = y - startPoint.y;
+  if (!moved && Math.abs(dx) < TAP_THRESHOLD && Math.abs(dy) < TAP_THRESHOLD) {
+    return;
+  }
+  moved = true;
+  pos.value = clampPos(originPos.x + dx, originPos.y + dy);
+}
+
+function onDragEnd(): void {
+  if (!dragging) {
+    return;
+  }
+  dragging = false;
+  if (moved) {
+    uni.setStorageSync(STORAGE_KEY, pos.value);
+  }
+  else {
+    emit("click");
+  }
+}
+
+// ===== touch（真机 / App）=====
+function onTouchStart(e: TouchEvent): void {
+  touchHandled = true;
+  const touch = e.touches[0];
+  onDragStart(touch.clientX, touch.clientY);
+}
+
+function onTouchMove(e: TouchEvent): void {
+  const touch = e.touches[0];
+  onDragMove(touch.clientX, touch.clientY);
+}
+
+function onTouchEnd(): void {
+  onDragEnd();
+  // 下一个宏任务复位，让补发的 mouse 兼容事件先被拦截
+  setTimeout(() => {
+    touchHandled = false;
+  }, 0);
+}
+
+// ===== mouse（H5 桌面）=====
+function onMouseDown(e: MouseEvent): void {
+  if (touchHandled) {
+    return;
+  }
+  e.preventDefault();
+  onDragStart(e.clientX, e.clientY);
+  const move = (ev: MouseEvent) => onDragMove(ev.clientX, ev.clientY);
+  const up = () => {
+    onDragEnd();
+    window.removeEventListener("mousemove", move);
+    window.removeEventListener("mouseup", up);
+  };
+  window.addEventListener("mousemove", move);
+  window.addEventListener("mouseup", up);
+}
 </script>
 
 <template>
-  <view class="float-add-btn" :style="{ bottom: `${180 + bottomOffset}rpx` }" @tap="emit('click')">
+  <view class="float-add-btn" :style="posStyle" @touchstart="onTouchStart" @touchmove.stop.prevent="onTouchMove"
+    @touchend="onTouchEnd" @mousedown="onMouseDown">
     <u-icon name="plus" size="52" color="#ffffff" />
   </view>
 </template>
@@ -25,7 +151,8 @@ const emit = defineEmits<{
 <style lang="scss" scoped>
 .float-add-btn {
   position: fixed;
-  right: 40rpx;
+  top: 0;
+  left: 0;
   z-index: 8;
   display: flex;
   align-items: center;
@@ -35,5 +162,8 @@ const emit = defineEmits<{
   border-radius: 50%;
   background: linear-gradient(135deg, #6ec2ff 0%, #2b8fff 100%);
   box-shadow: 0 12rpx 32rpx rgba(43, 143, 255, 0.4);
+  touch-action: none;
+  /* 屏蔽浏览器默认滚动手势，touchmove 才不被吞 */
+  user-select: none;
 }
 </style>