jtBaseApp/node_modules/vant/es/image-preview/ImagePreviewItem.mjs

import { createVNode as _createVNode } from "vue";
import { ref, watch, computed, reactive, defineComponent } from "vue";
import { clamp, numericProp, preventDefault, createNamespace, makeRequiredProp } from "../utils/index.mjs";
import { useTouch } from "../composables/use-touch.mjs";
import { useEventListener } from "@vant/use";
import { Image } from "../image/index.mjs";
import { Loading } from "../loading/index.mjs";
import { SwipeItem } from "../swipe-item/index.mjs";
const getDistance = (touches) => Math.sqrt((touches[0].clientX - touches[1].clientX) ** 2 + (touches[0].clientY - touches[1].clientY) ** 2);
const bem = createNamespace("image-preview")[1];
var stdin_default = defineComponent({
  props: {
    src: String,
    show: Boolean,
    active: Number,
    minZoom: makeRequiredProp(numericProp),
    maxZoom: makeRequiredProp(numericProp),
    rootWidth: makeRequiredProp(Number),
    rootHeight: makeRequiredProp(Number)
  },
  emits: ["scale", "close"],
  setup(props, {
    emit,
    slots
  }) {
    const state = reactive({
      scale: 1,
      moveX: 0,
      moveY: 0,
      moving: false,
      zooming: false,
      imageRatio: 0,
      displayWidth: 0,
      displayHeight: 0
    });
    const touch = useTouch();
    const swipeItem = ref();
    const vertical = computed(() => {
      const {
        rootWidth,
        rootHeight
      } = props;
      const rootRatio = rootHeight / rootWidth;
      return state.imageRatio > rootRatio;
    });
    const imageStyle = computed(() => {
      const {
        scale,
        moveX,
        moveY,
        moving,
        zooming
      } = state;
      const style = {
        transitionDuration: zooming || moving ? "0s" : ".3s"
      };
      if (scale !== 1) {
        const offsetX = moveX / scale;
        const offsetY = moveY / scale;
        style.transform = `scale(${scale}, ${scale}) translate(${offsetX}px, ${offsetY}px)`;
      }
      return style;
    });
    const maxMoveX = computed(() => {
      if (state.imageRatio) {
        const {
          rootWidth,
          rootHeight
        } = props;
        const displayWidth = vertical.value ? rootHeight / state.imageRatio : rootWidth;
        return Math.max(0, (state.scale * displayWidth - rootWidth) / 2);
      }
      return 0;
    });
    const maxMoveY = computed(() => {
      if (state.imageRatio) {
        const {
          rootWidth,
          rootHeight
        } = props;
        const displayHeight = vertical.value ? rootHeight : rootWidth * state.imageRatio;
        return Math.max(0, (state.scale * displayHeight - rootHeight) / 2);
      }
      return 0;
    });
    const setScale = (scale) => {
      scale = clamp(scale, +props.minZoom, +props.maxZoom + 1);
      if (scale !== state.scale) {
        state.scale = scale;
        emit("scale", {
          scale,
          index: props.active
        });
      }
    };
    const resetScale = () => {
      setScale(1);
      state.moveX = 0;
      state.moveY = 0;
    };
    const toggleScale = () => {
      const scale = state.scale > 1 ? 1 : 2;
      setScale(scale);
      state.moveX = 0;
      state.moveY = 0;
    };
    let fingerNum;
    let startMoveX;
    let startMoveY;
    let startScale;
    let startDistance;
    let doubleTapTimer;
    let touchStartTime;
    const onTouchStart = (event) => {
      const {
        touches
      } = event;
      const {
        offsetX
      } = touch;
      touch.start(event);
      fingerNum = touches.length;
      startMoveX = state.moveX;
      startMoveY = state.moveY;
      touchStartTime = Date.now();
      state.moving = fingerNum === 1 && state.scale !== 1;
      state.zooming = fingerNum === 2 && !offsetX.value;
      if (state.zooming) {
        startScale = state.scale;
        startDistance = getDistance(event.touches);
      }
    };
    const onTouchMove = (event) => {
      const {
        touches
      } = event;
      touch.move(event);
      if (state.moving || state.zooming) {
        preventDefault(event, true);
      }
      if (state.moving) {
        const {
          deltaX,
          deltaY
        } = touch;
        const moveX = deltaX.value + startMoveX;
        const moveY = deltaY.value + startMoveY;
        state.moveX = clamp(moveX, -maxMoveX.value, maxMoveX.value);
        state.moveY = clamp(moveY, -maxMoveY.value, maxMoveY.value);
      }
      if (state.zooming && touches.length === 2) {
        const distance = getDistance(touches);
        const scale = startScale * distance / startDistance;
        setScale(scale);
      }
    };
    const checkTap = () => {
      if (fingerNum > 1) {
        return;
      }
      const {
        offsetX,
        offsetY
      } = touch;
      const deltaTime = Date.now() - touchStartTime;
      const TAP_TIME = 250;
      const TAP_OFFSET = 5;
      if (offsetX.value < TAP_OFFSET && offsetY.value < TAP_OFFSET && deltaTime < TAP_TIME) {
        if (doubleTapTimer) {
          clearTimeout(doubleTapTimer);
          doubleTapTimer = null;
          toggleScale();
        } else {
          doubleTapTimer = setTimeout(() => {
            emit("close");
            doubleTapTimer = null;
          }, TAP_TIME);
        }
      }
    };
    const onTouchEnd = (event) => {
      let stopPropagation = false;
      if (state.moving || state.zooming) {
        stopPropagation = true;
        if (state.moving && startMoveX === state.moveX && startMoveY === state.moveY) {
          stopPropagation = false;
        }
        if (!event.touches.length) {
          if (state.zooming) {
            state.moveX = clamp(state.moveX, -maxMoveX.value, maxMoveX.value);
            state.moveY = clamp(state.moveY, -maxMoveY.value, maxMoveY.value);
            state.zooming = false;
          }
          state.moving = false;
          startMoveX = 0;
          startMoveY = 0;
          startScale = 1;
          if (state.scale < 1) {
            resetScale();
          }
          if (state.scale > props.maxZoom) {
            state.scale = +props.maxZoom;
          }
        }
      }
      preventDefault(event, stopPropagation);
      checkTap();
      touch.reset();
    };
    const onLoad = (event) => {
      const {
        naturalWidth,
        naturalHeight
      } = event.target;
      state.imageRatio = naturalHeight / naturalWidth;
    };
    watch(() => props.active, resetScale);
    watch(() => props.show, (value) => {
      if (!value) {
        resetScale();
      }
    });
    useEventListener("touchmove", onTouchMove, {
      target: computed(() => {
        var _a;
        return (_a = swipeItem.value) == null ? void 0 : _a.$el;
      })
    });
    return () => {
      const imageSlots = {
        loading: () => _createVNode(Loading, {
          "type": "spinner"
        }, null)
      };
      return _createVNode(SwipeItem, {
        "ref": swipeItem,
        "class": bem("swipe-item"),
        "onTouchstartPassive": onTouchStart,
        "onTouchend": onTouchEnd,
        "onTouchcancel": onTouchEnd
      }, {
        default: () => [slots.image ? _createVNode("div", {
          "class": bem("image-wrap")
        }, [slots.image({
          src: props.src
        })]) : _createVNode(Image, {
          "src": props.src,
          "fit": "contain",
          "class": bem("image", {
            vertical: vertical.value
          }),
          "style": imageStyle.value,
          "onLoad": onLoad
        }, imageSlots)]
      });
    };
  }
});
export {
  stdin_default as default
};