press-plus/press-debug-entrance/touch-mixin.js

易用的跨端组件库

export function getTouchMixin() {
  return {
    data() {
      const switchPos = {
        hasMoved: false, // exclude click event
        x: 20, // right
        y: 100, // bottom
        startX: 0,
        startY: 0,
        endX: 0,
        endY: 0,
      };

      return {
        switchPos,
        btnSwitchPos: { x: 20, y: 100 },
      };
    },
    methods: {
      onTouchStart(e) {
        this.switchPos.startX = e.touches[0].pageX;
        this.switchPos.startY = e.touches[0].pageY;
      },
      onTouchEnd() {
        if (!this.switchPos.hasMoved) {
          return;
        }
        this.switchPos.startX = 0;
        this.switchPos.startY = 0;
        this.switchPos.hasMoved = false;
        this.setSwitchPosition(this.switchPos.endX, this.switchPos.endY);
      },
      onTouchMove(e) {
        if (e.touches.length <= 0) {
          return;
        }
        const offsetX = e.touches[0].pageX - this.switchPos.startX;
        const offsetY = e.touches[0].pageY - this.switchPos.startY;
        let x = Math.floor(this.switchPos.x - offsetX);
        let y = Math.floor(this.switchPos.y - offsetY);
        [x, y] = this.getSwitchButtonSafeAreaXY(x, y);
        this.btnSwitchPos.x = x;
        this.btnSwitchPos.y = y;
        this.switchPos.endX = x;
        this.switchPos.endY = y;
        this.switchPos.hasMoved = true;
        e.preventDefault();
        e.stopPropagation();
      },
      setSwitchPosition(switchX, switchY) {
        [switchX, switchY] = this.getSwitchButtonSafeAreaXY(switchX, switchY);
        this.switchPos.x = switchX;
        this.switchPos.y = switchY;
        this.btnSwitchPos.x = switchX;
        this.btnSwitchPos.y = switchY;
      },
      getSwitchButtonSafeAreaXY(x, y) {
        const bottomThreshold = 20;
        const top = 0;
        const { fabSize } = this;
        const { windowWidth, windowHeight, windowTop, windowBottom } = uni.getSystemInfoSync();
        const docWidth = windowWidth;
        const docHeight = windowHeight - top;

        // check edge
        if (x + fabSize.width > docWidth) {
          x = docWidth - fabSize.width;
        }
        if (y + fabSize.height - windowTop > docHeight) {
          y = docHeight - fabSize.height + windowTop;
        }

        if (x < 0) {
          x = 0;
        }
        if (y < bottomThreshold + windowBottom) {
          y = bottomThreshold + windowBottom;
        }
        // safe area for iOS Home indicator
        return [x, y];
      },
    },
  };
}