[improvement] rename packages dir to src (#3659)

src/mixins/touch.js

@@ -0,0 +1,43 @@
+const MIN_DISTANCE = 10;
+function getDirection(x, y) {
+  if (x > y && x > MIN_DISTANCE) {
+    return 'horizontal';
+  }
+  if (y > x && y > MIN_DISTANCE) {
+    return 'vertical';
+  }
+  return '';
+}
+
+export const TouchMixin = {
+  data() {
+    return {
+      direction: ''
+    };
+  },
+
+  methods: {
+    touchStart(event) {
+      this.resetTouchStatus();
+      this.startX = event.touches[0].clientX;
+      this.startY = event.touches[0].clientY;
+    },
+
+    touchMove(event) {
+      const touch = event.touches[0];
+      this.deltaX = touch.clientX - this.startX;
+      this.deltaY = touch.clientY - this.startY;
+      this.offsetX = Math.abs(this.deltaX);
+      this.offsetY = Math.abs(this.deltaY);
+      this.direction = this.direction || getDirection(this.offsetX, this.offsetY);
+    },
+
+    resetTouchStatus() {
+      this.direction = '';
+      this.deltaX = 0;
+      this.deltaY = 0;
+      this.offsetX = 0;
+      this.offsetY = 0;
+    }
+  }
+};