[new feature] add IndexBar component

packages/index-bar/index.js

@@ -0,0 +1,92 @@
+import { use } from '../utils';
+import { TouchMixin } from '../mixins/touch';
+import { ParentMixin } from '../mixins/relation';
+
+const [sfc, bem] = use('index-bar');
+
+export default sfc({
+  mixins: [TouchMixin, ParentMixin('vanIndexBar')],
+
+  props: {
+    indexList: {
+      type: Array,
+      default() {
+        const indexList = [];
+        const charCodeOfA = 'A'.charCodeAt(0);
+
+        for (let i = 0; i < 26; i++) {
+          indexList.push(String.fromCharCode(charCodeOfA + i));
+        }
+
+        return indexList;
+      }
+    }
+  },
+
+  methods: {
+    onClick(event) {
+      this.scrollToElement(event.target);
+    },
+
+    onTouchStart(event) {
+      this.touchStart(event);
+    },
+
+    onTouchMove(event) {
+      this.touchMove(event);
+
+      if (this.direction === 'vertical') {
+        /* istanbul ignore else */
+        if (event.cancelable) {
+          event.preventDefault();
+        }
+
+        const { clientX, clientY } = event.touches[0];
+        const target = document.elementFromPoint(clientX, clientY);
+        this.scrollToElement(target);
+      }
+    },
+
+    scrollToElement(element, setActive) {
+      if (!element) {
+        return;
+      }
+
+      const { index } = element.dataset;
+      if (!index) {
+        return;
+      }
+
+      const match = this.children.filter(item => String(item.index) === index);
+      if (match[0]) {
+        match[0].scrollIntoView();
+      }
+    },
+
+    onTouchEnd() {
+      this.active = null;
+    }
+  },
+
+  render(h) {
+    return (
+      <div class={bem()}>
+        <div
+          class={bem('sidebar')}
+          onClick={this.onClick}
+          onTouchstart={this.onTouchStart}
+          onTouchmove={this.onTouchMove}
+          onTouchend={this.onTouchEnd}
+          onTouchcancel={this.onTouchEnd}
+        >
+          {this.indexList.map(index => (
+            <span class={bem('index')} data-index={index}>
+              {index}
+            </span>
+          ))}
+        </div>
+        {this.slots('default')}
+      </div>
+    );
+  }
+});