[new feature] add grid component (#3669)

src/grid/index.js

@@ -0,0 +1,49 @@
+import { createNamespace, suffixPx } from '../utils';
+import { ParentMixin } from '../mixins/relation';
+
+const [createComponent, bem] = createNamespace('grid');
+
+export default createComponent({
+  mixins: [ParentMixin('vanGrid')],
+
+  props: {
+    gutter: Number,
+    square: Boolean,
+    clickable: Boolean,
+    columnNum: {
+      type: Number,
+      default: 4
+    },
+    center: {
+      type: Boolean,
+      default: true
+    },
+    border: {
+      type: Boolean,
+      default: true
+    }
+  },
+
+  computed: {
+    style() {
+      const { gutter } = this;
+
+      if (gutter) {
+        return {
+          paddingLeft: suffixPx(gutter)
+        };
+      }
+    }
+  },
+
+  render(h) {
+    return (
+      <div
+        style={this.style}
+        class={[bem(), { 'van-hairline--top': this.border && !this.gutter }]}
+      >
+        {this.slots()}
+      </div>
+    );
+  }
+});