implement pinch to zoom

node_modules/component-matches-selector/index.js

@@ -0,0 +1,51 @@
+/**
+ * Module dependencies.
+ */
+
+try {
+  var query = require('query');
+} catch (err) {
+  var query = require('component-query');
+}
+
+/**
+ * Element prototype.
+ */
+
+var Element = require('global-object').Element;
+var proto = Element && Element.prototype || {};
+
+/**
+ * Vendor function.
+ */
+
+var vendor = proto.matches
+  || proto.webkitMatchesSelector
+  || proto.mozMatchesSelector
+  || proto.msMatchesSelector
+  || proto.oMatchesSelector;
+
+/**
+ * Expose `match()`.
+ */
+
+module.exports = match;
+
+/**
+ * Match `el` to `selector`.
+ *
+ * @param {Element} el
+ * @param {String} selector
+ * @return {Boolean}
+ * @api public
+ */
+
+function match(el, selector) {
+  if (!el || el.nodeType !== 1) return false;
+  if (vendor) return vendor.call(el, selector);
+  var nodes = query.all(selector, el.parentNode);
+  for (var i = 0; i < nodes.length; ++i) {
+    if (nodes[i] == el) return true;
+  }
+  return false;
+}