implement pinch to zoom

node_modules/component-delegate/index.js

@@ -0,0 +1,51 @@
+/**
+ * Module dependencies.
+ */
+
+try {
+  var closest = require('closest');
+} catch(err) {
+  var closest = require('component-closest');
+}
+
+try {
+  var event = require('event');
+} catch(err) {
+  var event = require('component-event');
+}
+
+/**
+ * Delegate event `type` to `selector`
+ * and invoke `fn(e)`. A callback function
+ * is returned which may be passed to `.unbind()`.
+ *
+ * @param {Element} el
+ * @param {String} selector
+ * @param {String} type
+ * @param {Function} fn
+ * @param {Boolean} capture
+ * @return {Function}
+ * @api public
+ */
+
+exports.bind = function(el, selector, type, fn, capture){
+  return event.bind(el, type, function(e){
+    var target = e.target || e.srcElement;
+    e.delegateTarget = closest(target, selector, true, el);
+    if (e.delegateTarget) fn.call(el, e);
+  }, capture);
+};
+
+/**
+ * Unbind event `type`'s callback `fn`.
+ *
+ * @param {Element} el
+ * @param {String} type
+ * @param {Function} fn
+ * @param {Boolean} capture
+ * @api public
+ */
+
+exports.unbind = function(el, type, fn, capture){
+  event.unbind(el, type, fn, capture);
+};