Right Click in ClojureScript?

Frequently in ClojureScript the Google Closure library (Event Handling |  Closure Library | Google Developers) is used instead of raw JS. The events (Closure Library API Documentation - JavaScript) namespace contains the goog.events.EventType enumeration which specifies each individual event type:

(ns test.core
  (:require [goog.dom :as dom]
            [goog.events :as events]))

(letfn [(menu-listener [event] 
          (.log js/console (str "contextmenu " (.-button event))))
        (click-listener [event]
          (let [btn (.-button event)
                msg (if (= btn 2) "Right-click" (str "Button " btn))] 
            (.log js/console msg)))]

  (events/listen (dom/getElement "click-target") "contextmenu" menu-listener)
  (events/listen (dom/getElement "click-target") "click" click-listener))   

;; src/test/core.cljs

.

<!DOCTYPE html>
<html>
  <head>
    <title>contextmenu</title>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  </head>
  <body>
    <p id="click-target">Right click on me</p> 
    <script src="out/test.js" type="text/javascript"></script>
  </body>
</html>

<!-- index.html -->

Observe:

  • A right-click (button 2) fires the contextmenu listener. The click listener doesn't get to see it (even if there is no contextmenu listener).
  • A second right-click will dismiss the context menu but neither listener is fired.

Using om I got right click as context-menu event. Button number is 2 for right button:

{:onContextMenu (fn [e]
                   (prn e (.-button e)))}

or in plain html+cljs:

  <div id="btn">Click me</div>

  (.addEventListener (.getElementById js/document "btn")
    "contextmenu" (fn [e] (prn e (.-button e))))

https://developer.mozilla.org/en/docs/Web/API/MouseEvent

Tags:

Clojure

Mouseevent

Clojurescript

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