commit 8bdba90edbc523912de55a46205ddb6dd0f1f0ef
Author: Jan Petykiewicz <anewusername@gmail.com>
Date:   Thu Apr 6 18:11:25 2017 -0700

    add webextension

diff --git a/webextension/content-script.js b/webextension/content-script.js
new file mode 100644
index 0000000..e8008b5
--- /dev/null
+++ b/webextension/content-script.js
@@ -0,0 +1,70 @@
+/*
+Unused
+Listen for messages from the page.
+If the message was from the page script, show an alert.
+
+window.addEventListener("message", function(event) {
+  if (event.source == window &&
+      event.data.direction &&
+      event.data.direction == "from-page-script") {
+    alert("Content script received message: \"" + event.data.message + "\"");
+  }
+});
+*/
+
+function handleMoonslicer(message) {
+  var result = message.querySelector('div.sheet-result')
+
+  var rx = /">([0-9]+)<\/span>/ 
+  var h0str = result.children[0].children[0].children[0].getAttribute("title");
+  var h1str = result.children[2].children[0].children[0].getAttribute("title");
+  var hit0 = Number(h0str.match(rx)[1]);
+  var hit1 = Number(h1str.match(rx)[1]);
+
+  var input_area = document.getElementById('textchat-input');
+  var textarea = input_area.querySelector("textarea");
+  var submit_button = input_area.querySelector("button.btn");
+  console.log('Hit0: ' + hit0 + ' Hit1: ' + hit1);
+
+  var old_text = textarea.value;
+  if (hit0 == 20 || hit1 == 20) {
+    textarea.value = "20! +[[1d6]] ice";
+    submit_button.click();
+  }
+  if (hit0 == 19 || hit1 == 19) {
+    textarea.value = "19! +[[1d4]] ice";
+    submit_button.click();
+  }
+  if (hit0 == 2 || hit1 == 2) {
+    textarea.value = "2! [[floor(1d4/2)]] ice to self";
+    submit_button.click();
+  } 
+  if (hit0 == 1 || hit1 == 1) {
+    textarea.value = "1! [[1d6]] ice to self";
+    submit_button.click();
+  }
+  textarea.value = old_text;
+}
+
+/*
+Send a message to the page script.
+*/
+function newMessageHandler(event) {
+  var message = event.target;
+  
+  if (message.classList.contains('you')) {
+    var labelElem = message.querySelector('div.sheet-rolltemplate-atk div.sheet-label');
+    var label = labelElem.querySelector('span a');
+    if (label && label.innerHTML == 'Moonslicer') {
+        handleMoonslicer(message);
+    };
+  };
+}
+
+/*
+Add messagePageScript() as a listener to click events on
+the "from-content-script" element.
+*/
+var textchat = document.getElementById("textchat");
+var content = textchat.getElementsByClassName("content")[0];
+content.addEventListener("DOMNodeInserted", newMessageHandler);
diff --git a/webextension/manifest.json b/webextension/manifest.json
new file mode 100644
index 0000000..cf87aef
--- /dev/null
+++ b/webextension/manifest.json
@@ -0,0 +1,19 @@
+{
+
+  "manifest_version": 2,
+  "name": "Test roll20",
+  "description": "Visit https://mdn.github.io/webextensions-examples/content-script-page-script-messaging.html for the demo. See https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Examples#page-to-extension-messaging",
+  "version": "1.0",
+  "homepage_url": "https://github.com/mdn/webextensions-examples/tree/master/page-to-extension-messaging",
+  "icons": {
+    "48": "icons/message-48.png"
+  },
+
+  "content_scripts": [
+    {
+      "matches": ["*://app.roll20.net/editor*"],
+      "js": ["content-script.js"]
+    }
+  ]
+
+}