1 files changed, 77 insertions, 0 deletions
diff --git a/devtools/shared/touch/simulator.js b/devtools/shared/touch/simulator.js
new file mode 100644
index 000000000..0e6d29282
--- /dev/null
+++ b/devtools/shared/touch/simulator.js
@@ -0,0 +1,77 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+var promise = require("promise");
+var defer = require("devtools/shared/defer");
+var Services = require("Services");
+
+const FRAME_SCRIPT =
+  "resource://devtools/shared/touch/simulator-content.js";
+
+var trackedBrowsers = new WeakMap();
+var savedTouchEventsEnabled =
+  Services.prefs.getIntPref("dom.w3c_touch_events.enabled");
+
+/**
+ * Simulate touch events for platforms where they aren't generally available.
+ * Defers to the `simulator-content.js` frame script to perform the real work.
+ */
+function TouchEventSimulator(browser) {
+  // Returns an already instantiated simulator for this browser
+  let simulator = trackedBrowsers.get(browser);
+  if (simulator) {
+    return simulator;
+  }
+
+  let mm = browser.frameLoader.messageManager;
+  mm.loadFrameScript(FRAME_SCRIPT, true);
+
+  simulator = {
+    enabled: false,
+
+    start() {
+      if (this.enabled) {
+        return promise.resolve({ isReloadNeeded: false });
+      }
+      this.enabled = true;
+
+      let deferred = defer();
+      let isReloadNeeded =
+        Services.prefs.getIntPref("dom.w3c_touch_events.enabled") != 1;
+      Services.prefs.setIntPref("dom.w3c_touch_events.enabled", 1);
+      let onStarted = () => {
+        mm.removeMessageListener("TouchEventSimulator:Started", onStarted);
+        deferred.resolve({ isReloadNeeded });
+      };
+      mm.addMessageListener("TouchEventSimulator:Started", onStarted);
+      mm.sendAsyncMessage("TouchEventSimulator:Start");
+      return deferred.promise;
+    },
+
+    stop() {
+      if (!this.enabled) {
+        return promise.resolve();
+      }
+      this.enabled = false;
+
+      let deferred = defer();
+      Services.prefs.setIntPref("dom.w3c_touch_events.enabled",
+                                savedTouchEventsEnabled);
+      let onStopped = () => {
+        mm.removeMessageListener("TouchEventSimulator:Stopped", onStopped);
+        deferred.resolve();
+      };
+      mm.addMessageListener("TouchEventSimulator:Stopped", onStopped);
+      mm.sendAsyncMessage("TouchEventSimulator:Stop");
+      return deferred.promise;
+    }
+  };
+
+  trackedBrowsers.set(browser, simulator);
+
+  return simulator;
+}
+
+exports.TouchEventSimulator = TouchEventSimulator;