Final overhaul to gamepad handling

src/components/input/gamepadtokey.js

@@ -251,13 +251,14 @@ require(['apphost'], function (appHost) {
         }
     }
 
+    var inputLoopTimer;
     function runInputLoop() {
         // Get the latest gamepad state.
         var gamepads = navigator.getGamepads();
         for (var i = 0, len = gamepads.length; i < len; i++) {
             var gamepad = gamepads[i];
             if (!gamepad) {
-                return;
+                continue;
             }
             // Iterate through the axes
             var axes = gamepad.axes;
@@ -279,8 +280,7 @@ require(['apphost'], function (appHost) {
             }
             // Iterate through the buttons to see if Left thumbstick, DPad, A and B are pressed.
             var buttons = gamepad.buttons;
-            var j;
-            for (j = 0, len = buttons.length; j < len; j++) {
+            for (var j = 0, len = buttons.length; j < len; j++) {
                 if (ProcessedButtons.indexOf(j) !== -1) {
                     if (buttons[j].pressed) {
                         switch (j) {
@@ -347,10 +347,50 @@ require(['apphost'], function (appHost) {
             }
         }
         // Schedule the next one
-        requestAnimationFrame(runInputLoop);
+        inputLoopTimer = requestAnimationFrame(runInputLoop);
     }
 
-    runInputLoop();
+    function startInputLoop() {
+        if (!inputLoopTimer) {
+            runInputLoop();
+        }
+    }
+
+    function stopInputLoop() {
+        cancelAnimationFrame(inputLoopTimer);
+        inputLoopTimer = undefined;
+    }
+
+    function isGamepadConnected() {
+        var gamepads = navigator.getGamepads();
+        for (var i = 0, len = gamepads.length; i < len; i++) {
+            var gamepad = gamepads[i];
+            if (gamepad) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    function attachGamepad(e) {
+        if (isGamepadConnected()) {
+            console.log("Gamepad connected! Starting input loop");
+            startInputLoop();
+        }
+    }
+
+    function dettachGamepad(e) {
+        if (!isGamepadConnected()) {
+            console.log("Gamepad disconnected! No other gamepads are connected, stopping input loop");
+            stopInputLoop();
+        } else {
+            console.log("Gamepad disconnected! There are gamepads still connected.");
+        }
+    }
+
+    // Event Listeners for any change in gamepads' state.
+    window.addEventListener("gamepaddisconnected", dettachGamepad);
+    window.addEventListener("gamepadconnected", attachGamepad);
 
     // The gamepadInputEmulation is a string property that exists in JavaScript UWAs and in WebViews in UWAs.
     // It won't exist in Win8.1 style apps or browsers.

src/components/input/keyboardnavigation.js

@@ -145,7 +145,11 @@ define(["inputManager", "layoutManager"], function (inputManager, layoutManager)
             }
         });
     }
+    // For hiding the mouse while playbackç
+    require(["components/input/mouseManager"]);
 
+    // Gamepad initialization. No script is required if no gamepads are at boot time, saving a bit of resources._10k
+    // Whenever the gamepad is connected, we hand all the control of the gamepad to gamepadtokey.js by removing the event handler
     function isGamepadConnected() {
         var gamepads = navigator.getGamepads();
         for (var i = 0, len = gamepads.length; i < len; i++) {
@@ -157,25 +161,16 @@ define(["inputManager", "layoutManager"], function (inputManager, layoutManager)
         return false;
     }
 
-    function attachGamepad(e) {
+    function attachGamepadScript(e) {
         if (isGamepadConnected()) {
-            require(["components/input/gamepadtokey"]);
             console.log("Gamepad connected! Attaching gamepadtokey.js script");
-        }
-    }
-
-    function dettachGamepad(e) {
-        if (!isGamepadConnected()) {
-            console.log("Gamepad disconnected! No other gamepads are connected, dettaching gamepadtokey.js");
-        } else {
-            console.log("Gamepad disconnected! There are gamepads still connected.");
+            window.removeEventListener("gamepadconnected", attachGamepadScript);
+            require(["components/input/gamepadtokey"]);
         }
     }
 
     // No need to check for gamepads manually at load time, the eventhandler will be fired for that
-    window.addEventListener("gamepaddisconnected", dettachGamepad);
-    window.addEventListener("gamepadconnected", attachGamepad);
-    require(["components/input/mouseManager"]);
+    window.addEventListener("gamepadconnected", attachGamepadScript);
 
     return {
         enable: enable,