Refactor for hardware extensions (#1555)

* Beginning refactor: renaming 'device' to 'peripheral', shortening function names, reordering functions, etc.

* Continuing refactoring: renaming some functions to be more verbose in the runtime, adding JSDocs, etc.

* Changing 'device' to 'peripheral', etc.

* Changing 'session' to 'socket'.

* Fixing EV3 menus and menu arg validation, reordering functions, etc.

* Add _send, add some references to documentation, etc.

* Factored out _outputCommand and _inputCommand, renamed some enums, etc.

* Fixed _outputCommand, some other minor cleanup.

* Make _outputCommand and _inputCommand public.

* Added TODO.

* Renamed BLE UUID enums to be clearer.

* Change WeDo2 in comments to WeDo 2.0, etc.

* Changed some WeDo2Motor command names, cleaned up some JSDocs.

* Beginning a major EV3 refactor.

* WeDo2 formatting and comment changes.

* Motor refactoring in EV3: motorTurnClockwise and motorTurnCounterClockwise initial working state.

* Add reminders to possibly cast motor menu args in WeDo2.

* Continue to move motor commands in EV3 to EV3Motor class, don't create new EV3Motor on every poll cycle, etc.

* Factoring EV3 polling value commands, etc.

* Fixing EV3 motor power, position and button pressed, and some commenting, etc.

* Move EV3 motor position parsing to EV3Motor class, move directCommand and directCompoundCommand functions, some commenting, etc.

* Changed WeDo2 motor label enum name.

* Removed some EV3 motor functions that aren't needed, changed menu label enum names, moved some opcodes up to enums.

* Fixing comments and documentation.

* Some commenting.

* Adding further documentation and references to PDFs, changed reply check to be safer, etc.

* Some comment changes.

* Moving some functions around in EV3 and WeDo2 to match.

* Commenting, etc.

* Some renaming of session, etc.

* Fix stopAllMotors in EV3.

* Fixing clearing of motors in EV3.

* Some comment changes.

* Change runtime .extensions/registerExtension to .peripheralExtensions/registerPeripheralExtension.

* Renaming outputCommand/inputCommand to generateOutputCommand/generateInputCommand, etc.

* Moved motorCommandIDs to EV3Motor class, renamed directCommand to generateCommand, etc.

* Adding a reminder to rename something.

* JSDoc fix in EV3Motor class.

* Fixing microbit function name.

* Adding a todo item.

* Changing Ev3 menu formats to be backwards compatible, moving a BLE function up.

* Fixing EV3 ports again, and button pressed returning a boolean.

* Fixing menu value to be a string in EV3.

src/engine/runtime.js

@@ -264,7 +264,10 @@ class Runtime extends EventEmitter {
             video: new Video(this)
         };
 
-        this.extensionDevices = {};
+        /**
+         * A list of extensions, used to manage hardware connection.
+         */
+        this.peripheralExtensions = {};
 
         /**
          * A runtime profiler that records timed events for later playback to
@@ -928,32 +931,56 @@ class Runtime extends EventEmitter {
             (result, categoryInfo) => result.concat(categoryInfo.blocks.map(blockInfo => blockInfo.json)), []);
     }
 
-    registerExtensionDevice (extensionId, device) {
-        this.extensionDevices[extensionId] = device;
+    /**
+     * Register an extension that communications with a hardware peripheral by id,
+     * to have access to it and its peripheral functions in the future.
+     * @param {string} extensionId - the id of the extension.
+     * @param {object} extension - the extension to register.
+     */
+    registerPeripheralExtension (extensionId, extension) {
+        this.peripheralExtensions[extensionId] = extension;
     }
 
-    startDeviceScan (extensionId) {
-        if (this.extensionDevices[extensionId]) {
-            this.extensionDevices[extensionId].startDeviceScan();
+    /**
+     * Tell the specified extension to scan for a peripheral.
+     * @param {string} extensionId - the id of the extension.
+     */
+    scanForPeripheral (extensionId) {
+        if (this.peripheralExtensions[extensionId]) {
+            this.peripheralExtensions[extensionId].scan();
         }
     }
 
-    connectToPeripheral (extensionId, peripheralId) {
-        if (this.extensionDevices[extensionId]) {
-            this.extensionDevices[extensionId].connectDevice(peripheralId);
+    /**
+     * Connect to the extension's specified peripheral.
+     * @param {string} extensionId - the id of the extension.
+     * @param {number} peripheralId - the id of the peripheral.
+     */
+    connectPeripheral (extensionId, peripheralId) {
+        if (this.peripheralExtensions[extensionId]) {
+            this.peripheralExtensions[extensionId].connect(peripheralId);
         }
     }
 
-    disconnectExtensionSession (extensionId) {
-        if (this.extensionDevices[extensionId]) {
-            this.extensionDevices[extensionId].disconnectSession();
+    /**
+     * Disconnect from the extension's connected peripheral.
+     * @param {string} extensionId - the id of the extension.
+     */
+    disconnectPeripheral (extensionId) {
+        if (this.peripheralExtensions[extensionId]) {
+            this.peripheralExtensions[extensionId].disconnect();
         }
     }
 
+    /**
+     * Returns whether the extension has a currently connected peripheral.
+     * @param {string} extensionId - the id of the extension.
+     * @return {boolean} - whether the extension has a connected peripheral.
+     */
     getPeripheralIsConnected (extensionId) {
         let isConnected = false;
-        if (this.extensionDevices[extensionId]) {
-            isConnected = this.extensionDevices[extensionId].getPeripheralIsConnected();
+        if (this.peripheralExtensions[extensionId]) {
+            isConnected = this.peripheralExtensions[extensionId].isConnected();
         }
         return isConnected;
     }