Implement isVoiceOverRunning and isClosedCaptioningEnabled methods for iOS

Also implement VoiceOverStatusChanged and
ClosedCaptioningStatusDidChange notifications

src/ios/CDVMobileAccessibility.h

@@ -20,8 +20,14 @@
 #import <Cordova/CDVPlugin.h>
 
 @interface CDVMobileAccessibility : CDVPlugin {
+    NSString* callbackId;
 }
 
+@property (strong) NSString* callbackId;
+
 - (void) isVoiceOverRunning:(CDVInvokedUrlCommand*)command;
+- (void) isClosedCaptioningEnabled:(CDVInvokedUrlCommand*)command;
+- (void) start:(CDVInvokedUrlCommand*)command;
+- (void) stop:(CDVInvokedUrlCommand*)command;
 
 @end

src/ios/CDVMobileAccessibility.m

@@ -26,6 +26,8 @@
 
 @implementation CDVMobileAccessibility
 
+@synthesize callbackId;
+
 // //////////////////////////////////////////////////
 
 - (id)settingForKey:(NSString*)key
@@ -49,16 +51,75 @@
 
 - (void)dealloc
 {
-    // since this is ARC, remove observers only
+    [self stop:nil];
+}
+
+- (void)onReset
+{
+    [self stop:nil];
 }
 
 // //////////////////////////////////////////////////
 
 #pragma Plugin interface
 
-- (void) isVoiceOverRunning:(CDVInvokedUrlCommand*)command
+- (void)isVoiceOverRunning:(CDVInvokedUrlCommand*)command
 {
-	// TODO:
+    CDVPluginResult* result = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsBool:UIAccessibilityIsVoiceOverRunning()];
+    [self.commandDelegate sendPluginResult:result callbackId:command.callbackId];
+}
+
+- (void)isClosedCaptioningEnabled:(CDVInvokedUrlCommand*)command
+{
+    CDVPluginResult* result = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsBool:UIAccessibilityIsClosedCaptioningEnabled()];
+    [self.commandDelegate sendPluginResult:result callbackId:command.callbackId];
+}
+
+
+- (void)mobileAccessibilityStatusChanged:(NSNotification *)notification
+{
+    if (self.callbackId) {
+        CDVPluginResult* result = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsDictionary:[self getMobileAccessibilityStatus]];
+        [result setKeepCallbackAsBool:YES];
+        [self.commandDelegate sendPluginResult:result callbackId:self.callbackId];
+    }
+}
+
+/* Get the current mobile accessibility status. */
+- (NSDictionary*)getMobileAccessibilityStatus
+{
+    NSMutableDictionary* mobileAccessibilityData = [NSMutableDictionary dictionaryWithCapacity:2];
+    [mobileAccessibilityData setObject:[NSNumber numberWithBool:UIAccessibilityIsVoiceOverRunning()] forKey:@"isVoiceOverRunning"];
+    [mobileAccessibilityData setObject:[NSNumber numberWithBool:UIAccessibilityIsClosedCaptioningEnabled()] forKey:@"isClosedCaptioningEnabled"];
+    return mobileAccessibilityData;
+}
+
+
+/* turn on MobileAccessibility monitoring*/
+- (void)start:(CDVInvokedUrlCommand*)command
+{
+    self.callbackId = command.callbackId;
+        
+    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(mobileAccessibilityStatusChanged:)
+        name:UIAccessibilityVoiceOverStatusChanged object:nil];
+    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(mobileAccessibilityStatusChanged:)
+        name:UIAccessibilityClosedCaptioningStatusDidChangeNotification object:nil];
+}
+
+- (void)stop:(CDVInvokedUrlCommand*)command
+{
+    // callback one last time to clear the callback function on JS side
+    if (self.callbackId)
+    {
+        CDVPluginResult* result = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsDictionary:[self getMobileAccessibilityStatus]];
+        [result setKeepCallbackAsBool:NO];
+        [self.commandDelegate sendPluginResult:result callbackId:self.callbackId];
+    }
+    self.callbackId = nil;
+    [[NSNotificationCenter defaultCenter] removeObserver:self
+        name:UIAccessibilityVoiceOverStatusChanged object:nil];
+    [[NSNotificationCenter defaultCenter] removeObserver:self
+        name:UIAccessibilityClosedCaptioningStatusDidChangeNotification object:nil];
 }
 
 @end

www/mobile-accessibility.js

@@ -22,12 +22,74 @@
 var argscheck = require('cordova/argscheck'),
     utils = require('cordova/utils'),
     exec = require('cordova/exec');
-   
+
 var MobileAccessibility = function() {
+    this._isVoiceOverRunning = false;
+    this._isClosedCaptioningEnabled = false;
+    // Create new event handlers on the window (returns a channel instance)
+    this.channels = {
+        voiceoverstatuschanged:cordova.addWindowEventHandler("voiceoverstatuschanged"),
+        closedcaptioningstatusdidchange:cordova.addWindowEventHandler("closedcaptioningstatusdidchange")
+    };
+    for (var key in this.channels) {
+        this.channels[key].onHasSubscribersChange = MobileAccessibility.onHasSubscribersChange;
+    }
 };
 
-MobileAccessibility.isVoiceOverRunning = function() {
-    exec(null, null, "MobileAccessibility", "isVoiceOverRunning", []);
+function handlers() {
+    return mobileAccessibility.channels.voiceoverstatuschanged.numHandlers +
+           mobileAccessibility.channels.closedcaptioningstatusdidchange.numHandlers;
 };
 
-module.exports = MobileAccessibility;
+/**
+ * Event handlers for when callbacks get registered for mobileAccessibility.
+ * Keep track of how many handlers we have so we can start and stop the native MobileAccessibility listener
+ * appropriately.
+ */
+MobileAccessibility.onHasSubscribersChange = function() {
+    // If we just registered the first handler, make sure native listener is started.
+    if (this.numHandlers === 1 && handlers() === 1) {
+        exec(mobileAccessibility._status, mobileAccessibility._error, "MobileAccessibility", "start", []);
+    } else if (handlers() === 0) {
+        exec(null, null, "MobileAccessibility", "stop", []);
+    }
+};
+
+MobileAccessibility.prototype.isVoiceOverRunning = function(callback) {
+    exec(callback, null, "MobileAccessibility", "isVoiceOverRunning", []);
+};
+
+MobileAccessibility.prototype.isClosedCaptioningEnabled = function(callback) {
+    exec(callback, null, "MobileAccessibility", "isClosedCaptioningEnabled", []);
+};
+
+/**
+ * Callback for mobileAccessibility status
+ *
+ * @param {Object} info keys: isVoiceOverRunning, isClosedCaptioningEnabled
+ */
+MobileAccessibility.prototype._status = function(info) {
+    if (info) {
+        var me = mobileAccessibility;
+        if (me._isVoiceOverRunning !== info.isVoiceOverRunning) {
+            cordova.fireWindowEvent("voiceoverstatuschanged", info);
+            me._isVoiceOverRunning = info.isVoiceOverRunning;
+        }
+        if (me._isClosedCaptioningEnabled !== info.isClosedCaptioningEnabled) {
+            cordova.fireWindowEvent("closedcaptioningstatusdidchange", info);
+            me._isClosedCaptioningEnabled = info.isClosedCaptioningEnabled;
+        }
+    }
+};
+
+/**
+ * Error callback for MobileAccessibility start
+ */
+MobileAccessibility.prototype._error = function(e) {
+    console.log("Error initializing MobileAccessibility: " + e);
+};
+
+var mobileAccessibility = new MobileAccessibility();
+               
+module.exports = mobileAccessibility;
+start