[CRD iOS] Fix accessibility focus on host connection flow

* Changes the accessibility focus order to Cancel button->PIN input->
  Pairing switch->Continue button.
* Makes the status label the default focus instead of the cancel button.

Bug: 770841
Change-Id: I02f0261a7b20da71485dacb4f7a09506fc09976b
Reviewed-on: https://chromium-review.googlesource.com/695838Reviewed-by: Scott Nichols <nicholss@chromium.org>
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505852}

remoting/ios/app/client_connection_view_controller.mm

@@ -17,6 +17,7 @@
 #import "remoting/ios/app/pin_entry_view.h"
 #import "remoting/ios/app/remoting_theme.h"
 #import "remoting/ios/app/session_reconnect_view.h"
+#import "remoting/ios/app/view_utils.h"
 #import "remoting/ios/domain/client_session_details.h"
 #import "remoting/ios/domain/host_info.h"
 #import "remoting/ios/facade/remoting_authentication.h"
@@ -411,6 +412,7 @@ static const CGFloat kKeyboardAnimationTime = 0.3;
   [_pinEntryView endEditing:YES];
   _statusLabel.text =
       [self stringWithHostNameForId:IDS_CONNECTING_TO_HOST_MESSAGE];
+  [self focusOnStatusLabel];
 
   _pinEntryView.hidden = YES;
 
@@ -449,6 +451,7 @@ static const CGFloat kKeyboardAnimationTime = 0.3;
   [_pinEntryView endEditing:YES];
   _statusLabel.text =
       [self stringWithHostNameForId:IDS_CONNECTED_TO_HOST_MESSAGE];
+  [self focusOnStatusLabel];
 
   _pinEntryView.hidden = YES;
   [_pinEntryView clearPinEntry];
@@ -476,6 +479,7 @@ static const CGFloat kKeyboardAnimationTime = 0.3;
 - (void)showReconnect {
   _statusLabel.text =
       [self stringWithHostNameForId:IDS_CONNECTION_CLOSED_FOR_HOST_MESSAGE];
+  [self focusOnStatusLabel];
 
   _iconView.backgroundColor = RemotingTheme.hostErrorColor;
 
@@ -551,6 +555,7 @@ static const CGFloat kKeyboardAnimationTime = 0.3;
     _reconnectView.errorText = message;
   }
   _reconnectView.hidden = NO;
+  remoting::SetAccessibilityFocusElement(_reconnectView);
 }
 
 - (void)didProvidePin:(NSString*)pin createPairing:(BOOL)createPairing {
@@ -623,4 +628,8 @@ static const CGFloat kKeyboardAnimationTime = 0.3;
                                  base::SysNSStringToUTF16(_remoteHostName));
 }
 
+- (void)focusOnStatusLabel {
+  remoting::SetAccessibilityFocusElement(_statusLabel);
+}
+
 @end

remoting/ios/app/pin_entry_view.mm

@@ -38,17 +38,19 @@ static const int kMinPinLength = 6;
   if (self) {
     self.backgroundColor = [UIColor clearColor];
 
+    NSString* rememberPinText =
+        l10n_util::GetNSString(IDS_REMEMBER_PIN_ON_THIS_DEVICE);
     _pairingSwitch = [[UISwitch alloc] init];
     _pairingSwitch.tintColor = RemotingTheme.pinEntryPairingColor;
     _pairingSwitch.transform = CGAffineTransformMakeScale(0.5, 0.5);
+    _pairingSwitch.accessibilityLabel = rememberPinText;
     _pairingSwitch.translatesAutoresizingMaskIntoConstraints = NO;
     [self addSubview:_pairingSwitch];
 
     _pairingLabel = [[UILabel alloc] init];
     _pairingLabel.textColor = RemotingTheme.pinEntryPairingColor;
     _pairingLabel.font = [UIFont systemFontOfSize:12.f];
-    _pairingLabel.text =
-        l10n_util::GetNSString(IDS_REMEMBER_PIN_ON_THIS_DEVICE);
+    _pairingLabel.text = rememberPinText;
     _pairingLabel.translatesAutoresizingMaskIntoConstraints = NO;
     [self addSubview:_pairingLabel];
 
@@ -99,6 +101,8 @@ static const int kMinPinLength = 6;
                                                  _pinButton, _pinEntry)];
 
     _supportsPairing = YES;
+
+    self.accessibilityElements = @[ _pinEntry, _pairingSwitch, _pinButton ];
   }
   return self;
 }
@@ -155,6 +159,7 @@ static const int kMinPinLength = 6;
 - (void)setSupportsPairing:(BOOL)supportsPairing {
   _supportsPairing = supportsPairing;
   _pairingSwitch.hidden = !_supportsPairing;
+  _pairingSwitch.isAccessibilityElement = _supportsPairing;
   [_pairingSwitch setOn:NO animated:NO];
   _pairingLabel.hidden = !_supportsPairing;
 }

remoting/ios/app/remoting_view_controller.mm

@@ -208,7 +208,7 @@ ConnectionType GetConnectionType() {
   [super viewWillAppear:animated];
 
   // Just in case the view controller misses the host list state event before
-  // the listener is registered.
+  // gthe listener is registered.
   [self refreshContent];
 }
 

remoting/ios/app/view_utils.h

@@ -22,6 +22,8 @@ void SetAccessibilityInfoFromImage(UIBarButtonItem* button);
 // Sets the a11y label of the UIButton according to the image it holds.
 void SetAccessibilityInfoFromImage(UIButton* button);
 
+void SetAccessibilityFocusElement(id element);
+
 }  // namespace remoting
 
 #endif  // REMOTING_IOS_APP_VIEW_UTILS_H_

remoting/ios/app/view_utils.mm

@@ -55,4 +55,9 @@ void SetAccessibilityInfoFromImage(UIButton* button) {
       [button imageForState:UIControlStateNormal].accessibilityLabel;
 }
 
+void SetAccessibilityFocusElement(id element) {
+  UIAccessibilityPostNotification(UIAccessibilityLayoutChangedNotification,
+                                  element);
+}
+
 }  // namespace remoting