UIAccessibility usability improvements for VoiceOver

MBProgressHUD.m

@@ -106,6 +106,10 @@ - (void)commonInit {
     self.alpha = 0.0f;
     self.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
     self.layer.allowsGroupOpacity = NO;
+    // Set this view's accessibility to false, as long as sub-elements are accessible
+    // Modal is used to prevent accessing elements behind "underneath" the progress HUD.
+    self.isAccessibilityElement = NO;
+    self.accessibilityViewIsModal = YES;
 
     [self setupViews];
     [self updateIndicators];
@@ -147,7 +151,7 @@ - (void)showAnimated:(BOOL)animated {
         NSTimer *timer = [NSTimer timerWithTimeInterval:self.graceTime target:self selector:@selector(handleGraceTimer:) userInfo:nil repeats:NO];
         [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
         self.graceTimer = timer;
-    } 
+    }
     // ... otherwise show the HUD immediately
     else {
         [self showUsingAnimation:self.useAnimation];
@@ -168,7 +172,7 @@ - (void)hideAnimated:(BOOL)animated {
             [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
             self.minShowTimer = timer;
             return;
-        } 
+        }
     }
     // ... otherwise hide the HUD immediately
     [self hideUsingAnimation:self.useAnimation];
@@ -206,6 +210,16 @@ - (void)didMoveToSuperview {
     [self updateForCurrentOrientationAnimated:NO];
 }
 
+#pragma mark - Accessibility
+
+- (void)postAccessibilityScreenChangedNotificationWith:(id)element {
+    UIAccessibilityPostNotification(UIAccessibilityScreenChangedNotification, element);
+}
+
+- (void)postAccessibilityLayoutChangedNotificationWith:(id)element {
+    UIAccessibilityPostNotification(UIAccessibilityLayoutChangedNotification, element);
+}
+
 #pragma mark - Internal show & hide operations
 
 - (void)showUsingAnimation:(BOOL)animated {
@@ -222,11 +236,16 @@ - (void)showUsingAnimation:(BOOL)animated {
     // Needed in case we hide and re-show with the same NSProgress object attached.
     [self setNSProgressDisplayLinkEnabled:YES];
 
+    // Notify UIAccessibility that the HUD (self) is shown after animation completes.
     if (animated) {
-        [self animateIn:YES withType:self.animationType completion:NULL];
+        [self animateIn:YES withType:self.animationType completion:^(BOOL finished) {
+            [self postAccessibilityScreenChangedNotificationWith:self];
+        }];
     } else {
         self.bezelView.alpha = 1.f;
         self.backgroundView.alpha = 1.f;
+
+        [self postAccessibilityScreenChangedNotificationWith:self];
     }
 }
 
@@ -237,6 +256,7 @@ - (void)hideUsingAnimation:(BOOL)animated {
     // call comes in while the HUD is animating out.
     [self.hideDelayTimer invalidate];
 
+    // Note that we post UIAccessibility notifications in the -done method.
     if (animated && self.showStarted) {
         self.showStarted = nil;
         [self animateIn:NO withType:self.animationType completion:^(BOOL finished) {
@@ -296,6 +316,10 @@ - (void)done {
 
     if (self.hasFinished) {
         self.alpha = 0.0f;
+
+        // Use a screen change on the superview to let UIAccessibility focus on the last clicked element.
+        [self postAccessibilityScreenChangedNotificationWith:self.superview];
+
         if (self.removeFromSuperViewOnHide) {
             [self removeFromSuperview];
         }
@@ -399,15 +423,15 @@ - (void)updateIndicators {
     }
     else if (mode == MBProgressHUDModeDeterminate || mode == MBProgressHUDModeAnnularDeterminate) {
         if (!isRoundIndicator) {
-            // Update to determinante indicator
+            // Update to determinate indicator
             [indicator removeFromSuperview];
             indicator = [[MBRoundProgressView alloc] init];
             [self.bezelView addSubview:indicator];
         }
         if (mode == MBProgressHUDModeAnnularDeterminate) {
             [(MBRoundProgressView *)indicator setAnnular:YES];
         }
-    } 
+    }
     else if (mode == MBProgressHUDModeCustomView && self.customView != indicator) {
         // Update custom view indicator
         [indicator removeFromSuperview];
@@ -417,6 +441,9 @@ - (void)updateIndicators {
     else if (mode == MBProgressHUDModeText) {
         [indicator removeFromSuperview];
         indicator = nil;
+
+        // For a text only HUD, make sure UIAccessibility focuses on the label.
+        [self postAccessibilityLayoutChangedNotificationWith:self.label];
     }
     indicator.translatesAutoresizingMaskIntoConstraints = NO;
     self.indicator = indicator;
@@ -428,6 +455,10 @@ - (void)updateIndicators {
     [indicator setContentCompressionResistancePriority:998.f forAxis:UILayoutConstraintAxisHorizontal];
     [indicator setContentCompressionResistancePriority:998.f forAxis:UILayoutConstraintAxisVertical];
 
+    // If indicators are updated, notify UIAccessibility.
+    // This may seem redundant, but is needed if multiple mode changes are used.
+    [self postAccessibilityLayoutChangedNotificationWith:self];
+
     [self updateViewsForColor:self.contentColor];
     [self setNeedsUpdateConstraints];
 }
@@ -710,6 +741,9 @@ - (void)setProgress:(float)progress {
         UIView *indicator = self.indicator;
         if ([indicator respondsToSelector:@selector(setProgress:)]) {
             [(id)indicator setValue:@(self.progress) forKey:@"progress"];
+            // Setting accessibilityValue allows for a gradual and accurate description of progress.
+            // This is used in conjunction with the UpdatesFrequently Accessibility Trait.
+            indicator.accessibilityValue = [NSString stringWithFormat:@"%2.f %%", (progress * 100)];
         }
     }
 }
@@ -824,6 +858,11 @@ @implementation MBRoundProgressView
 #pragma mark - Lifecycle
 
 - (id)init {
+    // Ensure that this is an accessibility element and set the trait to allow percentage completion to be accessible.
+    self.isAccessibilityElement = YES;
+    self.accessibilityLabel = @"Progress";
+    self.accessibilityTraits = UIAccessibilityTraitUpdatesFrequently;
+
     return [self initWithFrame:CGRectMake(0.f, 0.f, 37.f, 37.f)];
 }
 
@@ -832,6 +871,9 @@ - (id)initWithFrame:(CGRect)frame {
     if (self) {
         self.backgroundColor = [UIColor clearColor];
         self.opaque = NO;
+        self.isAccessibilityElement = YES;
+        self.accessibilityLabel = @"Progress";
+        self.accessibilityTraits = UIAccessibilityTraitUpdatesFrequently;
         _progress = 0.f;
         _annular = NO;
         _progressTintColor = [[UIColor alloc] initWithWhite:1.f alpha:1.f];
@@ -851,6 +893,7 @@ - (CGSize)intrinsicContentSize {
 - (void)setProgress:(float)progress {
     if (progress != _progress) {
         _progress = progress;
+        self.accessibilityValue = [NSString stringWithFormat:@"%2.f %%", (progress * 100)];
         [self setNeedsDisplay];
     }
 }
@@ -877,6 +920,8 @@ - (void)drawRect:(CGRect)rect {
     CGContextRef context = UIGraphicsGetCurrentContext();
     BOOL isPreiOS7 = kCFCoreFoundationVersionNumber < kCFCoreFoundationVersionNumber_iOS_7_0;
 
+    self.accessibilityFrame = [self convertRect: rect toCoordinateSpace: [[UIScreen mainScreen] coordinateSpace] ];
+
     if (_annular) {
         // Draw background
         CGFloat lineWidth = isPreiOS7 ? 5.f : 2.f;
@@ -945,6 +990,11 @@ @implementation MBBarProgressView
 #pragma mark - Lifecycle
 
 - (id)init {
+    // Ensure that this is an accessibility element and set the trait to allow percentage completion to be accessible.
+    self.isAccessibilityElement = YES;
+    self.accessibilityLabel = @"Progress";
+    self.accessibilityTraits = UIAccessibilityTraitUpdatesFrequently;
+
     return [self initWithFrame:CGRectMake(.0f, .0f, 120.0f, 20.0f)];
 }
 
@@ -957,6 +1007,9 @@ - (id)initWithFrame:(CGRect)frame {
         _progressRemainingColor = [UIColor clearColor];
         self.backgroundColor = [UIColor clearColor];
         self.opaque = NO;
+        self.isAccessibilityElement = YES;
+        self.accessibilityLabel = @"Progress";
+        self.accessibilityTraits = UIAccessibilityTraitUpdatesFrequently;
     }
     return self;
 }
@@ -973,6 +1026,9 @@ - (CGSize)intrinsicContentSize {
 - (void)setProgress:(float)progress {
     if (progress != _progress) {
         _progress = progress;
+        // Along with the UpdatesFrequently trait, this allows percentages to be read accessibly.
+        self.accessibilityValue = [NSString stringWithFormat:@"%2.f %%", (progress * 100)];
+
         [self setNeedsDisplay];
     }
 }
@@ -1002,6 +1058,8 @@ - (void)drawRect:(CGRect)rect {
     CGContextSetStrokeColorWithColor(context,[_lineColor CGColor]);
     CGContextSetFillColorWithColor(context, [_progressRemainingColor CGColor]);
 
+    self.accessibilityFrame = [self convertRect: rect toCoordinateSpace:[[UIScreen mainScreen] coordinateSpace]];
+
     // Draw background and Border
     CGFloat radius = (rect.size.height / 2) - 2;
     CGContextMoveToPoint(context, 2, rect.size.height/2);