    BOOL UIAccessibilityIsVoiceOverRunning();

In ViewDIdLoad

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(voiceOverStatusChanged)
                                                 name:UIAccessibilityVoiceOverStatusChanged
                                               object:nil];


    - (void)voiceOverStatusChanged
    {
        if(!UIAccessibilityIsVoiceOverRunning())
        {
            //do your changes
        }
    }

For Swift 4.2 and newer versions, you can check the following boolean provided by UIKit:

`UIAccessibility.isVoiceOverRunning`


As a supplement to all the previous correct answers, since iOS11 and according to this [Accessibility options recap][1], the new notification name to be used is :

- `UIAccessibilityVoiceOverStatusDidChange` (SWIFT &lt; 4.2).
- `UIAccessibilityVoiceOverStatusDidChangeNotification` (ObjC).

... while `UIAccessibilityVoiceOverStatusChanged` is deprecated.

**EDIT** for **SWIFT 4.2** ==&gt; `UIAccessibility.voiceOverStatusDidChangeNotification`

[1]: https://a11y-guidelines.orange.com/mobile_EN/dev-ios.html#accessibility-options

What is meant by 32bit or 64 bit machine?

It’s the processor architecture…a 32 bit machine can read and write 32bit data at a time same way with 64 bit machine….


whats the maximum memory that a 32 bit machine can access?

It is `2^32=4Gb` (4Gigabit = 0.5 GigaByte)

That means 4Gb ram?

If  I consider the same way for a 64 bit machine then I can have a ram of 16ExbiBytes ..is that possible?

Are my concepts right?

how much memory can be accessed by a 32 bit machine?

What configuration is needed to use annotations from `javax.validation.constraints` like `@Size`, `@NotNull`, etc.? Here&#39;s my code:

    import javax.validation.constraints.NotNull;
    import javax.validation.constraints.Size;
    
    public class Person {
    	  @NotNull
    	  private String id;
    	  
    	  @Size(max = 3)
    	  private String name;
    
          private int age;
    
    	  public Person(String id, String name, int age) {
    	    this.id = id;
    	    this.name = name;
    	    this.age = age;
    	  }
    }

When I try to use it in another class, validation doesn&#39;t work (i.e. the object is created without error):

    Person P = new Person(null, &quot;Richard3&quot;, 8229));

Why doesn&#39;t this apply constraints for `id` and `name`? What else do I need to do?

Annotations from javax.validation.constraints not working

I am trying to add accessibility features to an iOS app that has already been developed. 

There are a couple of UI features (e.g. buttons) that I like them to show up if the VoiceOver option in the accessibility menu of the iPhone settings is on and do not show up if the voiceover is off. 

Is there a way to check whether the voiceover option is on or not?

iOS Voiceover status

I am trying to add accessibility features to an iOS app that has already been developed.
There are a couple of UI features (e.g. buttons) that I like them to show up if the VoiceOver option in the accessibility menu of the iPhone settings is on and do not show up if the voiceover is off.
Is there a way to check whether the voiceover option is on or not?

I&#39;ve been searching stackoverflow, reading in the various blogs to get answer to my question &quot;Can I distribute my app to someone, without getting his device UDID?&quot;&lt;br&gt;&lt;br&gt;
The answers I found is all about &quot;NO! You must have the list of UDIDs&quot;&lt;br&gt;&lt;br&gt;
BUT, I&#39;ve people (private company) telling me that they used to install apps without giving their device UDIDs to developer. Developer used to send them .ipa file, they just drag&amp;drop it in itunes, that&#39;s it! I&#39;m dizzy..&lt;br&gt;&lt;br&gt;
By which way they did it without UDIDs? (I&#39;m against jailbreak, it&#39;s not option)&lt;br&gt;&lt;br&gt;
Or, maybe they&#39;re lying?

Can I distribute my App for any device without UDID?

I have a `UILabel` whose text I am getting from a server. Some of the text is to be identified as links, and on touching those links some action should be performed. e.g.  
  
NSString *str = @&quot;My phone number is [645-345-2345][1] and my address is [xyz][2]&quot;;


  [1]: https://stackoverflow.com/questions/ask
  [2]: https://stackoverflow.com/questions/ask  
  
This is the complete text for `UILabel`. I have only one `UILabel` for displaying this text (Text is dynamic. I just gave an example.). On clicking these links I need to perform actions like navigating to some different screen or make a call.  
I know that I can display such text with help of **OHAttributedLabel**. And the links can be displayed as follows :  
  
    [label1 addCustomLink:[NSURL URLWithString:@&quot;http://www.foodreporter.net&quot;] inRange:[txt rangeOfString:someString]];  
  
But I wonder how can I make these **text links** perform some action like navigation to different screen or making a call.  
Let me know if more explanation is required.
  

UILabel - string as text and links

I want to change below code with storyboard with Xcode 4.2.

    UIViewController * example     = [[ExampleViewController alloc] initWithNibName:@&quot;ExampleViewController&quot; bundle:nil];

Now ExampleViewController.xib file exist.
but I want to make it with storyboard.
please help me.
(I&#39;m not good at English. Sorry)

How do I change &quot;initwithNibName&quot; in storyboard?

![UIToolbar with UIBarButtonItem][1]

I have a `UIBarButtonItem` in my `UIToolbar` titled **Done**. Now I want to change the font from the default to **&quot;Trebuchet MS&quot;** with Bold. How can I do that?

  [1]: http://i.stack.imgur.com/EACXV.png

Change the font of a UIBarButtonItem

I&#39;m trying to complete the puzzle.

`__strong` is the default for all Objective-C retainable object pointers like NSObject, NSString, etc.. It&#39;s a strong reference. ARC balances it with a `-release` at the end of the scope.

`__unsafe_unretained` equals the old way. It&#39;s used for a weak pointer without retaining the retainable object.

`__weak` is like `__unsafe_unretained` except that it&#39;s an auto-zeroing weak reference meaning that the pointer will be set to nil as soon as the referenced object is deallocated. This eliminates the danger of dangling pointers and EXC_BAD_ACCESS errors.

But what exactly is `__autoreleasing` good for? I&#39;m having a hard time finding practical examples on when I need to use this qualifier. I believe it&#39;s only for functions and methods which expect a pointer-pointer such as:

    - (BOOL)save:(NSError**);

or

    NSError *error = nil;
    [database save:&amp;error];

which under ARC has to be declared this way:

    - (BOOL)save:(NSError* __autoreleasing *);

But this is too vague and I&#39;d like to fully understand *why*. The code snippets I find place the __autoreleasing inbetween the two stars, which looks weird to me. The type is `NSError**` (a pointer-pointer to NSError), so why place `__autoreleasing` inbetween the stars and not simply in front of `NSError**`? 

Also, there might be other situations in which I must rely on `__autoreleasing`.

In which situations do we need to write the __autoreleasing ownership qualifier under ARC?

Consider the following:

    &lt;label&gt;Range from 
        &lt;input name=&#39;min_value&#39;/&gt; to
        &lt;input name=&#39;max_value&#39; /&gt;
    &lt;/label&gt;

Is this semantically correct since the W3C recommendations state that a label is associated with **exactly** one form control?

Clicking into the second input shifts focus immediately to the first input? Can this be prevented?

How would one markup a min/max input combination to show that two inputs belong together?

Two input fields inside one label

I get an warning about **[Accessibility]Missing contentDescription attribute on image** in eclipse. This warning show at line 5 (declare `ImageView`) in XML code below.

This not make any error when build and run my application. But I really want to know why i get this warning.

This is my XML file:

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;LinearLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
                  android:layout_width=&quot;fill_parent&quot;
                  android:layout_height=&quot;wrap_content&quot;&gt;
        &lt;ImageView
            android:id=&quot;@+id/contact_entry_image&quot;
            android:src=&quot;@drawable/ic_launcher&quot;
            android:layout_width=&quot;wrap_content&quot;
            android:layout_height=&quot;wrap_content&quot;
            /&gt;
        &lt;TextView
            android:id=&quot;@+id/contact_entry_text&quot;
            android:text=&quot;&quot;
            android:layout_width=&quot;fill_parent&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:textSize=&quot;30sp&quot;
            /&gt;
    
    &lt;/LinearLayout&gt;

Please help me regarding this and thanks for your reading.


&#39;Missing contentDescription attribute on image&#39; in XML

Many ARIA demonstration websites use code such as:

    &lt;label for=&quot;name&quot; id=&quot;label-name&quot;&gt;Your Name&lt;/label&gt;
    &lt;input id=&quot;name&quot; aria-labelledby=&quot;label-name&quot; type=&quot;text&quot;&gt;

&lt;br&gt;
But what&#39;s the purpose of using &lt;code&gt;aria-labelledby&lt;/code&gt; attribute in this case? The &lt;code&gt;input&lt;/code&gt; element has already been labeled by the &lt;code&gt;label&lt;/code&gt; element which is using &lt;code&gt;for&lt;/code&gt; attribute, isn&#39;t it?

The purpose of using &quot;aria-labelledby&quot; on already labeled input elements?

Go to this ultra-simple fiddle in a Webkit browser and click on on of the inputs:

http://jsfiddle.net/eK4TT/

&lt;!-- language: lang-html --&gt;

    &lt;input type=&quot;text&quot;&gt;
    &lt;input type=&quot;text&quot;&gt;
    &lt;input type=&quot;text&quot;&gt;
    &lt;a href=&quot;#&quot;&gt;my first link&lt;/a&gt;
    &lt;a href=&quot;#&quot;&gt;my second link&lt;/a&gt;
    &lt;a href=&quot;#&quot;&gt;my third link&lt;/a&gt;

Then, notice that you can keyboard navigate through both the inputs and the links using the &lt;kbd&gt;Tab&lt;/kbd&gt; key (and &lt;kbd&gt;Shift&lt;/kbd&gt;+&lt;kbd&gt;Tab&lt;/kbd&gt; to navigate in reverse order).

Now, look at the same fiddle in Firefox on Mac OS and do the same thing. The inputs receive focus, but the links won&#39;t receive focus. It&#39;s not a CSS display problem. The focus leaps from the last input to the URL bar.

I&#39;ve tried endless combinations of `tabindex` declarations in the markup, and to no avail, e.g.:

http://jsfiddle.net/eK4TT/1/

What the heck is going on here? I will accept any answer that has:

a) a fiddle working in Firefox  
b) an explanation of what exactly is going on here in Mozilla&#39;s head. It appears to contradict the [spec][1].


  [1]: http://www.w3.org/TR/WCAG20-TECHS/H4

How to allow keyboard focus of links in Firefox?

I have read that the `role` attribute was added to [Bootstrap][1] for accessibility, and I would like to know how `&lt;form role=&quot;form&quot;&gt;` helps accessibility. See http://getbootstrap.com/css/#forms-example for an example of this specific usage.

*I [searched Bootstrap&#39;s repo for &quot;role&quot;][2] to no avail.*

My issue is that the information seems redundant. The notion that the element is a *form* is already expressed by the HTML tag itself (`&lt;form&gt;`), so what does it help if we also add that the element is playing the `role` of `form`? It would make sense to add `role=&quot;...&quot;` if `role` was going to be different than `form` (I don&#39;t know what - but let&#39;s pretend); as it stands (especially without concrete reasoning / use case examples), it is puzzling at best.

  [1]: http://getbootstrap.com/
  [2]: https://github.com/twbs/bootstrap/search?q=role

How does role=form help accessibility?

I have dynamic text to bind to `aria-label` on a HTML page.
This is an Angular 2 app. I am using something like this:

``` lang-ts
aria-label=&quot;Product details for {{productDetails?.ProductName}}&quot;
```

But I get an error:

&gt; Can&#39;t bind to &#39;aria-label&#39; since it isn&#39;t a known property of &#39;div&#39;. 

Is there any workaround for this?

Content Type	Original Author	Original Content on Stackoverflow
Question	Arash	View Question on Stackoverflow
Solution 1 - Ios	David Dunham	View Answer on Stackoverflow
Solution 2 - Ios	Rakesh iOS Dev	View Answer on Stackoverflow
Solution 3 - Ios	Lucas P.	View Answer on Stackoverflow
Solution 4 - Ios	XLE_22	View Answer on Stackoverflow

iOS Voiceover status

Ios Problem Overview

Ios Solutions

Solution 1 - Ios

Solution 2 - Ios

Solution 3 - Ios

Solution 4 - Ios

Annotations from javax.validation.constraints not working

how much memory can be accessed by a 32 bit machine?

Attributions