When VoiceOver is enabled, I'd like to find out if the user is performing the left/right flick action while a UIButton is selected.
There are few methods help you with when a specific element has received or lost focus:
accessibilityElementDidLoseFocus
accessibilityElementDidBecomeFocused
But nothing within the UIAccessibilityAction to help find if the user attempted a flick left or right.
Is there a way to find out what the user is attempting to do?
No. You should not attempt to override the left and right VoiceOver swipe gestures. if you need to adjust a value with swiping, consider implementing a custom control with the trait UIAccessibilityTraitAdjustable. If you need to support direct gesture interaction, adopt UIAccessibilityTraitAllowsDirectInteraction.
Edit: To answer your question, you might be able to watch focus change, issue a screen change notification, return new children, and focus the first. Please see my comment below about why this may be undesirable.
Related
I have a custom control to increment and decrement values. Now that I've added support for voice over, I've stumbled upon a problem.
My customView has the accessibility trait .adjustable and I implemented the correct methods for increasing and decreasing the values.
However, the voice over user can also double tap on that view to activate it. The problem is, that this triggers a gesture which is irrelevant to voice over users.
Is there a way to prevent an adjustable accessibility view from being activated so that the element is only adjustable, not double-tappable like a button?
There are two important properties to know when a double-tap occurs:
accessibilityActivate.
accessibilityActivationPoint.
In your case, you could just return true by overriding accessibilityActivate and if it's not enough, provide as well a CGPoint coordinate that triggers nothing (depends of your custom control and its neighborhood).
Otherwise, use the accessibilityElementIsFocused instance method to know wether you can trigger actions as this complete example shows up.
I ended up using UIAccessibility.isVoiceOverRunning to stop any tasks which would be triggered by a doubletap on that specific element.
I've created a custom view that acts like a UISlider - there is a "track", and a handle to "grab" to change the value. For particular reasons, I can't just make it a subclass of UISlider. I'm trying to make this slider as accessible as possible with VoiceOver. I have accessibilityIncrease and accessibilityDecrease on my custom view that handle single finger drag up and single finger drag down. This changes the value of the slider by 10% at a time.
However, I'd like to allow more fine grained control, just like a non-VoiceOver slider. By default , UISlider has double tap and hold, and you can drag up/down to "pan" the slider. I'd like to add exactly that to my custom view, but I can't find the correct incantation to handle the double tap and hold gesture.
Is there something I can do to mimic the double tap and hold gesture from UISlider on my custom view?
Thanks very much!!!
If you want to implement this kind of new gesture for VoiceOver users, just forget it.
The recommended gesture for this kind of UI control is definitely the implementation of adjustable value as you already did apparently.
I don't think it's a good idea to try and implement new VoiceOver gestures in an application because its users have their habits and they may be totally lost with your customed control if they cannot handle it unless you add an hint to explain but that's definitely not what I recommend anyway.
Otherwise, you could take a look at the pass through concept introduced in the What's New in Accessibility WWDC 2017 video that deals with the same idea but for a panning gesture...
I am working on the IOS application, related to voice over, my Question is : When accessibility voice over was enabled how can i get the swipe gestures left, right, top and down, what re the function for detecting these in swift?
First of all, you need to let VoiceOver know that about your view (or another element). So if you are in a view controller, this should work: self.view.isAccessibilityElement = true
Second, you need to let VoiceOver know that your view will handle user interactions on its own: self.view.accessibilityTraits = UIAccessibilityTraitAllowsDirectInteraction. After that your view should start getting gestures notifications.
Here's another relevant answer: https://stackoverflow.com/a/20712889/2219578
It isn't possible to catch the left, right, top and bottom VoiceOver gestures : I've seen neither a protocol nor a kind of notification for this.
However, you can detect a scrolling action and be aware of the element focus provided by VoiceOver.
I'm working on an app with a musical keyboard component.
I need 2 types of "sent events" to trigger the keys of the keyboard (UIButtons).
1) "Touch Down" triggers the buttons they way I need it to
2) The 2nd way I need buttons to be triggered is by sliding onto a button,from another button/key to the side of it as if it is "touched down" upon, when it is slid upon from the left or right.
How do I achieve this?
You can't do this using the built-in control events of the buttons, for the simple reason that you don't get an event in a button at all unless the touch is initially in that button (as I explain here: https://stackoverflow.com/a/40414929/341994).
Still, this doesn't sound very hard to do. The simplest approach is probably to put the touch response (such as a gesture recognizer) into the common superview of all the buttons. The superview can then track the gesture. And it can very easily find out which button the touch is currently inside at any given moment. So it can manage the whole interaction. It can even send messages to the buttons telling them when to highlight and unhighlight. (And if you aren't going to use the button touch handling for anything, you might even want to give up the idea that these are buttons; they could just be views or custom controls that look like buttons.)
i am trying to implement accessibility option in my book reader app. I have a slider(similar to ibooks) which is used for navigating between pages. i have seen this question posted by another user and implemented the same code in my app. Right now my slider is responding when i'm tapping on it. The voiceover is also speaking the label i have given in the code. But, the problem is that, i am unable to change the slider value and navigate to another page.. I dont know if it is the problem with my code or is it that i do not know how to replicate the gesture to change the value of the slider... Any help in this regard will be appreciated.... Thanku
Does the slider work with VoiceOver turned off?
If so, try swiping vertically up or down (top to bottom of display) after selecting the slider element with VoiceOver enabled.
Is it a UISlider, or something of your own devising? UISlider needs an actual vertical swipe once selected, and moves a pretty significant amount as a result — not a good experience for going to the next page.
If it's your own custom control, be sure you set UIAccessibilityTraitAdjustable.