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.)
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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...
So if any of you have used the tumblr mobile app recently, you'll notice that the reblog function has a tap and hold capability. Essentially when you tap and hold the reblog button, more buttons pop up around it so the user can just drag their finger over one of the new buttons and release to select it. I've been digging around and no one seems to have an answer to this specific question.I've always seen this as a very elegant way to have a sub menu and would like to implement it into my own apps. For ios btw.
Add gesture recognizer to a view. write a method to create buttons when long press gesture is done on the view.
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I am making app like sudoku (9*9 boxes) but it has only binary choices (on/off) and using button gave me horrible results. Can anyone give me demo version of 9*9 (or 3*3) box where depending upon the tap location, that specific box gets toggled (on/off)
You could create a custom subclass of UIView that had an attached tap gesture recognizer and interpreted the tap location to figure out which cell is being tapped, but it would be a lot of work.
It would be better to have custom view that contains a grid of buttons and set up the button actions to do what you want.
You said "...using button gave me horrible results." Can you elaborate? That should be a good way to go, so any "horrible results" are likely the result of something you did wrong, rather than that being the wrong way to go.
On the keyboard and in the native calculator app on iOS, it's possible to put your finger down on one button, like '0', and then move your finger to the another button, like '1', release your finger, and have it enter '1'. On the calculator it darkens the button under your finger.
If you start pressing a button, drag your finger outside of the buttons, and then move it back in, it'll continue to highlight the buttons under your finger. However, if you don't start on a button—like you start dragging from the calculator results label—and drag onto the buttons, the buttons do not highlight.
What's the best approach to mimic the calculator's behaviour for buttons? I'm mostly looking for code structuring guidance rather than code examples here!
It seems I won't be encapsulate each button in its own view class, but I'll have to have a Keyboard that handles all the touches, and manually draws the buttons.
I think the easiest way is to add handling for touch control events:
UIControlEventTouchDragInside
UIControlEventTouchDragOutside
UIControlEventTouchDragEnter
And link all the components with some kind of processing logic. Initial control event location and so on.
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.