According to the documentation, the event which should related to UISegmentedControl is value changed. Assuming I have a segmented control with previous and next, in my case I should be able to click next more than one time, the default behaviour of UISegmentedControl will not recognize the successif second click on same segment. SO how to deal with that?
Set the momentary property of your UISegmentedControl to TRUE.
You can do that in code or in Interface Builder (there is a checkbox in the Attributes Inspector).
Related
I tried and understood what could be the purpose of the accessibilityActivationPoint but in vain.
When a focused accessible element is activated, that property should indicate VoiceOver the specific area it's going to activate when a user double-taps the element (Apple reference) : for me, it's always the selected element itself.
I understood the selected element is considered as a block by VoiceOver, whatever the other elements inside. Once a double tap occurs to activate this block, VoiceOver calls accessibilityActivate to know what to perform (Apple reference).
1/. I've written many tests by creating a custom view including a switch control. Whatever the value of accessibilityActivationPoint inside (or outside on another switch control), the value of the switch control never changes. Is it a proper use case or am I totally wrong ?
2/. When we gather many elements inside one accessible element, how is VoiceOver able to activate one of them while they aren't accessible by definition ? Pointing one of them thanks to the accessibilityActivationPoint should work ?
Personally, I couldn't make it work and think that I'm really confusing accessibilityActivationPoint and accessibilityActivate.
Any help would be appreciated, thanks in advance.
Yes, you have the right idea with accessibilityActivate and accessibilityActivationPoint. Note that, in order for it to work, the accessibilityActivationPoint needs to be a point within the Control that you are trying to activate in on-screen coordinates (use the convert function!).
I think the short answer is "yes" to answer your second question, but, just to clear up confusion about when Accessibility Activation Point is useful, I'll go into more detail about it.
By default (aka, the default behavior for AcessibilityActivate()), when any view is activated by VoiceOver, VoiceOver will send a "tap gesture" to the center of the view. The position of this "tap gesture" can be changed by updating the accessibilityActivationPoint attribute on a view. Below, I have an example for how this property can be used.
Let's say you have a blank button (in the image below, the button is the gray box) next to some text:
For the purpose of accessibility, you may want to make the entire view that holds the button and text an Accessibility Element (so that VoiceOver users can easily understand that the button is associated with the text "Worldspace Attest"). In the image below, I am using Accessibility Inspector to show that the view holding both of these elements is an Accessibility Element.
Notice in these images that the button is not in the center of the view, but rather, it is to the right. When you activate this view using VoiceOver, the view will not select the button; instead, it will send a "tap" to the center of the view (which is the same as tapping the text, which does not do anything). In order to select the button, you have to set the view's accessibilityActivationPoint to be the on-screen coordinates of the button:
view.accessibilityActivationPoint = self.convert(button.center, to: UIApplication.shared.windows.first)
This should make it so that this button is usable by a VoiceOver user.
I hope this information clears up any confusion about the Accessibility Activation Point property. The example I used above can be found in this repository in the "Active Control Name" demo.
I am using voice over on checkbox.
The issue I am facing here is,
when user selects the checkbox for the first time it says 'checkbox selected' (which is correct as per accessibilityLabel set) but next time when user tries to de-select it says 'checkbox selected, checkbox de-selected' where it should only say 'checkbox de-selected', vice-a-versa.
So what is happening here is that, the previously set accessibilityLabel is not getting cleared up and when user tries to select or de-select it takes the both previous and currently set label.
Note- using custom checkbox, toggling UIButton with selected/de-selected image.
How to solve this conflict?
If you create your checkbox thanks to a UIButton item, I suggest to :
Untick the button UIAccessibilityTraits.
Provide a clear hint when the checkbox is first selected : "double tap to change the value".
Update your button accessibility label thanks to IBAction when the box is toggled.
However, it's always better to create a UIAccessibilityElement that contains your check box and a label that describes what it refers to ⟹ when you double tap this accessible wrapper with one finger, the checkbox value toggles and your initial problem disappears.
Following these steps will provide an appropriate user experience with no checkbox VoiceOver conflict that you noticed.
When you highlight text in iOS, a menu is shown giving options such as cut and copy, it floats above the text and is black. What is this called and how can i implement it in a tableview (to give options when a row is selected)
You mean this, this is a UIMenuController
https://developer.apple.com/library/ios/documentation/iPhone/Reference/UIMenuController_Class/
another bit of info:
http://nshipster.com/uimenucontroller/
How to use it:
https://www.captechconsulting.com/blogs/getting-started-with-uimenucontroller-in-ios-5
An actual example already coded up for you:
https://github.com/jszumski/uimenucontroller-example
It is called UIMenuController.
This menu is referred to as the editing menu. When you make this menu visible, UIMenuController positions it relative to a target rectangle on the screen; this rectangle usually defines a selection. The menu appears above the target rectangle or, if there is not enough space for it, below it.
You can also provide your own menu items via the menuItems property. When you modify the menu items, you can use the update method to force the menu to update its display.
I am trying to set the toggle state of a UIButton through the interface builder. I have done it successfully using code, but I need to get it working through the interface builder.
Im not sure what the issue is but for selected I set its image to 'flashOn' and for disabled I set it to 'flashOff'
When I hold down the image, it shows the 2nd image, but pressing the image does not toggle between these two images.
Im certain it's super simple so if you can suggest what I am missing I would appreciate it
A button's selected and disabled states need to be set in code.
Can you show your implementation for when you got desired results through code? I think, from what I can piece together from your question, that you have mixed up the states of the button.
Default - images will display for this button in any state unless another is specified explicitely
Disabled - image will display when button is disabled. (button will not switch from this state through user interaction as it is disabled)
Selected - image will display when the button is selected, which as far as I know is only when you set the button as selected through code.
Highlighted - image will display when you press and hold down on the button
The help indicates that adding gboGroupStyle to the ButtonOptions on a TButtonGroup:
"Specifies that the buttons should inherit the group style that is set on the container."
But this explanation still leaves me lost - any ideas?
The gboGroupStyle option in the TButtonGroup.ButtonOptions property has nothing to do with GroupIndex as it's known e.g. from TSpeedButton.
Setting of the gboGroupStyle option to True allows you to:
set the TButtonGroup.ItemIndex property, so you can predefine which button will be focused as default, nothing cool
click the buttons with ENTER or SPACE keys, what will fire the TGrpButtonItem.OnClick event of the button item (if assigned), perform its action, or fire the TButtonGroup.OnButtonClicked event
I agree the name of this is quite misleading, but that's what I found in the source code from Delphi-XE2.
gboGroupStyle makes the TButtonGroup act as a group - that means, one and only one button is selected at a given time. It is similar to grouping several TSpeedButtons with the GroupIndex, where only one button inside that group is selected at any time. The currently selected button can be read and written via the ItemIndex property of TButtonGroup. To visualize the selected button one can implement an OnBeforeDrawButton or OnDrawButton handler.
From my experimentation it looks like if gboGroupStyle is used then the ItemIndex property can be set to something other than -1, so that the TButtonGroup remembers the last button that was pressed.