I have a UITextView embedded in a UITableViewCell.
The text view has scrolling disabled, and grows in height with the text in it.
The text view has a link-like section of text that is attributed with a different color and underlined, and I have a tap gesture recognizer attached to the text view that detects whether the user tapped on the "link" portion of the text or not (This is accomplished using the text view's layoutManager and textContainerInset to detect whether the tap falls within the 'link' or not. It's basically a custom hit test function).
I want the table view cell to receive the tap and become selected when the user "misses" the link portion of the text view, but can't figure out how to do it.
The text view has userInteractionEnabled set to true. However, this does not block the touches from reaching the table view cell when there is no gesture recognizer attached.
Conversely, if I set it to false, for some reason cell selection stops altogether, even when tapping outside of the text view's bounds (but the gesture recognizer still works... WHY?).
What I've Tried
I have tried overriding gestureRecognizer(_ :shouldReceive:), but even when I return false, the table view cell does not get selected...
I have also tried implementing gestureRecognizerShouldBegin(_:), but there too, even if I perform my hit test and return false, the cell does not get the tap.
How can I forward the missed taps back to the cell, to highlight it?
After trying Swapnil Luktuke's answer(to the extent that I understood it, at least) to no avail, and every possible combination of:
Implementing the methods of UIGestureRecognizerDelegate,
Overriding UITapGestureRecognizer,
Conditionally calling ignore(_:for:), etc.
(perhaps in my desperation I missed something obvious, but who knows...)
...I gave up and decided to follow the suggestion by #danyapata in the comments to my question, and subclass UITextView.
Partly based on code found on this Medium post, I came up with this UITextView subclass:
import UIKit
/**
Detects taps on subregions of its attributed text that correspond to custom,
named attributes.
- note: If no tap is detected, the behavior is equivalent to a text view with
`isUserInteractionEnabled` set to `false` (i.e., touches "pass through"). The
same behavior doesn't seem to be easily implemented using just stock
`UITextView` and gesture recognizers (hence the need to subclass).
*/
class LinkTextView: UITextView {
private var tapHandlersByName: [String: [(() -> Void)]] = [:]
/**
Adds a custom block to be executed wjhen a tap is detected on a subregion
of the **attributed** text that contains the attribute named accordingly.
*/
public func addTapHandler(_ handler: #escaping(() -> Void), forAttribute attributeName: String) {
var handlers = tapHandlersByName[attributeName] ?? []
handlers.append(handler)
tapHandlersByName[attributeName] = handlers
}
// MARK: - Initialization
override init(frame: CGRect, textContainer: NSTextContainer?) {
super.init(frame: frame, textContainer: textContainer)
commonSetup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func awakeFromNib() {
super.awakeFromNib()
commonSetup()
}
private func commonSetup() {
self.delaysContentTouches = false
self.isScrollEnabled = false
self.isEditable = false
self.isUserInteractionEnabled = true
}
// MARK: - UIView
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
guard let attributeName = self.attributeName(at: point), let handlers = tapHandlersByName[attributeName], handlers.count > 0 else {
return nil // Ignore touch
}
return self // Claim touch
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesEnded(touches, with: event)
// find attribute name
guard let touch = touches.first, let attributeName = self.attributeName(at: touch.location(in: self)) else {
return
}
// Execute all handlers for that attribute, once:
tapHandlersByName[attributeName]?.forEach({ (handler) in
handler()
})
}
// MARK: - Internal Support
private func attributeName(at point: CGPoint) -> String? {
let location = CGPoint(
x: point.x - self.textContainerInset.left,
y: point.y - self.textContainerInset.top)
let characterIndex = self.layoutManager.characterIndex(
for: location,
in: self.textContainer,
fractionOfDistanceBetweenInsertionPoints: nil)
guard characterIndex < self.textStorage.length else {
return nil
}
let firstAttributeName = tapHandlersByName.allKeys.first { (attributeName) -> Bool in
if self.textStorage.attribute(NSAttributedStringKey(rawValue: attributeName), at: characterIndex, effectiveRange: nil) != nil {
return true
}
return false
}
return firstAttributeName
}
}
As ususal, I'll wait a couple of days before accepting my own answer, just in case something better shows up...
Keep all your views active (i.e. user interaction enabled).
Loop through the text view's gestures and disable the ones you do not need.
Loop through the table view's gestureRecognisers array, and make them depend on the text view's custom tap gesture using requireGestureRecognizerToFail.
If its a static table view, you can do this in view did load. For a dynamic table view, do this in 'willDisplayCell' for the text view cell.
I have a view in my storyboard that by default the alpha is set to 0. In certain cases the Swift file sets the alpha to 1. So either hidden or not. Before this view just contained 2 labels. I'm trying to add 2 buttons to the view.
For some reason the buttons aren't clickable at all. So when you tap it normally buttons change color slightly before you releasing, or while holding down on the button. But that behavior doesn't happen for some reason and the function connected to the button isn't being called at all.
It seems like an issue where something is overlapping or on top of the button. The button is totally visible and enabled and everything but not clickable. I tried Debug View Hierarchy but everything looks correct in that view.
Any ideas why this might be happening?
EDIT I tried making a class with the following code and in interface builder setting the container view to be that class.
class AnotherView: UIView {
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
for view in self.subviews {
if view.isUserInteractionEnabled, view.point(inside: self.convert(point, to: view), with: event) {
return true
}
}
return false
}
}
Go with hitTest(_:with:) method. When we call super.hitTest(point, with: event), the super call returns nil, because user interaction is disabled. So, instead, we check if the touchPoint is on the UIButton, if it is, then we can return UIButton object. This sends message to the selector of the UIButton object.
class AnotherView: UIView {
#IBOutlet weak var button:UIButton!
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
let view = super.hitTest(point, with: event)
if self.button.frame.contains(point) {
return button
}
return view
}
#IBAction func buttnTapped(sender:UIButton) {
}
}
i need to make my custom buttom which is made in cg to be darker when user pressed it, just like original uibutton highlighted state. I came up with making alpha 50% but then background view is visible and i don't want that. Here is my code for that:
func unhighlightButton(){
self.color = someColor
self.setNeedsDisplay()
}
override var isHighlighted: Bool {
didSet{
if isHighlighted == true{
self.gradientColor = someColor.withAlphaComponent(0.5)
self.setNeedsDisplay()
self.perform(#selector(unhighlightButton), with: nil, afterDelay: 0.1)
}
}
}
everyone knows that when you drag outside a button it don't cancel the highlight state right away by UIButton's default. UIControlEventTouchDragExit triggers when 70 pixels away. I want that distance to be 0. So after searching the solution of it, I tried to create a subclass like this:
import UIKit
class UINewButton: UIButton {
override func continueTrackingWithTouch(touch: UITouch, withEvent event: UIEvent?) -> Bool {
print("here")
let touchOutside = !CGRectContainsPoint(self.bounds, touch.locationInView(self))
if touchOutside {
let previousTochInside = CGRectContainsPoint(self.bounds, touch.previousLocationInView(self))
if previousTochInside {
print("Sending UIControlEventTouchDragExit")
self.sendActionsForControlEvents(.TouchDragExit)
self.highlighted = false
self.selected = false
}else{
print("Sending UIControlEventTouchDragOutside")
self.sendActionsForControlEvents(.TouchDragOutside)
}
}else{
let previousTouchOutside = !CGRectContainsPoint(self.bounds, touch.previousLocationInView(self))
if previousTouchOutside{
print("Sending UIControlEventTouchDragEnter")
self.sendActionsForControlEvents(.TouchDragEnter)
}else{
print("Sending UIControlEventTouchDragInside")
self.sendActionsForControlEvents(.TouchUpInside)
}
}
return super.continueTrackingWithTouch(touch, withEvent: event)
}
}
and create a button like this in a UIViewController
#IBOutlet var confirmButton: UINewButton!
I assumed when a UIButton being touched and dragged. It would call the function in this sequence:
beginTrackingWithTouch(when touched) -> continueTrackingWithTouch(when dragged) -> endTrackingWithTouch(when left)
But here is the weird part. Even though I override the function continueTrackingWithTouch, it still not been called. Cause the console window didn't show "here" where I put there in it. And the result remain the default distance 70. how come is that?
I tried to call the three functions mentioned above and return true if it needs one.
What did I missed?
After reading this article: UIControlEventTouchDragExit triggers when 100 pixels away from UIButton
Still not helping :( (plus it written in objective-C...)
Isn't the distance of 70px a property of the function so I can just changed?(How can I see the original function by the way? There is no detail in Apple Developer Documentation...)
Should I use button.addtarget in the UIViewController? But it seems like another way to do it.
Here is another question:
If I want to cancel the highlight state when dragged outside the button, is this right?
self.highlighted = false
self.selected = false
I don't know which one is the right one so I used it all.
please help! Just a newbie in swift but I have been stuck in this problem for 3 days. QQ
In Swift 3 the function signature has changed. It's now:
func continueTracking(_ touch: UITouch, with event: UIEvent?) -> Bool
API Reference
I have a table view cell that has a button on the top of the view so that part of it not in the cell. So i have done this in side the custom tableview cell class. -
override func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool {
if CGRectContainsPoint(buttonA.frame, point) {
buttonAPressed()
return true
} else if CGRectContainsPoint(buttonB.frame, point) {
buttonBPressed()
return true
} else if CGRectContainsPoint(buttonC.frame, point) {
buttonCPressed()
return true
}
return super.pointInside(point, withEvent: event)
}
So that the button hits are detected for the buttons. The problem is that I also have a big button behind the tableview. The problem is that the button behind is also detected as being pressed. Is there a way to stop the behind button from being pressed?