Trying to make a UIButton that when long pressed, exposes four subviews (UIButtons - north, east, south & west) that user can then slide finger to and lift for 4 separate actions.
extension UIButton {
func EnablePopOuts (North:Bool = true, nTitle:String, nColor:UIColor = .black, nAction: Selector) {
if North {
let northButton = UIButton(frame: self.frame)
northButton.translatesAutoresizingMaskIntoConstraints = false
let nA = NSLayoutConstraint(item: northButton, attribute: .height
, relatedBy: .equal, toItem: self, attribute: .height, multiplier: 1, constant: 0)
let nB = NSLayoutConstraint(item: northButton, attribute: .width
, relatedBy: .equal, toItem: self, attribute: .width, multiplier: 1, constant: 0)
let nC = NSLayoutConstraint(item: northButton, attribute: .bottom
, relatedBy: .equal, toItem: self, attribute: . top, multiplier: 1, constant: 0)
let nD = NSLayoutConstraint(item: northButton, attribute: .leading
, relatedBy: .equal, toItem: self, attribute: .leading, multiplier: 1, constant: 0)
self.addSubview(northButton)
self.didAddSubview(northButton)
self.addConstraints([nA,nB,nC,nD])
self.bringSubviewToFront(northButton)
northButton.setTitle(nTitle, for: .normal)
northButton.backgroundColor = nColor
northButton.addTarget(Main.self, action: nAction, for: .touchUpInside)
self.layoutIfNeeded()
self.layoutSubviews()
}
}
}
EnablePopOuts runs but the northButton doesn't appear.
Related
I want my button to be in the center of my footerView. I tried several methods but failed every time:
1.
override func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? {
let footerView = UIView(frame: CGRect.zero)
footerView.backgroundColor = UIColor(rgba: "#F9FAFB")
let button = UIButton(frame: CGRect(x:(footerView.frame.size.width - 30) / 2, y:(footerView.frame.size.height - 30) / 2, width: 30, height: 30)) button.setImage(UIImage(named: "gen-cog"), for: .normal)
button.addTarget(self, action: #selector(footerButtonAction), for: .touchUpInside)
footerView.addSubview(button)
}
Used auto layout, this centers my button but breaks width and height of it, which I set to 30 above.
let centerYCon = NSLayoutConstraint(item: button,
attribute: .centerY,
relatedBy: .equal,
toItem: footerView,
attribute: .centerY,
multiplier: 1.0,
constant: 0.0);
footerView.addConstraint(centerYCon)
let centerXCon = NSLayoutConstraint(item: button,
attribute: .centerX,
relatedBy: .equal,
toItem: footerView,
attribute: .centerX,
multiplier: 1.0,
constant: 0.0);
footerView.addConstraint(centerXCon)
footerView.addSubview(button)
3.
button.center = footerView.center
button.translatesAutoresizingMaskIntoConstraints = false
footerView.addSubview(button)
Now Add two more additional Constraints.
let widthConstraint = NSLayoutConstraint(item: button, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 30)
let heightConstraint = NSLayoutConstraint(item: button, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 30)
button.addConstraints([widthConstraint, heightConstraint])
I'm trying to set 2 labels, one under other with different font size in the header. The function is called like this:
viewController.navigationItem.titleView = self.setHeader()
And code responsible for generating label is :
private func setHeader(agentName: String = "", isTyping: Bool = false) -> UIView {
let headerLabel: UILabel = {
let label = UILabel()
label.text = self.title
label.font = UIFont.systemFont(ofSize: 21)
label.textColor = UIColor.white
return label
}()
let subheaderLabel: UILabel = {
let label = UILabel()
label.font = UIFont.systemFont(ofSize: 10)
return label
}()
let headerView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(headerLabel)
view.addConstraints([
NSLayoutConstraint(item: headerLabel, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: headerLabel, attribute: .leading, relatedBy: .equal, toItem: view, attribute: .leading, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: headerLabel, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 16),
NSLayoutConstraint(item: headerLabel, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 16)
])
return view
}()
if (!agentName.isEmpty) {
if (isTyping) {
subheaderLabel.text = agentName + " is typing ..."
} else {
subheaderLabel.text = agentName
}
headerView.addSubview(subheaderLabel)
}
return headerView
}
When I running IOS app there is nothing shown in the header. What is a reason?
I think you need to set the frame for the headerView. So in the initialization code for the headerView, use initializer with frame:
let headerView: UIView = {
// initialize the view with frame
let view = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 35))
// you want to call this on the headerLabel, not on view
headerLabel.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(headerLabel)
view.addConstraints([
NSLayoutConstraint(item: headerLabel, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: headerLabel, attribute: .leading, relatedBy: .equal, toItem: view, attribute: .leading, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: headerLabel, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 16),
NSLayoutConstraint(item: headerLabel, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 16)
])
return view
}()
Moreover, I believe headerLabel you want to set translatesAutoresizingMaskIntoConstraints on headerLabel rather than on headerView (headerView is positioned through frame and not Autolayout).
Also, notice that you add subheaderLabel to the view, but you never position it, don't forget about it either (although this should cause only subheaderLabel not to be rendered properly).
I am trying to add the root view and subviews to a viewcontroller programmatically, but the view is not filling to screen as expected:
override func loadView() {
self.view = UIView(frame: CGRect(x: 0.0, y: 0.0, width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height))
self.view.backgroundColor = UIColor.blue
}
override func viewDidLoad() {
let alertView = Bundle.main.loadNibNamed("CHRApptTakenAlertView", owner: self, options: nil)![0] as! CHRApptTakenAlertView
self.view.translatesAutoresizingMaskIntoConstraints = false
alertView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(alertView)
self.view.addConstraint(NSLayoutConstraint(item: alertView, attribute: NSLayoutAttribute.centerX, relatedBy: NSLayoutRelation.equal, toItem: self.view, attribute: NSLayoutAttribute.centerX, multiplier: 1, constant: 0))
self.view.addConstraint(NSLayoutConstraint(item: alertView, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: self.view, attribute: NSLayoutAttribute.centerY, multiplier: 1, constant: 0))
alertView.addConstraint(NSLayoutConstraint(item: alertView, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.width, multiplier: 1, constant: 350))
alertView.addConstraint(NSLayoutConstraint(item: alertView, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.height, multiplier: 1, constant: 250))
alertView.closeBtn.addTarget(self, action: #selector(self.closeBtnTouch), for: UIControlEvents.touchUpInside)
}
Remove the line self.view.translatesAutoresizingMaskIntoConstraints = false, and call self.view.layoutIfNeeded() after the adding the constraints.
When I add an NSLayoutConstraint to a view, it results in the view disappearing.
I am using the following code:
let test:UIView = UIView(frame: CGRectMake(0, 0, 100, 100))
test.backgroundColor = UIColor.blackColor()
self.view.addSubview(test)
test.translatesAutoresizingMaskIntoConstraints = false
let topCKCtr = NSLayoutConstraint(item: test, attribute: .CenterX, relatedBy: .Equal, toItem: test.superview, attribute: .CenterX, multiplier: 0.5, constant: 0)
topCKCtr.active = true
let topCKCtr1 = NSLayoutConstraint(item: test, attribute: .CenterY, relatedBy: .Equal, toItem: test.superview, attribute: .CenterY, multiplier: 0.5, constant: 0)
topCKCtr1.active = true
self.view.layoutIfNeeded()
self.view.setNeedsDisplay()
When I debug view hierarchy, i see that the view exists, even though it is not visible. See the below screenshot for details - only the constraint is visible, not the view:
There are so many things that needs to be discussed here.
When you use the following
test.translatesAutoresizingMaskIntoConstraints = false
Then it will totally rely on constraints to position and size a view.So you need to set height and width constraints of the view.
let topCKCtr2 = NSLayoutConstraint(item: test, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .Width, multiplier: 1.0, constant: 100)
let topCKCtr3 = NSLayoutConstraint(item: test, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .Height, multiplier: 1.0, constant: 100)
Finally This will be the code which you are looking for
let test:UIView = UIView(frame: CGRectMake(0, 0, 100, 100))
test.backgroundColor = UIColor.blackColor()
self.view.addSubview(test)
test.translatesAutoresizingMaskIntoConstraints = false
let topCKCtr = NSLayoutConstraint(item: test, attribute: .CenterX, relatedBy: .Equal, toItem: self.view, attribute: .CenterX, multiplier: 0.5, constant: 0)
topCKCtr.active = true
let topCKCtr1 = NSLayoutConstraint(item: test, attribute: .CenterY, relatedBy: .Equal, toItem: self.view, attribute: .CenterY, multiplier: 0.5, constant: 0)
topCKCtr1.active = true
let topCKCtr2 = NSLayoutConstraint(item: test, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .Width, multiplier: 1.0, constant: 100)
topCKCtr2.active = true
let topCKCtr3 = NSLayoutConstraint(item: test, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .Height, multiplier: 1.0, constant: 100)
topCKCtr3.active = true
I have Add Constraint in My func
func CreateButtonWithIndex(var index:Int) {
let path = loadPath()
var data = NSMutableDictionary(contentsOfFile: path)
let newButton = UIButton.buttonWithType(UIButtonType.System) as UIButton newButton.setTranslatesAutoresizingMaskIntoConstraints(false)
self.view.addSubview(newButton)
let newButtonConstraintL = NSLayoutConstraint(item: newButton, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 50)
let newButtonConstraintH = NSLayoutConstraint(item: newButton, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1.0, constant: 50)
// Read from Plist the coordinate
var reloadCoordX:[String] = data!.valueForKey("\(strDaPassare) X") as[String]
var reloadCoordY:[String] = data!.valueForKey("\(strDaPassare) Y") as[String]
var coordX: Int = ("\(reloadCoordX[index-1])").toInt()!
var coordY: Int = ("\(reloadCoordY[index-1])").toInt()!
// Add Constraint
newButtonConstraintX = NSLayoutConstraint(item: newButton, attribute: .CenterX, relatedBy: .Equal, toItem: view, attribute: .CenterX, multiplier: 1, constant: CGFloat(coordX))
newButtonConstraintY = NSLayoutConstraint(item: newButton, attribute: .CenterY, relatedBy: .Equal, toItem: view, attribute: .CenterY, multiplier: 1, constant: CGFloat(coordY))
}
And it's ok !!!! but this takes as a reference center of the UIView it self for the values of newButtonConstraintX and newButtonConstraintY . but if I want to set attribute for newButtonConstraintX and newButtonConstraintY for the Top left corner ?