I'm now using Xcode 8 GM (Version 8.0 (8A218a)) with Swift 3, my repo is: https://github.com/yeahdongcn/UIColor-Hex-Swift/tree/Swift-3.0 after I converted the Swift 2 syntax to Swift 3, I set two breakpoints in the following getter then I ran the test, the first one is not called, but the 2nd debugDescription gets called.
open override var description: String {
return self.hexString(true)
}
open override var debugDescription: String {
return self.hexString(true)
}
I created a playground it works the same
//: Playground - noun: a place where people can play
import UIKit
extension UIColor {
public func hexString(_ includeAlpha: Bool) -> String {
var r: CGFloat = 0
var g: CGFloat = 0
var b: CGFloat = 0
var a: CGFloat = 0
self.getRed(&r, green: &g, blue: &b, alpha: &a)
if (includeAlpha) {
return String(format: "#%02X%02X%02X%02X", Int(r * 255), Int(g * 255), Int(b * 255), Int(a * 255))
} else {
return String(format: "#%02X%02X%02X", Int(r * 255), Int(g * 255), Int(b * 255))
}
}
open override var description: String {
return self.hexString(true)
}
open override var debugDescription: String {
return self.hexString(true)
}
}
let color = UIColor.yellow
color.description
color.debugDescription
You cannot override a method in an extension. You would need to use a subclass. The compiler should be complaining.
It might have worked in Swift 2.x, but that was not correct behavior.
Related
I'm trying to create a growing TextEditor as input for a chat view.
The goal is to have a box which expands until 6 lines are reached for example. After that it should be scrollable.
I already managed to do this with strings, which contain line breaks \n.
TextEditor(text: $composedMessage)
.onChange(of: self.composedMessage, perform: { value in
withAnimation(.easeInOut(duration: 0.1), {
if (value.numberOfLines() < 6) {
height = startHeight + CGFloat((value.numberOfLines() * 20))
}
if value.numberOfLines() == 0 || value.isEmpty {
height = 50
}
})
})
I created a string extension which returns the number of line breaks by calling string.numberOfLines() var startHeight: CGFloat = 50
The problem: If I paste a text which contains a really long text, it's not expanding when this string has no line breaks. The text get's broken in the TextEditor.
How can I count the number of breaks the TextEditor makes and put a new line character at that position?
Here's a solution adapted from question and answer,
struct ChatView: View {
#State var text: String = ""
// initial height
#State var height: CGFloat = 30
var body: some View {
ZStack(alignment: .topLeading) {
Text("Placeholder")
.foregroundColor(.appLightGray)
.font(Font.custom(CustomFont.sofiaProMedium, size: 13.5))
.padding(.horizontal, 4)
.padding(.vertical, 9)
.opacity(text.isEmpty ? 1 : 0)
TextEditor(text: $text)
.foregroundColor(.appBlack)
.font(Font.custom(CustomFont.sofiaProMedium, size: 14))
.frame(height: height)
.opacity(text.isEmpty ? 0.25 : 1)
.onChange(of: self.text, perform: { value in
withAnimation(.easeInOut(duration: 0.1), {
if (value.numberOfLines() < 6) {
// new height
height = 120
}
if value.numberOfLines() == 0 || value.isEmpty {
// initial height
height = 30
}
})
})
}
.padding(4)
.overlay(
RoundedRectangle(cornerRadius: 8)
.stroke(Color.appLightGray, lineWidth: 0.5)
)
}
}
And the extension,
extension String {
func numberOfLines() -> Int {
return self.numberOfOccurrencesOf(string: "\n") + 1
}
func numberOfOccurrencesOf(string: String) -> Int {
return self.components(separatedBy:string).count - 1
}
}
I found a solution!
For everyone else trying to solve this:
I added a Text with the same width of the input field and then used a GeometryReader to calculate the height of the Text which automatically wraps. Then if you divide the height by the font size you get the number of lines.
You can make the text field hidden (tested in iOS 14 and iOS 15 beta 3)
If you're looking for an iOS 15 solution, I spent a while and figured it out. I didn't want to have to resort to UIKit or ZStacks with overlays or duplicative content as a "hack". I wanted it to be pure SwiftUI.
I ended up creating a separate struct that I could reuse anywhere I needed it, as well as add additional parameters in my various views.
Here's the struct:
struct FieldMultiEntryTextDynamic: View {
var text: Binding<String>
var body: some View {
TextEditor(text: text)
.padding(.vertical, -8)
.padding(.horizontal, -4)
.frame(minHeight: 0, maxHeight: 300)
.font(.custom("HelveticaNeue", size: 17, relativeTo: .headline))
.foregroundColor(.primary)
.dynamicTypeSize(.medium ... .xxLarge)
.fixedSize(horizontal: false, vertical: true)
} // End Var Body
} // End Struct
The cool thing about this is that you can have placeholder text via an if statement and it supports dynamic type sizes.
You can implement it as follows:
struct MyView: View {
#FocusState private var isFocused: Bool
#State private var myName: String = ""
var body: some View {
HStack(alignment: .top) {
Text("Name:")
ZStack(alignment: .trailing) {
if myName.isEmpty && !isFocused {
Text("Type Your Name")
.font(.custom("HelveticaNeue", size: 17, relativeTo: .headline))
.foregroundColor(.secondary)
}
HStack {
VStack(alignment: .trailing, spacing: 5) {
FieldMultiEntryTextDynamic(text: $myName)
.multilineTextAlignment(.trailing)
.keyboardType(.alphabet)
.focused($isFocused)
}
}
}
}
.padding()
.background(.blue)
}
}
Hope it helps!
What I want to achieve:
Display small, variable sized svgs in my app with auto layout.
The svgs contain pre-rendered latex formulas. The svgs are loaded asynchronously so I don't know upfront which size or aspect ratio they are.
The hardest pre-conditions I could imagine.
I tried several svg displaying libraries, and no one turned out to work with our svgs, so I decided to use a UIWebView.
The problem here is, that the svgs should not be scrollable and the UIWebView of minimal size.
The svgs should span all available width and have a height based on the aspect ratio.
What I tried:
class FormulaView: UIView, UIWebViewDelegate, XMLParserDelegate {
private var view: UIView!
#IBOutlet weak var webView: UIWebView!
#IBOutlet weak var topMargin: NSLayoutConstraint!
#IBOutlet weak var bottomMargin: NSLayoutConstraint!
private var width = -1.0
private var height = -1.0
// MARK: Initialisation
override init(frame: CGRect) {
super.init(frame: frame)
setUpView()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
setUpView()
}
// MARK: Set Up
// Performs the initial setup.
// Loads a XIB file into a view and returns this view.
func loadSVG(fromURL url: URL) {
let request = NSURLRequest(url: url)
webView.delegate = self
webView.loadRequest(request as URLRequest)
}
func loadSVG(fromString string: String) {
let url = URL(string: string)
if url == nil {
self.isHidden = true
return
}
self.loadSVG(fromURL: url!)
}
var tableView: UITableView?
private func viewFromNibForClass() -> UIView {
let bundle = Bundle(for: type(of: self))
let nib = UINib(nibName: String(describing: type(of: self)), bundle: bundle)
let view = nib.instantiate(withOwner: self, options: nil).first as! UIView
return view
}
private func setUpView() {
view = viewFromNibForClass()
view.frame = bounds
// Auto-layout stuff.
view.autoresizingMask = [
UIViewAutoresizing.flexibleWidth,
UIViewAutoresizing.flexibleHeight
]
addSubview(view)
// Formula should take no space if no formula is loaded
topMargin.constant = 0
bottomMargin.constant = 0
self.translatesAutoresizingMaskIntoConstraints = false
self.addConstraints([
NSLayoutConstraint(item: self, attribute: .top, relatedBy: .equal,
toItem: view, attribute: .top, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: self, attribute: .right, relatedBy: .equal,
toItem: view, attribute: .right, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: self, attribute: .bottom, relatedBy: .equal,
toItem: view, attribute: .bottom, multiplier: 1.0, constant: 0),
NSLayoutConstraint(item: self, attribute: .left, relatedBy: .equal,
toItem: view, attribute: .left, multiplier: 1.0, constant: 0)
])
}
// MARK: - UIWebView delegate
func webViewDidFinishLoad(_ webView: UIWebView) {
// Get xml of svg file
let xml = webView.stringByEvaluatingJavaScript(from: "document.documentElement.outerHTML")
let parser = XMLParser(data: (xml?.data(using: .utf8))!)
parser.delegate = self
parser.parse()
}
// MARK: - XMLParser delegate
func parser(_ parser: XMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String] = [:]) {
// Get width and height of svg
if elementName == "svg" {
self.height = Double(attributeDict["height"]?
.replacingOccurrences(of: "pt", with: "") ?? "")
?? -1.0
self.width = Double(attributeDict["width"]?
.replacingOccurrences(of: "pt", with: "") ?? "")
?? -1.0
let aspectRatio = self.width / self.height
tableView?.beginUpdates()
// Calculate height the webview should have based on the width and the normal aspect ratio of the svg
let webviewHeight = self.webView.bounds.size.width / CGFloat(aspectRatio)
if let constraint = (webView.constraints.filter {
$0.firstAttribute == .height && $0.secondAttribute == .notAnAttribute
}.first) {
constraint.constant = webviewHeight
} else {
webView.heightAnchor.constraint(equalToConstant: webviewHeight).isActive = true
}
// Apply a 24 margin as a svg is now loaded
topMargin.constant = 24
bottomMargin.constant = 24
tableView?.endUpdates()
self.layoutIfNeeded()
self.invalidateIntrinsicContentSize()
// Zoom webview appropriately that the svg is completely visible and no scrolling is neccessary or even possible
let scrollView = webView.scrollView
let zoom = webView.bounds.size.width / scrollView.contentSize.width
scrollView.maximumZoomScale = zoom
scrollView.setZoomScale(zoom, animated: true) // Error occurs here
// prevent scrolling
scrollView.isScrollEnabled = false
scrollView.isPagingEnabled = false
scrollView.isUserInteractionEnabled = false
scrollView.isDirectionalLockEnabled = true
}
}
}
This version seems to work fine as I tested it on the simulator,
but in some cases (EDIT: I only see these crashes in our Bug reporting tool), I get an error (CALayerInvalidGeometry: CALayer position contains NaN: [nan nan]) at this line scrollView.setZoomScale(zoom, animated: true).
It seems the calculating the zoom results in CGFloat.nan,
(1) but when does this occur,
(2) how can I prevent this and
(3) if it occurs, how can I calculate the zoom in these cases?
EDIT: Or in other words, why are webView.bounds.size.width and/or scrollView.contentSize.width non positiv values?
If I could reproduce it, I could say more, but unluckily I can't...
Thanks in advance,
Dennis
I'm having trouble drawing polylines, and I think I've deduced it to being an issue with iOS 11 beta 4. It was working yesterday with the same code, and now I've updated to beta 4 and it doesn't draw polylines.
Just confirmed this by trying it in Xcode 8 on iOS 10.3 simulator, and in Xcode 9b4 on the iOS 11b4 simulator.
Code:
import MapKit
class ViewController: UIViewController, MKMapViewDelegate {
let mapView = MKMapView()
override func viewDidLoad() {
super.viewDidLoad()
mapView.frame = CGRect(x: 10, y: 10, width: 300, height: 300)
mapView.delegate = self
mapView.region = MKCoordinateRegionMake(CLLocationCoordinate2D(latitude: 51.482736, longitude: -0.015253), MKCoordinateSpanMake(0.005, 0.005))
mapView.delegate = self
let coordinate1 = CLLocationCoordinate2D(latitude: 51.482736, longitude: -0.015253)
let coordinate2 = CLLocationCoordinate2D(latitude: 51.482736, longitude: -0.016253)
let polyline = MKPolyline(coordinates: [coordinate1, coordinate2], count: 2)
mapView.add(polyline, level: .aboveLabels)
view.addSubview(mapView)
}
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
let renderer = MKPolylineRenderer(overlay: overlay)
renderer.strokeColor = UIColor.red
renderer.lineWidth = 4.0
return renderer
}
}
iOS 10:
iOS 11:
Annotations are added to the map without issue.
Fixed in beta 5. We just had to wait.
I have this struct:
struct Direction {
let Left = CGPoint(x: -1, y: 0)
let Top = CGPoint(x: 0, y: -1)
let Right = CGPoint(x: 1, y: 0)
let Down = CGPoint(x: 0, y: 1)
let TopLeft = CGPoint(x: -1, y: -1)
let TopRight = CGPoint(x: 1, y: -1)
let DownLeft = CGPoint(x: -1, y: 1)
let DownRight = CGPoint(x: 1, y: 1)
let None = CGPointZero
}
And I try to use it like this:
class AClass {
var point:CGPoint!
init() {
self.point = Direction.None // Direction.Type does not have a member named 'None'
}
}
I've tried to set .None to a var and public but I don't seem to understand this.
Seems that you are trying to use static members of the struct, but you have only declared instance members. Add static to all properties.
struct Direction {
static let Left = CGPoint(x: -1, y: 0)
static let Top = CGPoint(x: 0, y: -1)
static let Right = CGPoint(x: 1, y: 0)
static let Down = CGPoint(x: 0, y: 1)
static let TopLeft = CGPoint(x: -1, y: -1)
static let TopRight = CGPoint(x: 1, y: -1)
static let DownLeft = CGPoint(x: -1, y: 1)
static let DownRight = CGPoint(x: 1, y: 1)
static let None = CGPointZero
}
If #Kirsteins's supposition is correct, and you need to use the struct values as static properties, then there's an alternative way of achieving the same result, but in my opinion in a better way: using an enum.
But swift enums accept characters, strings and numbers as raw values only, whereas a CGPoint is made up of a pair of floats. Fortunately swift gives us the capability of using a string literal to specify the pair, which is then converted into a CGFloat:
extension CGPoint : StringLiteralConvertible {
public static func convertFromStringLiteral(value: StringLiteralType) -> CGPoint {
return CGPointFromString(value)
}
public static func convertFromExtendedGraphemeClusterLiteral(value: StringLiteralType) -> CGPoint {
return convertFromStringLiteral(value)
}
}
This extension allows us to initialize a CGFloat as follows:
let point: CGPoint = "{1, -3}"
With that in our hands, we can define an enum as follows:
enum Direction : CGPoint {
case Left = "{-1, 0}"
case Top = "{0, -1}"
case Right = "{1, 0}"
case Down = "{0, 1}"
case TopLeft = "{-1, -1}"
case TopRight = "{1, -1}"
case DownLeft = "{-1, 1}"
case DownRight = "{1, 1}"
case None = "{0, 0}"
}
and use in your code snippet as:
class AClass {
var point:CGPoint!
init() {
self.point = Direction.None.toRaw()
}
}
Hello friends,
I am developing a functionality to display index number on map pin and set image on mapview of iPhone so please tell me any link or any idea to develop this functionality.
Thanks in advance.
What is an index number in the context? Is it just a digit that your code is displaying? If so your question is how to display text on a map. Use a map overlay. Same for images. Search for MKMapOverlay and go from there.
I have use this method for index number in annotation view.
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
guard !(annotation is MKUserLocation) else {
return nil
}
// Better to make this class property
let annotationIdentifier = "AnnotationIdentifier"
var annotationView = MKAnnotationView()
annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: annotationIdentifier)
annotationView.frame = CGRect(x: annotationView.frame.origin.x, y: annotationView.frame.origin.y, width: 80, height: 200)
annotationView.annotation = annotation
annotationView.tag = index
index += 1
let imageViewPin = UIImageView(frame: CGRect(x: 0, y: 0, width: 30, height: 40))
imageViewPin.center = CGPoint(x: annotationView.center.x, y: annotationView.center.y - 11)
imageViewPin.image = UIImage(named: "green_pin")
annotationView.addSubview(imageViewPin)
return annotationView
}
func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
debugPrint(view.tag)
}