After I began out growing iOS apps, 11 years in the past I put a number of apps on the App Retailer. Since they turned fewer and fewer because the revenue from them didn’t warrant updating them. Amongst these my most profitable one was iWoman, which I offered in 2015. My second-most-valuable (when it comes to income) remained my beloved SpeakerClock, the final app standing.
I had left SpeakerClock on-line for the principle cause that it stored producing like a mean of $100 per 30 days, even with out me doing something on it. For that cause, I didn’t wish to make it free, however somewhat put it to a comparatively excessive price ticket of $5. There’s additionally an In-App-Buy of one other $5. I figured “why kill the cow whereas it nonetheless produces some tasty milk”.
The opposite facet impact of those value tags was that – I imagine – solely individuals who actually wished what the app was providing would really buy it. My philosophy with this talking timer was to have the most important LED digits potential, with the performance that helps the talking fashion of TED Talks, which traditionally have defaulted to a most size of 18 minutes.
Some crashes launched by new iOS variations induced me to do small bug fixing releases (for iOS 3 in 2010, iOS 5 in 2011, and 2017 for iOS 10). Additionally, wanting again on the launch notes of these variations, I had made this precise promise:
“We now have completely modernised the code base in order that we are able to carry you some thrilling new options within the subsequent main launch”
However I didn’t lie with this assertion, a “subsequent main” launch would have been model 2.0. However I didn’t ever dare to show the model quantity up that prime. I solely elevated the third digit of the model quantity.
Apple did pressure me to do a brand new construct ultimately, once they cracked down on apps which weren’t up to date in too lengthy a time. And the latest replace they did themselves, when the Apple certificates had expired and so they re-signed my app on their servers with out me doing something.
Enter SwiftUI
Over the previous few months, I’ve grown very keen on SwiftUI. Being a developer on Apple platforms for greater than a decade made me fairly bored with having to maintain writing the identical MVC code numerous instances. And that might solely get you want normal performance, nothing really thrilling. So I jumped on the probability when one in all my purchasers requested me to implement a brand new iOS Widget in SwiftUI, within the fall of 2020. Apple had turned to SwiftUI as the one approach you possibly can create such widgets due to SwiftUIs capability to provide and protect a static view hierarchy which the system may present to the consumer at sure factors in a timeline with out substantial energy utilization.
My consumer was blissful in regards to the end result and so I used to be tasked with the subsequent degree of SwiftUI growth. I wanted to implement a watchOS app, additionally solely in SwiftUI. Improvement was fairly just like the widget, however this time I additionally wanted to cope with consumer interplay and communication with the iOS counterpart app. That each one took some a number of months greater than the widget, however once more elevated my SwiftUI expertise tremendously.
After having delivered the watch app, I had a bit additional time out there to do one thing for myself. I do have another concepts for apps, however my ideas turned to SpeakerClock. I figured that this extremely customized UI would lend itself properly to be carried out in SwiftUI.
Paths in Shapes
An important asset within the legacy code was the drawing of the massive purple LED digits and the way they prepare themselves in portrait versus panorama, in a pleasant animation. So my first SwiftUI view was one which had a Path factor with the SwiftUI instructions including the trail parts to make up the person bars of the LED. My first error right here involved utilizing a GeometryReader to find out the size of the trail. The LED digits have a hard and fast facet ratio and the drawing coordinates are primarily based on these.
struct LEDDigit: View
{
var digit: Int? = nil
var physique: some View
{
GeometryReader { proxy in
let (w, h) = proxy.unitSize
// high horizontal line
Path { path in
path.transfer(to: CGPoint(x: 24 * w, y: 7 * h))
path.addLine(to: CGPoint(x: 60 * w, y: 7 * h))
path.addLine(to: CGPoint(x: 62 * w, y: 10 * h))
path.addLine(to: CGPoint(x: 57 * w, y: 15 * h))
path.addLine(to: CGPoint(x: 24 * w, y: 15 * h))
path.addLine(to: CGPoint(x: 21 * w, y: 10 * h))
path.closeSubpath()
}
.activeLEDEffect(when: [0, 2, 3, 5, 7, 8, 9].comprises(digit))
...
}Whereas this produces the proper output, it causes the person Paths to animate individually when rotating the gadget. I solved this drawback by transferring the person path’s code right into a Form the place I’m including the bars solely primarily based on whether or not I’m on the lookout for the lively or inactive LED parts. The trail(in rect: CGRect) perform arms us the required dimension, so we don’t a GeometryReader any extra.
struct LEDDigitShape: Form
{
var digit: Int? = nil
var isActive: Bool
func path(in rect: CGRect) -> Path
{
let w = rect.dimension.width / 73
let h = rect.dimension.peak / 110
var path = Path()
// high horizontal line
if [0, 2, 3, 5, 7, 8, 9].comprises(digit) == isActive
{
path.transfer(to: CGPoint(x: 24 * w, y: 7 * h))
path.addLine(to: CGPoint(x: 60 * w, y: 7 * h))
path.addLine(to: CGPoint(x: 62 * w, y: 10 * h))
path.addLine(to: CGPoint(x: 57 * w, y: 15 * h))
path.addLine(to: CGPoint(x: 24 * w, y: 15 * h))
path.addLine(to: CGPoint(x: 21 * w, y: 10 * h))
path.closeSubpath()
}
...
}That is used such:
struct LEDDigit: View
{
var digit: Int? = nil
var physique: some View
{
ZStack
{
LEDDigitShape(digit: digit, dot: dot, isActive: false)
.activeLEDEffect(isActive: false)
LEDDigitShape(digit: digit, dot: dot, isActive: true)
.activeLEDEffect(isActive: true)
}
}The 2 members of the ZStack draw all of the inactive LED parts behind the lively LED parts. It nonetheless wanted to be two Shapes as a result of one form can solely have a single drawing fashion. The inactive parts are merely crammed in a grey. The lively parts are full of purple and have a purple glow round them simulating some radiance.
With this method a digit is all the time drawn in its entirety which lends itself to easy resizing.
Structure and Orientation Woes
The subsequent step was to combination a number of LED digits and lay them out over the display screen with totally different positions for panorama and portrait orientations, with a easy animation if you rotate the gadget.
I’ve mainly two layouts:
- Hour digits, Colon, Minute digits (in a
HStack)- in horizontal format with the outer sides touching the secure space insets - A
VStackof Hour digits and Minute digits – in vertical format
Sounds straightforward, however my makes an attempt with HStacks and VStacks failed miserably. In the beginning of the rotation animation the digits would all the time get a really small body increasing into the ultimate one.
I can solely think about that someway the SwiftUI format system doesn’t keep in mind that these are the identical views. So I attempted giving them static identifiers and I additionally tried geometry matching. However I couldn’t shake these animation artefacts. There should be some piece lacking in my understanding about view id.
Ultimately I got here again to doing my very own format inside a GeometryReader, setting body’s width/peak and applicable offsets (i.e. translation) for particular person parts. This works very properly and likewise lets me have a separate animation for the opacity of the colon.
The colon sticks to the fitting facet of the hour digits and disappears in portrait format. By sorting view modifiers in a sure approach I used to be capable of get this impact that the colon fades in with a slight delay.
var physique: some View
{
GeometryReader { proxy in
let digitSize = self.digitSize(proxy: proxy)
let colonSize = self.colonSize(proxy: proxy)
let centeringOffset = self.centeringOffset(proxy: proxy)
let isLandscape = proxy.isLandscape
let timerSize = self.timerSize(proxy: proxy)
Group
{
LEDNumber(worth: mannequin.countdown.minutes)
.body(width: digitSize.width * 2, peak: digitSize.peak)
.animation(nil)
LEDColon()
.body(width: colonSize.width, peak: colonSize.peak)
.offset(x: digitSize.width * 2, y: 0)
.animation(nil)
.opacity(isLandscape ? 1 : 0)
.animation(isPadOrPhone ? (isLandscape ? .easeInOut.delay(0.2)
: .easeInOut) : nil)
LEDNumber(worth: mannequin.countdown.seconds)
.body(width: digitSize.width * 2, peak: digitSize.peak)
.offset(x: isLandscape ? digitSize.width * 2 + colonSize.width : 0,
y: isLandscape ? 0 : digitSize.peak)
.animation(nil)
}
.offset(x: centeringOffset.width,
y: centeringOffset.peak)You may see that I’m particularly disabling animation with .animation(nil) for essentially the most elements as a result of I discovered that the animation in any other case is all the time out of sync with the rotation resizing animation. The LED colon alternatively has its personal animation with an extra delay of 0.2 seconds.
The second cause why I explicitly disabled animations is as a result of on the Mac model these animations would lag behind the resizing of the app’s window. This resizing additionally switches between each layouts relying on the way you drag the window nook, kind of like “responsive design” as we have now seen on HTML net pages. Extra on Mac issues additional down under.
Multi-Modal Buttons
One other problem that had me attempt a number of approaches involved the preset buttons (high left) and visitors mild buttons (middle backside). These buttons have a distinct perform for a single faucet (choose) versus a protracted press (set).
The principle drawback is that you simply can not have a easy .onLongPressGesture as a result of this prevents the conventional faucets from being dealt with. One method is to have a .simultaneousGesture for the lengthy press, however then the faucet motion is executed proper (i.e. “simultaneous”) after the lengthy press motion in case you elevate the finger over the button. The opposite method is to make use of a .highPriorityGesture which once more disables the built-in faucet.
I ended up with the next method which makes use of the gesture masks to selectively disable the lengthy press gesture if there isn’t any lengthy press motion and to disable the faucet gesture if a protracted press was detected.
struct LEDButton<Content material: View>: View
{
var motion: ()->()
var longPressAction: (()->())?
@ViewBuilder var content material: ()->Content material
@State fileprivate var didLongPress = false
var physique: some View
{
Button(motion: {}, label: content material) // will need to have empty motion
.contentShape(Circle())
.buttonStyle(PlainButtonStyle()) // wanted for Mac
.simultaneousGesture(LongPressGesture().onEnded({ _ in
didLongPress = true
longPressAction!()
didLongPress = false
}), together with: longPressAction != nil ? .all : .subviews)
.highPriorityGesture(TapGesture().onEnded({ _ in
motion()
}), together with: didLongPress ? .subviews : .all)
}
}This method makes use of a customized TapGesture in tandem with the LongPressGesture. A @State variable retains monitor of the lengthy press. We do have to reset didLongPress to false or else all subsequent faucets would proceed to be ignored. I discovered that I don’t want a dispatch async for placing it again to false.
I imagine that the explanation for that’s that the primary setting of the variable causes the physique to be up to date and thus the together with: to disable the faucet gesture whereas in progress. Thus the faucet doesn’t fireplace upon releasing the lengthy press. Good to know: The .all permits the gesture and the .subviews disables a gesture.
Opposite to different approaches I’ve seen on the web this method preserves the usual habits of Button for highlighting, Whilst you press a customized button like this, it makes it barely clear.
A Mac Model – For Free?
The large promise of SwiftUI is that you’d get a Mac model of your app for little additional work, successfully “free of charge”. So I made a decision to place this to the take a look at additionally produce a macOS model. I set the focused gadgets to iPhone, iPad, Mac and selected the “Optimize Interface for Mac” as a result of that sounded to me like the higher end result.
This optimized mode induced some points for my customized buttons, as a result of they obtained changed with empty spherical rects destroying my customized look. You may stop this modification by including .buttonStyle(PlainButtonStyle()).
Aside from this my code actually did run as a local Mac app fairly properly. Behind the scenes although it’s all Mac Catalyst. As I perceive it, which means UIKit remains to be on the helm, on Mac only a macOS model of it.
I left the code signing settings alone as I wished to have customers have the ability to set up the Mac and iOS variations with the identical buy. This “common buy” is enabled by having the identical bundle identifier for each variations.
Some very minor tweaks have been required for adjusting some minimal and most button sizes. There’s a bug on macOS that stumped me for some time. Solely on Mac I discovered that after I tapped in sure spots in my app this is able to trigger gestures to cease working. Then after I triggered a brand new format by resizing the window, every thing returned again to regular.
My workaround for this was to connect the Pan Gesture (for setting the timer) solely to the LED digits. This manner there isn’t any interference and all buttons proceed to work usually. The system may get confused by having too many conflicting gestures on high of one another.
A side-effect of the Mac model is that you simply begin to connect keyboard shortcuts to buttons. This was additionally a cause why I wished to get Button to work with faucet and lengthy press versus making a customized view that’s not a button.
let title = "(index+1)"
PresetButton()
.keyboardShortcut(KeyEquivalent(title.first!), modifiers: [.command])This manner you possibly can set off the preset buttons additionally with COMMAND plus quantity. And never only for the Mac app, however that works for iPads with hooked up keyboard as nicely.
That obtained me considering, that perhaps it will be nice to permit the area bar to cease/begin the timer, like we’re used to from video gamers. For that objective I’ve an empty utterly black button behind the LED digits:
Button(motion: { mannequin.isTimerActive.toggle() },
label: {
Rectangle()
.foregroundColor(.black)
.body(width: timerSize.width, peak: timerSize.peak)
.onTapGesture(rely: 2) { mannequin.restoreGreenTime() }
})
.keyboardShortcut(.area, modifiers: [])
.buttonStyle(PlainButtonStyle())This button permits me so as to add a keyboard shortcut for area to behave the identical as a faucet. Curiously having a two-tap gesture hooked up to the Rectangle() poses no drawback.
I submitted the Mac construct proper after the one for iOS however initially obtained a stunning rejection:
The consumer interface of your app is just not according to the macOS Human Interface Tips. Particularly:
We discovered that the app comprises iOS contact management directions comparable to faucet and swipe.
The explanation for that was that I put again the assistance display screen with a textual content I had beforehand written with iOS in thoughts. I wanted to interchange mentions of swiping with dragging and as a substitute of tapping you might be clicking. I’ve exhausting coded the textual content and formatting for now and with and #if I can swap the textual content between a model for Mac and one for iOS.
Group
{
Textual content("Setting the Timer")
.font(.headline)
.padding(.backside, 5)
#if targetEnvironment(macCatalyst)
Textual content("To regulate the timer, click on on the LED digits and drag horizontally.")
.font(.physique)
.padding(.backside, 5)
#else
Textual content("To regulate the timer swipe left and proper.")
.font(.physique)
.padding(.backside, 5)
#endif
}As soon as I had made these adjustments the Mac app was authorised in a short time.
Conclusion
I’ve skilled first hand how I can rewrite an app in SwiftUI and the nice pleasure that may be had from deleting all of your crufty Goal-C code when doing so.
SwiftUI is my new love and this manner my app is now not a “baby from one other mom”. This restores some enthusiasm in me to truly lastly actually add some long-promised “thrilling new options”. For starters I’m considering of getting a watchOS companion app which exhibits the timer and permits you to distant management it. One other concept could be to retailer my presets on iCloud in order that they’re the identical on all my gadgets.
I might love to listen to from you what you consider the method of re-implementing elements of apps and even complete apps in SwiftUI.
Additionally printed on Medium.
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