[XRAY-2] Part 3 - Move swift ui extensions to their own repository (#1)

Works on xiiagency/Xray#2

Package.swift

@@ -0,0 +1,29 @@
+// swift-tools-version:5.5
+import PackageDescription
+
+let package =
+  Package(
+    name: "SwiftUIExtensions",
+    platforms: [
+      .iOS(.v15),
+      .watchOS(.v8),
+    ],
+    products: [
+      .library(
+        name: "SwiftUIExtensions",
+        targets: ["SwiftUIExtensions"]
+      ),
+    ],
+    dependencies: [],
+    targets: [
+      .target(
+        name: "SwiftUIExtensions",
+        dependencies: []
+      ),
+      // NOTE: Re-enable when tests are added.
+//      .testTarget(
+//        name: "SwiftUIExtensionsTests",
+//        dependencies: ["SwiftUIExtensions"]
+//      ),
+    ]
+  )

README.md

@@ -0,0 +1,3 @@
+# SwiftUIExtensions
+
+Provides extensions and utilities for SwiftUI.

Sources/SwiftUIExtensions/DoWithoutAnimation.swift

@@ -0,0 +1,12 @@
+import SwiftUI
+
+/**
+ Performs the provided block in a transaction with animations disabled.
+ Useful for cancelling some animations that are hard to control (e.g. navigation view transitions).
+ NOTE: This is a bit finicky, use at your own risk.
+ */
+public func doWithoutAnimations(_ block: @escaping () -> Void) {
+  var transaction = Transaction(animation: nil)
+  transaction.disablesAnimations = true
+  withTransaction(transaction, block)
+}

Sources/SwiftUIExtensions/HiddenView.swift

@@ -0,0 +1,14 @@
+import SwiftUI
+
+/**
+ A specialty view that has no visible representation (clear 0x0 pixel view) but can still have functionality attached (e.g. onChange(of:)).
+ NOTE: If used in a container view that has spacing (e.g. VStack) this view will still be counted as one and will add unintended spacing.
+ */
+public struct HiddenView : View {
+  public init() { }
+  
+  public var body: some View {
+    Color.clear
+      .frame(width: 0, height: 0)
+  }
+}

Sources/SwiftUIExtensions/MomentarySwitch.swift

@@ -0,0 +1,58 @@
+import Foundation
+
+/**
+ An implementation of a momentary switch: one that has an on/off state, can be turned on repeatedly, turns off after a delay.
+ 
+ If triggered multiple times before the off delay is elapses, it re-schedules the reaction (relative to the last time it was triggered).
+
+ Ideally used for triggering animations on user interaction, and auto-reverting once they've stopped interacting for enough time.
+ 
+ NOTE: The switch itself will operate on the background thread, but the on/off callbacks are executed on the `@MainActor`.
+ */
+public class MomentarySwitch {
+  /**
+   Reference to the currently scheduled task to fire the latest known "off" event.
+   */
+  private var scheduledOffTask: Task<Void, Never>? = nil
+  
+  public init() { }
+
+  /**
+   Triggers the supplied `switchOn `closure and schedules to run the supplied `switchOff` closure after a delay.
+   If there's already an unfinished task (switch is on):
+   - we will cancel the previous "off" task and create a new one with an updated time and `switchOff` closure.
+   - the `switchOn` callback will NOT be called.
+   */
+  public func trigger(
+    offDelaySeconds: Double = 0.0,
+    switchOn: @escaping () -> Void,
+    switchOff: @escaping () -> Void
+  ) {
+    if let scheduledOffTask = scheduledOffTask {
+      // If there is a scheduled off task, cancel it.
+      scheduledOffTask.cancel()
+    } else {
+      // Otherwise, trigger the "on" action.
+      switchOn()
+    }
+
+    // Start a task to trigger the "off" action after the requested delay.
+    scheduledOffTask = Task {
+      // The task is kicked off right away, but we need to wait for the requested delay.
+      try? await Task.sleep(nanoseconds: UInt64(offDelaySeconds * 1_000_000_000))
+      
+      // If the task was cancelled while we were waiting, nothing to do.
+      if Task.isCancelled {
+        return
+      }
+      
+      // Otherwise, trigger the "off" action on the main actor.
+      Task { @MainActor in
+        switchOff()
+      }
+      
+      // Also clear the task reference.
+      scheduledOffTask = nil
+    }
+  }
+}

Sources/SwiftUIExtensions/OnScenePhaseChangedModifier.swift

@@ -0,0 +1,34 @@
+import SwiftUI
+
+extension View {
+  /**
+   Adds a modifier for this view that fires an action when the `ScenePhase` has changed.
+   
+   `action` is called on the main thread. Avoid performing long-running tasks on the main thread.
+   */
+  public func onScenePhaseChanged(_ action: @escaping (ScenePhase) -> Void) -> some View {
+    modifier(ScenePhaseModifier(onChanged: action))
+  }
+}
+
+/**
+ A modifier that monitors the `ScenePhase` of the current scene and reports changes to the provided callback.
+ */
+private struct ScenePhaseModifier : ViewModifier {
+  /**
+   The current `ScenePhase` of the application scene.
+   */
+  @Environment(\.scenePhase) private var scenePhase: ScenePhase
+  
+  /**
+   Callback to trigger whenever the `ScenePhase` has changed.
+   */
+  let onChanged: (ScenePhase) -> Void
+  
+  /**
+   Attaches an `.onChange` modifier to the modified view that monitors changes in `ScenePhase`.
+   */
+  func body(content: Content) -> some View {
+    content.onChange(of: scenePhase, perform: onChanged)
+  }
+}

Sources/SwiftUIExtensions/View+Extensions.swift

@@ -0,0 +1,68 @@
+import SwiftUI
+
+extension View {
+  /**
+   Resets the text case of the View.
+   Equivalent to: `textCase(nil)`
+   */
+  public func standardcase() -> some View {
+    textCase(nil)
+  }
+  
+  /**
+   Sets the text case of the View to uppercase.
+   Equivalent to: `textCase(.uppercase)`
+   */
+  public func uppercase() -> some View {
+    textCase(.uppercase)
+  }
+  
+  /**
+   Sets the text case of the View to lowercase.
+   Equivalent to `textCase(.lowercase)`
+   */
+  public func lowercase() -> some View {
+    textCase(.lowercase)
+  }
+  
+  /**
+   Sets the view's frame to stretch to fill its parent by setting maxWidth (and/or) maxHeight based on the requested `Axis`.
+   - By default it will stretch `.horizontal` as it's the more common scenario.
+   - Also allows for adjusting internal alignment with `.center` used as the default.
+   */
+  public func stretch(
+    _ axes: Axis.Set = [.horizontal],
+    alignment: Alignment = .center
+  ) -> some View {
+    frame(
+      maxWidth: axes.contains(.horizontal) ? .infinity : nil,
+      maxHeight: axes.contains(.vertical) ? .infinity : nil,
+      alignment: alignment
+    )
+  }
+}
+
+/**
+ Provide static members for various standard sets of `Axis`.
+ */
+extension Axis.Set {
+  /**
+   An empty set of `Axis`.
+   */
+  public static let None: Axis.Set = []
+  
+  /**
+   A set of `Axis` containing only `.horizontal`.
+   */
+  public static let Horizontal: Axis.Set = [.horizontal]
+  
+  /**
+   A set of `Axis` containing only `.vertical`.
+   */
+  public static let Vertical: Axis.Set = [.vertical]
+  
+  /**
+   A set of `Axis` containing both the `.horizontal` and `.vertical` values.
+   */
+  public static let All: Axis.Set = [.horizontal, .vertical]
+}

Sources/SwiftUIExtensions/iOSHelpers.swift

@@ -0,0 +1,49 @@
+#if os(iOS)
+import UIKit
+
+/**
+ Dismisses the keyboard from anywhere in the application.
+ NOTE: Only available on iOS.
+ */
+public func hideKeyboard() {
+  UIApplication.shared
+    .sendAction(
+      #selector(UIResponder.resignFirstResponder),
+      to: nil,
+      from: nil,
+      for: nil
+    )
+}
+
+/**
+ Opens the given URL  if it can be opened on the current device. Does nothing otherwise.
+ */
+public func sendUserToApplicationUrl(_ url: URL) {
+  // Ensure the url for the app can actually be opened.
+  guard UIApplication.shared.canOpenURL(url) else {
+    return
+  }
+  
+  // Finally, send the user to the requested app url.
+  UIApplication.shared.open(url)
+}
+
+/**
+ Opens the given URL string if it can be parsed and opened on the current device. Does nothing otherwise.
+ */
+public func sendUserToApplicationUrl(_ urlString: String) {
+  // Make sure the URL can be parsed first.
+  guard let url = URL(string: urlString) else {
+    return
+  }
+  
+  sendUserToApplicationUrl(url)
+}
+
+/**
+ Opens the App's setting screen in the OS' Settings app.
+ */
+public func sendUserToApplicationSettings() {
+  sendUserToApplicationUrl(UIApplication.openSettingsURLString)
+}
+#endif