Create engaging content for Swift Playgrounds

let numOfTiles = 100
let squareLength = 150.0

    // Dance floor
    ForEach(0 ..< numOfTiles, id: \.self) { index in
        let i: CGFloat = CGFloat(index / 10)
        let j: CGFloat = CGFloat(index % 10)

        let x = (squareLength * i) - (squareLength)
        let y = (squareLength * j) - (squareLength * 2)

        Rectangle()
            .frame(width: squareLength, height: squareLength)
            .border(.black, width: 3)
            .position(x: x, y: y)
            .randomizedColorEffect(startAnimation: startParty)
    }
    .blur(radius: 15)
    .opacity(startParty ? 1.0 : 0.0)

ForEach(data.creatures) { creature in
    Text(creature.emoji)
        .resizableFont()
        .animatedScalingEffect(startAnimation: startParty)
        .randomizedOffsetEffect(startAnimation: startParty,
                                x: midX * 0.6,
                                y: midY * 0.6)
        .animatedRotationEffect(startAnimation: startParty)
        .opacity(startParty ? 1.0 : 0.0)
}

Text("🪩")
    .resizableFont()
    .animatedRotationEffect(startAnimation: startParty)
    .opacity(startParty ? 1 : 0)

@GuideBook(title: "Creature Party!", icon: icon.png, background: background.png, firstFile: CreatureDance.swift) {
    
}

@WelcomeMessage(title: "Welcome to Creature Party!") {
		In Creature Party, you'll take this app of dancing creatures to the next level with the help of colors, shapes, animations, and plenty of emoji!
}

@Guide {
        @Step(title: "Pump up the jams") {
            
        }
    }
}

@ContentAndMedia {
  	Tonight, the creatures are gonna party like it's 2022. 🐙💃🦝🕺🦦 
}

@TaskGroup(title: "Walkthroughs") {
		Here are the walkthroughs! These will help explain all of the new code.                 
}

@Task(type: walkthrough, id: "partyMode", title: "Setting up the Party", file: CreatureDance.swift) {
}

@Page(id: "1.modifier", title: "") {
  	This is a [view modifier](https://developer.apple.com/documentation/swiftui/viewmodifier). Modifiers let you create unique versions of a view in SwiftUI. 
}

ForEach(data.creatures) { creature in
		Text(creature.emoji)
			.resizableFont()
			/*#-code-walkthrough(1.modifier)*/
			.animatedScalingEffect(startAnimation: startParty)
			/*#-code-walkthrough(1.modifier)*/
      .randomizedOffsetEffect(startAnimation: startParty,
      												x: midX * 0.6,
				                      y: midY * 0.6)
      .animatedRotationEffect(startAnimation: startParty)
      .opacity(startParty ? 1.0 : 0.0)
}

@Page(id: "1.struct", title: "") {
  	Custom view modifiers are structures that contain code for explaining how to modify whatever view the given modifier is attached to.  
}
@Page(id: "1.body", title: "") {
  	The body method allows you to add custom view modifications. For example, here you're adding a scaling animation that grows and shrinks the `Creature` over a certain period of time. 
}

@Task(type: walkthrough, id: "protocol", title: "A Little More on Protocols", file: CreatureDance.swift) {
    @Page(id: "2.protocol", title: "") {
      All custom view modifiers implement the `ViewModifier` protocol. 
    }
    @Page(id: "2.body", title: "") {
      The `ViewModifier` protocol requires all structures that implement it to write the `body(content:)` method.   
    }
    @Page(id: "2.usage", title: "") {
      After you've written content for your `body(content:)` method, you can use it on any view you want. Here you'll use it on each `Creature` to add a rotation animation.
    }
}

@TaskGroup(title: "Experiments") {
    Time to set this party off! You can use experiments to add some extra pazazz to the dance floor.
    @Task(type: experiment, id: "colors", title: "Dancing in the Strobe Light", file: CreatureDance.swift) {

    }
}

@Page(id: "3.code", title: "", isAddable: true) {
    ```
    .colorMultiply(creatureColor)
    ``` 
}

ForEach(data.creatures) { creature in
		Text(creature.emoji)
    		.resizableFont()
        /*#-code-walkthrough(1.modifier)*/
        .animatedScalingEffect(startAnimation: startParty)
        /*#-code-walkthrough(1.modifier)*/
        .randomizedOffsetEffect(startAnimation: startParty,
        												x: midX * 0.6,
        												y: midY * 0.6)
        /*#-code-walkthrough(2.usage)*/
        .animatedRotationEffect(startAnimation: startParty)
        /*#-code-walkthrough(2.usage)*/
        .opacity(startParty ? 1.0 : 0.0)
        //#-learning-task(colors)
}

@Page(id: "3.lights", title: "") {
  	Next, add some colors to the creatures so it looks like they're dancing under the lights! 
}

@Task(type: experiment, id: "timer", title: "Switch it Up", file: CreatureDance.swift) {
    @Page(id: "4.lights", title: "") {
      	Now that you have some colors, you can add some code to change the color of the creatures using a timer. Let's add one!
    }
    @Page(id: "4.code", title: "", isAddable: true) {
        ```
        .onTapGesture {
          if let timer = timer {
            timer.invalidate()
            self.timer = nil
          } else {
            creatureColor = Color.randomColor
            timer = Timer.scheduledTimer(withTimeInterval: 2.0, repeats: true, block: { timer in
                                                                                       creatureColor = Color.randomColor
                                                                                      })
          }
        }
        ``` 
    }
}