[sneak preview] B4XTurtle - library for teaching kids programming

[Erel]

This is an early draft of a new library inspired by Logo programming language and Teaching Kids Programming project: https://teachingkidsprogramming.org/

The idea is to program in B4X language with all of B4X features and to make it very simple to start with something that you can see and play with.

It will be cross platform.

Code for this example:

Sub Process_Globals
    Private MainForm As Form
    Private Turtle1 As B4XTurtle
    Private xui As XUI
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    MainForm.RootPane.LoadLayout("1")
    MainForm.Show
    TurtleStart
End Sub

Sub TurtleStart
    Turtle1.X = 20
    Turtle1.Y = 50
    Turtle1.Angle = 90
    Turtle1.MoveForward(230)
    HalfCircle
    HalfCircle
    Turtle1.Y = 50
    Turtle1.X = 140
    Turtle1.Angle = 90
    Turtle1.MoveForward(120)
    Turtle1.TurnLeft(90)
    Turtle1.MoveForward(100)
    Turtle1.X = 200
    Turtle1.Y = 50
    Turtle1.Angle = 90
    Turtle1.MoveForward(220)
    Turtle1.Y = 50
    Turtle1.X = 250
    Turtle1.Angle = 60
    Turtle1.MoveForward(250)
    Turtle1.Y = 50
    Turtle1.Angle = 120
    Turtle1.MoveForward(250)
    Turtle1.PenColor = xui.Color_Blue
    For i = 1 To 2000
        Turtle1.MoveForward(2 - i / 1000)
        Turtle1.TurnLeft(1)
    Next
End Sub

Sub HalfCircle
    Turtle1.Angle = 0
    Turtle1.MoveForward(20)
    For i = 1 To 180
        Turtle1.MoveForward(1)
        Turtle1.TurnLeft(1)
    Next
    Turtle1.MoveForward(20)
End Sub

 

[Alexander Stolte]

In my apprenticeship we started programming with "java hamster". Maybe you can do something similar in B4X but with dogs who has to hide bones or so.

 

[Erel]

Sub Turtle1_Start
    Turtle1.SetPenSize(1).SetSpeedFactor(30)
    Turtle1.SetX(Turtle1.Width / 2).SetY(Turtle1.Height - 100)
    Turtle1.TurnLeft(90)
    Tree(13, 100)
End Sub

Sub Tree (Level As Int, Size As Float)
    If Level > 0 Then
        Turtle1.SetPenSize(Level / 2)
        Turtle1.MoveForward(Size).TurnLeft(10)
        Tree(Level - 1, Size * 0.8)
        Turtle1.TurnRight(40)
        Tree(Level - 1, Size * 0.8)
        Turtle1.TurnLeft(30)
        Turtle1.PenUp.MoveBackward(Size).PenDown
    End If
End Sub

Based on: https://personal.utdallas.edu/~veerasam/logo/

 

[Erel]

Sub Button1_Click
    Turtle1.ClearScreen.MoveHome.SetX(Turtle1.Width / 2 - 100)
    For i = 1 To 3
        Turtle1.SetPenSize(4).SetPenColor(Rnd(xui.Color_Black, xui.Color_White))
        KochCurve(5, 400)
        Turtle1.TurnLeft(120)
    Next
End Sub

Sub KochCurve (Level As Int, Size As Float)
    If Level < 1 Then 
        Turtle1.MoveForward(Size)
        Return
    End If
    KochCurve(Level - 1, Size / 3)
    Turtle1.TurnLeft(60)
    KochCurve(Level - 1, Size / 3)
    Turtle1.TurnRight(120)
    KochCurve(Level - 1, Size / 3)
    Turtle1.TurnLeft(60)
    KochCurve(Level - 1, Size / 3)
End Sub

 

[Erel]

Sub Button1_Click
    Turtle1.ClearScreen.MoveHome
    Dim NumberOfEdges As Int = TextField1.Text
    For i = 1 To NumberOfEdges
        Turtle1.SetPenColor(Rnd(xui.Color_Black, xui.Color_White))
        Turtle1.MoveForward(100)
        Turtle1.TurnLeft(360 / NumberOfEdges)
    Next
End Sub

 

[William Lancee]

Its simple beauty reminds me of a poem by Philip Child I had to study as a child.
"Entelechy"...
"The acorn bears the oak (tree) within itself.
Old chap, the child is father to the man"

 

[Erel]

And now on Android:

 

[walterf25]

Oh man, this is cool, I just started trying to teach my 7 year old daughter, and I can use this now to show her the basic principles, I remember in summer school i took a programming class when I was around 14 years old and we used Logo Writer, which is when I fell in love with programming, great job as always @Erel.

Walter

 

[Erel]

Oh man, this is cool, I just started trying to teach my 7 year old daughter, and I can use this now to show her the basic principles, I remember in summer school i took a programming class when I was around 14 years old and we used Logo Writer, which is when I fell in love with programming, great job as always @Erel.

I will release the first version in a day or two. I will need the help of teachers and parents with this project. Please try it when it is released and post your feedback.

 

[llama]

Erel, you are a star- 80s BBC Turtle style coding - Will take a look and thank you,

 

[rabbitBUSH]

Its simple beauty reminds me of

Those nightmare Recursion exercises in ComSci practice sessions.

I'll have a go at twisting some poor soul's minds if a chance arises.

 

[R D Boozer]

I used to teach Logo to children in the early 1980s. A few years later, I spent some time developing what I considered was a more intuitive alternative to it, but I just let it sit. I didn't actually try to get it out there. Anyway, I'll check out your B4X/Logo hybrid when I get a chance.
Thanks. Your experiments are always interesting.

 

[PCowling]

About 20 years ago when I first started teaching Computing I used to teach fractals in logo to my Year 8 students (12 years old). Love seeing this. As an aside thanks for the algorithms thread and examples, it's brilliant.

In my years teaching I have had two projects completed in B4A as it was, by students, after sharing it with them. Both went onto study Computing at Uni.

 

[Erel]

First version released: https://www.b4x.com/android/forum/threads/🐢-b4xturtle-library-for-teachers-and-parents.116699/