open System.Windows.Forms
open System.Drawing
let f = new Form(Text="Paint biatch", TopMost=true)
f.Show()
let mutable g= Graphics.FromHwnd(f.Handle)
let mutable click= false
let mutable x=0
let mutable y=0
let mutable size=10
let mutable bru= Brushes.Red

f.MouseDown.Add(fun e->
    click<-true
)

f.MouseUp.Add(fun e->
    click<-false
)


f.MouseMove.Add(fun e->

x<-e.Location.X
y<-e.Location.Y
if click then
    g.FillEllipse(bru,x-(size/2),y-(size/2),size,size)
)

f.Resize.Add(fun e->

    g<- Graphics.FromHwnd(f.Handle)
)

let pan1= new Panel(Dock=DockStyle.Top)
f.Controls.Add(pan1)

let invBtn= new Button(Text="ClearAll",Dock=DockStyle.Left)
pan1.Controls.Add(invBtn)
let sizeBtn= new Button(Text="change size",Dock=DockStyle.Left)
pan1.Controls.Add(sizeBtn)
let sizeBox= new TextBox(Dock=DockStyle.Left)
pan1.Controls.Add(sizeBox)

invBtn.Click.Add(fun e ->
    f.Invalidate()

)


let asas= ref 10
sizeBtn.Click.Add(fun e ->
    if System.Int32.TryParse(sizeBox.Text,asas ) then
        size<-asas.Value
        sizeBox.Text<-""

)

let btnColor1= new Button(BackColor=Color.Black,Dock=DockStyle.Right)
pan1.Controls.Add(btnColor1)


btnColor1.Click.Add(fun e ->
    bru<-Brushes.Black
)

let btnColor2= new Button(BackColor=Color.Red,Dock=DockStyle.Right)
pan1.Controls.Add(btnColor2)


btnColor2.Click.Add(fun e ->
    bru<-Brushes.Red
)

let btnColor3= new Button(BackColor=Color.Green,Dock=DockStyle.Right)
pan1.Controls.Add(btnColor3)


btnColor3.Click.Add(fun e ->
    bru<-Brushes.Green
)