open System.Windows.Forms
open System.Drawing
let f = new Form(Text="Paint biatch", TopMost=true,Height=700,Width=1000)
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
let mutable pns= Pens.Red
let mutable rectMode= false
let mutable x0,y0=0,0
let mutable  ellisMode = false
let mutable  penMode = false

f.MouseDown.Add(fun e->
    click<-true
    if rectMode ||  ellisMode then
        x0<-e.Location.X
        y0<-e.Location.Y
)

f.MouseUp.Add(fun e->
    click<-false
    if rectMode then
        g.DrawRectangle(pns,x0,y0,e.Location.X-x0,e.Location.Y-y0)
    if ellisMode then
        g.DrawEllipse(pns,x0,y0,e.Location.X-x0,e.Location.Y-y0)

)


f.MouseMove.Add(fun e->

x<-e.Location.X
y<-e.Location.Y
if click && rectMode=false && ellisMode=false 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
    pns<-Pens.Black

)

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


btnColor2.Click.Add(fun e ->
    bru<-Brushes.Red
    pns<-Pens.Black

)

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


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

)

let btnRect= new Button(Text="rect",Dock=DockStyle.Right)
pan1.Controls.Add(btnRect)


btnRect.Click.Add(fun e ->
   rectMode<-true
   ellisMode<-false
   penMode<-false
)

let btnEllise= new Button(Text="ellisse",Dock=DockStyle.Right)
pan1.Controls.Add(btnEllise)


btnEllise.Click.Add(fun e ->
   rectMode<-false
   ellisMode<-true
   penMode<-false
)


let btnPen= new Button(Text="DarwMode",Dock=DockStyle.Right)
pan1.Controls.Add(btnPen)


btnPen.Click.Add(fun e ->
   rectMode<-false
   ellisMode<-false
   penMode<-true
)