In smalltalk$/$squeak language write a counter that uses the MVC$-$tutorial$.$ I cannot get it working to save my life. Here is the tutorial$-$ Case Study: The Counter View

$-$ Here's a simple example where:

$-$ The model $($an instance of $`$Counter$`)$ is a simple numeric value

$-$ The view $($an instance of $`$CounterView$`$ shows the value of what is

represented by $`$Counter$`$

$-$ And the controller $($an instance of $`$CounterController$`$ implements a

menu allowing one to increment or decrement the $`$Counter$`\text{'}$s value.

Change set for running this demo in Squeak:

$```$smalltalk

Model subclass: #Counter

instanceVariableNames: 'value $\text{'}$

classVariableNames: $\text{'}\text{'}$

poolDictionaries: $\text{'}\text{'}$

category: $\text{'}$MVC$-$Tutorial'!

MouseMenuController subclass: #CounterController

instanceVariableNames: $\text{'}\text{'}$

classVariableNames: $\text{'}\text{'}$

poolDictionaries: $\text{'}\text{'}$

category: $\text{'}$MVC$-$Tutorial'!

View subclass: #CounterView

instanceVariableNames: $\text{'}\text{'}$

classVariableNames: $\text{'}\text{'}$

poolDictionaries: $\text{'}\text{'}$

category: $\text{'}$MVC$-$Tutorial'!

$!$CounterView commentStamp: $\text{'}$BG $10/27/200315$:$43\text{'}$ prior: $0!$

This is the view for the first example from the MVC tutorial from Kranser and Pope.

To open the simple counter window, execute this statement:

CounterView open

The menu of the counter is called with the left mouse button.

To open the enhanced couter window, execute this statement:

CounterView openWithGraphicalButtons!

$!$Counter methodsFor: 'accessing' stamp: $\text{'}$BG $10/27/200312$:$51\text{'}!$

value

$"$ Answer the current value of the receiver"

$^$value! $!$

$!$Counter methodsFor: 'accessing' stamp: $\text{'}$BG $10/27/200312$:$52\text{'}!$

value: aNumber

$"$ Initialize the counter to value aNumber"

value :$=$ aNumber.

self changed. $"$ to update displayed value $"!!$

$!$Counter methodsFor: 'initialize$-$release' stamp: $\text{'}$BG $10/27/200312$:$51\text{'}!$

initialize

$"$ Set the intitial value to $0."$

self value: $0.!!$

$!$Counter methodsFor: 'operations' stamp: $\text{'}$BG $10/27/200312$:$52\text{'}!$

decrement

$"$ subtract $1$ from the value of the counter $"$

self value: value $-1.!!$

$!$Counter methodsFor: 'operations' stamp: $\text{'}$BG $10/27/200312$:$52\text{'}!$

increment

$"$ add $1$ to the value of the counter $"$

self value: value $+1.!!$

$!$Counter class methodsFor: 'instance creation' stamp: $\text{'}$BG $10/27/200312$:$53\text{'}!$

new

$"$ Answer an initialized instance of the receiver"

$^$super new initialize $"$ return a new instance"! $!$

$!$CounterController methodsFor: 'control defaults' stamp: $\text{'}$BG $10/27/200313$:$01\text{'}!$

isControlActive

$^$super isControlActive & sensor blueButtonPressed not! $!$

$!$CounterController methodsFor: 'initialize$-$release' stamp: $\text{'}$BG $10/27/200312$:$59\text{'}!$

initialize

"initialize a manue of commands for changing the value of the model"

super initialize.

self redButtonMenu:

$($PopUpMenu labels: 'increment$\backslash$decrement$\text{'}$ withCRs$)$

redButtonMessages: #$($increment decrement$)$

$"$ here we use the red button menu $"!!$

$!$CounterController methodsFor: 'menu messages' stamp: $\text{'}$BG $10/27/200313$:$00\text{'}!$

decrement

$"$ subtract $1$ from the value of the counter $"$

self model decrement! $!$

$!$CounterController methodsFor: 'menu messages' stamp: $\text{'}$BG $10/27/200313$:$00\text{'}!$

increment

$"$ add $1$ to the value of the counter $"$

self model increment! $!$

$!$CounterController methodsFor: 'pluggable menus' stamp: $\text{'}$BG $10/27/200313$:$17\text{'}!$

getPluggableYellowButtonMenu: shiftKeyState

$^$ nil! $!$

$!$CounterView methodsFor: 'controller access' stamp: $\text{'}$BG $10/27/200313$:$04\text{'}!$

defaultControllerClass

$"$ answer the class of a typically useful controller"

$^$CounterController.

$!!$

$!$CounterView methodsFor: 'displaying' stamp: $\text{'}$BG $10/27/200314$:$34\text{'}!$

displayView

$|$ box pos displayText $|$

box :$=$ self insetDisplayBox.

pos :$=$ box origin $+(4$ @ $(($box extent y $/3)$ rounded$)).$

displayText :$=(\text{'}$value: $\text{'},$ self model value printString$)$ asDisplayText.

displayText foregroundColor: Color black

backgroundColor: Color white.

displayText displayAt: pos.! $!$

$!$CounterView methodsFor: 'updating' stamp: $\text{'}$BG $10/27/200313$:$03\text{'}!$

update: aParameter

"simply redislplay everything"

self display.! $!$

$!$CounterView class methodsFor: 'instance creation' stamp: $\text{'}$BG $10/27/200313$:$09\text{'}!$

open

$"$ open a view for a new counter"

$"$ select and execute this comment to test this method:"

"CounterView open"

$|$ aCounterView topView $|$

aCounterView :$=$ CounterView new

model: Counter new.

aCounterView borderWidth: $2.$

aCounterView insideColor: Color white.

topView :$=$ StandardSystemView new

label: 'Counter'.

topView minimumSize: $80$ @ $40$;

maximumSize: $120$ @ $100.$

topView addSubView: aCounterView.

topView controller open

$!!$

$!$CounterView class methodsFor: 'instance creation' stamp: $\text{'}$BG $10/27/200315$:$41\text{'}!$

openWithGraphicalButtons

$"$ open a view for a new counter"

$"$ select and execute this comment to test this method:"

"CounterView openWithGraphicalButtons"

$|$ aCounterView topView incrButton decrButton

incrSwitchView decrSwitchView dt textStyle $|$

aCounterView :$=$ CounterView new

model: Counter new.

aCounterView borderWidthLeft: $1$ right: $2$ top: $2$ bottom: $2.$

aCounterView insideColor: Color white.

topView :$=$ ColorSystemView new

label: 'Counter'.

topView minimumSize