To create a user interface using ModelValueViewContainer from Coad and Nicola:

• Make your View class a subclass of ModelValueViewContainer

  ModelValueViewContainer subclass: #CountWindow
  	instanceVariableNames: ''
  	classVariableNames: ''
  	poolDictionaries: ''
  	category: 'Count Views'
  

• Create a buildView: method to create the View.

  buildViewOn: aCount
  	self addDisplayBoxOn: aCount.
  	self addIncrementButtonOn: aCount.
  	self addDecrementButtonOn: aCount.
  	self addResetButtonOn: aCount.
  

• TO MAKE A DISPLAY BOX:
  1. Use makeDisplayBoxOn:for: to create display box views.
  2. Use constraintFrame:corner: to layout the views.
  3. Use addView:in: to compose the views.

     addDisplayBoxOn: aCount
     	| itemView itemArea |
     	itemView := self makeDisplayBoxOn: aCount for: #value.
     	itemArea := self constraintFrame: 1/3 @ 1/2
     			corner: 2/3 @ 1.
     	self addView: itemView in: itemArea.
     

• TO MAKE A BUTTON:
  1. Use makeButton:on:for: to create buttons.
  2. Use constraintFrame:corner: to layout the views.
  3. Use addView:in: to compose the views.

  addDecrementButtonOn: aCount
  	| button buttonArea |
  	button := self makeButton: 'decrement' 
  		on: aCount for: #decrement.
  	buttonArea := self constraintFrame: 1/3 @ 0
  			corner: 2/3 @ (1/3).
  	self addView: button in: buttonArea.
  
  addIncrementButtonOn: aCount
  	| button buttonArea |
  	button := self makeButton: 'increment' 
  		on: aCount for: #increment.
  	buttonArea := self constraintFrame: 0 @ 0
  			corner: 1/3 @ (1/3).
  	self addView: button in: buttonArea.
  
  addResetButtonOn: aCount
  	| button buttonArea |
  	button := self makeButton: 'reset' on: aCount for: #reset.
  	buttonArea := self constraintFrame: 2/3 @ 0
  			corner: 1 @ (1/3).
  	self addView: button in: buttonArea.
  

• Be sure to send the changed: message to update text views.