title: mouse events on image in smalltalk
body: <p>I have the following class in small talk</p>
  
  <pre><code>Object subclass: #SnookerBall
      instanceVariableNames: 'image type position'
      classVariableNames: ''
      poolDictionaries: ''
      category: 'mmn16'
  
  initialize
      self initialize.
      image := ImageMorph new image: (Form fromFileNamed: 'ball_1.gif').
      image position:100@100.
  </code></pre>
  
  <p>now I want to implement the mouse events on the image. 
  basically I need to simulate a snooker ball.
  So I need the mouse events (clicked, dragged and so on) and make it look animated.</p>
  
  <p>Please help
  Thank you in advanced</p>
  
  <p>Ok I have a SnookerBall class edited </p>
  
  <pre><code>ImageMorph subclass: #SnookerBall
      instanceVariableNames: ''
      classVariableNames: ''
      poolDictionaries: ''
      category: 'Snooker'
  </code></pre>
  
  <p>and initialize method</p>
  
  <pre><code>initialize
      self image: (Form fromFileNamed: 'ball_1.gif');
      extent:40@40;
      position:0@0.
  </code></pre>
  
  <p>I'm trying to execute:</p>
  
  <pre><code>b:=SnookerBall new.
  b openInWorld.
  </code></pre>
  
  <p>and I have an error : MessageNotUnderstood: UndefinedObject>>hasPositiveExtent</p>
  
  <p>please help</p>