title: How can I retrieve the value of a PASTE (copy-pasta) event in a GWT TextBox?
body: <p>Hello fellow SO members,</p>
  
  <p>I want to prevent the user from copy-pasting values in my TextBox IF AND ONLY IF the values do not respect a certain condition.</p>
  
  <p>For instance, I created a DigitsOnlyTextBox which will be used for phone numbers.
  I already made it so only <code>Character.isDigit</code> characters can be typed into the box, and the user cannot copy-paste values into it, using :</p>
  
  <pre><code>this.sinkEvents(Event.ONPASTE);
  </code></pre>
  
  <p>and</p>
  
  <pre><code>public void onBrowserEvent(Event event) {
      super.onBrowserEvent(event);
  
      // Permet d'empêcher le copier-coller, donc d'entrer des caractères non-numériques
  
      if (event.getTypeInt() == Event.ONPASTE) {
          event.stopPropagation();
          event.preventDefault();
      }
  }
  </code></pre>
  
  <p>But I'd like to verify if the copy-pasted String is "digits only" and if so, let the event happen (therefore the text added).</p>
  
  <p>tl;dr :
  see title</p>
  
  <p>Thank you for your time.
  Sincerely.</p>