title: Create Mousedownevent on contenteditable HTML
body: <p>Trying to implement a custom widget extending HTML.
  It has contenteditable set to true and shall support setting the caret below the mouse on hovering over.
  For this purpose, I want to fire a programmatic Mousedown event.</p>
  
  <pre><code>void calledWithNativeEventFromHovering(NativeEvent nativeEvent){
  
      NativeEvent mouseDownEvent = Document.get().createMouseDownEvent( 1, nativeEvent.getScreenX(), nativeEvent.getScreenY(), nativeEvent.getClientX(), nativeEvent.getClientY(), false, false, false, false, NativeEvent.BUTTON_LEFT );
  
      //Variant 1
      DomEvent.fireNativeEvent( mouseDownEvent, this, getElement() );
  
      //Variant 2
      getElement().dispatchEvent( mouseDownEvent );
  }
  </code></pre>
  
  <p>It does not trigger setting the caret, however I can catch both events with a mousedown handler.
  For debugging purposes, I looked at the respective native events.</p>
  
  <p><em>Actual mousedown click: preventDefault: false, currentTarget: element of the widget</em></p>
  
  <p><em>Variant 1: preventDefault: false, currentTarget: null</em></p>
  
  <p><em>Variant 2: preventDefault: true, currentTarget: element of the widget</em></p>
  
  <p>How to create a Native MouseDownEvent which acts exactly like the one from an actual clickdown? Open for JSNI suggestions, too.</p>