<canvas height="100">
   <simplelayout inset="10" spacing="10"/>
 
   <checkbox>Lock mouse events
     <handler name="onvalue">
       if (this.value){
         
       } 
     </handler>
 
     <handler name="onclick" reference="LzGlobalMouse" args="who">
       <![CDATA[ 
       //need to use LzGlobalMouse, since we don't get clicks if we're
       //checked. NB that LzGlobalMouse sends its events before the view
       //receives the events, so we can just unlock it here, and the
       //checkbox can do its normal onclick handling.
       if (this.value && who == this){
         
       }
       ]]>
     </handler>
   </checkbox>
 
   <button>click me!</button>
 
   <text resize="true">
     <method name="showEvent" args="what, who">
       this.setText(what +": " + who);
     </method>
 
     <handler name="onmouseover" reference="" args="who">
       this.showEvent("mouseover" , who);
     </handler>
     <handler name="onmouseout" reference="" args="who">
       this.showEvent("mouseout" , who);
     </handler>
 
     <handler name="onmousedown" reference="" args="who">
       this.showEvent("mousedown" , who);
     </handler>
     <handler name="onmouseup" reference="" args="who">
       this.showEvent("mouseup" , who);
     </handler>
 
     <handler name="onclick" reference="" args="who">
       this.showEvent("mouseclick" , who);
     </handler>
   </text>
 </canvas>