The first step in defining a floating view is to create the content nodes that define wht the view looks like. These nodes need to overlay venkman.xul and venkman-floater.xul, because XUL does not support moving nodes between documents.

Content nodes for the ``Breakpoint View'', from venkman-views.xml...
    <!-- breakpoint view -->

    <floatingview id="breaks" title="&Break.label;" flex="1">
      <vbox id="break-view-content" flex="1">
        <tree flex="1" id="break-tree" persist="height" hidecolumnpicker="true"

            <treecol id="breaks:col-0" label="&BreakCol0.label;"
              primary="true" flex="5" persist="hidden width"/>
            <splitter class="tree-splitter"/>
            <treecol id="breaks:col-1" flex="1" label="&BreakCol1.label;"
              persist="hidden width"/>
            <splitter class="tree-splitter"/>

          <treechildren id="break-body"/>