def show(self, parent=None):
        """Show the tree view if not already show.  If optional
        `parent` widget is passed, the tree is displayed inside the
        passed parent widget."""
        # If UI already exists, raise it and return.
        if self.ui and self.ui.control:
            try:
                self.ui.control.Raise()
            except __HOLE__:
                pass
            else:
                return
        else:
            # No active ui, create one.
            if parent:
                self.ui = self.view.ui(self, parent=parent, kind='subpanel')
            else:
                self.ui = self.view.ui(self, parent=parent)
dataset/ETHPy150Open enthought/mayavi/tvtk/pipeline/browser.py/PipelineBrowser.show