if service.isSeekBar(node)
return false
elseif service.isEditView(node) and service.isShowInputWindow()
if service.toPreviousWord()
return true
else
service.beep()
 end
elseif service.isShowInputWindow()
service.getEditText()
elseif tostring(service.getCustomActions(node))~="[]"
service.execute("上个导航类型",node)
else
return false
end
return true