// TODO:绑定事件

function setAll(){

  if(selectAll.prop('checked')){

    selectAllLabel.hide();

    deselectAllLabel.show();

    langs.prop('checked',true);

  }

  else{

    selectAllLabel.show();

    deselectAllLabel.hide();

    langs.prop('checked',false);

  }

}

selectAll.change(setAll);

function inverse(){

  langs.get().forEach(function(x){x.checked = !x.checked;});

  checkAll();

}

invertSelect.click(inverse);

function checkAll(){

  var allchecked = langs.get().every(x=>x.checked);

  if(allchecked){

    selectAllLabel.hide();

    deselectAllLabel.show();

    selectAll.prop('checked',true);

  }

  else{

    selectAllLabel.show();

    deselectAllLabel.hide();

    selectAll.prop('checked',false);

  }

}

langs.change(checkAll);