layout_weight visibility android **http://schemas.android.com/apk/res/android app ''http://schemas.android.com/apk/res-auto style 22android.support.v7.internal.widget.ButtonBarLayout ?attr/buttonBarStyle Button !!?attr/buttonBarNeutralButtonStyle android.support.v4.widget.Space ""?attr/buttonBarNegativeButtonStyle ""?attr/buttonBarPositiveButtonStyle <