public final void setButtonsEnabled(boolean enabled) {
    referencesPanel.setButtonsEnabled(enabled);
    hierarchiesPanel.setButtonsEnabled(enabled);
    supplierPricelistPanel.setButtonsEnabled(enabled);

    insertButton1.setEnabled(enabled);
    editButton1.setEnabled(enabled);
    deleteButton1.setEnabled(enabled);
    exportButton1.setEnabled(enabled);

    treePanel.setEnabled(enabled);
  }