// Restores a previously deleted material
public void restoreMaterial(int materialId)
{
// Delete form Db
MaterialModel.restoreMaterial(materialId);
// Remove from deleted list and add to active list
MaterialModel restoredMaterial = deletedMaterialList.Where(mat => mat.materialId == materialId).First();
deletedMaterialList.Remove(restoredMaterial);
materialList.Add(restoredMaterial);
originalMaterialList.Add(restoredMaterial);
// Refilter the materials
filterMaterials();
}