/************************************************************************/
#region Internal methods
/// <summary>
/// Saves the current values of display index in the attached property
/// </summary>
internal void SaveDisplayIndex()
{
foreach (DataGridColumn column in this)
{
DataGridColumns.SetDisplayIndex(column, column.DisplayIndex);
}
}
/// <summary>
/// Restores the values of display index from the attached property
/// </summary>
internal void RestoreDisplayIndex()
{
foreach (DataGridColumn column in this)
{
int displayIndex = DataGridColumns.GetDisplayIndex(column);
if (displayIndex != -1)
{
column.DisplayIndex = displayIndex;
}
}
}
/************************************************************************/
#region Methods (column state)
/// <summary>
/// Gets a string that represents the state of the columns
/// </summary>
/// <returns>
/// A string that describes the state of this column collection
/// </returns>
public string GetColumnState()
{
StringBuilder builder = new StringBuilder();
foreach (DataGridColumn column in this)
{
int isVisible = column.Visibility == Visibility.Visible ? 1 : 0;
ListSortDirection?direction = DataGridColumns.GetSortDirection(column);
int sort = direction.HasValue ? (int)direction.Value + 1 : 0;
builder.Append($"{column.DisplayIndex};{isVisible};{sort},");
}
if (builder.Length > 0)
{
/* remove last comma */
builder.Remove(builder.Length - 1, 1);
}
return(builder.ToString());
}
/// <summary>
/// Restores the column state using the specified string.
/// </summary>
/// <param name="state">The state string</param>
/// <remarks>
/// Use the string obtained by <see cref="GetColumnState"/> to restore
/// </remarks>
public void RestoreColumnState(string state)
{
if (!string.IsNullOrWhiteSpace(state))
{
string[] cols = state.Split(',');
for (int idx = 0; idx < cols.Length; idx++)
{
if (idx < Count)
{
string[] parms = cols[idx].Split(';');
if (parms.Length > 0)
{
if (int.TryParse(parms[0], out int displayIndex))
{
this[idx].DisplayIndex = displayIndex;
}
}
if (parms.Length > 1)
{
if (int.TryParse(parms[1], out int isVisible))
{
this[idx].Visibility = isVisible == 0 ? Visibility.Collapsed : Visibility.Visible;
}
}
if (parms.Length > 2)
{
/* direction is stored 1 greater than its value so zero can signify none */
if (int.TryParse(parms[2], out int direction) && direction > 0)
{
ClearColumnSortDirections();
DataGridColumns.SetSortDirection(this[idx], (ListSortDirection)(direction - 1));
}
}
}
}
}
}
