void OnPointerDown(PointerDownEvent e)
{
if (m_Active)
{
e.StopImmediatePropagation();
return;
}
if (CanStartManipulation(e))
{
var ve = (e.currentTarget as VisualElement);
m_Header = ve.GetFirstAncestorOfType <MultiColumnCollectionHeader>();
preview = m_Column.collection.resizePreview;
if (preview)
{
if (m_PreviewElement == null)
{
m_PreviewElement = new MultiColumnHeaderColumnResizePreview();
}
VisualElement previewParent = m_Header.GetFirstAncestorOfType <ScrollView>()?.parent ?? m_Header.parent;
previewParent.hierarchy.Add(m_PreviewElement);
}
columnLayout = m_Header.columnLayout;
m_Start = ve.ChangeCoordinatesTo(m_Header, e.localPosition);
BeginDragResize(m_Start.x);
m_Active = true;
target.CaptureMouse();
e.StopPropagation();
}
}
void Apply(MultiColumnCollectionHeader header)
{
int minCount = Math.Min(m_OrderedColumnStates.Count, header.columns.Count);
int nextValidOrderedIndex = 0;
for (var orderedIndex = 0; (orderedIndex < m_OrderedColumnStates.Count) && (nextValidOrderedIndex < minCount); orderedIndex++)
{
var columnState = m_OrderedColumnStates[orderedIndex];
Column column = null;
// Find column by name
if (!string.IsNullOrEmpty(columnState.name))
{
if (header.columns.Contains(columnState.name))
{
column = header.columns[columnState.name];
}
}
else
{
if (columnState.index > header.columns.Count - 1)
{
continue;
}
column = header.columns[columnState.index];
// If the column has a name then we assume it is not the same column anymore
if (!string.IsNullOrEmpty(column.name))
{
column = null;
}
}
if (column == null)
{
continue;
}
header.columns.ReorderDisplay(column.displayIndex, nextValidOrderedIndex++);
column.visible = columnState.visible;
column.width = columnState.width;
column.desiredWidth = columnState.actualWidth;
}
header.sortDescriptions.Clear();
foreach (var sortDesc in m_SortDescriptions)
{
header.sortDescriptions.Add(sortDesc);
}
}
/// <summary>
/// Saves the state of the specified header control.
/// </summary>
/// <param name="header">The header control of which state will be saved.</param>
void Save(MultiColumnCollectionHeader header)
{
m_SortDescriptions.Clear();
m_OrderedColumnStates.Clear();
foreach (var sortDesc in header.sortDescriptions)
{
m_SortDescriptions.Add(sortDesc);
}
foreach (var column in header.columns.displayList)
{
var columnState = new ColumnState()
{
index = column.index, name = column.name, actualWidth = column.desiredWidth, width = column.width.value, visible = column.visible
};
m_OrderedColumnStates.Add(columnState);
}
}
