/// <summary>
/// Presents the user with a dialog box for managing the columns.
/// </summary>
/// <param name="sender">The object that originated the event.</param>
/// <param name="e">The event data.</param>
void OnMore(Object sender, ExecutedRoutedEventArgs e)
{
// This will extract the context menu that generated this event from the generic arguments.
ContextMenu contextMenu = sender as ContextMenu;
// From the context menu, we need the target that orignated the event and from that we can finally get the column set on which we want to operate.
ColumnViewColumnHeader columnViewColumnHeader = contextMenu.PlacementTarget as ColumnViewColumnHeader;
ListView listView = VisualTreeExtensions.FindAncestor <ListView>(columnViewColumnHeader);
ColumnView columnView = listView.View as ColumnView;
// This dialog box is used to add, remove, move or resize the columns in the view. It can't operate directly on the set of columns because those are
// linked dynamically to the view, so we'll create a shallow clone of the values.
ColumnViewChooseDetail columnViewChooseDetail = new ColumnViewChooseDetail();
foreach (ColumnViewColumn columnViewColumn in columnView.Columns)
{
columnViewChooseDetail.ListBox.Items.Add(new ColumnDescription(columnViewColumn));
}
// Present the user with the chance to manage the columns. If the OK key is hit then copy the values out of the shallow copy and into the live column
// set where they'll update the view.
if (columnViewChooseDetail.ShowDialog() == true)
{
foreach (ColumnDescription columnDescription in columnViewChooseDetail.ListBox.Items)
{
ColumnViewColumn columnViewColumn = columnDescription.Column;
columnViewColumn.IsVisible = columnDescription.IsVisible;
columnViewColumn.Width = columnDescription.Width;
}
}
}
/// <summary>
/// Handles a change to the Column property.
/// </summary>
/// <param name="dependencyObject">The object that originated the event.</param>
/// <param name="dependencyPropertyChangedEventArgs">The property change event arguments.</param>
static void OnColumnPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
{
// Extract the ColumnViewColumnHeader and the property from the generic event arguments.
ColumnViewColumnHeader columnViewColumnHeader = dependencyObject as ColumnViewColumnHeader;
ColumnViewColumn columnViewColumn = dependencyPropertyChangedEventArgs.NewValue as ColumnViewColumn;
// This will force the sorting properties to reflect the sort order of the underlying column.
columnViewColumnHeader.UpdateSortDirection();
// This will keep the header property 'HasFilters' reconciled to the same property in the column it represents.
columnViewColumnHeader.SetValue(ColumnViewColumnHeader.hasFiltersPropertyKey, columnViewColumnHeader.Column.HasFilters);
}
/// <summary>
/// Handles a change to the dependency properties.
/// </summary>
/// <param name="dependencyObject">The object that originated the event.</param>
/// <param name="dependencyPropertyChangedEventArgs">The event arguments.</param>
static void OnIsSelectedPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
{
// The filter is closed when the selection is turned off. The selection is a property that combines the keystrokes and the mouse gestures into a single
// state the shows the menu header has been selected by the user for some operation. The visual cues for the header are driven by this property and so
// is the state of the filter drop down.
ColumnViewColumnHeader columnViewColumnHeader = dependencyObject as ColumnViewColumnHeader;
if ((Boolean)dependencyPropertyChangedEventArgs.OldValue)
{
if (columnViewColumnHeader.IsFilterOpen)
{
columnViewColumnHeader.SetValue(ColumnViewColumnHeader.IsFilterOpenProperty, false);
}
}
}
/// <summary>
/// Occurs when a particular instance of a context menu opens.
/// </summary>
/// <param name="sender">The object where the event handler is attached.</param>
/// <param name="e">The event data.</param>
void OnOpened(Object sender, RoutedEventArgs e)
{
// Extract the context menu from the generic event arguments.
ContextMenu contextMenu = sender as ContextMenu;
// We're going to clean out the context menu and re-evaluate the contents based on the context where the menu was opened.
contextMenu.Items.Clear();
// This is the header that opened the context menu. From it, we need the ListView that hosts the ColumnView (that contains all the columns that we're
// trying to manage with this context menu).
ColumnViewColumnHeader columnViewColumnHeader = contextMenu.PlacementTarget as ColumnViewColumnHeader;
ListView listView = VisualTreeExtensions.FindAncestor <ListView>(columnViewColumnHeader);
ColumnView columnView = listView.View as ColumnView;
// The task now is to fill in the menu items. We don't allow the user to resize a padding column, but will allow them to resize all the columns.
if (columnViewColumnHeader.Role != ColumnViewColumnHeaderRole.Padding)
{
this.Items.Add(new MenuItem()
{
Command = Commands.FitColumn, CommandTarget = columnViewColumnHeader, Header = "Size Column to Fit"
});
}
this.Items.Add(new MenuItem()
{
Command = Commands.FitAllColumns, CommandTarget = listView, Header = "Size All Columns to Fit"
});
this.Items.Add(new Separator());
// This will order the fixed menu items by their ordinal. An 'ordinal' is a numeric value that the designer can assign to the fixed menu items to
// determine the order (or even if they'll appear) as a fixed menu item (that is, a quick way to add or remove a column, as opposed to selecting the
// 'More...' button and using the list box to select an column).
SortedList <Int32, ColumnViewColumn> commonColumns = new SortedList <Int32, ColumnViewColumn>();
foreach (ColumnViewColumn columnViewColumn in columnView.Columns)
{
if (columnViewColumn.Ordinal.HasValue && !commonColumns.ContainsKey(columnViewColumn.Ordinal.Value))
{
commonColumns.Add(columnViewColumn.Ordinal.Value, columnViewColumn);
}
}
// This will create a dedicated menu item for each of the columns that has been assigned an 'ordinal'. This allows the user to quickly add or remove
// frequently used columns. Note that we attempt to format the column headers the way they would appear in the actual column header.
foreach (KeyValuePair <Int32, ColumnViewColumn> keyValuePair in commonColumns)
{
ColumnViewColumn columnViewColumn = keyValuePair.Value;
MenuItem menuItem = new MenuItem();
Binding isVisibleBinding = new Binding()
{
Path = new PropertyPath(ColumnViewColumn.IsVisibleProperty)
};
isVisibleBinding.Source = columnViewColumn;
BindingOperations.SetBinding(menuItem, MenuItem.IsCheckedProperty, isVisibleBinding);
menuItem.Header = columnViewColumn.Description;
menuItem.IsCheckable = true;
this.Items.Add(menuItem);
}
// Place a separator in the context menu if there is a section above it with dedicated menu items for the column visibility settings.
if (commonColumns.Count != 0)
{
this.Items.Add(new Separator());
}
// Finally, a general purpose dialog box for managing the column set.
this.Items.Add(new MenuItem()
{
Command = Commands.More, Header = "More..."
});
}