/// <summary>
/// Handles only single selection with keyboard.
/// </summary>
public void HandleKeyUp(int selectedIndex)
{
OnSelectionNotReady?.Invoke(this, EventArgs.Empty);
Listbox.SelectedIndexChanged -= Listbox_SelectedIndexChanged;
Listbox.SelectedIndex = selectedIndex;
if (Listbox.SelectedIndex == -1)
{
OnSelectionReady?.Invoke(this, EventArgs.Empty);
}
else
{
_mouseDownIndex = selectedIndex;
_mouseUpIndex = selectedIndex;
SelectionOld = GetListboxItemsSelection(Listbox.Items.Count, Listbox.SelectedIndices);
SelectedItemsOrdered?.Clear();
SelectedItemsOrdered = new List <string> {
Listbox.SelectedItem.ToString()
};
SelectedIndexesOrdered?.Clear();
SelectedIndexesOrdered = new List <int> {
Listbox.SelectedIndex
};
HandleSelectionChange();
OnSelectionReady?.Invoke(this, EventArgs.Empty);
}
Listbox.SelectedIndexChanged += Listbox_SelectedIndexChanged;
}
public void Cancel(bool unsubscribeToEvents = true)
{
if (unsubscribeToEvents)
{
UnsubscribeToEvents();
Listbox = null;
}
SelectedIndexesOrdered?.Clear();
SelectedItemsOrdered?.Clear();
_mouseDownIndex = -1;
_posY = -1;
_ctrlPressed = false;
_shiftPressed = false;
_mouseUpIndex = -1;
SelectionOld = null;
_shiftSelectionStartIndex = -1;
}
/// <summary>
/// Returns the selection in order they were selected. Handles all combinations of selections with mouse click, ctrl
/// click, shift click and
/// combinations of them. It also supports selecting with dragging and selecting items. It DOES NOT support dragging +
/// ctrl or shift pressed.
/// </summary>
/// <param name="selectionType"></param>
/// <param name="itemsSelection"></param>
/// <param name="selectedIndexesOrderedOld"></param>
/// <param name="mouseDownIndex"></param>
/// <param name="mouseUpIndex"></param>
/// <param name="listbox"></param>
/// <returns></returns>
private List <int> GetSelectedIndexesInOrder(HowSelectionHasChanged selectionType,
IReadOnlyCollection <bool> itemsSelection, List <int> selectedIndexesOrderedOld, int mouseDownIndex,
int mouseUpIndex, ListBox listbox)
{
var output = new List <int>();
switch (selectionType)
{
case HowSelectionHasChanged.Error: break;
case HowSelectionHasChanged.NoChange:
output = selectedIndexesOrderedOld;
break;
case HowSelectionHasChanged.WithClick:
SelectedIndexesOrdered?.Clear();
output.Add(mouseUpIndex);
_shiftSelectionStartIndex = mouseUpIndex;
break;
case HowSelectionHasChanged.WithClickDrag:
mouseUpIndex =
SpecialCase_CheckIfDragSelectionEndedOutsideFormAndCorrectMouseUpIndex(mouseUpIndex,
itemsSelection, listbox);
mouseDownIndex =
SpecialCase_CheckIfDragSelectionStartedOutsideFormAndCorrectMouseDownIndex(mouseDownIndex,
itemsSelection, listbox);
if (mouseDownIndex < mouseUpIndex)
{
output.AddRange(MakeSelection(mouseDownIndex, mouseUpIndex, true));
}
else if (mouseDownIndex > mouseUpIndex)
{
output.AddRange(MakeSelection(mouseUpIndex, mouseDownIndex, false));
}
else
{
output.Add(mouseDownIndex);
}
_shiftSelectionStartIndex = mouseDownIndex;
break;
case HowSelectionHasChanged.IncreaseWithCtrLandClick:
case HowSelectionHasChanged.DecreaseWithCtrLandClick:
output.AddRange(IndexSelectOrDeselect(selectedIndexesOrderedOld, mouseUpIndex));
_shiftSelectionStartIndex = mouseUpIndex;
break;
case HowSelectionHasChanged.WithCtrLandClickDrag:
case HowSelectionHasChanged.WithShiftAndClickDrag:
case HowSelectionHasChanged.WithShiftAndCtrlClickDrag:
output.AddRange(selectedIndexesOrderedOld);
RevertSelection(ref listbox, selectedIndexesOrderedOld);
SelectedIndexesOrdered.Clear();
break;
case HowSelectionHasChanged.WithShiftAndClick:
if (_shiftSelectionStartIndex < mouseUpIndex)
{
output.AddRange(MakeSelection(_shiftSelectionStartIndex, mouseUpIndex, true));
}
else if (_shiftSelectionStartIndex > mouseUpIndex)
{
output.AddRange(MakeSelection(mouseUpIndex, _shiftSelectionStartIndex, false));
}
listbox.SetSelected(_shiftSelectionStartIndex,
true); //this is not set if item earlier deselected with ctrl.
break;
case HowSelectionHasChanged.WithShiftAndCtrlClick:
output.AddRange(selectedIndexesOrderedOld);
if (_shiftSelectionStartIndex < mouseUpIndex)
{
output.AddRange(MakeSelection(_shiftSelectionStartIndex + 1, mouseUpIndex,
true)); //+1 is because it is added already
}
else if (_shiftSelectionStartIndex > mouseUpIndex)
{
output.AddRange(MakeSelection(mouseUpIndex, _shiftSelectionStartIndex - 1,
false)); //-1 is because it is added already
}
listbox.SetSelected(_shiftSelectionStartIndex,
true); //this is not set if item earlier deselected with ctrl.
break;
default:
throw new ArgumentOutOfRangeException(nameof(selectionType), selectionType, null);
}
return(output);
}
