/// <summary>
/// Enforces selection rules based on current/maximum length and trying over to next control in a group.
/// </summary>
protected override void OnBeforeSelectionChanged(object sender, DynamicTextSelectionChangedEventArgs args)
{
// Never select the sign
bool?sign = null;
var text = Text;
if (NumberBase == NumericTextBoxNumberBase.Decimal)
{
if (text.StartsWith("+", StringComparison.OrdinalIgnoreCase))
{
sign = true;
}
else if (text.StartsWith("-", StringComparison.OrdinalIgnoreCase))
{
sign = false;
}
}
if (sign.HasValue && args.SelectionStart == 0)
{
args.SelectionStart = 1;
}
// Apply base class rules
base.OnBeforeSelectionChanged(sender, args);
}
/// <summary>
/// Handles the selection changed event.
/// </summary>
private void OnSelectionChanged(object sender, RoutedEventArgs args)
{
// Apply rules
var change = new DynamicTextSelectionChangedEventArgs(this, SelectionStart, SelectionLength);
OnBeforeSelectionChanged(this, change);
// Change focus when necessary
var newFocus = change.Focus;
if (newFocus != this)
{
newFocus.Focus(FocusState.Keyboard);
return;
}
// Set new selection index and length
SelectionStart = change.SelectionStart;
SelectionLength = change.SelectionLength;
// Update cursor
LayoutCursor();
}
/// <summary>
/// Enforces selection rules based on current/maximum length and trying over to next control in a group.
/// </summary>
protected virtual void OnBeforeSelectionChanged(object sender, DynamicTextSelectionChangedEventArgs args)
{
// Move to next control (if any) when at edge...
var nextControl = GroupNext;
var textLength = Text.Length;
var selectedIndex = args.SelectionStart;
var maxLength = MaxLength;
if (maxLength > 0 && selectedIndex >= maxLength && nextControl != null)
{
// Set new control with cursor at start
args.Focus = nextControl;
args.SelectionStart = 0;
args.SelectionLength = 0;
return;
}
// Select one character (over-type) when within text but is at maximum length
if (maxLength > 0 && textLength >= maxLength)
{
// Move back one character at end
if (selectedIndex >= maxLength)
{
args.SelectionStart = selectedIndex - 1;
}
// Select one character
args.SelectionLength = 1;
}
// Over-type when only remaining character is pad character
if (textLength == 1 && PadChar.HasValue && Text == PadChar.Value.ToString())
{
args.SelectionStart = 0;
args.SelectionLength = 1;
}
}
