protected override void OnElementChanged(ElementChangedEventArgs <Slider> e)
{
base.OnElementChanged(e);
if (e.NewElement != null)
{
if (Control == null)
{
var slider = new FormsSlider();
SetNativeControl(slider);
slider.Ready += (sender, args) =>
{
UpdateThumbColor();
UpdateThumbImage();
};
Control.Minimum = e.NewElement.Minimum;
Control.Maximum = e.NewElement.Maximum;
Control.Value = e.NewElement.Value;
Control.IsThumbToolTipEnabled = false;
slider.ValueChanged += OnNativeValueChanged;
defaultforegroundcolor = slider.Foreground;
defaultbackgroundcolor = slider.Background;
// Even when using Center/CenterAndExpand, a Slider has an oddity where it looks
// off-center in its layout by a smidge. The default templates are slightly different
// between 8.1/UWP; the 8.1 rows are 17/Auto/32 and UWP are 18/Auto/18. The value of
// the hardcoded 8.1 rows adds up to 49 (when halved is 24.5) and UWP are 36 (18). Using
// a difference of about 6 pixels to correct this oddity seems to make them both center
// more correctly.
//
// The VerticalAlignment needs to be set as well since a control would not actually be
// centered if a larger HeightRequest is set.
if (Element.VerticalOptions.Alignment == LayoutAlignment.Center && Control.Orientation == Microsoft.UI.Xaml.Controls.Orientation.Horizontal)
{
Control.VerticalAlignment = Microsoft.UI.Xaml.VerticalAlignment.Center;
slider.Margin = WinUIHelpers.CreateThickness(0, 7, 0, 0);
}
_pointerPressedHandler = new PointerEventHandler(OnPointerPressed);
_pointerReleasedHandler = new PointerEventHandler(OnPointerReleased);
Control.AddHandler(PointerPressedEvent, _pointerPressedHandler, true);
Control.AddHandler(PointerReleasedEvent, _pointerReleasedHandler, true);
Control.AddHandler(PointerCanceledEvent, _pointerReleasedHandler, true);
}
double stepping = Math.Min((e.NewElement.Maximum - e.NewElement.Minimum) / 1000, 1);
Control.StepFrequency = stepping;
Control.SmallChange = stepping;
UpdateFlowDirection();
UpdateSliderColors();
}
}
public static void SetForeground(this FrameworkElement element, WBrush foregroundBrush)
{
if (element == null)
{
throw new ArgumentNullException("element");
}
element.SetValue(GetForegroundProperty(element), foregroundBrush);
}
void ControlOnLoaded(object sender, RoutedEventArgs routedEventArgs)
{
WireUpFormsVsm();
// The defaults from the control template won't be available
// right away; we have to wait until after the template has been applied
_defaultBrush = Control.Foreground;
_defaultFontFamily = Control.FontFamily;
UpdateFont();
UpdateTextColor();
}
void SetDefaultSwitchColor()
{
if (_defaultOnColor == null && Cell is SwitchCell)
{
var nativeSwitch = FrameworkElementExtensions.GetFirstDescendant <ToggleSwitch>(this);
var rects = nativeSwitch.GetDescendantsByName <Microsoft.UI.Xaml.Shapes.Rectangle>("SwitchKnobBounds");
foreach (var rect in rects)
{
_defaultOnColor = rect.Fill;
}
UpdateOnColor();
}
}
void UpdateButtonBackgroundColor(Color value)
{
WBrush brush = value.ToBrush();
_minus = GetTemplateChild("Minus") as Microsoft.UI.Xaml.Controls.Button;
_plus = GetTemplateChild("Plus") as Microsoft.UI.Xaml.Controls.Button;
if (_minus != null)
{
_minus.Background = brush;
}
if (_plus != null)
{
_plus.Background = brush;
}
}
void UpdateButtonBackgroundColor(Color value)
{
if (value == null)
{
return;
}
WBrush brush = Maui.ColorExtensions.ToNative(value);
_minus = GetTemplateChild("Minus") as Microsoft.UI.Xaml.Controls.Button;
_plus = GetTemplateChild("Plus") as Microsoft.UI.Xaml.Controls.Button;
if (_minus != null)
{
_minus.Background = brush;
}
if (_plus != null)
{
_plus.Background = brush;
}
}
