Ooui-tws-port/Ooui.Forms/Renderers/SwitchRenderer.cs

99 lines
3.0 KiB
C#

using System;
using Xamarin.Forms;
namespace Ooui.Forms.Renderers
{
public class SwitchRenderer : ViewRenderer<Switch, SwitchRenderer.SwitchElement>
{
public override SizeRequest GetDesiredSize (double widthConstraint, double heightConstraint)
{
var size = new Size (54, 38);
return new SizeRequest (size, size);
}
protected override void Dispose (bool disposing)
{
if (disposing)
Control.Change -= OnControlValueChanged;
base.Dispose (disposing);
}
protected override void OnElementChanged (ElementChangedEventArgs<Switch> e)
{
if (e.OldElement != null)
e.OldElement.Toggled -= OnElementToggled;
if (e.NewElement != null) {
if (Control == null) {
var input = new SwitchElement ();
SetNativeControl (input);
Control.Change += OnControlValueChanged;
}
Control.IsChecked = Element.IsToggled;
e.NewElement.Toggled += OnElementToggled;
}
base.OnElementChanged (e);
}
void OnControlValueChanged (object sender, EventArgs e)
{
((IElementController)Element).SetValueFromRenderer (Switch.IsToggledProperty, Control.IsChecked);
}
void OnElementToggled (object sender, EventArgs e)
{
Control.IsChecked = Element.IsToggled;
}
public class SwitchElement : Div
{
public event EventHandler Change;
bool isChecked = false;
readonly Div knob = new Div ();
public bool IsChecked {
get => isChecked;
set {
isChecked = value;
UpdateUI ();
}
}
public SwitchElement ()
{
AppendChild (knob);
knob.Style.Position = "absolute";
knob.Style.BorderRadius = "10px";
knob.Style.Cursor = "pointer";
knob.Style.Top = "2px";
knob.Style.Width = "18px";
knob.Style.Height = "34px";
Style.BorderRadius = "10px";
Style.Cursor = "pointer";
Style.BorderStyle = "solid";
Style.BorderWidth = "2px";
Click += (s, e) => {
IsChecked = !IsChecked;
Change?.Invoke (this, EventArgs.Empty);
};
UpdateUI ();
}
void UpdateUI ()
{
Style.BackgroundColor = isChecked ? "#337ab7" : "#888";
Style.BorderColor = Style.BackgroundColor;
knob.Style.BackgroundColor = isChecked ? "#FFF" : "#EEE";
if (isChecked) {
knob.Style.Left = "34px";
}
else {
knob.Style.Left = "2px";
}
}
}
}
}