maui-linux/Handlers/SliderHandler.Linux.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System;
using Microsoft.Maui.Graphics;
using Microsoft.Maui.Handlers;

namespace Microsoft.Maui.Platform.Linux.Handlers;

/// <summary>
/// Linux handler for Slider control.
/// </summary>
public class SliderHandler : ViewHandler<ISlider, SkiaSlider>
{
    public static IPropertyMapper<ISlider, SliderHandler> Mapper = new PropertyMapper<ISlider, SliderHandler>(ViewHandler.ViewMapper)
    {
        ["Minimum"] = MapMinimum,
        ["Maximum"] = MapMaximum,
        ["Value"] = MapValue,
        ["MinimumTrackColor"] = MapMinimumTrackColor,
        ["MaximumTrackColor"] = MapMaximumTrackColor,
        ["ThumbColor"] = MapThumbColor,
        ["Background"] = MapBackground,
        ["IsEnabled"] = MapIsEnabled
    };

    public static CommandMapper<ISlider, SliderHandler> CommandMapper = new(ViewHandler.ViewCommandMapper);

    public SliderHandler() : base(Mapper, CommandMapper)
    {
    }

    public SliderHandler(IPropertyMapper? mapper, CommandMapper? commandMapper = null)
        : base(mapper ?? Mapper, commandMapper ?? CommandMapper)
    {
    }

    protected override SkiaSlider CreatePlatformView()
    {
        return new SkiaSlider();
    }

    protected override void ConnectHandler(SkiaSlider platformView)
    {
        base.ConnectHandler(platformView);
        platformView.ValueChanged += OnValueChanged;
        platformView.DragStarted += OnDragStarted;
        platformView.DragCompleted += OnDragCompleted;

        if (VirtualView != null)
        {
            MapMinimum(this, VirtualView);
            MapMaximum(this, VirtualView);
            MapValue(this, VirtualView);
            MapIsEnabled(this, VirtualView);
        }
    }

    protected override void DisconnectHandler(SkiaSlider platformView)
    {
        platformView.ValueChanged -= OnValueChanged;
        platformView.DragStarted -= OnDragStarted;
        platformView.DragCompleted -= OnDragCompleted;
        base.DisconnectHandler(platformView);
    }

    private void OnValueChanged(object? sender, SliderValueChangedEventArgs e)
    {
        if (VirtualView != null && PlatformView != null && Math.Abs(VirtualView.Value - e.NewValue) > 0.0001)
        {
            VirtualView.Value = e.NewValue;
        }
    }

    private void OnDragStarted(object? sender, EventArgs e)
    {
        VirtualView?.DragStarted();
    }

    private void OnDragCompleted(object? sender, EventArgs e)
    {
        VirtualView?.DragCompleted();
    }

    public static void MapMinimum(SliderHandler handler, ISlider slider)
    {
        if (handler.PlatformView != null)
        {
            handler.PlatformView.Minimum = slider.Minimum;
        }
    }

    public static void MapMaximum(SliderHandler handler, ISlider slider)
    {
        if (handler.PlatformView != null)
        {
            handler.PlatformView.Maximum = slider.Maximum;
        }
    }

    public static void MapValue(SliderHandler handler, ISlider slider)
    {
        if (handler.PlatformView != null && Math.Abs(handler.PlatformView.Value - slider.Value) > 0.0001)
        {
            handler.PlatformView.Value = slider.Value;
        }
    }

    public static void MapMinimumTrackColor(SliderHandler handler, ISlider slider)
    {
        if (handler.PlatformView != null && slider.MinimumTrackColor != null)
        {
            handler.PlatformView.ActiveTrackColor = slider.MinimumTrackColor.ToSKColor();
        }
    }

    public static void MapMaximumTrackColor(SliderHandler handler, ISlider slider)
    {
        if (handler.PlatformView != null && slider.MaximumTrackColor != null)
        {
            handler.PlatformView.TrackColor = slider.MaximumTrackColor.ToSKColor();
        }
    }

    public static void MapThumbColor(SliderHandler handler, ISlider slider)
    {
        if (handler.PlatformView != null && slider.ThumbColor != null)
        {
            handler.PlatformView.ThumbColor = slider.ThumbColor.ToSKColor();
        }
    }

    public static void MapBackground(SliderHandler handler, ISlider slider)
    {
        if (handler.PlatformView != null)
        {
            if (slider.Background is SolidPaint solidPaint && solidPaint.Color != null)
            {
                handler.PlatformView.BackgroundColor = solidPaint.Color.ToSKColor();
            }
        }
    }

    public static void MapIsEnabled(SliderHandler handler, ISlider slider)
    {
        if (handler.PlatformView != null)
        {
            handler.PlatformView.IsEnabled = slider.IsEnabled;
            handler.PlatformView.Invalidate();
        }
    }
}