OnDeviceExtension.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using Windows.System.Profile;

// TODO: For Uno we probably want to extend this with extra properties the light up on WASM/iOS/MacOS/Android/etc...?
//       Or is this just XAML conditional Markup that Uno provides? https://platform.uno/docs/articles/platform-specific-xaml.html
// TODO: Do we want a Trigger version of this as well?

namespace CommunityToolkit.WinUI;

/// <summary>
/// The OnDevice markup extension allows you to customize UI appearance on a per-DeviceFamily basis.
/// </summary>
/// <example>
/// The next TextBlock will show the text 'Hello' on desktop computers, 'World' on Xbox and 'Hi' on all other devices
/// <code>
///     <TextBlock Text="{ui:OnDevice Default=Hi, Desktop=Hello, Xbox=World}"
///                xmlns:ui="using:CommunityToolkit.WinUI.UI" />
/// </code>
/// </example>
public partial class OnDeviceExtension : MarkupExtension
{
    /// <summary>
    /// Gets the current device family.
    /// </summary>
    private string DeviceFamily { get; } = AnalyticsInfo.VersionInfo.DeviceFamily;

    /// <summary>
    /// Gets or sets the default value for this property
    /// </summary>
    public object? Default { get; set; }

    /// <summary>
    /// Gets or sets a value for this property on Desktop
    /// </summary>
    public object? Desktop { get; set; }

    /// <summary>
    /// Gets or sets a value for this property on Holographic
    /// </summary>
    public object? Holographic { get; set; }

    /// <summary>
    /// Gets or sets a value for this property on IoT
    /// </summary>
    public object? IoT { get; set; }

    /// <summary>
    /// Gets or sets a value for this property on Team
    /// </summary>
    public object? Team { get; set; }

    /// <summary>
    /// Gets or sets a value for this property on Xbox
    /// </summary>
    public object? Xbox { get; set; }

    /// <summary>
    /// Returns an object value for the current DeviceFamily, Default is used when it is not set.
    /// </summary>
    /// <returns>The object value to set on the property where the extension is applied.</returns>
    protected override object? ProvideValue()
    {
        switch (DeviceFamily)
        {
            case "Windows.Desktop":
                return this.Desktop ?? this.Default;
            case "Windows.Holographic":
                return this.Holographic ?? this.Default;
            case "Windows.IoT":
                return this.IoT ?? this.Default;
            case "Windows.Team":
                return this.Team ?? this.Default;
            case "Windows.Xbox":
                return this.Xbox ?? this.Default;
            default:
                return this.Default;
        }
    }
}