Connected.Components/Components/ExpansionPanel/ExpansionPanel.razor.cs

using Connected.Annotations;
using Connected.Utilities;
using Microsoft.AspNetCore.Components;

namespace Connected.Components;

public partial class ExpansionPanel : UIComponent, IDisposable
{
	private bool _nextPanelExpanded;
	private bool _isExpanded;
	private bool _collapseIsExpanded;

	[CascadingParameter] private ExpansionPanels Parent { get; set; }

	protected string Classname =>
	new CssBuilder("mud-expand-panel")
		.AddClass("mud-panel-expanded", IsExpanded)
		.AddClass("mud-panel-next-expanded", NextPanelExpanded)
		.AddClass("mud-disabled", Disabled)
		.AddClass($"mud-elevation-{Parent?.Elevation.ToString()}")
		.AddClass($"mud-expand-panel-border", Parent?.DisableBorders != true)
		.AddClass(Class)
	.Build();

	protected string PanelContentClassname =>
	new CssBuilder("mud-expand-panel-content")
		.AddClass("mud-expand-panel-gutters", DisableGutters || Parent?.DisableGutters == true)
		.AddClass("mud-expand-panel-dense", Dense || Parent?.Dense == true)
	.Build();

	/// <summary>
	/// Explicitly sets the height for the Collapse element to override the css default.
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Appearance)]
	public int? MaxHeight { get; set; }

	/// <summary>
	/// RenderFragment to be displayed in the expansion panel which will override header text if defined.
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Behavior)]
	public RenderFragment TitleContent { get; set; }

	/// <summary>
	/// The text to be displayed in the expansion panel.
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Behavior)]
	public string Text { get; set; }

	/// <summary>
	/// If true, expand icon will not show
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Appearance)]
	public bool HideIcon { get; set; }

	/// <summary>
	/// Custom hide icon.
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Appearance)]
	public string Icon { get; set; } = Icons.Material.Filled.ExpandMore;

	/// <summary>
	/// If true, removes vertical padding from childcontent.
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Appearance)]
	public bool Dense { get; set; }

	/// <summary>
	/// If true, the left and right padding is removed from childcontent.
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Appearance)]
	public bool DisableGutters { get; set; }

	/// <summary>
	/// Raised when IsExpanded changes.
	/// </summary>
	[Parameter] public EventCallback<bool> IsExpandedChanged { get; set; }

	internal event Action<ExpansionPanel> NotifyIsExpandedChanged;
	/// <summary>
	/// Expansion state of the panel (two-way bindable)
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Behavior)]
	public bool IsExpanded
	{
		get => _isExpanded;
		set
		{
			if (_isExpanded == value)
				return;
			_isExpanded = value;

			NotifyIsExpandedChanged?.Invoke(this);
			IsExpandedChanged.InvokeAsync(_isExpanded).ContinueWith(t =>
			{
				if (_collapseIsExpanded != _isExpanded)
				{
					_collapseIsExpanded = _isExpanded;
					InvokeAsync(() => StateHasChanged());
				}
			});
		}
	}

	/// <summary>
	/// Sets the initial expansion state. Do not use in combination with IsExpanded.
	/// Combine with MultiExpansion to have more than one panel start open.
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Behavior)]
	public bool IsInitiallyExpanded { get; set; }

	/// <summary>
	/// If true, the component will be disabled.
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Behavior)]
	public bool Disabled { get; set; }

	/// <summary>
	/// Child content of component.
	/// </summary>
	[Parameter]
	[Category(CategoryTypes.ExpansionPanel.Behavior)]
	public RenderFragment ChildContent { get; set; }

	public bool NextPanelExpanded
	{
		get => _nextPanelExpanded;
		set
		{
			if (_nextPanelExpanded == value)
				return;
			_nextPanelExpanded = value;
			//InvokeAsync(StateHasChanged);
		}
	}

	public void ToggleExpansion()
	{
		if (Disabled)
		{
			return;
		}

		IsExpanded = !IsExpanded;
	}

	public void Expand(bool update_parent = true)
	{
		if (update_parent)
			IsExpanded = true;
		else
		{
			_isExpanded = true;
			_collapseIsExpanded = true;
			IsExpandedChanged.InvokeAsync(_isExpanded);
		}
	}

	public void Collapse(bool update_parent = true)
	{
		if (update_parent)
			IsExpanded = false;
		else
		{
			_isExpanded = false;
			_collapseIsExpanded = false;
			IsExpandedChanged.InvokeAsync(_isExpanded);
		}
	}

	protected override void OnInitialized()
	{
		// NOTE: we can't throw here because we need to be able to instanciate the type for the API Docs to infer default values
		//if (Parent == null)
		//    throw new ArgumentNullException(nameof(Parent), "ExpansionPanel must exist within a ExpansionPanels component");
		base.OnInitialized();
		if (!IsExpanded && IsInitiallyExpanded)
		{
			_isExpanded = true;
			_collapseIsExpanded = true;
		}

		Parent?.AddPanel(this);
	}

	public void Dispose()
	{
		Parent?.RemovePanel(this);
	}
}