PowerToys/src/modules/cmdpal/Microsoft.CmdPal.UI/Dock/DockItemControl.xaml.cs

// Copyright (c) Microsoft Corporation
// The Microsoft Corporation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using Microsoft.CmdPal.UI.Controls;
using Microsoft.CmdPal.UI.ViewModels;
using Microsoft.CmdPal.UI.ViewModels.Dock;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using Microsoft.UI.Xaml.Input;
using Microsoft.UI.Xaml.Markup;

namespace Microsoft.CmdPal.UI.Dock;

[ContentProperty(Name = nameof(Icon))]
public sealed partial class DockItemControl : Control
{
    public DockItemControl()
    {
        DefaultStyleKey = typeof(DockItemControl);
    }

    public static readonly DependencyProperty ToolTipProperty =
        DependencyProperty.Register(nameof(ToolTip), typeof(string), typeof(DockItemControl), new PropertyMetadata(null));

    public string ToolTip
    {
        get => (string)GetValue(ToolTipProperty);
        set => SetValue(ToolTipProperty, value);
    }

    public static readonly DependencyProperty TitleProperty =
        DependencyProperty.Register(nameof(Title), typeof(string), typeof(DockItemControl), new PropertyMetadata(null, OnTextPropertyChanged));

    public string Title
    {
        get => (string)GetValue(TitleProperty);
        set => SetValue(TitleProperty, value);
    }

    public static readonly DependencyProperty SubtitleProperty =
        DependencyProperty.Register(nameof(Subtitle), typeof(string), typeof(DockItemControl), new PropertyMetadata(null, OnTextPropertyChanged));

    public string Subtitle
    {
        get => (string)GetValue(SubtitleProperty);
        set => SetValue(SubtitleProperty, value);
    }

    public static readonly DependencyProperty IconProperty =
        DependencyProperty.Register(nameof(Icon), typeof(object), typeof(DockItemControl), new PropertyMetadata(null, OnIconPropertyChanged));

    public object Icon
    {
        get => GetValue(IconProperty);
        set => SetValue(IconProperty, value);
    }

    public static readonly DependencyProperty TextVisibilityProperty =
        DependencyProperty.Register(nameof(TextVisibility), typeof(Visibility), typeof(DockItemControl), new PropertyMetadata(null, OnTextPropertyChanged));

    public Visibility TextVisibility
    {
        get => (Visibility)GetValue(TextVisibilityProperty);
        set => SetValue(TextVisibilityProperty, value);
    }

    private const string IconPresenterName = "IconPresenter";

    private FrameworkElement? _iconPresenter;

    private static void OnTextPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is DockItemControl control)
        {
            control.UpdateTextVisibility();
            control.UpdateAlignment();
        }
    }

    private static void OnIconPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (d is DockItemControl control)
        {
            control.UpdateIconVisibility();
            control.UpdateAlignment();
        }
    }

    internal bool HasTitle => !string.IsNullOrEmpty(Title);

    internal bool HasSubtitle => !string.IsNullOrEmpty(Subtitle);

    internal bool HasText => HasTitle || HasSubtitle;

    private void UpdateTextVisibility()
    {
        UpdateTextVisibilityState();
    }

    private void UpdateTextVisibilityState()
    {
        // Determine which visual state to use based on title/subtitle presence
        var stateName = (HasTitle, HasSubtitle) switch
        {
            (true, true) => "TextVisible",
            (true, false) => "TitleOnly",
            (false, true) => "SubtitleOnly",
            (false, false) => "TextHidden",
        };

        VisualStateManager.GoToState(this, stateName, true);
    }

    private void UpdateIconVisibility()
    {
        if (Icon is IconBox icon)
        {
            var dt = icon.DataContext;
            var src = icon.Source;

            if (_iconPresenter is not null)
            {
                // n.b. this might be wrong - I think we always have an Icon (an IconBox),
                // we need to check if the box has an icon
                _iconPresenter.Visibility = Icon is null ? Visibility.Collapsed : Visibility.Visible;
            }

            UpdateIconVisibilityState();
        }
    }

    private void UpdateIconVisibilityState()
    {
        var hasIcon = Icon is not null;
        VisualStateManager.GoToState(this, hasIcon ? "IconVisible" : "IconHidden", true);
    }

    private void UpdateAlignment()
    {
        // If this item has both an icon and a label, left align so that the
        // icons don't wobble if the text changes.
        //
        // Otherwise, center align.
        var requestedTheme = ActualTheme;
        var isLight = requestedTheme == ElementTheme.Light;
        var showText = HasText;
        if (Icon is IconBox icoBox &&
            icoBox.DataContext is DockItemViewModel item &&
            item.Icon is IconInfoViewModel icon)
        {
            var showIcon = icon is not null && icon.HasIcon(isLight);
            if (showText && showIcon)
            {
                HorizontalAlignment = HorizontalAlignment.Left;
                return;
            }
        }

        HorizontalAlignment = HorizontalAlignment.Center;
    }

    private void UpdateAllVisibility()
    {
        UpdateTextVisibility();
        UpdateIconVisibility();
        UpdateAlignment();
    }

    protected override void OnApplyTemplate()
    {
        base.OnApplyTemplate();
        IsEnabledChanged -= OnIsEnabledChanged;

        PointerEntered -= Control_PointerEntered;
        PointerExited -= Control_PointerExited;

        PointerEntered += Control_PointerEntered;
        PointerExited += Control_PointerExited;

        IsEnabledChanged += OnIsEnabledChanged;

        // Get template children for visibility updates
        _iconPresenter = GetTemplateChild(IconPresenterName) as FrameworkElement;

        // Set initial visibility
        UpdateAllVisibility();
    }

    private void Control_PointerEntered(object sender, PointerRoutedEventArgs e)
    {
        VisualStateManager.GoToState(this, "PointerOver", true);
    }

    private void Control_PointerExited(object sender, PointerRoutedEventArgs e)
    {
        VisualStateManager.GoToState(this, "Normal", true);
    }

    protected override void OnPointerPressed(PointerRoutedEventArgs e)
    {
        if (IsEnabled)
        {
            base.OnPointerPressed(e);
            VisualStateManager.GoToState(this, "Pressed", true);
        }
    }

    private void OnIsEnabledChanged(object sender, DependencyPropertyChangedEventArgs e)
    {
        VisualStateManager.GoToState(this, IsEnabled ? "Normal" : "Disabled", true);
    }
}