Terminal.Gui/UnitTests/View/Navigation/SetFocusTests.cs

using Xunit.Abstractions;

namespace Terminal.Gui.ViewTests;

public class SetFocusTests (ITestOutputHelper _output) : TestsAllViews
{
    [Fact]
    public void SetFocus_With_Null_Superview_Does_Not_Throw_Exception ()
    {
        var view = new View
        {
            Id = "view",
            CanFocus = true
        };
        Assert.True (view.CanFocus);
        Assert.False (view.HasFocus);

        Exception exception = Record.Exception (() => view.SetFocus ());
        Assert.Null (exception);

        Assert.True (view.CanFocus);
        Assert.True (view.HasFocus);
    }

    [Fact]
    public void SetFocus_SetsFocus ()
    {
        var view = new View
        {
            Id = "view",
            CanFocus = true
        };
        Assert.True (view.CanFocus);
        Assert.False (view.HasFocus);

        view.SetFocus ();
        Assert.True (view.HasFocus);
    }

    [Fact]
    public void SetFocus_NoSubView_Focused_Is_Null ()
    {
        var view = new View
        {
            Id = "view",
            CanFocus = true
        };
        Assert.True (view.CanFocus);
        Assert.False (view.HasFocus);

        view.SetFocus ();
        Assert.True (view.HasFocus);
        Assert.Null (view.GetFocused ());
    }

    [Fact]
    public void SetFocus_SubView_Focused_Is_Set ()
    {
        var view = new Window
        {
            Id = "view",
            CanFocus = true
        };

        var subview = new View
        {
            Id = "subview",
            CanFocus = true
        };
        view.Add (subview);
        Assert.True (view.CanFocus);
        Assert.False (view.HasFocus);

        view.SetFocus ();
        Assert.True (view.HasFocus);
        Assert.Equal (subview, view.GetFocused ());
    }

    [Fact]
    public void SetFocus_SetsFocus_DeepestSubView ()
    {
        var view = new View
        {
            Id = "view",
            CanFocus = true
        };

        var subview = new View
        {
            Id = "subview",
            CanFocus = true
        };
        view.Add (subview);

        view.SetFocus ();
        Assert.True (subview.HasFocus);
        Assert.Equal (subview, view.GetFocused ());
    }

    [Fact]
    public void SetFocus_SetsFocus_DeepestSubView_CompoundSubView ()
    {
        var view = new View
        {
            Id = "view",
            CanFocus = true
        };

        var subView = new View
        {
            Id = "subView",
            CanFocus = true
        };

        var subViewSubView1 = new View
        {
            Id = "subViewSubView1",
            CanFocus = false
        };

        var subViewSubView2 = new View
        {
            Id = "subViewSubView2",
            CanFocus = true
        };

        var subViewSubView3 = new View
        {
            Id = "subViewSubView3",
            CanFocus = false
        };
        subView.Add (subViewSubView1, subViewSubView2, subViewSubView3);

        view.Add (subView);

        view.SetFocus ();
        Assert.True (subView.HasFocus);
        Assert.Equal (subView, view.GetFocused ());
        Assert.Equal (subViewSubView2, subView.GetFocused ());
    }

    [Fact]
    public void SetFocus_CompoundSubView_SetFocus_Sets ()
    {
        var view = new View
        {
            Id = "view",
            CanFocus = true
        };

        var subView = new View
        {
            Id = "subView",
            CanFocus = true
        };

        var subViewSubView1 = new View
        {
            Id = "subViewSubView1",
            CanFocus = true
        };

        var subViewSubView2 = new View
        {
            Id = "subViewSubView2",
            CanFocus = true
        };

        var subViewSubView3 = new View
        {
            Id = "subViewSubView3",
            CanFocus = true
        };
        subView.Add (subViewSubView1, subViewSubView2, subViewSubView3);

        view.Add (subView);

        view.SetFocus ();
        Assert.True (view.HasFocus);
        Assert.True (subView.HasFocus);
        Assert.Equal (subView, view.GetFocused ());
        Assert.True (subViewSubView1.HasFocus);
        Assert.Equal (subViewSubView1, subView.GetFocused ());

        subViewSubView2.SetFocus ();
        Assert.True (view.HasFocus);
        Assert.True (subView.HasFocus);
        Assert.False (subViewSubView1.HasFocus);
        Assert.True (subViewSubView2.HasFocus);
        Assert.False (subViewSubView3.HasFocus);
    }

    [Fact]
    public void SetFocus_Peer_LeavesOther ()
    {
        var view = new View
        {
            Id = "view",
            CanFocus = true
        };

        var subview1 = new View
        {
            Id = "subview1",
            CanFocus = true
        };

        var subview2 = new View
        {
            Id = "subview2",
            CanFocus = true
        };
        view.Add (subview1, subview2);

        view.SetFocus ();
        Assert.Equal (subview1, view.GetFocused ());
        Assert.True (subview1.HasFocus);
        Assert.False (subview2.HasFocus);

        subview2.SetFocus ();
        Assert.Equal (subview2, view.GetFocused ());
        Assert.True (subview2.HasFocus);
        Assert.False (subview1.HasFocus);
    }

    [Fact]
    public void SetFocus_Peer_LeavesOthers_Subviews ()
    {
        var top = new View
        {
            Id = "top",
            CanFocus = true
        };

        var view1 = new View
        {
            Id = "view1",
            CanFocus = true
        };

        var subView1 = new View
        {
            Id = "subView1",
            CanFocus = true
        };

        view1.Add (subView1);

        var subView1SubView1 = new View
        {
            Id = "subView1subView1",
            CanFocus = true
        };

        subView1.Add (subView1SubView1);

        var view2 = new View
        {
            Id = "view2",
            CanFocus = true
        };

        top.Add (view1, view2);
        Assert.False (view1.HasFocus);
        Assert.False (view2.HasFocus);

        view1.SetFocus ();
        Assert.True (view1.HasFocus);
        Assert.True (subView1.HasFocus);
        Assert.True (subView1SubView1.HasFocus);
        Assert.Equal (subView1, view1.GetFocused ());
        Assert.Equal (subView1SubView1, subView1.GetFocused ());

        view2.SetFocus ();
        Assert.False (view1.HasFocus);
        Assert.True (view2.HasFocus);
    }
}