Arrow-key navigation between flag-filter chips

Assisted-by: Claude:claude-opus-4-7:Claude Code

Assisted-by: Claude:claude-opus-4-7:Claude Code

ILSpy.Tests/Views/FlagsFilterPopupKeyboardTests.cs

@@ -0,0 +1,123 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System.Linq;
+
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Headless;
+using Avalonia.Headless.NUnit;
+using Avalonia.Input;
+using Avalonia.VisualTree;
+
+using AwesomeAssertions;
+
+using ILSpy.Metadata.Filters;
+using ILSpy.Views.Filters;
+
+using NUnit.Framework;
+
+namespace ICSharpCode.ILSpy.Tests.Views.Filters;
+
+/// <summary>
+/// Pins arrow-key navigation between chips inside <see cref="FlagsFilterPopup"/>.
+/// The popup is composed of one <see cref="MutexChipGroup"/> per axis plus an
+/// <see cref="IndependentFlagGroup"/>; without explicit directional-navigation wiring
+/// the user can only Tab between every focusable element (chips + Clear button), which
+/// is awkward for a power-user filter. Arrow keys should hop chip-by-chip.
+/// </summary>
+[TestFixture]
+public class FlagsFilterPopupKeyboardTests
+{
+	[System.Flags]
+	enum SampleAttrs : uint
+	{
+		Public = 1,
+		Private = 2,
+		VisibilityMask = 0x3,
+		Static = 0x10,
+		Abstract = 0x20,
+	}
+
+	[AvaloniaTest]
+	public void Right_Arrow_From_The_First_Chip_Moves_Focus_To_The_Next_Chip_In_The_Same_Group()
+	{
+		// Build the popup, push it onto a window so focus management works, focus the
+		// first chip, send Right. Default Avalonia DirectionalNavigation should carry
+		// focus through siblings inside the WrapPanel.
+		var schema = FlagsSchemaInferer.For(typeof(SampleAttrs));
+		var state = new FilterState(schema);
+		var popup = new FlagsFilterPopup(state);
+		var window = new Window { Content = popup };
+		window.Show();
+
+		var chips = popup.GetVisualDescendants().OfType<ToggleButton>().ToList();
+		chips.Should().HaveCountGreaterThan(1, "test relies on at least two chips being present");
+		var first = chips[0];
+		first.Focus();
+		first.IsFocused.Should().BeTrue("setup precondition — first chip must accept focus before we exercise arrow nav");
+
+		window.KeyPress(Key.Right, RawInputModifiers.None, PhysicalKey.ArrowRight, keySymbol: null);
+
+		var newlyFocused = chips.SingleOrDefault(c => c.IsFocused);
+		newlyFocused.Should().NotBeNull("Right arrow must transfer focus to a sibling chip");
+		ReferenceEquals(newlyFocused, first).Should().BeFalse(
+			"Right arrow must move focus AWAY from the first chip, not stay on it");
+	}
+
+	[AvaloniaTest]
+	public void Down_Arrow_From_A_Chip_In_The_First_Group_Lands_On_A_Chip_In_The_Next_Group()
+	{
+		// Vertical traversal: pressing Down from a chip in the first mutex group must move
+		// into the second group (or the independent-flags group if there's only one mutex
+		// group). Without arrow-traversal wiring the focus would stay inside the same
+		// WrapPanel because WrapPanel is a horizontal-flow container.
+		var schema = FlagsSchemaInferer.For(typeof(SampleAttrs));
+		var state = new FilterState(schema);
+		var popup = new FlagsFilterPopup(state);
+		var window = new Window { Content = popup };
+		window.Show();
+
+		var groups = popup.GetVisualDescendants()
+			.OfType<UserControl>()
+			.Where(c => c is MutexChipGroup || c is IndependentFlagGroup)
+			.ToList();
+		groups.Should().HaveCountGreaterThan(1,
+			"test relies on at least two filter groups (one mutex + one independent, or two mutex)");
+
+		// First group is a MutexChipGroup full of ToggleButton chips; second group is an
+		// IndependentFlagGroup full of Button pills. Allow either control type as a valid
+		// landing slot so we're testing the cross-group jump, not the chip type.
+		var firstGroupChips = groups[0].GetVisualDescendants().OfType<ToggleButton>().ToList();
+		var secondGroupTargets = groups[1].GetVisualDescendants()
+			.Where(d => d is ToggleButton || d is Button)
+			.ToList();
+		var anchor = firstGroupChips[0];
+		anchor.Focus();
+		anchor.IsFocused.Should().BeTrue();
+
+		window.KeyPress(Key.Down, RawInputModifiers.None, PhysicalKey.ArrowDown, keySymbol: null);
+
+		var focusedNow = popup.GetVisualDescendants()
+			.OfType<Control>()
+			.FirstOrDefault(c => c.IsFocused && (c is ToggleButton || c is Button));
+		focusedNow.Should().NotBeNull("Down arrow must keep focus on some chip in the popup");
+		secondGroupTargets.Contains(focusedNow!).Should().BeTrue(
+			"Down arrow from the first group must land on a chip/pill in the next group");
+	}
+}

ILSpy/Controls/FlagsFilterPopup.cs

@@ -25,9 +25,12 @@ using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
+using Avalonia.Input;
+using Avalonia.Interactivity;
 using Avalonia.Layout;
 using Avalonia.Media;
 using Avalonia.Styling;
+using Avalonia.VisualTree;
 
 using ILSpy.Metadata.Filters;
 
@@ -104,10 +107,93 @@ namespace ILSpy.Views.Filters
 				Child = stack,
 			};
 
+			// Arrow-key nav between chips. Avalonia doesn't ship WPF's DirectionalNavigation
+			// attached property, so we handle Left/Right/Up/Down ourselves. Tunnel so we
+			// intercept before inner controls (the Clear button consumes Enter; arrow keys
+			// otherwise pass through to whatever has focus and do nothing).
+			AddHandler(KeyDownEvent, OnArrowKeyDown, RoutingStrategies.Tunnel);
+
 			state.PropertyChanged += OnStateChanged;
 			RefreshSummary();
 		}
 
+		void OnArrowKeyDown(object? sender, KeyEventArgs e)
+		{
+			if (e.Key is not (Key.Left or Key.Right or Key.Up or Key.Down))
+				return;
+			// e.Source on a tunneled key event is the focused element about to receive it,
+			// regardless of whether FocusManager has stabilised in this headless tick.
+			// Fall back to FocusManager for completeness — both should usually agree.
+			var focused = (e.Source as Control)
+				?? (TopLevel.GetTopLevel(this)?.FocusManager?.GetFocusedElement() as Control);
+			if (focused is null)
+				return;
+
+			var groups = this.GetVisualDescendants()
+				.Where(c => c is MutexChipGroup or IndependentFlagGroup)
+				.OfType<Control>()
+				.ToList();
+			if (groups.Count == 0)
+				return;
+
+			Control? target = null;
+			if (e.Key is Key.Left or Key.Right)
+			{
+				// Flat document-order traversal: every chip / pill across the whole popup
+				// is one sequence. Left = previous, Right = next, wrap at ends so the user
+				// doesn't get stuck.
+				var flat = ChipsInDocumentOrder(groups).ToList();
+				int idx = flat.IndexOf(focused);
+				if (idx < 0)
+					return;
+				int step = e.Key == Key.Right ? 1 : -1;
+				target = flat[(idx + step + flat.Count) % flat.Count];
+			}
+			else
+			{
+				// Up / Down: jump to the previous / next group's first chip. Lets the user
+				// hop between axes without arrowing through every value chip in between.
+				int currentGroup = FindGroupContaining(groups, focused);
+				if (currentGroup < 0)
+					return;
+				int step = e.Key == Key.Down ? 1 : -1;
+				int newGroup = currentGroup + step;
+				if (newGroup < 0 || newGroup >= groups.Count)
+					return;
+				target = ChipsIn(groups[newGroup]).FirstOrDefault();
+			}
+
+			if (target is not null)
+			{
+				target.Focus();
+				e.Handled = true;
+			}
+		}
+
+		static int FindGroupContaining(IReadOnlyList<Control> groups, Control element)
+		{
+			for (int i = 0; i < groups.Count; i++)
+				if (groups[i] == element || groups[i].GetVisualDescendants().Contains(element))
+					return i;
+			return -1;
+		}
+
+		// Each group exposes its own NavigableElements list — using that instead of a
+		// blanket descendant-walk skips past internal template parts (e.g. ComboBox's
+		// own toggle button) so arrow nav lands only on user-facing chips/pills.
+		static IEnumerable<Control> ChipsIn(Control group) => group switch {
+			MutexChipGroup mutex => mutex.NavigableElements,
+			IndependentFlagGroup indep => indep.NavigableElements,
+			_ => Enumerable.Empty<Control>(),
+		};
+
+		static IEnumerable<Control> ChipsInDocumentOrder(IEnumerable<Control> groups)
+		{
+			foreach (var group in groups)
+				foreach (var chip in ChipsIn(group))
+					yield return chip;
+		}
+
 		void OnStateChanged(object? sender, PropertyChangedEventArgs e) => RefreshSummary();
 
 		void RefreshSummary() => summary.Text = FilterStatePresenter.Describe(state);

ILSpy/Controls/IndependentFlagGroup.cs

@@ -41,6 +41,12 @@ namespace ILSpy.Views.Filters
 		readonly Dictionary<string, Button> pills = new();
 		readonly ComboBox modeBox;
 
+		/// <summary>
+		/// Every user-facing pill in document order. Used by the popup's arrow-key
+		/// navigation to skip past internal template parts of the All/Any ComboBox.
+		/// </summary>
+		public IEnumerable<Control> NavigableElements => pills.Values;
+
 		public IndependentFlagGroup(FilterState state, IReadOnlyList<IndependentFlag> flags)
 		{
 			this.state = state ?? throw new ArgumentNullException(nameof(state));

ILSpy/Controls/MutexChipGroup.cs

@@ -48,6 +48,20 @@ namespace ILSpy.Views.Filters
 		readonly Dictionary<uint, ToggleButton> valueChips = new();
 		bool suppress;
 
+		/// <summary>
+		/// Every user-facing chip in document order — the Any-chip first, then each
+		/// value chip. Used by the popup's arrow-key navigation to skip past internal
+		/// template parts (ComboBox toggle buttons etc.) that descendant-walking would
+		/// otherwise pick up.
+		/// </summary>
+		public IEnumerable<Control> NavigableElements {
+			get {
+				yield return anyChip;
+				foreach (var (_, chip) in valueChips)
+					yield return chip;
+			}
+		}
+
 		public MutexChipGroup(FilterState state, MutexGroup group)
 		{
 			this.state = state ?? throw new ArgumentNullException(nameof(state));