Polish global search clear control with Lucide icon

SignalSelectionWizardWindow.xaml

@@ -180,6 +180,58 @@
                 </Setter.Value>
             </Setter>
         </Style>
+
+        <!-- Modern search-field clear affordance: quiet at rest, obvious on hover/focus,
+             and large enough to hit without looking like a separate toolbar button. -->
+        <Style x:Key="GlobalSearchClearButton" TargetType="Button">
+            <Setter Property="Width" Value="28"/>
+            <Setter Property="Height" Value="28"/>
+            <Setter Property="Padding" Value="0"/>
+            <Setter Property="Margin" Value="2,0,3,0"/>
+            <Setter Property="Background" Value="Transparent"/>
+            <Setter Property="BorderBrush" Value="Transparent"/>
+            <Setter Property="BorderThickness" Value="1"/>
+            <Setter Property="Foreground" Value="#667085"/>
+            <Setter Property="Cursor" Value="Hand"/>
+            <Setter Property="HorizontalContentAlignment" Value="Center"/>
+            <Setter Property="VerticalContentAlignment" Value="Center"/>
+            <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
+            <Setter Property="ClipToBounds" Value="False"/>
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="Button">
+                        <Border x:Name="Chrome"
+                                Width="28" Height="28"
+                                CornerRadius="8"
+                                Background="{TemplateBinding Background}"
+                                BorderBrush="{TemplateBinding BorderBrush}"
+                                BorderThickness="{TemplateBinding BorderThickness}"
+                                SnapsToDevicePixels="True">
+                            <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                        </Border>
+                        <ControlTemplate.Triggers>
+                            <Trigger Property="IsMouseOver" Value="True">
+                                <Setter TargetName="Chrome" Property="Background" Value="#EEF3F8"/>
+                                <Setter TargetName="Chrome" Property="BorderBrush" Value="#D8E2EC"/>
+                                <Setter Property="Foreground" Value="#475467"/>
+                            </Trigger>
+                            <Trigger Property="IsPressed" Value="True">
+                                <Setter TargetName="Chrome" Property="Background" Value="#E3EBF4"/>
+                                <Setter TargetName="Chrome" Property="BorderBrush" Value="#C9D7E5"/>
+                            </Trigger>
+                            <Trigger Property="IsKeyboardFocused" Value="True">
+                                <Setter TargetName="Chrome" Property="Background" Value="#EEF4FF"/>
+                                <Setter TargetName="Chrome" Property="BorderBrush" Value="#7AA7F7"/>
+                                <Setter Property="Foreground" Value="#2563EB"/>
+                            </Trigger>
+                            <Trigger Property="IsEnabled" Value="False">
+                                <Setter TargetName="Chrome" Property="Opacity" Value="0.45"/>
+                            </Trigger>
+                        </ControlTemplate.Triggers>
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
     </Window.Resources>
 
     <Grid Margin="12">
@@ -246,13 +298,31 @@
                                 </Style>
                             </TextBlock.Style>
                         </TextBlock>
-                        <Button Grid.Column="2"
-                                Content="×"
-                                Style="{StaticResource MiniChipButton}"
-                                Padding="8,2"
-                                Margin="3"
+                        <Button x:Name="GlobalSearchClearButton"
+                                Grid.Column="2"
                                 Click="ClearGlobalFilter_Click"
-                                ToolTip="Clear global search"/>
+                                ToolTip="Clear search"
+                                AutomationProperties.Name="Clear global search">
+                            <Button.Style>
+                                <Style TargetType="Button" BasedOn="{StaticResource GlobalSearchClearButton}">
+                                    <Style.Triggers>
+                                        <DataTrigger Binding="{Binding Text, ElementName=GlobalSearchTextBox}" Value="">
+                                            <Setter Property="Visibility" Value="Collapsed"/>
+                                        </DataTrigger>
+                                    </Style.Triggers>
+                                </Style>
+                            </Button.Style>
+                            <Viewbox Width="14" Height="14"
+                                     HorizontalAlignment="Center" VerticalAlignment="Center"
+                                     Stretch="Uniform" SnapsToDevicePixels="True">
+                                <Path Data="{StaticResource LucideX}"
+                                      Fill="Transparent"
+                                      Stroke="{Binding Foreground, RelativeSource={RelativeSource AncestorType={x:Type Button}}}"
+                                      StrokeThickness="1.9"
+                                      StrokeStartLineCap="Round" StrokeEndLineCap="Round"
+                                      StrokeLineJoin="Round"/>
+                            </Viewbox>
+                        </Button>
                     </Grid>
                 </Border>
 

tests/ARSAS.Tests/SignalSelectionGlobalSearchClearRegressionTests.cs

@@ -0,0 +1,76 @@
+using System.Xml.Linq;
+
+namespace ARSAS.Tests;
+
+public sealed class SignalSelectionGlobalSearchClearRegressionTests
+{
+    [Fact]
+    public void GlobalSearchClear_UsesLucideVectorModernHitTargetAndHidesWhenEmpty()
+    {
+        var source = File.ReadAllText(FindRepoFile("SignalSelectionWizardWindow.xaml"));
+        var document = XDocument.Parse(source);
+        XNamespace presentation = "http://schemas.microsoft.com/winfx/2006/xaml/presentation";
+        XNamespace x = "http://schemas.microsoft.com/winfx/2006/xaml";
+
+        var reusableStyle = document.Descendants(presentation + "Style")
+            .Single(style => (string?)style.Attribute(x + "Key") == "GlobalSearchClearButton");
+        var reusableSetters = reusableStyle.Elements(presentation + "Setter").ToArray();
+
+        string? SetterValue(string property)
+            => reusableSetters.Single(setter => (string?)setter.Attribute("Property") == property)
+                .Attribute("Value")?.Value;
+
+        Assert.Equal("28", SetterValue("Width"));
+        Assert.Equal("28", SetterValue("Height"));
+        Assert.Equal("Transparent", SetterValue("Background"));
+        Assert.Equal("{x:Null}", SetterValue("FocusVisualStyle"));
+        Assert.Equal("False", SetterValue("ClipToBounds"));
+
+        var clearButton = document.Descendants(presentation + "Button")
+            .Single(button => (string?)button.Attribute(x + "Name") == "GlobalSearchClearButton");
+
+        Assert.Equal("ClearGlobalFilter_Click", (string?)clearButton.Attribute("Click"));
+        Assert.Equal("Clear search", (string?)clearButton.Attribute("ToolTip"));
+        Assert.Equal("Clear global search", (string?)clearButton.Attribute("AutomationProperties.Name"));
+        Assert.Null(clearButton.Attribute("Content"));
+        Assert.Null(clearButton.Attribute("Style"));
+
+        var icon = clearButton.Descendants(presentation + "Path").Single();
+        Assert.Equal("{StaticResource LucideX}", (string?)icon.Attribute("Data"));
+        Assert.Equal("1.9", (string?)icon.Attribute("StrokeThickness"));
+
+        var viewbox = clearButton.Descendants(presentation + "Viewbox").Single();
+        Assert.Equal("14", (string?)viewbox.Attribute("Width"));
+        Assert.Equal("14", (string?)viewbox.Attribute("Height"));
+
+        var localStyle = clearButton.Element(presentation + "Button.Style")?
+            .Element(presentation + "Style")
+            ?? throw new Xunit.Sdk.XunitException("Global search clear button local style is missing.");
+        Assert.Equal("{StaticResource GlobalSearchClearButton}", (string?)localStyle.Attribute("BasedOn"));
+
+        var emptyTextTrigger = localStyle.Descendants(presentation + "DataTrigger")
+            .Single(trigger => (string?)trigger.Attribute("Value") == string.Empty);
+        Assert.Contains("ElementName=GlobalSearchTextBox", (string?)emptyTextTrigger.Attribute("Binding") ?? string.Empty, StringComparison.Ordinal);
+        Assert.Contains(emptyTextTrigger.Elements(presentation + "Setter"), setter =>
+            (string?)setter.Attribute("Property") == "Visibility" &&
+            (string?)setter.Attribute("Value") == "Collapsed");
+
+        Assert.DoesNotContain("Content=\"×\"", source, StringComparison.Ordinal);
+        Assert.DoesNotContain("Style=\"{StaticResource MiniChipButton}\"", clearButton.ToString(), StringComparison.Ordinal);
+    }
+
+    private static string FindRepoFile(string relativePath)
+    {
+        DirectoryInfo? directory = new(AppContext.BaseDirectory);
+        while (directory != null)
+        {
+            var candidate = Path.Combine(directory.FullName, relativePath);
+            if (File.Exists(candidate))
+                return candidate;
+            directory = directory.Parent;
+        }
+
+        throw new FileNotFoundException(
+            $"Could not locate repository file '{relativePath}' from '{AppContext.BaseDirectory}'.");
+    }
+}