Enhance filtering system by introducing customizable text filtering options and improving filter control creation

Author: JakkuSakura

samples/TreeDataGridDemo/ViewModels/CountriesPageViewModel.cs

@@ -25,54 +25,49 @@ public CountriesPageViewModel()
                 {
                     // Text column with advanced filter
                     new TextColumn<Country, string?>(
-                        "Country", 
-                        x => x.Name, 
-                        (r, v) => r.Name = v, 
-                        new GridLength(6, GridUnitType.Star), 
+                        "Country",
+                        x => x.Name,
+                        (r, v) => r.Name = v,
+                        new GridLength(6, GridUnitType.Star),
                         new TextColumnOptions<Country>
                         {
                             IsTextSearchEnabled = true,
                             IsFilterEnabled = true // This will create a TextFilter automatically
                         }),
-                        
+
                     // Use a template column with filtering for region
                     new TemplateColumn<Country>(
-                        "Region", 
+                        "Region",
                         "RegionCell",
                         "RegionEditCell",
                         new GridLength(3, GridUnitType.Star),
                         new TemplateColumnOptions<Country>
                         {
-                            IsFilterEnabled = true,
-                            FilterValueSelector = x => x.Region // Value selector for filtering
+                            // Value selector for filtering
+                            FilterValueSelector = x => x.Region,
+                            Filter = new TextValueFilter(),
+                            FilterControlFactory = (col) => new TextFilterControl(col, "custom filter..."),
                         }),
-                        
+
                     // Population column with numeric filtering
                     new TextColumn<Country, int>(
-                        "Population", 
-                        x => x.Population, 
-                        new GridLength(3, GridUnitType.Star), 
-                        new TextColumnOptions<Country>
-                        {
-                            IsFilterEnabled = true
-                        }),
-                        
+                        "Population",
+                        x => x.Population,
+                        new GridLength(3, GridUnitType.Star),
+                        new TextColumnOptions<Country> { IsFilterEnabled = true }),
+
                     // Area column with numeric filtering
                     new TextColumn<Country, int>(
-                        "Area", 
-                        x => x.Area, 
-                        new GridLength(3, GridUnitType.Star), 
-                        new TextColumnOptions<Country>
-                        {
-                            IsFilterEnabled = true,
-                            StringFormat = "{0:N0}"
-                        }),
-                        
+                        "Area",
+                        x => x.Area,
+                        new GridLength(3, GridUnitType.Star),
+                        new TextColumnOptions<Country> { IsFilterEnabled = true, StringFormat = "{0:N0}" }),
+
                     // GDP column
                     new TextColumn<Country, int>(
-                        "GDP", 
-                        x => x.GDP, 
-                        new GridLength(3, GridUnitType.Star), 
+                        "GDP",
+                        x => x.GDP,
+                        new GridLength(3, GridUnitType.Star),
                         new TextColumnOptions<Country>
                         {
                             TextAlignment = TextAlignment.Right,

src/Avalonia.Controls.TreeDataGrid/Models/TreeDataGrid/CheckBoxColumnOptions.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 
 namespace Avalonia.Controls.Models.TreeDataGrid
 {
@@ -30,11 +30,11 @@ public class CheckBoxColumnOptions<TModel> : ColumnOptions<TModel>, IFilterContr
         /// <param name="column">The column for which to create a filter control.</param>
         /// <param name="initialValue">The initial filter value.</param>
         /// <returns>A filter control that can be used to filter the column.</returns>
-        public IFilterControl? CreateFilterControl(IColumn column, object? initialValue)
+        public IFilterControl? CreateFilterControl(IColumn column)
         {
-            if (column is CheckBoxColumn<TModel> && IsFilterEnabled)
+            if (column is CheckBoxColumn<TModel> col && IsFilterEnabled)
             {
-                return new CheckBoxFilterControl(IsThreeStateFilter, initialValue);
+                return new CheckBoxFilterControl(col, IsThreeStateFilter, null);
             }
 
             return null;

src/Avalonia.Controls.TreeDataGrid/Models/TreeDataGrid/Filters.cs

@@ -4,11 +4,60 @@
 
 namespace Avalonia.Controls.Models.TreeDataGrid;
 
+/// <summary>
+/// Defines the mode of text filtering.
+/// </summary>
+public enum TextFilterMode
+{
+    /// <summary>
+    /// Check if the value contains the filter text.
+    /// </summary>
+    Contains,
+    
+    /// <summary>
+    /// Check if the value starts with the filter text.
+    /// </summary>
+    StartsWith,
+    
+    /// <summary>
+    /// Check if the value ends with the filter text.
+    /// </summary>
+    EndsWith
+}
+
 /// <summary>
 /// A filter that checks text values.
 /// </summary>
 public class TextValueFilter : IValueFilter<string>
 {
+    /// <summary>
+    /// Gets or sets the filter mode to use.
+    /// </summary>
+    public TextFilterMode FilterMode { get; set; } = TextFilterMode.Contains;
+    
+    /// <summary>
+    /// Gets or sets whether filtering is case sensitive.
+    /// </summary>
+    public bool CaseSensitive { get; set; } = false;
+    
+    /// <summary>
+    /// Initializes a new instance of <see cref="TextValueFilter"/> with default settings.
+    /// </summary>
+    public TextValueFilter()
+    {
+    }
+    
+    /// <summary>
+    /// Initializes a new instance of <see cref="TextValueFilter"/> with specified filter mode.
+    /// </summary>
+    /// <param name="mode">The filter mode to use.</param>
+    /// <param name="caseSensitive">Whether filtering is case sensitive.</param>
+    public TextValueFilter(TextFilterMode mode, bool caseSensitive = false)
+    {
+        FilterMode = mode;
+        CaseSensitive = caseSensitive;
+    }
+    
     /// <summary>
     /// Determines if the value passes the filter.
     /// </summary>
@@ -19,8 +68,23 @@ public bool Passes(object? condition, string? value)
     {
         if (condition is not string filterText || string.IsNullOrWhiteSpace(filterText))
             return true;
-
-        return value != null && value.Contains(filterText, StringComparison.OrdinalIgnoreCase);
+            
+        if (value == null)
+            return false;
+            
+        // Determine string comparison
+        StringComparison comparison = CaseSensitive ? 
+            StringComparison.Ordinal : 
+            StringComparison.OrdinalIgnoreCase;
+        
+        // Apply filter based on mode
+        return FilterMode switch
+        {
+            TextFilterMode.Contains => value.Contains(filterText, comparison),
+            TextFilterMode.StartsWith => value.StartsWith(filterText, comparison),
+            TextFilterMode.EndsWith => value.EndsWith(filterText, comparison),
+            _ => value.Contains(filterText, comparison) // Default to Contains
+        };
     }
 }