Merge pull request #729 from irihitech/wrap_count

Add new readonly property: LineCount for ElasticWrapPanel

src/Ursa/Controls/ElasticWrapPanel.cs

@@ -11,10 +11,8 @@ public class ElasticWrapPanel : WrapPanel
 {
     static ElasticWrapPanel()
     {
-        IsFillHorizontalProperty.Changed.AddClassHandler<Control>(OnIsFillPropertyChanged);
-        IsFillVerticalProperty.Changed.AddClassHandler<Control>(OnIsFillPropertyChanged);
-
         AffectsMeasure<ElasticWrapPanel>(IsFillHorizontalProperty, IsFillVerticalProperty);
+        AffectsArrange<ElasticWrapPanel>(IsFillHorizontalProperty, IsFillVerticalProperty);
     }
 
     #region AttachedProperty
@@ -60,9 +58,15 @@ public class ElasticWrapPanel : WrapPanel
     public static readonly StyledProperty<bool> IsFillVerticalProperty =
         AvaloniaProperty.Register<ElasticWrapPanel, bool>(nameof(IsFillVertical));
 
-    private static void OnIsFillPropertyChanged(AvaloniaObject d, AvaloniaPropertyChangedEventArgs e)
+    private int _lineCount;
+
+    public static readonly DirectProperty<ElasticWrapPanel, int> LineCountProperty = AvaloniaProperty.RegisterDirect<ElasticWrapPanel, int>(
+        nameof(LineCount), o => o.LineCount);
+
+    public int LineCount
     {
-        (d as ElasticWrapPanel)?.InvalidateMeasure();
+        get => _lineCount;
+        private set => SetAndRaise(LineCountProperty, ref _lineCount, value);
     }
 
     #endregion
@@ -376,7 +380,7 @@ public class ElasticWrapPanel : WrapPanel
                 lineUIEles.Clear();
             }
         }
-
+        LineCount = lineUVCollection.Count;
         lineUVCollection.ForEach(col => col.Dispose());
         lineUVCollection.Clear();
         return finalSize;

tests/HeadlessTest.Ursa/Controls/ElasticWrapPanelTests/Tests.cs

@@ -0,0 +1,72 @@
+using System.Security.Cryptography.X509Certificates;
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Controls.Shapes;
+using Avalonia.Headless.XUnit;
+using Avalonia.Layout;
+using Ursa.Controls;
+
+namespace HeadlessTest.Ursa.Controls.ElasticWrapPanelTests;
+
+public class Tests
+{
+    [AvaloniaFact]
+    public void LineCount_Correct()
+    {
+        var window = new Window() { };
+        var panel = new ElasticWrapPanel
+        {
+            Width = 200,
+            Height = 200,
+            Orientation = Orientation.Horizontal,
+        };
+        window.Content = panel;
+        window.Show();
+        Assert.Equal(0, panel.LineCount);
+    }
+    
+    [AvaloniaFact]
+    public void LineCount_Correct_1()
+    {
+        var window = new Window() { };
+        var panel = new ElasticWrapPanel
+        {
+            Width = 200,
+            Height = 200,
+            Orientation = Orientation.Horizontal,
+        };
+        var rect = new Rectangle
+        {
+            Width = 100,
+            Height = 100,
+        };
+        panel.Children.Add(rect);
+        window.Content = panel;
+        window.Show();
+        Assert.Equal(1, panel.LineCount);
+    }
+    
+    [AvaloniaFact]
+    public void LineCount_Correct_2()
+    {
+        var window = new Window() { };
+        var panel = new ElasticWrapPanel
+        {
+            Width = 200,
+            Height = 200,
+            Orientation = Orientation.Horizontal,
+        };
+        for (int i = 0; i < 3; i++)
+        {
+            var rect = new Rectangle
+            {
+                Width = 100,
+                Height = 100,
+            };
+            panel.Children.Add(rect);
+        }
+        window.Content = panel;
+        window.Show();
+        Assert.Equal(2, panel.LineCount);
+    }
+}