From e681efaf2b9d18128dbaee6195e71f1578040ea4 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@users.noreply.github.com>
Date: Mon, 4 Nov 2019 13:38:09 +0100
Subject: [PATCH] Merge pull request #3196 from donandren/issues/3165

fix WrapPanel issue #3165 item width/height should trigger new measure
---
 src/Avalonia.Controls/WrapPanel.cs            |  2 +-
 .../WrapPanelTests.cs                         | 78 +++++++++++++------
 2 files changed, 54 insertions(+), 26 deletions(-)

diff --git a/src/Avalonia.Controls/WrapPanel.cs b/src/Avalonia.Controls/WrapPanel.cs
index 7c88401615..d06a71a9f8 100644
--- a/src/Avalonia.Controls/WrapPanel.cs
+++ b/src/Avalonia.Controls/WrapPanel.cs
@@ -42,7 +42,7 @@ namespace Avalonia.Controls
         /// </summary>
         static WrapPanel()
         {
-            AffectsMeasure<WrapPanel>(OrientationProperty);
+            AffectsMeasure<WrapPanel>(OrientationProperty, ItemWidthProperty, ItemHeightProperty);
         }
 
         /// <summary>
diff --git a/tests/Avalonia.Controls.UnitTests/WrapPanelTests.cs b/tests/Avalonia.Controls.UnitTests/WrapPanelTests.cs
index fd93df46b8..82f94b4f3c 100644
--- a/tests/Avalonia.Controls.UnitTests/WrapPanelTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/WrapPanelTests.cs
@@ -12,14 +12,14 @@ namespace Avalonia.Controls.UnitTests
         public void Lays_Out_Horizontally_On_Separate_Lines()
         {
             var target = new WrapPanel()
-                         {
-                            Width = 100,
-                            Children =
+            {
+                Width = 100,
+                Children =
                             {
                                 new Border { Height = 50, Width = 100 },
                                 new Border { Height = 50, Width = 100 },
                             }
-                         };
+            };
 
             target.Measure(Size.Infinity);
             target.Arrange(new Rect(target.DesiredSize));
@@ -33,14 +33,14 @@ namespace Avalonia.Controls.UnitTests
         public void Lays_Out_Horizontally_On_A_Single_Line()
         {
             var target = new WrapPanel()
-                         {
-                            Width = 200,
-                            Children =
+            {
+                Width = 200,
+                Children =
                             {
                                 new Border { Height = 50, Width = 100 },
                                 new Border { Height = 50, Width = 100 },
                             }
-                         };
+            };
 
             target.Measure(Size.Infinity);
             target.Arrange(new Rect(target.DesiredSize));
@@ -54,15 +54,15 @@ namespace Avalonia.Controls.UnitTests
         public void Lays_Out_Vertically_Children_On_A_Single_Line()
         {
             var target = new WrapPanel()
-                         {
-                            Orientation = Orientation.Vertical,
-                            Height = 120,
-                            Children =
+            {
+                Orientation = Orientation.Vertical,
+                Height = 120,
+                Children =
                             {
                                 new Border { Height = 50, Width = 100 },
                                 new Border { Height = 50, Width = 100 },
                             }
-                         };
+            };
 
             target.Measure(Size.Infinity);
             target.Arrange(new Rect(target.DesiredSize));
@@ -76,15 +76,15 @@ namespace Avalonia.Controls.UnitTests
         public void Lays_Out_Vertically_On_Separate_Lines()
         {
             var target = new WrapPanel()
-                         {
-                            Orientation = Orientation.Vertical,
-                            Height = 60,
-                            Children =
+            {
+                Orientation = Orientation.Vertical,
+                Height = 60,
+                Children =
                             {
                                 new Border { Height = 50, Width = 100 },
                                 new Border { Height = 50, Width = 100 },
                             }
-                         };
+            };
 
             target.Measure(Size.Infinity);
             target.Arrange(new Rect(target.DesiredSize));
@@ -98,17 +98,17 @@ namespace Avalonia.Controls.UnitTests
         public void Applies_ItemWidth_And_ItemHeight_Properties()
         {
             var target = new WrapPanel()
-                        {
-                            Orientation = Orientation.Horizontal,
-                            Width = 50,
-                            ItemWidth = 20,
-                            ItemHeight = 15,
-                            Children =
+            {
+                Orientation = Orientation.Horizontal,
+                Width = 50,
+                ItemWidth = 20,
+                ItemHeight = 15,
+                Children =
                             {
                                 new Border(),
                                 new Border(),
                             }
-                        };
+            };
 
             target.Measure(Size.Infinity);
             target.Arrange(new Rect(target.DesiredSize));
@@ -117,5 +117,33 @@ namespace Avalonia.Controls.UnitTests
             Assert.Equal(new Rect(0, 0, 20, 15), target.Children[0].Bounds);
             Assert.Equal(new Rect(20, 0, 20, 15), target.Children[1].Bounds);
         }
+
+        [Fact]
+        void ItemWidth_Trigger_InvalidateMeasure()
+        {
+            var target = new WrapPanel();
+
+            target.Measure(new Size(10, 10));
+
+            Assert.True(target.IsMeasureValid);
+
+            target.ItemWidth = 1;
+
+            Assert.False(target.IsMeasureValid);
+        }
+
+        [Fact]
+        void ItemHeight_Trigger_InvalidateMeasure()
+        {
+            var target = new WrapPanel();
+
+            target.Measure(new Size(10, 10));
+
+            Assert.True(target.IsMeasureValid);
+
+            target.ItemHeight = 1;
+
+            Assert.False(target.IsMeasureValid);
+        }
     }
 }