From 325573e4c0328189cf2353b31fc68780224bbc57 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Jean-Philippe=20Bruy=C3=A8re?= <jp_bruyere@hotmail.com>
Date: Tue, 2 Nov 2021 12:47:48 +0100
Subject: [PATCH] make treeView subdata fetching working with IEnumerable

---
 Crow/src/ItemTemplate.cs                      | 62 ++++++++++++-------
 Samples/ShowCase/ShowCase.cs                  |  2 +
 .../Experimental/testLoadCtxTree.crow         | 44 +++++++++++++
 3 files changed, 84 insertions(+), 24 deletions(-)
 create mode 100644 Samples/common/ui/Interfaces/Experimental/testLoadCtxTree.crow

diff --git a/Crow/src/ItemTemplate.cs b/Crow/src/ItemTemplate.cs
index c263b656..9c67d57e 100644
--- a/Crow/src/ItemTemplate.cs
+++ b/Crow/src/ItemTemplate.cs
@@ -226,7 +226,6 @@ namespace Crow
 			il = dm.GetILGenerator (256);
 			System.Reflection.Emit.Label end = il.DefineLabel ();
 			System.Reflection.Emit.Label test = il.DefineLabel ();
-
 			//get the dataSource of the arg0
 			il.Emit (OpCodes.Ldarg_0);
 			il.Emit (OpCodes.Callvirt, CompilerServices.miGetDataSource);
@@ -241,15 +240,20 @@ namespace Crow
 				}else
 					emitGetSubData(il, dataType);
 			}
-			il.Emit (OpCodes.Isinst, typeof(System.Collections.ICollection));
 			il.Emit (OpCodes.Dup);//duplicate children for testing if it's a collection for childs counting
+			il.Emit (OpCodes.Isinst, typeof(System.Collections.ICollection));
 			il.Emit (OpCodes.Brtrue, test);//if true, jump to perform count
-			il.Emit (OpCodes.Pop);//pop null
-			il.Emit (OpCodes.Ldc_I4_0);//push false
+			il.Emit (OpCodes.Isinst, typeof(System.Collections.IEnumerable));//test if enumerable
+			System.Reflection.Emit.Label pushTrue = il.DefineLabel ();
+			il.Emit (OpCodes.Brtrue, pushTrue);
+			il.Emit (OpCodes.Ldc_I4_0);//is not an enumerable, so push false for return
+			il.Emit (OpCodes.Br, end);
+			il.MarkLabel (pushTrue);
+			il.Emit (OpCodes.Ldc_I4_1);//is an enumerable, so push true for return
 			il.Emit (OpCodes.Br, end);
 
 			il.MarkLabel (test);
-
+			il.Emit (OpCodes.Isinst, typeof(System.Collections.ICollection));
 			il.Emit (OpCodes.Callvirt, CompilerServices.miGetColCount);
 			il.Emit (OpCodes.Ldc_I4_0);
 			il.Emit (OpCodes.Cgt);
@@ -260,31 +264,41 @@ namespace Crow
 			HasSubItems = (BooleanTestOnInstance)dm.CreateDelegate (typeof(BooleanTestOnInstance));
 			#endregion
 		}
+		static void emitcallvirtornot (ILGenerator il, MethodInfo mi) {
+			if (mi.IsStatic)
+				il.Emit (OpCodes.Call, mi);
+			else
+				il.Emit (OpCodes.Callvirt, mi);
+		}
 		//data is on the stack
 		void emitGetSubData(ILGenerator il, Type dataType){
 			if (dataType.IsValueType)
 				il.Emit (OpCodes.Unbox_Any, dataType);
-			MethodInfo miGetDatas = dataType.GetMethod (fetchMethodName, new Type[] {});
-			if (miGetDatas == null)
-				miGetDatas = iface.SearchExtMethod (dataType, fetchMethodName);
-
-			if (miGetDatas == null) {//in last resort, search among properties
-				PropertyInfo piDatas = dataType.GetProperty (fetchMethodName);
-				if (piDatas == null) {
-					FieldInfo fiDatas = dataType.GetField (fetchMethodName);
-					if (fiDatas == null)//and among fields
-						throw new Exception ("Fetch data member not found in ItemTemplate: " + fetchMethodName);
-					il.Emit (OpCodes.Ldfld, fiDatas);
-					return;
-				}
-				miGetDatas = piDatas.GetGetMethod ();
-				if (miGetDatas == null)
+			MemberInfo miGetData = dataType.GetMember (fetchMethodName, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)
+				.FirstOrDefault(mmi => (mmi is MethodInfo mmmi && mmmi.GetParameters().Length == 0) || mmi.MemberType != MemberTypes.Method);
+
+			if (miGetData == null) {
+				MethodInfo extMethd = iface.SearchExtMethod (dataType, fetchMethodName);
+				if (extMethd == null)
+					throw new Exception ("Fetch data member not found in ItemTemplate: " + fetchMethodName);
+				emitcallvirtornot (il, extMethd);
+				return;
+			}
+			if (miGetData is MethodInfo mi) {
+				emitcallvirtornot (il, mi);
+				return;
+			}
+			if (miGetData is PropertyInfo pi) {
+				if (!pi.CanRead)
 					throw new Exception ("Write only property for fetching data in ItemTemplate: " + fetchMethodName);
+				emitcallvirtornot (il, pi.GetGetMethod ());
+				//il.Emit (OpCodes.Call, pi.GetGetMethod ());
+				return;
+			}
+			if (miGetData is FieldInfo fi) {
+				il.Emit (OpCodes.Ldfld, fi);
+				return;
 			}
-            if (miGetDatas.IsStatic)
-			    il.Emit (OpCodes.Call, miGetDatas);
-            else
-                il.Emit (OpCodes.Callvirt, miGetDatas);
         }
 	}
 
diff --git a/Samples/ShowCase/ShowCase.cs b/Samples/ShowCase/ShowCase.cs
index 7b25d718..49663438 100644
--- a/Samples/ShowCase/ShowCase.cs
+++ b/Samples/ShowCase/ShowCase.cs
@@ -188,5 +188,7 @@ namespace ShowCase
 				NotifyValueChanged (Crow.Interface.POLLING_INTERVAL);
 			}
 		}
+		public IEnumerable<System.Runtime.Loader.AssemblyLoadContext> AllLoadContexts =>
+			System.Runtime.Loader.AssemblyLoadContext.All;
     }
 }
\ No newline at end of file
diff --git a/Samples/common/ui/Interfaces/Experimental/testLoadCtxTree.crow b/Samples/common/ui/Interfaces/Experimental/testLoadCtxTree.crow
new file mode 100644
index 00000000..3a1dd0ef
--- /dev/null
+++ b/Samples/common/ui/Interfaces/Experimental/testLoadCtxTree.crow
@@ -0,0 +1,44 @@
+<TreeView IsRoot="true" Name="lbCtxs"  Data="{AllLoadContexts}" UseLoadingThread = 'false' >
+			<!--<ItemTemplate DataType="System.Reflection.Assembly">
+				<ListItem CornerRadius="2" Margin="0" Height="Fit" Width="Stretched"
+						Selected="{Background=${ControlHighlight}}"
+						Unselected="{Background=Transparent}">
+					<HorizontalStack>
+						<Label Text="{}" Width="Stretched"/>
+					</HorizontalStack>
+				</ListItem>
+			</ItemTemplate>-->
+			<ItemTemplate DataType="System.Runtime.Loader.AssemblyLoadContext" Data="Assemblies">
+				<ListItem
+						Selected="{/exp.Background=${ControlHighlight}}"
+						Unselected="{/exp.Background=Transparent}">
+					<Expandable Name="exp" Caption="{}" MouseDoubleClick="/onClickForExpand" BubbleEvents="All">
+						<Template>
+							<VerticalStack>
+								<Border CornerRadius="2" Margin="0" Height="Fit" MouseDoubleClick="./onClickForExpand"
+										Foreground="Transparent"
+										MouseEnter="{Foreground=DimGrey}"
+										MouseLeave="{Foreground=Transparent}">
+									<HorizontalStack Background="{./Background}" Spacing="1">
+										<Image Margin="1" Width="9" Height="9" Focusable="true" MouseDown="./onClickForExpand"
+											Path="{./Image}"
+											Visible="{./IsExpandable}"
+											SvgSub="{./IsExpanded}"
+											MouseEnter="{Background=LightGrey}"
+											MouseLeave="{Background=Transparent}"/>
+										<Image Margin="1" Width="16" Height="16"
+											Path="#Crow.Icons.folder.svg" SvgSub="{./IsExpanded}"/>
+										<Label Text="{}"/>
+									</HorizontalStack>
+								</Border>
+								<Container Name="Content" Visible="false"/>
+							</VerticalStack>
+						</Template>
+						<HorizontalStack Height="Fit">
+							<Widget Width="12" Height="10"/>
+							<VerticalStack Height="Fit" Name="ItemsContainer"/>
+						</HorizontalStack>
+					</Expandable>
+				</ListItem>
+			</ItemTemplate> 
+		</TreeView>
\ No newline at end of file
-- 
2.47.3