From 5ea4d03f077f830e6101463e8692856a1f0f9efe Mon Sep 17 00:00:00 2001
From: =?utf8?q?Jean-Philippe=20Bruy=C3=A8re?= <jp_bruyere@hotmail.com>
Date: Thu, 18 Mar 2021 17:20:28 +0100
Subject: [PATCH] drawing optimisation:group double drawing solved,
 Region.Reset()

---
 Crow/src/Mono.Cairo/Region.cs        |  6 ++++++
 Crow/src/Widgets/Group.cs            | 19 ++++++-------------
 Crow/src/Widgets/PrivateContainer.cs |  3 +--
 Crow/src/Widgets/Widget.cs           | 20 +++++++++++---------
 4 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/Crow/src/Mono.Cairo/Region.cs b/Crow/src/Mono.Cairo/Region.cs
index 5e8d8d60..f2c111d7 100644
--- a/Crow/src/Mono.Cairo/Region.cs
+++ b/Crow/src/Mono.Cairo/Region.cs
@@ -192,5 +192,11 @@ namespace Crow.Cairo
 		{
 			return NativeMethods.cairo_region_xor_rectangle (Handle, ref rectangle);
 		}
+		public void Reset () {
+			if (IsEmpty)
+				return;
+			NativeMethods.cairo_region_destroy (Handle);
+			handle = NativeMethods.cairo_region_create ();			
+		}
 	}
 }
diff --git a/Crow/src/Widgets/Group.cs b/Crow/src/Widgets/Group.cs
index 69fc614e..5f6a97f8 100644
--- a/Crow/src/Widgets/Group.cs
+++ b/Crow/src/Widgets/Group.cs
@@ -309,12 +309,8 @@ namespace Crow
 		}
 		protected override void UpdateCache (Context ctx)
 		{
-			Rectangle rb = Slot + Parent.ClientRectangle.Position;
-
-
-			Context gr = new Context (bmp);
-
 			if (!Clipping.IsEmpty) {
+				Context gr = new Context (bmp);
 				for (int i = 0; i < Clipping.NumRectangles; i++)
 					gr.Rectangle(Clipping.GetRectangle(i));
 				gr.ClipPreserve();
@@ -348,14 +344,11 @@ namespace Crow
 					gr.Rectangle(Clipping.GetRectangle(i));
 				gr.Stroke ();*/
 				#endif
-			}
-			gr.Dispose ();
-
-			ctx.SetSource (bmp, rb.X, rb.Y);
-			ctx.Paint ();
-
-			Clipping.Dispose();
-			Clipping = new Region ();
+				gr.Dispose ();
+				Clipping.Reset ();				
+			}/*else
+				Console.WriteLine("GROUP REPAINT WITH EMPTY CLIPPING");*/
+			paintCache (ctx, Slot + Parent.ClientRectangle.Position);
 		}
 		#endregion
 
diff --git a/Crow/src/Widgets/PrivateContainer.cs b/Crow/src/Widgets/PrivateContainer.cs
index bb0bf531..6bdff7da 100644
--- a/Crow/src/Widgets/PrivateContainer.cs
+++ b/Crow/src/Widgets/PrivateContainer.cs
@@ -224,8 +224,7 @@ namespace Crow
 
 			ctx.SetSource (bmp, rb.X, rb.Y);
 			ctx.Paint ();
-			Clipping.Dispose();
-			Clipping = new Region ();
+			Clipping.Reset ();			
 		}
 		#endregion
 
diff --git a/Crow/src/Widgets/Widget.cs b/Crow/src/Widgets/Widget.cs
index 1553dab4..4c35c153 100644
--- a/Crow/src/Widgets/Widget.cs
+++ b/Crow/src/Widgets/Widget.cs
@@ -1810,14 +1810,11 @@ namespace Crow
 				onDraw (gr);
 			}
 
-			IsDirty = false;
+			IsDirty = false;			
 
 			DbgLogger.EndEvent (DbgEvtType.GORecreateCache);
 		}
-		protected virtual void UpdateCache(Context ctx){
-			DbgLogger.StartEvent(DbgEvtType.GOUpdateCache, this);
-
-			Rectangle rb = Slot + Parent.ClientRectangle.Position;
+		protected void paintCache(Context ctx, Rectangle rb) {
 			if (clearBackground) {
 				ctx.Operator = Operator.Clear;
 				ctx.Rectangle (rb);
@@ -1827,8 +1824,11 @@ namespace Crow
 
 			ctx.SetSource (bmp, rb.X, rb.Y);
 			ctx.Paint ();
-			Clipping.Dispose ();
-			Clipping = new Region ();
+		}
+		protected virtual void UpdateCache(Context ctx){
+			DbgLogger.StartEvent(DbgEvtType.GOUpdateCache, this);			
+			paintCache (ctx, Slot + Parent.ClientRectangle.Position);
+			Clipping.Reset ();			
 			DbgLogger.EndEvent (DbgEvtType.GOUpdateCache);
 		}
 		/// <summary> Chained painting routine on the parent context of the actual cached version
@@ -1866,9 +1866,11 @@ namespace Crow
 				}
 
 				if (cacheEnabled) {
-					if (IsDirty)
+					if (IsDirty) {
 						RecreateCache ();
-					UpdateCache (ctx);
+						paintCache (ctx, Slot + Parent.ClientRectangle.Position);
+					}else
+						UpdateCache (ctx);
 					if (!IsEnabled)						
 						paintDisabled (ctx, Slot + Parent.ClientRectangle.Position);					
 				} else {
-- 
2.47.3