Group#computeTrim starts to fail when parent tree is set as the control of an unselect TabItem, problem can be seing in ControlExample. The fix is stop reparenting in TabItem#setControl().

2 files changed, 44 insertions, 19 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT/wpf/org/eclipse/swt/widgets/TabFolder.java b/bundles/org.eclipse.swt/Eclipse SWT/wpf/org/eclipse/swt/widgets/TabFolder.java
index f53969ce02..8e7beda5a9 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/wpf/org/eclipse/swt/widgets/TabFolder.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/wpf/org/eclipse/swt/widgets/TabFolder.java
@@ -222,6 +222,20 @@ Control [] _getChildren () {
 	return result;
 }
 
+public Rectangle getClientArea () {
+	checkWidget ();
+	Rectangle rect = super.getClientArea ();
+	int clientHandle = clientHandle ();
+	int topHandle = topHandle ();
+	int point = OS.gcnew_Point (0, 0);
+	int result = OS.UIElement_TranslatePoint (clientHandle, point, topHandle);
+	rect.x = (int) OS.Point_X (result);
+	rect.y = (int) OS.Point_Y (result);
+	OS.GCHandle_Free (point);
+	OS.GCHandle_Free (result);
+	return rect;
+}
+
 /**
  * Returns the item at the given, zero-relative index in the
  * receiver. Throws an exception if the index is out of range.
@@ -340,13 +354,29 @@ boolean hasItems () {
 	return true;
 }
 
-void HandleSelectionChange (int sender, int e) {
+void HandleSelectionChanged (int sender, int e) {
 	if (!checkEvent (e)) return;
-	if (ignoreSelection) return;
+	int removed = OS.SelectionChangedEventArgs_RemovedItems (e);
+	if (OS.ICollection_Count (removed) > 0) {
+		int oldSelection = OS.IList_default (removed, 0);
+		TabItem item = (TabItem) display.getWidget (oldSelection);
+		OS.GCHandle_Free (oldSelection);
+		Control control = item.getControl(); 
+		if (control != null && !control.isDisposed ()) {
+			control.setVisible (false);
+		}
+	}
+	OS.GCHandle_Free (removed);
 	int selectedItem = OS.Selector_SelectedItem (handle);
 	if (selectedItem == 0) return;
 	TabItem item = (TabItem) display.getWidget (selectedItem);
 	OS.GCHandle_Free (selectedItem);
+	
+	Control control = item.getControl(); 
+	if (control != null && !control.isDisposed ()) {
+		control.setVisible (true);
+	}
+	if (ignoreSelection) return;
 	Event event = new Event ();
 	event.item = item;
 	postEvent (SWT.Selection, event);
@@ -354,7 +384,7 @@ void HandleSelectionChange (int sender, int e) {
 
 void hookEvents () {
 	super.hookEvents ();
-	int handler = OS.gcnew_SelectionChangedEventHandler (jniRef, "HandleSelectionChange");
+	int handler = OS.gcnew_SelectionChangedEventHandler (jniRef, "HandleSelectionChanged");
 	OS.Selector_SelectionChanged (handle, handler);
 	OS.GCHandle_Free (handler);
 }
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/wpf/org/eclipse/swt/widgets/TabItem.java b/bundles/org.eclipse.swt/Eclipse SWT/wpf/org/eclipse/swt/widgets/TabItem.java
index ff37292228..dca8e1e6d7 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/wpf/org/eclipse/swt/widgets/TabItem.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/wpf/org/eclipse/swt/widgets/TabItem.java
@@ -272,26 +272,21 @@ public void setControl (Control control) {
 		if (control.isDisposed()) error (SWT.ERROR_INVALID_ARGUMENT);
 		if (control.parent != parent) error (SWT.ERROR_INVALID_PARENT);
 	}
+	if (this.control != null && this.control.isDisposed ()) {
+		this.control = null;
+	}
 	Control oldControl = this.control, newControl = control;
 	this.control = control;
-	int children = OS.Panel_Children (contentHandle);
-	int parentHandle = parent.parentingHandle ();
-	int parentChildren = OS.Panel_Children (parentHandle);
-	if (newControl != null) {
-		int topHandle = newControl.topHandle ();
-		OS.UIElementCollection_Remove (parentChildren, topHandle);
-		OS.UIElementCollection_Add (children, topHandle);
-		if (OS.FrameworkElement_IsLoaded (handle)) {
-			newControl.setBounds (parent.getClientArea ());
-		}
+	int index = parent.indexOf (this);
+	if (index != parent.getSelectionIndex ()) {
+		if (newControl != null) newControl.setVisible (false);
+		return;
 	}
-	if (oldControl != null) {
-		int topHandle = oldControl.topHandle ();
-		OS.UIElementCollection_Remove (children, topHandle);
-		OS.UIElementCollection_Add (parentChildren, topHandle);
+	if (newControl != null) {
+		newControl.setBounds (parent.getClientArea ());
+		newControl.setVisible (true);
 	}
-	OS.GCHandle_Free (children);
-	OS.GCHandle_Free (parentChildren);
+	if (oldControl != null) oldControl.setVisible (false);
 }
 
 public void setImage (Image image) {