Bug 458844 - [GTK3] TabItem hierarchy change breaks shared control

Fix for correct re-parenting for the case where the tab-control is
migrated between tabs via setControl.

Test with Junit Gtk2/3 and with own array of tests also.

Change-Id: I57b70f32ce86569c7ff9697909df0f83bfcb6167
Signed-off-by: Leo Ufimtsev <lufimtse@redhat.com>

3 files changed, 48 insertions, 52 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/ExpandItem.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/ExpandItem.java
index c599913e2c..8e0a4deac9 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/ExpandItem.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/ExpandItem.java
@@ -510,7 +510,7 @@ public void setControl (Control control) {
 			//As ExpandItem's child can be created before the ExpandItem, our only
 			//option is to reparent the child upon the setControl(..) call.
 			//This is simmilar to TabFolder.
-			gtk_widget_reparent (control, clientHandle ());
+			gtk_widget_reparent (control.topHandle (), clientHandle ());
 		}
 	}
 	parent.layoutItems (0, true);
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TabItem.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TabItem.java
index 6fb8801961..efd1d7e691 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TabItem.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TabItem.java
@@ -287,46 +287,45 @@ public void setControl (Control control) {
 		if (control.parent != parent) error (SWT.ERROR_INVALID_PARENT);
 	}
 
-		if (control != null && OS.GTK3) {
-			/*
-			* Bug 454936 (see also other 454936 references in TabFolder)
-			* Architecture Fix:
-			*  We reparent the child to be a child of the 'tab' rather than tabfolder's parent swtFixed container.
-			*  Note, this reparenting is only on the GTK side, not on the SWT side.
-			*
-			*  Note, GTK2 and GTK3 child nesting behaviour is different now.
-			*  GTK2:
-			*    swtFixed
-			*    |-- GtkNoteBook
-			*    |   |-- tabLabel1
-			*    |   |-- tabLabel2
-			*    |-- swtFixed (child1)  //child is sibling of Notebook
-			*    |-- swtFixed (child2)
-			*
-			*  GTK3+:
-			*  	swtFixed
-			*  	|--	GtkNoteBook
-			*  		|-- tabLabel1
-			*  		|-- tabLabel2
-			*  		|-- swtFixed (child1) //child now child of Notebook.
-			*  		|-- swtFixed (child2)
-			*
-			*  This corrects the hierarchy so that children are beneath gtkNotebook (as oppose to
-			*  being siblings) and thus fixes DND and background color issues.
-			*  In gtk2, reparenting doesn't function properly (tab content appear blank),
-			*  so this is a gtk3-specific behavior.
-			*
-			*  Note about the reason for reparenting:
-			*   Reparenting (as oppose to adding widget to a tab in the first place) is neccessary
-			*   because you can have a situation where you create a widget before you create a tab. e.g
-			*     TabFolder tabFolder = new TabFolder(shell, 0);
-			*     Composite composite = new Composite(tabFolder, 0);
-			*     TabItem tabItem = new TabItem(tabFolder, 0);
-			*     tabitem.setControl(composite);
-			*/
-			gtk_widget_reparent (control, pageHandle);
-		}
-
+	if (control != null && OS.GTK3) {
+		/*
+		* Bug 454936 (see also other 454936 references in TabFolder)
+		* Architecture Fix:
+		*  We reparent the child to be a child of the 'tab' rather than tabfolder's parent swtFixed container.
+		*  Note, this reparenting is only on the GTK side, not on the SWT side.
+		*
+		*  Note, GTK2 and GTK3 child nesting behaviour is different now.
+		*  GTK2:
+		*    swtFixed
+		*    |-- GtkNoteBook
+		*    |   |-- tabLabel1
+		*    |   |-- tabLabel2
+		*    |-- swtFixed (child1)  //child is sibling of Notebook
+		*    |-- swtFixed (child2)
+		*
+		*  GTK3+:
+		*  	swtFixed
+		*  	|--	GtkNoteBook
+		*  		|-- tabLabel1
+		*  		|-- tabLabel2
+		*  		|-- swtFixed (child1) //child now child of Notebook.
+		*  		|-- swtFixed (child2)
+		*
+		*  This corrects the hierarchy so that children are beneath gtkNotebook (as oppose to
+		*  being siblings) and thus fixes DND and background color issues.
+		*  In gtk2, reparenting doesn't function properly (tab content appear blank),
+		*  so this is a gtk3-specific behavior.
+		*
+		*  Note about the reason for reparenting:
+		*   Reparenting (as oppose to adding widget to a tab in the first place) is neccessary
+		*   because you can have a situation where you create a widget before you create a tab. e.g
+		*     TabFolder tabFolder = new TabFolder(shell, 0);
+		*     Composite composite = new Composite(tabFolder, 0);
+		*     TabItem tabItem = new TabItem(tabFolder, 0);
+		*     tabitem.setControl(composite);
+		*/
+		OS.gtk_widget_reparent (control.topHandle (), pageHandle);
+	}
 
 	Control oldControl = this.control, newControl = control;
 	this.control = control;
@@ -345,7 +344,9 @@ public void setControl (Control control) {
 		newControl.setBounds (parent.getClientArea ());
 		newControl.setVisible (true);
 	}
-	if (oldControl != null) oldControl.setVisible (false);
+
+	if (oldControl != null && newControl != null && oldControl != newControl)
+		oldControl.setVisible (false);
 }
 
 void setFontDescription (long /*int*/ font) {
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Widget.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Widget.java
index 10a310646e..d3713f9fc3 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Widget.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Widget.java
@@ -979,22 +979,17 @@ long /*int*/ gtk_visibility_notify_event (long /*int*/ widget, long /*int*/ even
 	return 0;
 }
 
-void gtk_widget_reparent (Control control, long /*int*/ newParent) {
-	long /*int*/ widget = control.topHandle ();
-	long /*int*/ oldParent = control.parent.topHandle ();
-	gtk_widget_reparent(widget, oldParent, newParent);
-}
-
 /**
  * Reparent on gtk side.
  * Note: Composites with a setControl() function should probably use this function
  * to correct hierarchy on gtk side.
- * @param control
+ * @param widget  the handle to the widget. (usually topHandle())
+ * @param newParent  handle to the new widget.
  */
-//Note, we do not actually call  * 'gtk_widget_reparent(...) as it's deprecated as of gtk 3.14
-void gtk_widget_reparent (long /*int*/ widget, long /*int*/ oldParent, long /*int*/ newParent) {
+void gtk_widget_reparent (long /*int*/ widget, long /*int*/ newParent) {
+	//Note, we do not actually call  * 'gtk_widget_reparent(...) as it's deprecated as of gtk 3.14
 	OS.g_object_ref (widget); //so that it won't get destroyed due to lack of references.
-	OS.gtk_container_remove (oldParent, widget);
+	OS.gtk_container_remove (OS.gtk_widget_get_parent (widget), widget);
 	OS.gtk_container_add (newParent, widget);
 	OS.g_object_unref (widget);
 }