Bug 534089 – [GTK3] Tabfolder setControl(..) breaks with a table that

has composite controls.

Temporarily make use of the deprecated gtk_widget_reparent(..)
as alternative fix would require deep investigation and we need
something functional for photon.

Bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=5340893
Change-Id: I351518383ce77343ccd10e1f1a45750e5663d5c8
Signed-off-by: Leo Ufimtsev <lufimtse@redhat.com>

2 files changed, 19 insertions, 5 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GTK.java b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GTK.java
index f361fc1325..ef0023c904 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GTK.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GTK.java
@@ -9085,7 +9085,6 @@ public class GTK extends OS {
 	public static final native void _gtk_widget_reparent(long /*int*/ widget, long /*int*/ new_parent);
 	/** deprecated as of 3.14 */
 	public static final void gtk_widget_reparent(long /*int*/ widget, long /*int*/ new_parent) {
-		assert !GTK3; // On Gtk3, use Control.gtk_widget_reparent(..);
 		lock.lock();
 		try {
 			_gtk_widget_reparent(widget, new_parent);
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java
index 239c99b77f..f2a8c61ff6 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java
@@ -2729,10 +2729,25 @@ static void gtk_widget_reparent (Control control, long /*int*/ newParentHandle)
 		long /*int*/ parentContainer = GTK.gtk_widget_get_parent (widget);
 		assert parentContainer != 0 : "Improper use of Control.gtk_widget_reparent. Widget currently has no parent.";
 		if (parentContainer != 0) {
-			OS.g_object_ref (widget); //so that it won't get destroyed due to lack of references.
-			GTK.gtk_container_remove (parentContainer, widget);
-			GTK.gtk_container_add (newParentHandle, widget);
-			OS.g_object_unref (widget);
+
+			// gtk_widget_reparent (..) is deprecated as of Gtk 3.14 and removed in Gtk4.
+			// However, the current alternative of removing/adding widget from/to a container causes errors. (see note below).
+			// TODO - research a better way to reparent. See 534089.
+			GTK.gtk_widget_reparent(widget, newParentHandle);
+
+			// Removing/Adding containers doesn't seem to reparent sub-gdkWindows properly and throws errors.
+			// Steps to reproduce:
+			//  - From bug 534089, download the first attachment plugin: "Plug-in to reproduce the problem with"
+			//  - Import it into your eclipse. Launch a child eclipse with this plugin. Ensure child workspace is cleaned upon launch so that you see welcome screen.
+			//  - Upon closing the welcome screen, you will see an eclipse error message: "org.eclipse.swt.SWTError: No more handles"
+			//  - The following is printed into the console: 'gdk_window_new(): parent is destroyed'
+			// After some research, I found that gtk_widget_repartent(..) also reparents sub-windows, but moving widget between containers doesn't do this,
+			// This seems to leave some gdkWindows with incorrect parents.
+//			OS.g_object_ref (widget);
+//			GTK.gtk_container_remove (parentContainer, widget);
+//			GTK.gtk_container_add (newParentHandle, widget);
+//			OS.g_object_unref (widget);
+
 			control.fixParentGdkWindow();
 		}
 	} else { // Gtk2.