Prevent toolbox getting lost when minimising windows

On X, window managers don't like WM_TRANSIENT_FOR being altered while a
window is visible; this meant that if you opened TikZiT and opened a
second main window and minimised the main window that had focus, the
toolbox and properties window would both disappear, with no way to get
them back (well, almost - the properties window could be retreived with
the menu item that shows/hides it).

Tested with KWin, Metacity (Gnome 2's WM), Mutter (Gnome 3) and xfwm4
(XFCE 4).  Metacity and Mutter still behave a little oddly - you have to
click one of the main windows *twice* to get it to focus.  KWin and
xfwm4 work fine.

1 files changed, 21 insertions, 0 deletions

diff --git a/tikzit/src/gtk/gtkhelpers.m b/tikzit/src/gtk/gtkhelpers.m
index e6b1aef..9d26af5 100644
--- a/tikzit/src/gtk/gtkhelpers.m
+++ b/tikzit/src/gtk/gtkhelpers.m
@@ -251,4 +251,25 @@ void text_buffer_clear_tag (GtkTextBuffer *buffer, GtkTextTag *tag) {
     gtk_text_buffer_remove_tag (buffer, tag, &start, &end);
 }
 
+void utility_window_attach (GtkWindow *util_win, GtkWindow *parent_win) {
+    if (parent_win == gtk_window_get_transient_for (util_win))
+        return;
+
+    // HACK: X window managers tend to move windows around when they are
+    //       unmapped and mapped again, so we save the position
+    gint x, y;
+    gtk_window_get_position (util_win, &x, &y);
+
+    // HACK: Altering WM_TRANSIENT_FOR on a non-hidden but unmapped window
+    //       (eg: when you have minimised the original parent window) can
+    //       cause the window to be lost forever, so we hide it first
+    gtk_widget_hide (GTK_WIDGET (util_win));
+    gtk_window_set_focus_on_map (util_win, FALSE);
+    gtk_window_set_transient_for (util_win, parent_win);
+    gtk_widget_show (GTK_WIDGET (util_win));
+
+    // HACK: see above
+    gtk_window_move (util_win, x, y);
+}
+
 // vim:ft=objc:ts=8:et:sts=4:sw=4