Fix the config box treeview width in GTK3.

My trickery in GTK2 to start with some branches of the tree collapsed
but give the widget all the width it will need when they open later
was not working in GTK3, for the same reason I've needed several other
fixes recently: just after creation, GTK3 widgets report their
preferred size as zero.

Fixed by doing basically the same trick I was doing in GTK2, but
deferring it until the "map" event happens later on.

diff --git a/unix/gtkdlg.c b/unix/gtkdlg.c
index a584501c963c493b672b71d58e7cf65ecd6d5f6e..a6c8f984cad002084b8a0e002ea96d520532078d 100644 (file)
--- a/unix/gtkdlg.c
+++ b/unix/gtkdlg.c
@@ -83,6 +83,9 @@ struct dlgparam {
 #if !GTK_CHECK_VERSION(2,0,0)
     GtkWidget *currtreeitem, **treeitems;
     int ntreeitems;
+#else
+    int nselparams;
+    struct selparam *selparams;
 #endif
     int retval;
 };
@@ -2977,6 +2980,32 @@ void set_dialog_action_area(GtkDialog *dlg, GtkWidget *w)
 #endif
 }
 
+#if GTK_CHECK_VERSION(2,0,0)
+void initial_treeview_collapse(struct dlgparam *dp, GtkWidget *tree)
+{
+    /*
+     * Collapse the deeper branches of the treeview into the state we
+     * like them to start off in. See comment below in do_config_box.
+     */
+    int i;
+    for (i = 0; i < dp->nselparams; i++)
+        if (dp->selparams[i].depth >= 2)
+            gtk_tree_view_collapse_row(GTK_TREE_VIEW(tree),
+                                       dp->selparams[i].treepath);
+}
+#endif
+
+#if GTK_CHECK_VERSION(3,0,0)
+void treeview_map_event(GtkWidget *tree, gpointer data)
+{
+    struct dlgparam *dp = (struct dlgparam *)data;
+    GtkAllocation alloc;
+    gtk_widget_get_allocation(tree, &alloc);
+    gtk_widget_set_size_request(tree, alloc.width, -1);
+    initial_treeview_collapse(dp, tree);
+}
+#endif
+
 int do_config_box(const char *title, Conf *conf, int midsession,
                  int protcfginfo)
 {
@@ -3207,33 +3236,43 @@ int do_config_box(const char *title, Conf *conf, int midsession,
     }
 
 #if GTK_CHECK_VERSION(2,0,0)
-    {
-       GtkRequisition req;
-       int i;
+    /*
+     * We want our tree view to come up with all branches at depth 2
+     * or more collapsed. However, if we start off with those branches
+     * collapsed, then the tree view's size request will be calculated
+     * based on the width of the collapsed tree, and then when the
+     * collapsed branches are expanded later, the tree view will
+     * jarringly change size.
+     *
+     * So instead we start with everything expanded; then, once the
+     * tree view has computed its resulting width requirement, we
+     * collapse the relevant rows, but force the width to be the value
+     * we just retrieved. This arranges that the tree view is wide
+     * enough to have all branches expanded without further resizing.
+     */
 
-       /*
-        * We want our tree view to come up with all branches at
-        * depth 2 or more collapsed. However, if we start off
-        * with those branches collapsed, then the tree view's
-        * size request will be calculated based on the width of
-        * the collapsed tree. So instead we start with them all
-        * expanded; then we ask for the current size request,
-        * collapse the relevant rows, and force the width to the
-        * value we just computed. This arranges that the tree
-        * view is wide enough to have all branches expanded
-        * safely.
-        */
+    dp.nselparams = nselparams;
+    dp.selparams = selparams;
 
+#if !GTK_CHECK_VERSION(3,0,0)
+    {
+        /*
+         * In GTK2, we can just do the job right now.
+         */
+       GtkRequisition req;
        gtk_widget_size_request(tree, &req);
-
-       for (i = 0; i < nselparams; i++)
-           if (selparams[i].depth >= 2)
-               gtk_tree_view_collapse_row(GTK_TREE_VIEW(tree),
-                                          selparams[i].treepath);
-
+        initial_treeview_collapse(&dp, tree);
        gtk_widget_set_size_request(tree, req.width, -1);
     }
-#endif
+#else
+    /*
+     * But in GTK3, we have to wait until the widget is about to be
+     * mapped, because the size computation won't have been done yet.
+     */
+    g_signal_connect(G_OBJECT(tree), "map",
+                     G_CALLBACK(treeview_map_event), &dp);
+#endif /* GTK 2 vs 3 */
+#endif /* GTK 2+ vs 1 */
 
 #if GTK_CHECK_VERSION(2,0,0)
     g_signal_connect(G_OBJECT(treeselection), "changed",
@@ -3241,7 +3280,6 @@ int do_config_box(const char *title, Conf *conf, int midsession,
 #else
     dp.ntreeitems = nselparams;
     dp.treeitems = snewn(dp.ntreeitems, GtkWidget *);
-
     for (index = 0; index < nselparams; index++) {
         g_signal_connect(G_OBJECT(selparams[index].treeitem), "select",
                          G_CALLBACK(treeitem_sel),