In May 2000, I proposed a patch to improve tooltip browsing. It eliminates
the wait before tooltips pop up if you're just moving the mouse along the
toolbar. As soon as you do anything but moving the mouse, normal behaviour
returns - there's a timeout before tooltip pops up. Normal behaviour also
returns a certain time after the last tooltip pops down.

Tim Janik responded with some comments. Here is a version with his
suggested changes, first submitted June 2000. I've updated it so it is
against CVS Feb 6 2000.

Tim Janik <timj@gtk.org> wrote:
> the way i read your patch, you stay in sticky mode even if you perform
> normal actions like pressing a button or a key.
> there, you should actually leave sticky mode, i.e. the tooltips only popup
> with a (shorter) sticky delay if we just recently showed a tooltip and
> only processed enter/leave events meanwhile.
I've done as suggested. It won't catch button or key presses in
widgets which do not use this tooltip, but that's not much of a
problem in practice.

> rather than comparing the timestamp against the sticky delay, i'd probably
> use it to constrain the code path (in the above patch) for usage of the
> sticky_delay to a certain threshold, say 3 seconds (so when a tooltip popped
> down, and the next one is supposed to popup with sticky_delay, that'll only
> happen within the next three seconds).

OK. I've hardcoded 1 s. STICKY_REVERT_DELAY. I hate to hardcode   
things, but it isn't very useful to tune.

Index: ChangeLog
===================================================================
RCS file: /cvs/gnome/gtk+/ChangeLog,v
retrieving revision 1.1707
diff -u -r1.1707 ChangeLog
--- ChangeLog	2001/02/06 03:08:31	1.1707
+++ ChangeLog	2001/02/06 19:27:19
@@ -1,3 +1,25 @@
+2001-02-06  Jon K Hellan  <hellan@acm.org>
+
+
Implement fast browsing of tooltips:
+

+
* gtk/gtktooltips.h (struct _GtkTooltips): Add sticky_delay,
+
use_sticky_delay and last_popdown
+
(gtk_tooltips_set_sticky_delay): Declare it.
+

+
* gtk/gtktooltips.c (gtk_tooltips_init): Initialize sticky_delay,
+
use_sticky_delay and last_popdown.
+
(gtk_tooltips_set_sticky_delay): New public function. Set sticky
+
delay.
+
(gtk_tooltips_draw_tips, gtk_tooltips_set_active_widget): Record
+
time of popdown.
+
(gtk_tooltips_set_active_widget): Unset sticky behaviour if widget
+
is NULL.
+
(gtk_tooltips_recently_shown): New static function.  Return true
+
if < sticky_delay has elapsed since last popdown.
+
(gtk_tooltips_event_handler): Display window after sticky_delay
+
(presumably < normal delay) if < STICKY_REVERT_DELAY has elapsed
+
since last popdown.
+
 Mon Feb  5 22:05:57 2001  Owen Taylor  <otaylor@redhat.com>
 
 	* gdk/linux-fb/gdkimage-fb.c (_gdk_fb_get_image): Fix syntax
Index: gtk/gtktooltips.h
===================================================================
RCS file: /cvs/gnome/gtk+/gtk/gtktooltips.h,v
retrieving revision 1.16
diff -u -r1.16 gtktooltips.h
--- gtk/gtktooltips.h	2000/08/30 00:33:38	1.16
+++ gtk/gtktooltips.h	2001/02/06 19:27:19
@@ -68,6 +68,9 @@
   guint   delay : 30;
   guint	  enabled : 1;
   gint	  timer_tag;
+  guint   sticky_delay;
+  gboolean use_sticky_delay;
+  GTimeVal last_popdown;
 };
 
 struct _GtkTooltipsClass
@@ -82,6 +85,8 @@
 void
	 gtk_tooltips_disable
   (GtkTooltips   *tooltips);
 void
	 gtk_tooltips_set_delay
   (GtkTooltips   *tooltips,
 
				    guint
   delay);
+void
	 gtk_tooltips_set_sticky_delay (GtkTooltips   *tooltips,
+
				    guint
   sticky_delay);
 void
	 gtk_tooltips_set_tip
   (GtkTooltips   *tooltips,
 
				    GtkWidget
  *widget,
 
				    const gchar   *tip_text,
Index: gtk/gtktooltips.c
===================================================================
RCS file: /cvs/gnome/gtk+/gtk/gtktooltips.c,v
retrieving revision 1.30
diff -u -r1.30 gtktooltips.c
--- gtk/gtktooltips.c	2000/12/04 16:11:51	1.30
+++ gtk/gtktooltips.c	2001/02/06 19:27:20
@@ -38,6 +38,8 @@
 
 
 #define DEFAULT_DELAY 500           /* Default delay in ms */
+#define STICKY_REVERT_DELAY 1000    /* Delay before sticky tooltips revert
+
			     * to normal */
 
 static void gtk_tooltips_class_init        (GtkTooltipsClass *klass);
 static void gtk_tooltips_init              (GtkTooltips      *tooltips);
@@ -103,8 +105,12 @@
   tooltips->tips_data_list = NULL;
   
   tooltips->delay = DEFAULT_DELAY;
+  tooltips->sticky_delay = 0;
   tooltips->enabled = TRUE;
   tooltips->timer_tag = 0;
+  tooltips->use_sticky_delay = FALSE;
+  tooltips->last_popdown.tv_sec = -1;
+  tooltips->last_popdown.tv_usec = -1;
 }
 
 GtkTooltips *
@@ -215,6 +221,16 @@
   tooltips->delay = delay;
 }
 
+void
+gtk_tooltips_set_sticky_delay (GtkTooltips *tooltips,
+
		       guint        sticky_delay)
+{
+  g_return_if_fail (tooltips != NULL);
+  g_return_if_fail (GTK_IS_TOOLTIPS (tooltips));
+
+  tooltips->sticky_delay = sticky_delay;
+}
+
 GtkTooltipsData*
 gtk_tooltips_data_get (GtkWidget       *widget)
 {
@@ -310,7 +326,10 @@
   if (!tooltips->tip_window)
     gtk_tooltips_force_window (tooltips);
   else if (GTK_WIDGET_VISIBLE (tooltips->tip_window))
-    gtk_widget_hide (tooltips->tip_window);
+    {
+      gtk_widget_hide (tooltips->tip_window);
+      g_get_current_time (&tooltips->last_popdown);
+    }
 
   gtk_widget_ensure_style (tooltips->tip_window);
   style = tooltips->tip_window->style;
@@ -369,7 +388,11 @@
                                 GtkWidget   *widget)
 {
   if (tooltips->tip_window)
-    gtk_widget_hide (tooltips->tip_window);
+    {
+      if (GTK_WIDGET_VISIBLE (tooltips->tip_window))
+
g_get_current_time (&tooltips->last_popdown);
+      gtk_widget_hide (tooltips->tip_window);
+    }
   if (tooltips->timer_tag)
     {
       gtk_timeout_remove (tooltips->timer_tag);
@@ -396,8 +419,24 @@
 	    }
 	}
     }
+  else
+    {
+      tooltips->use_sticky_delay = FALSE;
+    }
 }
 
+static gboolean
+gtk_tooltips_recently_shown (GtkTooltips *tooltips)
+{
+  GTimeVal now;
+  glong msec;
+  
+  g_get_current_time (&now);
+  msec = (now.tv_sec  - tooltips->last_popdown.tv_sec) * 1000 +
+
  (now.tv_usec - tooltips->last_popdown.tv_usec) / 1000;
+  return (msec < STICKY_REVERT_DELAY);
+}
+
 static gint
 gtk_tooltips_event_handler (GtkWidget *widget,
                             GdkEvent  *event)
@@ -429,14 +468,31 @@
       if (tooltips->enabled &&
 	  (!old_tips_data || old_tips_data->widget != widget))
 	{
+
  guint delay;
+
  
 	  gtk_tooltips_set_active_widget (tooltips, widget);
 	  
-
  tooltips->timer_tag = gtk_timeout_add (tooltips->delay,
+
  if (tooltips->use_sticky_delay  &&
+
      gtk_tooltips_recently_shown (tooltips))
+
    delay = tooltips->sticky_delay;
+
  else
+
    delay = tooltips->delay;
+
  tooltips->timer_tag = gtk_timeout_add (delay,
 
					 gtk_tooltips_timeout,
 
					 (gpointer) tooltips);
 	}
       break;
 
+    case GDK_LEAVE_NOTIFY:
+      {
+
gboolean use_sticky_delay;
+
+
use_sticky_delay = tooltips->tip_window &&
+
	GTK_WIDGET_VISIBLE (tooltips->tip_window);
+
gtk_tooltips_set_active_widget (tooltips, NULL);
+
tooltips->use_sticky_delay = use_sticky_delay;
+      }
+      break;
     default:
       gtk_tooltips_set_active_widget (tooltips, NULL);
       break;