Problems with GtkEntry's grabbing focus

[Douglas Vechinski <douglas vechinski dynetics com>]

I'm writing a GTK+ application that uses an OpenGL capable drawing area 
widget (via  the GtkGLExt extension).  This drawing area responds to 
various mouse events.  There are several other widgets for other various 
settings.  I have been trying to also get the drawing area widget to 
respond to key press events and have been unable to do so.  In the 
process of  creating a stripped down version of the code that I was 
going to include with this post, the stripped version responded to key 
press events.  After some more thinking I believe the problem with the 
original was that the drawing area widget was not getting the focus when 
the mouse point was inside it.

Thus, I tried adding Enter Notify and Leave Notify events to this 
window.  When the mouse enters the drawing area, I use a 
gtk_window_get_focus to store which widget currently had the focus, and 
then make the drawing area grab the focus.  I now am able to receive key 
press events in this widget.  When the mouse leaves the drawing area, in 
the Leave Notify callback I call a gtk_widget_grab_focus with the widget 
I obtained from the get_focus durng the Enter Notify.  The problem that 
I am having is that if the previously focused widget was something like 
a GtkEntry widget, then when it grabs the focus the entire contents is 
hightlighted and if a key is pressed, the contents is erased.  Why is 
the entire contents hightlighted when it grabs the focus?  It would be 
nice  in such cases that the cursor returned back to where it was 
previously.  Given a widget pointer, is there a way to tell what type of 
widget it is so that if it is an entry widget I can do something so that 
the text is unselected.   I'm assuming that a similar problem may occur 
with a TextView widget but have not confirmed this.