Resizing widgets and GtkScrolledWindow

[nicholas allen <nicholas allen ireland sun com>]

Hi again,

Thanks to everyone for the help they have given us so far with  our 
problems. We am very grateful. Sorry to bother you again but hopefully 
this will be the last time!

I am trying to write peers for Java AWT components using Gtk widgets. I 
have managed to fix some problems I had with using gtk_widget_set_usize 
and gtk_widget_set_uposition for setting the bounds of a widget. These 
were the wrong functions to be using and now I have written a custom 
widget container which I use as the peer for a Java panel. The custom 
widget does nothing with the layout of its children so that this can be 
left to the Java layout managers. I have basically used the approach in 
the GtkFixed widget class as a starting point and stripped out things 
that were unecessary. Everything is working great now and widgets are 
also added in the correct Z order which was previously not possible 
using GtkFixed widget. What happens now is that Java's layout managers 
layout the components and this in turn causes the appropriate size and 
location to be set on its native Gtk widget. This is now done by using 
gtk_widget_size_allocate instead of gtk_widget_set_usize and 
gtk_widget_set_uposition. This seems to work very well with only one 
problem: any widget inside a GtkScrolledWindow does not show scrollbars. 
For the text area and list compoinents in java I create GtkText and 
GtkCList widgets respectively and put these inside a GtkScrolledWindow. 
When the widget is resized and scrollbars should appear they aren't 
displayed. This is now the only problem I have left for full AWT 
implementation for Java so it would be cool to fix this.

As an example of how I'm creating these here is how the text area is 
created:

scrollWindow = gtk_scrolled_window_new (NULL, NULL);
	gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW(scrollWindow), 
GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
        gtk_widget_show (scrollWindow);
        textArea = gtk_text_new(NULL, NULL);
        
	/* TODO: We have to use line wrap as GTk does not support horizontal 
scrolling in GtkText widgets yet.
           This will need to be changed when this feature is supported. */
        
        gtk_text_set_line_wrap (GTK_TEXT(textArea), TRUE);
        gtk_text_set_word_wrap (GTK_TEXT(textArea), FALSE);
        gtk_widget_show (textArea);
        gtk_container_add (GTK_CONTAINER(scrollWindow), textArea);
        eventBox = gtk_event_box_new ();
        gtk_widget_show(eventBox);
        gtk_container_add (GTK_CONTAINER(eventBox), scrollWindow);

Note that I place the scrolled window inside an event box to ensure that 
I get GdkEvents generated for the widget so that I can easily intercept 
these events and post them to Java's event queue. I don't think this has 
anything to do with the problem. It is obviously something to do with my 
new custom widget that does no layout of components and the change to 
gtk_widget_size_allocate as mentioned above. However, not being 100% 
familiar with the internals of Gtk I'm not sure with where to begin on 
trying to solve this problem. Can any one give me some pointers on where 
I may be going wrong or what I should be doing differently?

Thanks again for your previous help - particularly to Havoc Pennington 
(BTW we now have your book on order so hopefully we'll be asking less 
questions in the future!)

--
Nick Allen
Software Engineer
Sun Microsystems Ireland Ltd
Hamilton House
East Point Business Park
Dublin 3

email: nicholas allen ireland sun com