Re: The Right Way To Resize Images?

[Mike Benham <moxie thoughtcrime org>]

For the benefit of the mail archive, I'm going to answer my own questions.

On Sun, 19 May 2002, Mike Benham wrote:
> I'm displaying GtkImages in a GtkScrolledWindow, but sometimes I want to
> resize an image so that it fits in the viewable area of the
> GtkScrolledWindow.  I can resize images fine using GdkPixbuf routines, but
> I can't figure out what the viewable area of a GtkScrolledWindow is.  In
> fact, I can't determine the size of any widgets except GtkWindow (which
> GtkScrolledWindow doesn't inherit from).

In the case of GtkScrolledWindow, the methods
gtk_scrolled_window_get_hadjustment() and
gtk_scrolled_window_get_vadjustment() will return GtkAdjustment structures
that contain information about the state of the the horizontal and
vertical scrollbars.  Those structures contain an elment called page_size,
which is the size of the viewable area that the scrollbars control.

So:

gtk_scrolled_window_get_hadjustment(GTK_SCROLLED_WINDOW(window))->page_size
will return the viewable width and
gtk_scrolled_window_get_vadjustment(GTK_SCROLLED_WINDOW(window))->page_size
will return the viewable height.

> It seems like get_size() should be a base method on GtkWidget?  Am
> I missing something?

It still seems like this should be true.

> Also, I can't seem to force a GtkTreeView repaint.  If I update a
> GtkListStore, the GtkTreeView/GtkTreeViewColumn doesn't seem to notice
> until it normally repaints (like when it receives a mouseover event, etc).

Turns out I was modifying the model from an external thread without using
the gdk global mutex primitives.  Once I started treating model updates as
a critical region, the view updated instantly.

- Mike

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