Re: Control what happens when GtkTextView is resized: keep the bottom part visible

[Todor Todorov <ttodorov gmx net>]

I don't believe there is a way to get the size before the change. I do 
not believe that there is much requirement for that. If you are looking 
for a more elegant solution, you would have to reimplement GtkViewport 
or GtkScrolledWindow to keep track of the visible view now and before.

Regards,

Todor

On 11/14/2009 07:10 AM, Eduardo M KALINOWSKI wrote:
> Todor Todorov wrote:
>    
> > Well, since resizing the widget by itself does not do any scrolling,
> > whichever value you get from the adjustment _is_ the current scroll
> > value. In the same way you have the function *_get_upper(), you have
> > *_get_lower() and *_get_value()... Just change the computation however
> > you need it to be. Did you even looked up the functions I used in the
> > API docs? You would have seen the rest....
> >
> >      
> You're right, I was wrong about the requirements.
>
> I've come to the conclusion that what is necessary is to keep the value
> (upper - (value + page_size)) constant when resizing happens. This value
> represents the size of the part of the scrollable widget (a GtkTextView
> in this case) that remains below the currently displayed portion. That
> means adjusting the value (which as you said by default is not changed).
>
> Well, upper never changes when resizing a widget, so it's only necessary
> to keep (value + page_size) constant. But page_size _does_ change when
> resizing happens, so a question very similar to my previous one still
> holds: is there a way to know the value that the adjustment's page_size
> had before the resize operation, to compare with the new value caused by
> the resizing, so that the calculations can be done?
>
> I've been able to solve it by storing page_size in a variable at the end
> of the function and reusing it in the next call, but this is far from
> elegant. Is there some better way?
>
>