[pygtk] Check if end of a TextView is visible

[René 'Necoro' Neumann]

Well - just a quick idea (not tested and correctly formulated):

visible = textview.get_visible_rect()
max_y_pos = visible.y + visible.height
last_line_pos = sum(textview.get_line_yrange(textbuffer.get_end_iter()))

if last_line_pos > max_y_pos:
	print "Line not visible"
else:
	print "Line visible"

Hint: This takes a line as being "visible" iff it is completely visible
- if it is enough to see parts of the last line, replace the "sum" by an
access to the first element of the tuple (get_line_yrange returns a (y,
height)-tuple)

Regards,
René

Greenpickle schrieb:
> I have a TextView in a ScrolledWindow, and a process writes output to
> it; every time a line is written, it scrolls to the end using
> TextView.scroll_to_iter.  However, this means it's hard to scroll up to
> view earlier output.
> 
> What I want to do is check if the last line is visible before printing a
> line, then print the line, then scroll to the end only if the last line
> was visible before:
> 
> textbuffer = textview.get_buffer()
> scroll = [if end is visible]
> textbuffer.insert(textbuffer.get_end_iter(), output + '\n')
> if scroll:
> textview.scroll_to_iter(textbuffer.get_end_iter(), .0)
> 
>  - So that it's possible to view stuff earlier on without being scrolled
> back to the end all the time, but you can return to auto-scrolling by
> scrolling back to the end manually.  I haven't been able found any
> functions for TextViews/TextIters/TextMarks in any reference that would
> do this.
> 
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