Re: Auto Scrolling

[Brian <dol-sen telus net>]

On Thu, 2004-10-28 at 13:46 -0700, Leo Przybylski wrote:
> Hello,
>
> I'm trying to tail a file using a GtkTextView. Is that the right way I 
> should be going about it? Does anyone have examples or anything for an 
> autoscrolliing GtkTextView ???
>
> Leo

Here is code I cut from my specialized terminal app in python.  I hope
it is readable enough.  It should if you know python at all.


#!/usr/bin/env python

# A constant that represents the maximum distance from the
# bottom of the slider for the slider to stick.  Too small and
# you won't be able to make it stick when text is added rapidly
SLIDER_CLOSE_ENOUGH = 0.5 # of the page size

        # a portion of the global init code
        dprint("TERMINAL: get & connect to vadjustments")
        #dprint(TABS[:-1])
        for x in TABS[:-1]:
            adj = self.term.scrolled_window[x].get_vadjustment()
            self.term.vadjustment +=  [adj]
            id = self.term.vadjustment[x].connect("value_changed",self.set_scroll)
            self.term.vhandler_id += [id]
            # create autoscroll end marks to seek to &
            end_mark = self.term.buffer[x].create_mark(("end_mark"+str(x)), 
self.term.buffer[x].get_end_iter(), False)
            self.term.end_mark += [end_mark]


    def set_scroll(self,  vadjustment):
        """Sets autoscrolling on when moved to bottom of scrollbar"""
        self.term.auto_scroll[self.term.current_tab] = ((vadjustment.upper - \
                                                        vadjustment.get_value()) - \
                                                        vadjustment.page_size < \
                                                         (SLIDER_CLOSE_ENOUGH * vadjustment.page_size))
        return

        

        
   def append(self, num, text, tagname = None):
        """ Append text to a text buffer.  Line numbering based on
            the process window line count is automatically added.
            BUT -- if multiple text buffers are going to be updated,
            always update the process buffer LAST to guarantee the
            line numbering is correct.
            Optionally, text formatting can be applied as well
        """
        line_number = self.term.buffer[TAB_PROCESS].get_line_count() 
        iter = self.term.buffer[num].get_end_iter()
        lntext = '000000' + str(line_number) + ' '
        self.term.buffer[num].insert_with_tags_by_name(iter, lntext[-7:] , 'linenumber')
        if tagname == None:
           self.term.buffer[num].insert(iter, text)
        else:
           self.term.buffer[num].insert_with_tags_by_name(iter, text, tagname)
        if self.term.auto_scroll[num] and num == self.term.current_tab:
            self.scroll_current_view()

-- 
Brian <dol-sen telus net>