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Subject: Re: lcd_clear_display and lcd_stop_scroll

Re: lcd_clear_display and lcd_stop_scroll

From: Kjell Ericson <>
Date: Tue, 14 Jan 2003 21:29:20 +0100 (MET)

On Tue, 14 Jan 2003, Daniel Stenberg wrote:

> > If you today do a lcd_puts_scroll() and have a text scrolling or being
> > paused. A call to lcd_clear_display() will keep that text scrolling or
> > paused.
> > I belive it shall clear the display and stop+clear all scrolls.
> No. If you want that, then stop the scroll and clear the screen.

Well, then I have to modify some kind of menue code. Because when I entered a
setting menu and made lcd_stop_scroll, a line from the prior menu was shown
(happened when changing the scroll speed).
I'm not up in Linux right now, so I can't test it. But it was very clear (in
the simulator) when I added this "ok"/"canceled" thing in the menues.

> > If the scroll is paused before a call to lcd_clear_display(), the text will
> > also appear suddenly at a call to lcd_stop_scroll(), lcd_stop_scroll_line()
> > or lcd_scroll_resume().
> Yes?

The thing is that someone uses lcd_puts_scroll in a menu, and then make a
sub-call without stopping all scrolls. I could ofcourse make the
child-function call the lcd_stop_scroll()-function, but then all possible
child-functions must do this too.
Of course fixing the faulty caller I'm talking about isn't a totally wrong
way, but I thought that the functionality of lcd_clear_display() should be to
totally clear the display (which also means stopping/forgetting all scrolls).

Question: Why do you want to clear the display, but keep any information in
some kind of scroll?

Isn't the problem here that the lcd_stop_scroll() function is slow in the
The code for the Player is very fast :-)

BTW: I rewrote parts in almost all scrolling code for the Player. I found
bugs and not-so-good implementations.

> The recorder screen flickers badly atm.

I agree something must be fixed. Thanks for testing the code in real hardware.
The simulator didn't give any kind of flickering when I tested.

But something else is also wrong if it is flickering, because if you don't
have any scroll visible the screen shouldn't be updated (?) if I guess how
you tested it.

BTW: In what menu/function did it flicker? I like to try it in the

  // Kjell
Received on 2003-01-14

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