[mythtv] [mythtv-commits] Ticket #7778: Up and down scrolling directions are reversed in MythGallery

[Clayton Smith]

>
>  The scrolling seems to work as designed (and as originally implemented
>>  in [1735] ).  The bindings used are "SCROLLUP" (with help text, "Scroll
>>  image up," and default binding of 2) and "SCROLLDOWN" (with help text,
>>  "Scroll image down," and default binding of 8).  When you use the
>> SCROLLUP
>>  binding (2), the /image/ is moved up while the viewport remains fixed, so
>>  you see a portion of the image lower than the portion you were seeing.
>>  Similarly, when you use the SCROLLDOWN binding (8), the image is moved
>>  down while the viewport remains fixed, so you see a portion of the image
>>  higher than the portion you were seeing.
>>
>>  If that's the case, then why doesn't SCROLLLEFT move the image left and
>>  SCROLLRight move the image right?  They both move the viewport, as one
>>  would expect.
>>
>>
>
> Well, I didn't write the code, so I couldn't tell you.  All I can say for
> sure, though, is that this is how it's always worked.
>
> Perhaps a patch to the key description, then?  As it is, it works like the
> keys on the numeric keypad on a keyboard indicate it should work, and
> changing which keys it uses is as simple as changing bindings in
> MythControls.  So, unless we really change things/simplify things/make it
> more consistent with the rest of MythTV, I would argue we shouldn't change
> it since it's always been this way.


Note that the current behaviour is already inconsistent with MythBrowser,
which uses 8 for MOUSEDOWN and 2 for MOUSEUP, obviously intended for use
with a remote control.

Changing the key descriptions doesn't seem like a good idea to me, since
we'd end up with:

    SCROLLUP - Scroll image down
    SCROLLDOWN - Scroll image up

Or else SCROLLUP/SCROLLDOWN could be described as moving the viewport, which
would differ from SCROLLLEFT/SCROLLRIGHT, which move the image.

Given the code, I can't explain this as anything but a bug.  Just because
it's a long standing bug doesn't mean it sholudn't be fixed.  If there's
anyone out there who likes it the way it is now, I'd be interested to hear
why.

  > My preference, however, would be to completely get rid of the SCROLLUP,
>  SCROLLDOWN, SCROLLLEFT, and SCROLLRIGHT bindings used /only/ by
>  MythGallery and change the plugin to use the global UP, DOWN, LEFT, and
>  RIGHT bindings used everywhere else in Myth--where UP would scroll the
>  viewport up (so you see a higher portion of the picture) and DOWN would
>  scroll the viewport down (so you see a lower portion of the picture).
>  Using the global directional keybindings works well for *both* keyboards
>  and remotes (and would work fine for a remote without arrows if the user
>  overrides the global bindings for the directional keys in the Gallery
>  context to use numbers as now).  I have a patch in the works that would
>  allow users to add a new keybinding to a context using MythControls--
>  effectively allowing users to override bindings in lower contexts with the
>  GUI keybinding editor instead of direct DB editing.
>
>  UP/LEFT are already used to move to the previous image, and DOWN/RIGHT
>  move to the next image.  Are you proposing changing the behaviour so that
>  these keys behave differently during zooming, and not using the numeric
>  keypad any more for scrolling?
>

Ah, didn't realize that those were already used--though I think using the
> global PREVVIEW (Home) and NEXTVIEW (End) for previous and next image would
> be more consistent with the rest of Myth***.  If we did that, then
> UP/DOWN/LEFT/RIGHT could be used to move the zoomed-in image
> up/down/left/right, and we wouldn't need to use the number-key hack we
> currently have--though I don't know what would work well for ROTRIGHT (3),
> ROTLEFT (1), RECENTER (5), ZOOMOUT (7), ZOOMIN (9), and FULLSIZE (0), so
> maybe it's not worth changing these.
>

But my remote (Windows Media Center using Mythbuntu's default configuration)
doesn't have any buttons mapped to Home or End.  I'm guessing other remotes
are similar, so I wouldn't like to see Home/End become the only way to move
between images.

Really, I'm completely happy with the key bindings in MythGallery, except
for the fact that this bug reverses the vertical scrolling directions.


> I really don't know or use MythGallery, so as I mentioned, I'll let someone
> else who has more of a stake in the resolution decide.
>

I'd be interested to hear from other people who use MythGallery.  It could
be that people just don't know about zooming and scrolling -- I discovered
it just by mashing on my remote's keys to see whether anything interesting
would happen.  :-)

Regards,
Clayton
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