Announcing easystroke, a gesture recognition app

[reacocard]

Taking advantage of the additional axes of a wiimote would probably be feasible, but don't have one to test this on (is there even a way to hook it up to your computer?).

Yes there is, all you need is a bluetooth adapter for the computer. I've used a wiimote as a presentation remote before under ubuntu, using cwiid to turn the wiimote buttons into normal buttons. I haven't investigated the axis abilities at all, but wmgui shows it can get the signals quite readily.

[pibach]

The hardest part would actually be to control cellwriter, which would have to be patched.

according to man cellwriter it has the options --windows-x and --windows-y to specify where it should pop up. But I cannot get this to work.

Another issue with cellwriter is that cellwriter --show-window does sometimes not bring up the window when running compiz (works fine on Xfwm4 though and also clicking the tray icon always works). I can get this fixed by restarting cellwriter, weired.

Another downer is that execution of easystroke commands takes a bit long, for cellwriter to come up it takes for example ~2s, whereas cellwriter pops up immediately if I just hit its tray icon.

[Tom Jaeger]

The only solution here is to patch cellwriter and create, say, a dbus interface. I'd send the author an email, but I'm kind of swamped at the moment.

Another downer is that execution of easystroke commands takes a bit long, for cellwriter to come up it takes for example ~2s, whereas cellwriter pops up immediately if I just hit its tray icon.

This is weird. Is it only cellwriter that has this problem? In any case, restarting cellwriter every time you want to use it is not an ideal solution anyway.

[Risujin]

Hi guys! I'm the author of CellWriter. Peter sent me an email about this thread, maybe I can be of help.

The only solution here is to patch cellwriter and create, say, a dbus interface. I'd send the author an email, but I'm kind of swamped at the moment.

CellWriter uses something much hackier, it just has an open fifo in its settings directory that accepts input to toggle the window.

This is weird. Is it only cellwriter that has this problem? In any case, restarting cellwriter every time you want to use it is not an ideal solution anyway.

Running CellWriter when it is already running does not start a second instance or "restart". The second instance just toggles the main window and quits. It doesn't communicate the --window-x/y parameters this way though, it only checks those when it is started for real. This is fixable of course, if this is really useful for you guys.

[all2ez]

Hi,

I'd like to announce easystroke, a new gesture recognition application for linux. Gesture recognition means that you can draw arbitrary curves on the screen by holding down a specific mouse button, and if the program recognizes their shape, it will perform certain actions.

Did you ever know that you're my hero,
and everything I would like to be?
I can fly higher than an eagle,
'cause you are the wind beneath my wings.

Seriously, this is a great program! I'm sorry to perpetuate the comparisons to Stroke-it, but I use that in Windows and have been waiting for a satisfying alternative in Linux. You have given me what I wanted and more, thanks a lot and keep up the great work!

[pibach]

It doesn't communicate the --window-x/y parameters this way though, it only checks those when it is started for real. This is fixable of course, if this is really useful for you guys.

Hi Risujin, great to have you here!

I think the challenging goal is a "Tabuntu" edition with comprehensive pen integration, (at least) at the level Vista does it. Cellwriter and easystroke are the core apps in this respect. So lets discuss how to get them work flawlessly together.

Current workflow for pen-based text input is to activate Cellwriter by clicking its tray icon and moving its window to the desired position. To get this more efficient I suggested to open cellwriter on an easystroke gesture at the position of the gesture. This gesture activation might also be better (and easier to implement) than the auto-activation (mimicking the Vista TIP behavior) we discussed above.

I don't know if fixing the --window-x/y in conjunction with --show-window would be best, as it seems to introduce some delay (Risujin, could you explain this delay?). But anyway this seams to be the most straight forward approach.

Another option might be a direct activation/window placement for common applications from within easystroke, for example, to activate xvkbd at the gesture position. Probably this is quicker and also more general? What do you guys think?

Another important problem is that most tablet users just don't know that there is such a good pen support when using Linux on a tablet PC. The question here is how to package and deliver these tablet goodies to get some more visibility. This should be coordinated with the activities in Ubuntu Netbook Remix and MID Edition. Risujin, what is your suggestion in this respect?

BTW, I installed the Window-Picker-Applet from Netbook Remix, which does a good job at maximizing screen real estate, perfect for devices with low resolutions/small displays.

--Peter

[pibach]

No follow up post?

Probably wmctrl or devilspie could serve placing windows close to the pen's position?

[Tom Jaeger]

Sorry I haven't replied earlier, I've been very busy with other things lately. I had already worked on the automated cellwriter invocation, so I'm just going to dump the code on you that I have so far. It's proof-of-concept code, it'll just kill cellwriter and restart it later instead of hiding and showing it. It doesn't do any overlap detection and will happily move a window partially off the screen. Also, trying to quit cellwriter the regular way will make the X server hang.

To do placement properly, we'll need to somehow get the coordinates of the cellwriter window. I originally suggested dbus for this, but I've now realized that this won't work because the size of the window might change over time, and i don't think dbus makes callbacks particularly easy. So we're probably going to have to use X11 anyway to get a hold of the cellwriter window and watch it for size changes. Moving the window is also possible, but it might take some trickery to wait for the right moment. So it seems like we're good as far as cellwriter is concerned, but it might still be a good idea to make cellwriter's --window-x and --window-y parameters work when cellwriter is already running.

In other news, my PPA contains updated packages that fix a few minor bugs. I'll make a proper release in time for the intrepid beta freeze.

EDIT: Just looked at cellwriter's source, right now there is a 1-Hz timer responsible for checking the fifo, which causes the delays. I'll send risujin a patch.

EDIT2: Updated cellwriter package in my PPA.

[pibach]

Thanks for the update, I'll give this a try.
But isn't the window placement possible by simply engaging wmctrl? There is the following placement option:
"<MVARG> Specifies a change to the position and size
of the window. The format of the argument is:
<G>,<X>,<Y>,<W>,<H>"
Regarding cellwriter I hope that Risujin will do that window-show at x/y fix so there's no workaround needed (in conjunction with your patch this should be fine).

I still see the Grab&Drag scroll option of easystroke being a killer feature, if it works for all apps such as OpenOffice or Epiphany (which do not provide G&D scrolling natively).

What about this simple approach: There's already a gesture timeout implemented. Now check after the timeout if the gesture was a straight vertical movement (up or down). If yes, switch scrolling mode on.

Another demanding feature are right click and middle click (plus Ctrl-click) gestures that act on the originating position.

[Tom Jaeger]

Thanks for the update, I'll give this a try.
But isn't the window placement possible by simply engaging wmctrl?

Moving the window is easy, that's just a XMoveWindow() call. But it's important to move the window after it has been mapped and moved by cellwriter, so there's some additional work to do.

I still see the Grab&Drag scroll option of easystroke being a killer feature, if it works for all apps such as OpenOffice or Epiphany (which do not provide G&D scrolling natively).

I actually like the side button idea better, but in any event, this'll have to wait for a little bit. Next on my list is application-dependent actions and preferences. I already worked out roughly how the GUI is supposed to look like, I just need to find the time to implement it.

Another demanding feature are right click and middle click (plus Ctrl-click) gestures that act on the originating position.

Unfortunately, this is impossible as there is no way to execute XTest requests in an atomic way.