On Thu, Mar 31, 2011 at 9:21 PM, Peter Hutterer <peter.hutte...@who-t.net> wrote: > On Wed, Mar 30, 2011 at 11:51:22PM -0700, Jason Gerecke wrote: >> On Wed, Mar 30, 2011 at 9:04 PM, Peter Hutterer >> <peter.hutte...@who-t.net> wrote: >> > On Wed, Mar 30, 2011 at 01:54:45PM -0700, Jason Gerecke wrote: >> >> Since the worker functions now check that they have the appropriate >> >> number of arguments, its possible to decrease the number of arguments >> >> required by 'set'. Since all it really needs is a device number and >> >> a property, the minimum argc is now 2. >> >> >> >> A handy side-effect of this change is that its now possible to run >> >> e.g. `xsetwacom --set $ID StripLeftDown` to reset the action to >> >> its default. >> > >> > is that because we delete the property then so it falls back to using the >> > button mapping? >> > >> Correct. >> >> > this formulation is a bit unfortunate, since it doesn't actually set to the >> > default. if I map the button to say 8, then run the above command it would >> > revert back to 8, not to the default (4 or whatever it is), right? >> > >> > Cheers, >> > Peter >> > >> I'm not quite sure what you mean here. If no action has been defined, >> the driver falls back to its predefined button. If you run e.g. >> `xsetwacom --set $ID LeftStripUp 8`, the action "button +8" is >> assigned (because of parse_action's simple button handling). When you >> move your finger along the strip, the driver notices an action has >> been set and will send the button 8 event. If you then run `xsetwacom >> --set $ID LeftStripUp` the action is deleted. Moving your finger along >> the strip again, the driver will not find an action and fall back to >> its predefined mapping (which should be button 5) > > Where is this 5 coming from? shouldn't this be the equivalent of "button > +5" in the driver? > > Cheers, > Peter > getWheelButton (in wcmCommon.c) is responsible for finding both the "fakeButton" and "fakeKey" that could be associated with various device events. In the case of our hypothetical "strip left up", it gets the button from 'priv->striplup' and the key from 'priv->strip_keys[0]'. The former is defined during wcmAllocate and is never changed. The latter is changed by wcmUpdateButtonKeyActions (after a long call chain beginning with wcmSetProperty) whenever X detects a change in the WACOM_PROP_STRIPBUTTONS property. getWheelButton then returns both of these to sendWheelStripEvents. If a "key" is defined, it will preferentially decode it and send the necessary events. Otherwise, it interprets the raw integer fakeButton as the X button to send a button press event for.
When xsetwacom is given arguments to StripLeftUp, it converts them into an action and modifies the appropriate offset into WACOM_PROP_STRIPBUTTONS. When the appropriate motion is made the driver notices an action is sent and sends it. When it is run without arguments, it clears the offset, so the same motion results in the driver not finding an action and sending the default button. Note that xsetwacom works the same way for "Button X"! Running with arguments sets an action the driver will preferentially use; running without arguments clears the action, forcing the driver to fall back on the raw integer defined in the button[] array. The only thing I find a little mystifying is how priv->strip_keys is initially set. My first thought was that it was done when the properties were first created -- this doesn't look to be true. My second thought was that perhaps the entire priv structure was zeroed out prior to initialization -- can't find evidence of this either. I would think unless strip_keys[] were initialized somewhere it'd be filled with random junk, defeating the logic used and resulting in completely undefined behavior... Jason --- Day xee-nee-svsh duu-'ushtlh-ts'it; nuu-wee-ya' duu-xan' 'vm-nvshtlh-ts'it. Huu-chan xuu naa~-gha. ------------------------------------------------------------------------------ Create and publish websites with WebMatrix Use the most popular FREE web apps or write code yourself; WebMatrix provides all the features you need to develop and publish your website. http://p.sf.net/sfu/ms-webmatrix-sf _______________________________________________ Linuxwacom-devel mailing list Linuxwacom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxwacom-devel
