On Tue, Sep 13, 2011 at 7:13 AM, Chris Bagwell <chris@xxxxxxxxxxxxxx> wrote: > On Tue, Sep 13, 2011 at 3:09 AM, Henrik Rydberg <rydberg@xxxxxxxxxxx> wrote: >> Hi Jason, >> >>> Adds INPUT_PROP_POINTER or INPUT_PROP_DIRECT as necessary to the >>> hardware supported by the Wacom driver. The DIRECT property is >>> assigned to devices with an embedded screen (i.e. touchscreens >>> and display tablets). The POINTER property is assigned to those >>> without embedded screens. >>> >>> Signed-off-by: Jason Gerecke <killertofu@xxxxxxxxx> >>> --- >> >> According to the discussion leading up to the properties interface >> (https://lkml.org/lkml/2010/12/15/263), a tablet is a direct pointer >> device, as opposed to a touchpad, which is an indirect pointer >> device. The distinction determines the direction of two-finger scroll, >> for instance. The question is then what behavior should be assigned to >> a large tablet without an embedded screen. It should have POINTER set >> for sure, but should it also have DIRECT set? We have discussed and debated the above before the patch was posted. As Ikbel pointed out, a standalone tablet can be DIRECT or INDIRECT, depending on how it is used. So, it is more a property that is decided by the client than by the kernel driver. > Here are all the possible combinations based on my understanding of > their intended usage. > > * Touch interface without screen should have POINTER only to > indicate pointer needed and to treat absolute coordinates as relative > movement. Relative movement is product's default behavior as > documented in its own manual and what I think should be advertised by > default. > * Pen interface without screen should have both POINTER and DIRECT to > indicate pointer needed and to treat absolute coordinates as absolute > movement. Reporting it as DIRECT indicates it can only be used as DIRECT. We don't want client to make that assumption. User-land clients can distinguish a touch POINTER from a pen POINTER by the tool types. > * Touch interfaces with screen should have DIRECT only to indicate no > pointer displayed and absolute coordinates as absolute movement. > * Pen interface with screen should have DIRECT only to indicate no > pointer displayed and absolute coordinates as absolute movement. > * A Pen+Touch touchscreen (only the wacom_w8001.c), should have DIRECT > only to indicate no pointer displayed and absolute coordinates as > absolute movement. > > Assuming we all agree on those combination, then in the patch the > Graphire and Intuos tablets are missing a DIRECT, the touchscreens are > correct, and the Bamboo's need to add DIRECT for the PEN interface > only. I agree with all the other assumptions except this one. Ping -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
