[lkml]   [2010]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH] input: mt: Interface and MT_TOOL documentation updates
    On Fri, Dec 10, 2010 at 12:01 PM, Henrik Rydberg <> wrote:
    > On 12/10/2010 08:00 PM, Ping Cheng wrote:
    >> On Fri, Dec 10, 2010 at 10:13 AM, Henrik Rydberg <> wrote:
    >>>> Can we make MT_TOOL_ENVELOPE cover a bit more cases by:
    >>>> 1. Removing ", and is only used for legacy hardware";
    >>>> 2. Adding "Or the number of contacts inside the bounding rectangle is
    >>>> reported if hardware provides the number but not the real contact
    >>>> positions" to the end of the paragraph.
    >>> You might disagree, but "old" is still somewhat apt in this situation.
    >> It's ok if we say the new type was inspired by legacy hardware. But
    >> saying that it "is only used for legacy hardware" closes the door for
    >> future development. That's not what we are trying to do, right?
    > Well, in a sense we are. I would agree that data aiming to provide gestures as a
    > 2D transformation matrix can be handled quite well with two tracked points and a
    > finger count. However, a multitouch interface where users manipulate different
    > objects on the screen simultaneously is a different story.
    >>> How would you suggest we report the number of fingers?
    >> I guess if we want to make it generic, we could have something like
    >> ABS_MT_NUM_CONTACTS to go with MT_TOOL_ENVELOPE. Clients, such as
    >> synaptics touchpads, that only care about the number of contacts
    >> inside the envelope don't need to process the contact positions even
    >> when they are reported. This also resolve the potential that
    >> BTN_TOOL_QUADTAP is not enough to tell us how many contacts are on the
    >> surface.
    > I really would like to avoid adding a new way to solve an old problem, in
    > particular given the statement above. Adding something like BTN_TOOL_QUINTAP
    > would hurt a little bit, but not nearly as much.

    If we plan to add BTN_TOOL_QUINTAP, you can ignore my previous comments.

    >> Maybe we should also tell the clients whether they are going to get
    >> the contact positions or not.
    > I may not understand what you mean here, but if you are referring to an up-front
    > declaration of what MT_TOOL types are to be expected, we did discuss this
    > before, without any conclusion. Perhaps it is relevant to outline why this would
    > be important.

    With BTN_TOOL_QUINTAP, this question can be ignored too.

    Thank you.


     \ /
      Last update: 2010-12-10 22:19    [W:0.029 / U:108.616 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site