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Re: Wacom tablets in CarbonLib 1.5.

The thing I don't understand is that I expect to be able to extract a
pressure at any time I receive a mouse down event, but it appears
(CarbonEvents.h) that I will only get either a proximity or a point
event - not both?

At the point I receive the Mouse Down, how can I extract the pressure if
kEventParamTabletEventType is kEventTabletProximity?

Regards
Simon

On Thursday, February 28, 2002, at 05:09 PM, Raleigh Ledet wrote:

> It is extremely important to note that Tablet Proximity and Pointer
> events can be embedded into ANY mouse Event.
>
> It may seem odd to look for Tablet Pointer events in Mouse Move events,
> but Tablet Pointer events embedded in Mouse Move events do contain
> valid information. For example, you can get TILT or ROTATION or Z-Axis
> data. Granted the pressure value should always be zero, so if your
> application does not care about the rest of the data when there is no
> pressure, then you can safely ignore Tablet Pointer events in Mouse
> Move events. (But do not ignore Proximity Events!!!)
>
> Here is just one case where Proximity Events can occur on a Mouse Down.
> If the user places a pen on the tablet, outside of the active area and
> drags the pen inside the active area, a Mouse Down event may be
> generated with an embedded proximity event.
>
> Only on the proximity events can you determine if the user is using a
> tip, erasure, or mouse device. The user can set a side-switch to
> erasure. If they press the side switch while drawing, your app should
> start erasing. Your app will receive a proximity Leaving event for the
> tip and a Proximity Enter for the erasure in the middle of a drag
> operation.
>
> Generally, you will get the Proximity events in the Drag and Move
> events, but that is NOT GUARANTEED! Proximity events have been known to
> occur in the Up and Down mouse events as well.
>
> There are a few other cases that I can think of off hand, so it is best
> to check all mouse events for embedded tablet proximity events.
>
> Also, it is a good idea to install handlers for pure tablet events as
> well. On some cases, tablet events may get sent as pure tablet events
> if the cursor does not move.
>
> In a few months, Wacom will publish some new Tablet Developer
> documentation and Sample code for MacOS X. If you e-mail and ask me, I
> will put you on a mailing list with the sole purpose of notifying you
> when Wacom releases the new document.
>
> Regards,
> raleigh
>
> On Thursday, February 28, 2002, at 07:58 AM, carbon-development-
> email@hidden wrote:
>
>> On a kEventMouseDown event, you check kEventParamTabletEventType to see
>> if it contains a kEventParamTabletPointRec or
>> kEventParamTabletProximityRec. I think its strange to check for
>> kEventParamTabletProximityRec on kEventMouseDown and conversely,
>> kEventParamTabletPointRec on kEventMouseMoved?
>>
>> Under what circumstances should I expect a proximity record on mouse
>> down?
>>
> -------------------------------------------------------------------------------
> Raleigh Ledet email@hidden
> Wacom Technology Corp. Towards the Harmonious
> Mac Software Engineer Development Between
> Human
> and Computer.
> --------------------------------------------------------------------------------
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References: 
 >Re: carbon-development digest, Vol 2 #155 - 20 msgs (From: Raleigh Ledet <email@hidden>)



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