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Fwd: Advanced Pointer Events: Use Cases

From: Arthur Barstow <art.barstow@nokia.com>
Date: Tue, 16 Mar 2010 08:10:47 -0400
Message-Id: <982F58E9-F916-4018-A77F-9245B175ED0D@nokia.com>
To: www-dom <www-dom@w3.org>, Charles Pritchard <chuck@jumis.com>
Charles - Doug suggested your email be forwarded to www-dom list.

Charles' email below followed a related thread whose head is:

  Event handlers - Pointer Devices
  http://lists.w3.org/Archives/Public/public-webapps/2010JanMar/ 
0737.html

-Art Barstow

Begin forwarded message:

> From: ext Charles Pritchard <chuck@jumis.com>
> Date: March 10, 2010 12:11:59 AM EST
> To: "public-webapps@w3.org" <public-webapps@w3.org>
> Subject: Advanced Pointer Events: Use Cases
> Archived-At: <http://www.w3.org/mid/4B972A1F.2030904@jumis.com>
>
> Here are a few use cases.
>
> Touch-based event.
>
> Case 1:
>
> A user has a multi-touch pad, and, by using two fingers they may  
> signal
> the same
> event that would have otherwise required the pressing of a button.  
> This
> may reduce
> strain, especially smaller devices such as laptops and mobile phones,
> where pressing
> a button while using the touch pad can be uncomfortable.
>
> Case 2:
>
> The developer of a multimedia program would like to allow the user to
> control
> the audio volume without interrupting the screen display; they map the
> volume
> control to movement on the touch pad, provided that either a button is
> pressed,
> or a second finger is present on the touch pad.
>
> Pen-based event.
>
> Case 1:
>
> A user has a pressure sensitive pen device, and would like fine  
> control
> over their
> strokes when using an online drawing application ( likely using the
> canvas element ).
>
> Case 2:
>
> A developer is trying to create their own OCR system for a non- 
> Roman script;
> they've found that accuracy can be improved if pressure/angular  
> changes
> are taken into account.
>
> Case 3:
>
> As a method to teach wrist control and improve dexterity, a software
> game may be
> distributed as an educational tool.
>
>
> Additional Data in Alternate pointing events.
>
> Case 1:
>
> A developer would like to save absolute information about
> the distance, in inches, between pointer events; for recording
> purposes on a signature.
>
> Case 2
>
> A heavy-use computer is installed at a museum. Instead of
> a mouse it has nine buttons, which move the mouse cursor
> 30 pixels in a given direction.
>
> An interactive application built for both mouse events and
> events emulated by buttons, accounts for the 30px
> jump in movements, the data is provided by the alternate
> pointer (the nine button device).
>
> Case 3
>
> A novelty touchscreen is released as an orb.
> Mouse movements work normally, but absolute
> position on the orb is also available.
>
> Case 4
>
> A zero contact mouse is held in space, and tilted
> to simulate mouse movement. It also reports
> on distance, taking into account that the user
> may be moving further from or closer to the screen.
>
>
> Implementation considerations:
>
> Currently, mouse based events can be tricky to work with;  
> implementation
> irregularities with
> event bubbling are especially difficult.
>
> Touch-based events have been popularized; they designed for a
> multi-touch device,
> and may trigger / require some mouse events.
>
> Event handling must gracefully degrade, "onmouse" hooks are the
> primary method to forward and backward compatibility: "onclick" is  
> required
> by the popular "ontouch" interface.
>
> Most touch and pen devices send mouse events.
>
> Pen-based events may have additional information,
> Such data could be accessed by a standard API; but it's out of the  
> scope
> of this document.
>
>
>
>
Received on Tuesday, 16 March 2010 12:12:00 GMT

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