W3C home > Mailing lists > Public > public-web-intents@w3.org > December 2011

Re: Web Intents - Scenario: TV System (part 6)

From: Bjartur Thorlacius <svartman95@gmail.com>
Date: Wed, 07 Dec 2011 18:03:17 -0000
To: WebIntents <public-web-intents@w3.org>, "Clarke Stevens" <C.Stevens@cablelabs.com>
Message-ID: <op.v54sfryjewg2x1@bxr>
On Tue, 06 Dec 2011 22:11:48 -0000, Clarke Stevens  
<C.Stevens@cablelabs.com> wrote:
> My question on the use case is related to context and state.
>
> It seems that the primary model for Intents is that (please correct me  
> if I'm wrong)
>
>  1.  A (verb) request is made
>  2.  A list of (nouns) that can handle (verb) is returned
>  3.  The user selects from the list of (nouns) the one to handle the  
> (verb).
>
> Does the user application know which (noun) handled the (verb)?
>
> Here's the potential problem:
>
> If the (verb) is "on" then perhaps several dozen devices in my home will  
> respond. In the case of my big TV, I actually want a specific TV in  
> front of me to turn on as well as the surround system connected to it.  
> When I turn up the volume on my TV, I really want that command to go to  
> the surround system, not the TV. When I turn off the system, I may need  
> to know that the TV and the surround system are both on in case the  
> power is a toggle switch and I don't put them in the wrong state. When I  
> go to a different room in the house I want to control a different TV.
>
> The point is, something has to keep track of context and state. An  
> application can certainly do this, but does this work with Intents? The  
> user can't be bothered with selecting the (noun) every time the (verb)  
> is invoked. Does Intents give enough information to the user application  
> so that it can keep track of this? Also, what happens if the user  
> browses to a different web page? Is all that information lost?
>
> As I've said before, I'm convinced that Intents can be used to discover  
> devices, but I still have a lot of questions about whether it is the  
> right tool for the other communications tasks.
>
> Thanks,
> -Clarke
>
> From: timeless <timeless@gmail.com<mailto:timeless@gmail.com>>
> Date: Tue, 6 Dec 2011 12:07:27 -0700
> To: WebIntents  
> <public-web-intents@w3.org<mailto:public-web-intents@w3.org>>
> Subject: Web Intents - Scenario: TV System (part 6)
>
> While this article talks about a TV, I'm really only using a "TV"  
> because it's something with which most people are familiar. TVs  
> traditionally have a number of knobs to control unrelated settings, many  
> also support infrared remote controls. Often we're so lazy that we avoid  
> walking to our TVs and instead rely on these remotes to control them  
> instead (or we may claim that by doing this we avoid interrupting  
> everyone else's view).
>
> I've been meaning to introduce detailed use cases for a while. Home  
> Media Centers are much more complicated than the TV below, mine [1]  
> certainly is.
>
> 13 TV Controls Scenario.
> Imagine a TV as having the following inputs:
>
> A. Power button
> B. Mute button
> C. Volume spinner
> D. Source selector
> E. Channel selector
> F. Brightness selector
>
> Each of these is commonly found on a TV, and one can often get a dozen  
> remotes that can all control some of these items on that same one TV.  
> There is no requirement that all remotes have buttons to control all of  
> these items (some remotes are more limited/simplistic than others, some  
> are less universal than others, and some have been programmed so certain  
> buttons  control other devices instead).
>
> If we accept controlling each of these as an independent action (and  
> hopefully you do), then we can assign intents for them. But obviously  
> the TV wants to advertise supporting all of them. And that's fine.
>
> When I get a programmable remote, I teach it about a device, and then  
> the device lets me select which actions I want to program for that  
> device.
>
> Supporting roughly that is the goal.
>
> 14 Use Case: Programmable remote control for a Home Entertainment  
> system.
>
> Steps:
> 1. User's UA discovers HN (TV, Stereo, VCR, DVD)
The UA now has a comprehensive list of verbs and valid patients (nouns).  
Invoking "power off" now implies use of one of the devices previously  
discovered to be able to be powered off.
> 2. User loads "programmable remote control" web page
> 3. Page has buttons for:
What exactly is the page? A list of verbs that /might/ be a subset of  
previously UA-discovered verbs? With no indication whatsoever as to what  
verbs are in fact usable in the current context? Or is a set of widgets  
for constructing commands?
> A. Power button
> B. Mute button
> C. Volume spinner
> D. Source selector
> E. Channel selector
> F. Brightness selector
What if one of these constructs a command that no device can comply with?

> 4. User presses "power button" (A) on page
> 5. Page triggers <power> action (Ai)
So, the user uses the UA to tell the page to tell the UA to toggle the  
power of a device?

> 6. UA offers list of "powerable" devices:
> TV, Stereo, VCR, DVD
> 7. User selects TV
> 8. UA remembers all Actions the TV supports but only maps TV -power to  
> page (Ai:TV)
> 9. Page triggers <power> action (At)
> 10. UA sends TV the power signal (At:TV) -- wake on LAN?
> 11. User selects "channel up" (E) on page
> 12. Page triggers <adjust-channel> action (Ei)
> 13. UA has a list of channel-adjustable devices:
> TV, VCR
> * our stereo doesn't do am/fm/xm (don't ask)
> 14. UA suggests TV indicating it's already used for <power> action by  
> this page, but offers the user the choice of the VCR
> 15. User chooses TV
> 16. UA remembers maps TV-adjust-channel to page (Ei:TV)
Does this imply that the page can no longer be used to adjust the channel  
of the VCR?

> We've now mapped 3 actions to our page. User is happy. Ideally the UA  
> will remember these mappings so the next time the page loads, the user  
> won't need to map them unless an action fails or the user wants to  
> adjust them.
>
The user is more likely to have a concept of a current device, with  
Play/Pause being directed there straight away, while having another  
mechanism to change devices. That has nothing to do with what page or  
pages are loaded.

What information does the web page have to better make decisions as to  
what verb to use that the user and UA do not, and why can the page not  
declaratively communicate that information to the UA? Why is there a web  
page involved at all?

-- 
-,Bjartur
Received on Wednesday, 7 December 2011 18:04:13 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 7 December 2011 18:04:14 GMT