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Widgets: Screenshots

From: Scott Wilson <scott.bradley.wilson@gmail.com>
Date: Tue, 22 May 2012 15:44:28 +0100
Message-Id: <1D261B84-B3ED-4C6A-9E40-1582688EC373@gmail.com>
To: public-native-web-apps@w3.org, public-webappstore@w3.org
Hi all,

Apologies for cross posting but this one is something that affects both native web apps, and web app stores.

In the first drafts of the Widgets spec [1] we had identified screenshots as something that stores find useful when creating detail pages about widgets available, however this didn't make it into the final spec [2] for some pretty good reasons. However, it would be good to have at least something.

Typically a web app store will want to provide some illustration of what the running app does, and screenshots are an obvious solution. For Widgets as Web Apps, the question then is how to supply these images.

As noted in the rejection of the original proposal [2] the issues are:

1. Package bloat. 

Especially for mobile distribution, its extra files you probably will never need on your phone. Likewise for other limited devices such as STBs, providing screenshots is almost certainly not needed, and takes us possibly limited storage space.

2. Context. A widget can look different on different devices or using different view modes. This means that for the user, the screenshot may not actually look like the widget if it runs on their device.

One possible solution is not to package the screenshots at all, but provide a link to an image service that provides them on demand. This could also make use of user-agent identification to select the appropriate image to use.

Example:

		<screenshot src="http://myserver.com/ultimatefightingwidget/screens/1.png" caption="The game in action!">

Multiple elements could be used, processed in document order to provide the complete set of screenshots for a slideshow or serial presentation:

		<screenshot src="http://myserver.com/ultimatefightingwidget/screens/1.png" caption="The game in action!">
		<screenshot src="http://myserver.com/ultimatefightingwidget/screens/2.png" caption="Multiplayer action!">
		<screenshot src="http://myserver.com/ultimatefightingwidget/screens/3.png" caption="You've been decapitated!">

(This could use folder-based localization of config.xml so no need for multiple child caption elements.)

The downside of this is that the widget author then needs to have a server somewhere providing this capability, and stores need to handle the case of this server being unavailable.

Another option is to support both linked and included screenshots; for stores, we could recommend that stores unpack the screenshots from the package when supplying widgets to devices, substituting the link to the screenshot service. That would need a different solution, maybe reuse the example element above but point to a file in the package, and provide some extra metadata for image services to use, e.g.:

		<screenshot caption="The game in action!">
			<img src="screenshots/img1.png"/>
			<img src="screenshots/iphone/img1.png" user-agent="Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_0 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8A293 Safari/6531.22.7"/>
			<img src="screenshots/iphone/img1.png" user-agent="Opera/9.80 (S60; SymbOS; Opera Mobi/275; U; en) Presto/2.4.13 Version/10.00"/>
		</screenshot>

Thoughts?

S

[1] http://www.w3.org/TR/widgets/
[2] http://lists.w3.org/Archives/Public/public-webapps/2009AprJun/0197.html
Received on Tuesday, 22 May 2012 14:46:06 GMT

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