There is a "feature" in QML that the property name has to start with lower case
letter. Although, this is only enforced in the "onXyzChanged" paradigm.
Properties starting with '_' do generate the change notify signal, but the only
way they can be utilize that is to create own property as
SomeComponent {
variant myCopyProperty: _property // platform specific property in
SomeComponent
onMyCopyPropertyChanged: console.log("_property changed")
}
This isn't too appealing for the developers.
Can one make signal connections in QML? The documentation is always
"connecting" to the onXyzChanged convention - not to the actual xyzChanged
signal.
The grouped properties would be THE solution, but unfortunately not possible.
-P
>-----Original Message-----
>From: qt-components-bounces+pekka.e.jokela=nokia....@qt.nokia.com
>[mailto:qt-components-bounces+pekka.e.jokela=nokia....@qt.nokia.com] On
>Behalf Of ext mathias.malmqv...@nokia.com
>Sent: 04.03.2011 20:09
>To: Hartz Henrik (Nokia-MS-Qt/Oslo); qt-components@qt.nokia.com
>Subject: Re: [Qt-components] Platform-specific properties in a cross-
>platform world
>
>
>In the "custom" branch implementation I've stayed away from using the
>"__" prefix
>altogether, mainly because QML fails to automatically create the
>"Changed" signals
>for these properties. I.e. if a property is defined like this
>
>property bool __myPrivateProperty
>
>this won't work
>
>on__myPrivatePropertyChanged: print("it changed!")
>
>nor will this:
>
>__onMyPrivatePropertyChanged: print("it changed!")
>
>
>I'm not sure I like the __ convention, but it's probably just because
>I'm not a JS developer
>and haven't got used to seeing it.
>
>Anyway, just created http://bugreports.qt.nokia.com/browse/QTBUG-17950
>
>Grouped properties could perhaps be used for private and platform
>specific properties, but
>the necessary support is lacking, see
>http://bugreports.qt.nokia.com/browse/QTBUG-15269
>
>
>Cheers
>Mathias
>
>------------------------------------------------------------
>Mathias Malmqvist
>UX Prototype Lead
>10 Great Pulteney Street, London, W1F 9NB, UK
>Got no reply? Try giving me a call:
>Mobile: +44 (0)77 6522 2738
>http://www.nokia.com
>________________________________________
>From: qt-components-bounces+mathias.malmqvist=nokia....@qt.nokia.com
>[qt-components-bounces+mathias.malmqvist=nokia....@qt.nokia.com] on
>behalf of ext henrik.ha...@nokia.com [henrik.ha...@nokia.com]
>Sent: Thursday, March 03, 2011 3:43 PM
>To: qt-components@qt.nokia.com
>Subject: [Qt-components] Platform-specific properties in a cross-
>platform world
>
>Hi,
>
>After some internal discussions, we're wondering the best approach for
>making a cross-platform API for Qt Quick components. A bit of
>background; currently, we have a common API that we use an apichecker
>test to verify conformance - and we're quite OK there. However, there
>are a few properties and features that are platform specific - for
>instance 'focusable' on MeeGo's ImplicitSizeItem, needed for some
>specific item interaction features, or Symbian having 'title' in it's
>Page.
>
>The convention we have used so far is;
> * '__' is private and should not be used. Best approach is to have a
>QtObject {id:property} with properties for hiding private properties
> * '_' is platform specific, and should be used with care..
>
>however, neither of these illustrate which platform you are locking
>yourself to - and it does not allow encapsulating the platform specific
>property for e.g. Symbian.
>
>Question to the list; are there better techniques for exposing
>properties to a common element from a specific implementation - and be
>able to use such properties in the implementation effectively? Can
>attached properties be used for this without breaking the ability to
>deploy the App to a different platform that doesn't have this property?
>
>Others, please pipe up if I forgot some details about our discussion.
>
>Cheers,
>Henrik
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