Ubuntu – What are the accessibility problems of Qt

accessibilityqtunity-2d

Jonathan Ridell said in a blog post that there were accessibility problems with Qt. I would just like to know what those problems are. Thank you very much and keep up the excelent work. Ubuntu Rocks!

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I haven't done any development in Qt, but my gloss on the subject of accessibility there is that the concern might be a bit overblown. My understanding is that while GTK has built-in ATK support, Qt has to use a 'bridge' component to tie its native system to the accepted Linux accessibility framework.

Update -- I might have been premature in calling this issue overblown. For instance, as user9237 says, it doesn't look like AT-SPI was really ever implemented. So the trolltech doc quoted looks to be a bit "optimistic" . Here is an interesting blog post, unfortunately still a bit old, covering a lot of these issues : Qt/KDE and the state of free accessibility.

Here's Mark Doffman's code site for Qt AT-SPI. Of which he says,

This project is a Qt plugin that bridges the QAccessible API’s to the AT-SPI 2 protocol enabling Qt applications to be used with Orca, Accerciser, and GOK.

The possibly bogus Trolltech/Nokia link:

Here's what Qt docs say about Qt accessibility (from trolltech/nokia):

Accessibility support in Qt consists of a generic interface, implemented for a technology >on each platform: MSAA on Windows, Mac OS X accessibility on the Mac, and Unix/X11 AT-SPI >on Linux. Qt's accessibility interface closely follows the MSAA (Microsoft Active >Accessibility) standard, which most clients support. Other technologies used by Qt >provide similar functionality.*

A slightly newer document gives an overview of Qt accessibility.

By contrast, here's a quick run-down on accessibility interfaces from the Gnome project:
GAIL (GNOME Accessibility Implementation Library) is an implementation of the accessibility interfaces defined by ATK. GTK is a toolkit which is already mapped to ATK by the GAIL module. License, download and other information can be found here. The GAIL source code also serves as an excellent tutorial for advanced ATK usage. In addition, you may be interested in the GAIL Reference Manual.

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Ubuntu – Why was Qt chosen for unity-2d and Nux for 3d

Nux wasn't exactly chosen - it was created from scratch and is developed alongside Unity. For some information on what it is and the benefits see this posting from Unity developer Jason Smith. Also there is a question that goes into much more detail on the inner workings of Nux.

Qt has recently been praised by Canonical's Matt Zimmerman on his blog for being stable on ARM platforms as well as x86; for being cross platform; and for having a mature touch input system.

I know this doesn't completely answer your question but it gives some insight into reasoning behind these decisions.

Ubuntu – Where is the Accessibility mouse click lock

Have you looked at xte? It's part of the xautomation package.

sudo apt-get install xautomation

It's pretty stable, so you shouldn't need to do any compiling or hacking.

Typing xte "mousedown 1" on a console seems to do what you're looking for. It simulated a click and hold of the first mouse button. The button appears to stay clicked until I click another mouse button.

To make the UI work the way you want, you could add xte "mousedown 1" to a keybinding. When you hit that key, you'll get the click-and-hold you describe.

If you want the click-and-hold behaviour on a mouse click, you could try looking at Compiz. I believe Compiz allows binding commands to mouse button presses.

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Ubuntu – Why was Qt chosen for unity-2d and Nux for 3d

Ubuntu – Where is the Accessibility mouse click lock

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