Schlagwort: Scratch

The last major release of Raspbian was the Buster version we launched alongside Raspberry Pi 4 last year. There was a minor release a couple of months later, which was mostly just bug-fixes for the first release (hence no blog post), but today’s release has a few changes that we thought it was worth bringing to your attention.

File manager changes

We previously made some significant changes to the PCmanFM file manager included as part of the Raspberry Pi Desktop; we added a cutdown mode which excludes a lot of the less commonly used functionalities, and we set this as the default mode.

One of the things we removed for this mode is the Places view, an optional view for the left-hand pane of the window which provides direct access to a few specific locations in the file system. We felt that the directory browser was more useful, so we chose to show that instead. But one useful feature of Places is that it displays external devices, such as USB drives, and these are somewhat awkward to find in the file manager otherwise.

So for this release, the Places view has been reinstated, but rather than being a separate switchable view, it is a small panel at the top of the directory browser. This hopefully gives the best of both worlds: easy access to USB drives, and a directory view. You can customise what is shown in the Places view on the Layout page of the file manager Preferences dialogue, or you can turn it off completely if you’d rather just have the directory browser.

There are a few other small changes to the file manager: there is now a new folder icon on the taskbar, and the expanders in the directory browser (the little triangles next to directory names) are now only shown when a directory has subdirectories.

Finally, the folder and file icons used in the file manager have been replaced with some new, cleaner designs. These are designed to make it more obvious at a glance what sort of file an icon represents, and also to fit better with the slightly flatter GUI appearance we moved to for Buster.

Orca screen reader

One area of the desktop which we have been wanting to improve for some time is accessibility, particularly for those with visual impairments. To this end, we asked the accessibility charity AbilityNet to assess the Raspberry Pi Desktop to see how usable it was for those with disabilities, and where we could make improvements.

They gave us a lot of very helpful feedback, and their number one suggestion was that we needed to make the Orca screen reader work with the desktop.

Orca is an application which uses synthesised speech to read out menus, window titles, button labels, and the like. It’s a standard Linux application, but people who have tried it on Raspberry Pi found that it didn’t actually work with Raspbian. (When I first installed it, all it did was to make slightly alarming growling noises instead of speaking!)

After quite a bit of fiddling and head-scratching, Orca now works as intended. It will read out many of the pre-installed applications, and should work with a lot of other Linux software packages as well.

Unfortunately, there are a few areas where it won’t work. Orca hooks into various user interface toolkits — the software which is used to draw buttons, menus, etc. on the screen. It is fully compatible with the GTK toolkit (which is used for most of the desktop) and Qt (which is used for the VLC media player and the qpdfview PDF viewer). But many applications (such as Thonny, Sonic Pi, and Scratch) are built on toolkits which are not compatible with the screen reader. Also, the current release of Chromium is not compatible with Orca, but the forthcoming version 80 release, which should be available in a few months, will be Orca-compatible. In the meantime, if you want an Orca-compatible browser, you can install Firefox by entering the following into a terminal window:

sudo apt install firefox-esr

(Please note that we do not recommend using Firefox on Raspbian unless you need Orca compatibility, as it is not optimised for video playback on the Pi in the same way as Chromium.)

Orca doesn’t have a menu entry — the settings dialog shown above can be opened by holding down the Insert key and then pressing the space bar, or by typing orca -s into a terminal window.

Please note that Orca currently doesn’t work with Bluetooth audio devices, so we recommend using it with either the Pi’s own HDMI output or headphone socket, or with a USB or HAT external audio device.

Orca can either be installed from Recommended Software, in the Universal Access category, or by entering the following into a terminal window:

sudo apt install orca

This is hopefully just the start of making the Raspberry Pi Desktop more accessible for those with disabilities, as we are planning to do more work in this area in the future.

New Scratch blocks

Scratch 3 has added the ability to load a project from the command line at launch (scratch3 filename.sb3).

There are also two new blocks in the Sense HAT extension, ‘display stage’ and ‘display sprite’. The first of these shows the current stage on the SenseHAT LED array; the second shows the current sprite on the LEDs.

Thonny improvements

A lot of work has been done on Thonny to improve performance, particularly when debugging. In previous releases, setting breakpoints caused performance to slow down significantly — this was particularly obvious when running PyGame Zero games, where the frame rate was very slow. The new version is substantially faster, as you can see if you set breakpoints in any of…

Code the Classics

…the Python games from Eben’s book Code the Classics – Volume 1, which are now installable from Recommended Software, and can be found in the Games menu.

If you want to look at the code for the games, this can be found in /usr/share/code-the-classics.

Volume control / mixer

In previous releases, there was an Audio Device Preferences application in the main menu to enable device-specific settings to be made for external audio devices. This has now been removed; all these settings are now available directly from the volume plugin on the taskbar: with an external device selected as the output or input device, right-click the volume icon and choose the Output Device Settings… or Input Device Settings… option to open the configuration dialog.

Screen blanking

The option to disable the timeout which blanks the screen after a few minutes has been added to Raspberry Pi Configuration. To try and reduce clutter in this application, the options from the System tab are now split across two tabs; all display-related options, including screen blanking, are now on the new Display tab.

We’ve also been able to reinstate the pixel doubling option for Raspberry Pi 4; this was originally implemented in a manner incompatible with the KMS video driver used on Raspberry Pi 4, but we’ve now found a way to make it work with KMS. (The pixel doubling option is designed to make the Raspberry Pi’s screen easier to use for people with visual disabilities — it doubles the size of every pixel, scaling the entire screen by a factor of two.)

We’ve made one minor change to key shortcuts: in previous versions of Raspbian, the combination Ctrl-Alt-Delete launched the task manager. We felt it might be better to be consistent with the behaviour of Windows PCs since the dawn of time, so now Ctrl-Alt-Delete launches the shutdown options dialog. If you want to access the task manager with a key shortcut, you can now do so using Ctrl-Shift-Escape — also consistent with the behaviour of Windows.

There are also numerous other small bug fixes and robustness improvements across the board.

How do I get it?

The new image is available for download from the usual place: our Downloads page.

To update an existing image, use the usual terminal command:

sudo apt update sudo apt full-upgrade

We hope you like the changes — as ever, all feedback is welcome, so please leave a comment below!

Website: LINK