Why the Linux guest-system, on my Linux-tablet, is only a shell.

According to some of my own postings, I possess an old Android-based tablet, which is a Samsung Galaxy Tab S, first generation, onto which I installed a Linux guest-system, using the Android apps “GNURoot (Debian)” and “XSDL”, both available from Google Play. The latter of these apps emulates a simple X-server, which Linux-programs running under the first app can make use of.

The desktop-manager which I chose to use for my Linux guest-system is LXDE, precisely because that desktop-manager does not strictly require that Linux-based daemons be running.

But there are certain standard, LXDE-features which will not even work on that setup:

  • The Trash Bin
  • The LXDE-Settings Panel
  • (etc.)

The LXDE Trash Bin requires the package ‘gvfs’, and the Settings Panel requires the package ‘lxde-settings-daemon’. Both these dependencies launch daemons – i.e., programs that run in the background, and that make up part of a real Linux-session.

The ability to run daemons, essentially, requires that the user have a rooted tablet. Because I never rooted my tablet, I am without any daemons, that would normally belong to any Linux guest-system.

Continue reading Why the Linux guest-system, on my Linux-tablet, is only a shell.

“Help! No Volume Mute under Plasma 5!”

One of the subjects I blog about, is a computer I named ‘Plato’, which is running Debian / Stretch (Debian 9), and the desktop manager of which is Plasma 5, which is the successor to KDE 4.x .

One of the features which KDE 4 definitely had, was an icon in the notification-tray, from which we could control our volume levels easily, as well as to mute the sound temporarily, eventually to be unmuted again, at which point the earlier, unmuted settings should be remembered. At first glance it would seem that Plasma 5 has done away with this capability. Trying to solve this can cause people to spend hours searching the Internet, changing their Plasma 5 preferences, and maybe even forgetting their Plasma 5 preferences, because they disabled all their System Sounds from there.

Recently, I was on a fact-finding mission about this, and am willing to share my solutions.

Under Plasma 5, we really only need to have 2 packages installed, in order to control our volume-levels, etc., assuming that we have gotten our hardware recognized first. Those packages would be:

  1. ‘plasma-pa’
  2. ‘pavucontrol’

The first of these packages integrates with Plasma, and is also responsible for the icon in the notification tray. The second package gives us more control, over our sound-levels specifically, since Plasma 5 uses the Pulse Audio sound-server by default.

If we can see the icon in the notification tray, then a detail which we may overlook after we left-click on that icon, is a tiny little loudspeaker-symbol, on the left end of one of the volume sliders:

screenshot_20180423_150952_c

Left-clicking on this little symbol will cause the volume-bar to the right of it to become slightly pale, which will mean, that the device in question has been muted. I’m saying that ‘we’ could overlook that we even have this feature, because earlier, ‘I’ did not know that I have this feature.

But, this is only what the ‘plasma-pa’ package can show us. The ‘pavucontrol’ package gives us the ability to fine-tune our sound-levels as shown below:

screenshot_20180423_151117

Now, there’s an aspect to how this setup now works, which is slightly more complicated than how KDE 4 used to handle it. The Pulse Audio server attempts to adjust playback as well as recording levels, on a per-application basis. Thus, the view above is almost empty, because there were no applications playing back any sounds, at the moment I recorded this screen-shot.

A frustrating fact which can exist with this, is that some applications will only play a sound for 2 seconds, during which an additional volume-bar appears in the GUI, and after which that volume-bar disappears again, even if we did not have enough time to adjust one volume level. This happens to result from the design-decision, that volume-control should exist at the per-application level. Hence, even if we use media-control keys on our keyboard, those keys will only affect the one main application which happens to be playing, at any given moment. They won’t affect System Sounds.

But this description might sound like I have to say, ‘There is no problem,’ when in fact, under Debian / Stretch, There Is a problem. That problem, as I see it, lies in the fact that by default, the one volume-bar which the GUI has shown above, for all System Sounds, may not even work.

(Updated 04/26/2018 … )

Continue reading “Help! No Volume Mute under Plasma 5!”

Installing a “Wacom” graphics / digitizer tablet under Linux.

I’ve just received my “Wacom Intuos PT S 2″ digitizer tablet – aka graphics tablet – which I had specifically bought, because there is some support for the Wacom series of tablets under Linux. I was able to get it working 100%, and also did get the ‘wireless kit’ to work, that I had ordered with it.

Under Linux, we need to have at least these two packages installed, in order to get this hardware to work:

  • ‘xserver-xorg-input-wacom’
  • ‘libwacom2′

If available, the following should also be installed:

  • ‘libwacom-bin’

Additionally I should mention that I did this on the Debian / Stretch computer I name ‘Plato’, on which I have Plasma 5 as my desktop manager. Although Debian and Linux do support Wacom, apparently, Plasma 5 as such does not. This effectively means that individual applications may have tablet-support, but that We’re not given a graphical module for the System Settings panel, from which to customize our tablet. For that reason, I needed to write a shell-script which does this for me:

 

#!/bin/bash

xsetwacom --set "Wacom Intuos PT S 2 Finger touch" Touch off
xsetwacom --set "Wacom Intuos PT S 2 Pen stylus" Button 2 key "shift"
xsetwacom --set "Wacom Intuos PT S 2 Pen stylus" Button 3 key "ctrl"

xsetwacom --set "Wacom Intuos PT S 2 Pad pad" Button 1 key "button +3"
xsetwacom --set "Wacom Intuos PT S 2 Pad pad" Button 3 key "del"


xsetwacom --set "Wacom Intuos PT S 2 Pad pad" Button 8 key "ctrl" "c"
xsetwacom --set "Wacom Intuos PT S 2 Pad pad" Button 9 key "ctrl" "v"

xsetwacom --set "Wacom Intuos PT S 2 (WL) Finger touch" Touch off
xsetwacom --set "Wacom Intuos PT S 2 (WL) Pen stylus" Button 2 key "shift"
xsetwacom --set "Wacom Intuos PT S 2 (WL) Pen stylus" Button 3 key "ctrl"

xsetwacom --set "Wacom Intuos PT S 2 (WL) Pad pad" Button 1 key "button +3"
xsetwacom --set "Wacom Intuos PT S 2 (WL) Pad pad" Button 3 key "del"


xsetwacom --set "Wacom Intuos PT S 2 (WL) Pad pad" Button 8 key "ctrl" "c"
xsetwacom --set "Wacom Intuos PT S 2 (WL) Pad pad" Button 9 key "ctrl" "v"

 

Presumably, any other users with Plasma 5 desktop-managers will need to write similar scripts. Simply typing in the command ‘xsetwacom’ without any arguments, will display its basic usage.

It should also be noted, that after an X-server module has been installed, that will act as the input driver, at the very least, the X-server also needs to be restarted, before that driver will be loaded.

(Updated 03/24/2018 : )

Continue reading Installing a “Wacom” graphics / digitizer tablet under Linux.

KdeWallet, and Using Smb4K, under Plasma 5

One fact which I’ve written about before, is that I have an up-to-date Linux computer, that uses the ‘Plasma 5′ desktop manager, which is actually the successor to ‘KDE 4′. When using this desktop manager, we can still install numerous packages that ‘belong’ to the old, KDE 4, and most of them will continue to work. One of those is ‘smb4k’, which is a point-and-click utility, to mount a network SMB share – aka, a Windows-file-share, such that it will be visible in our home folder, as though that share was a local sub-folder.

There exist command-line methods to do the same thing, which would mount that network share, and declare it’s of the ‘cifs’ file-system-type, but the use of a simple GUI to do so may be easier.

But then one problem which ensues, is that Smb4K will use the KDE 4 Wallet, to store our password, for that share. It will function in this way, by depending on the package ‘kde-runtime’. In truth, this latter package probably pulls in numerous (old) KDE 4 libraries, and not just the old KWallet, but the existence of this KDE 4 Wallet, on our Plasma 5 machine, is most obvious…

Continue reading KdeWallet, and Using Smb4K, under Plasma 5