[SOLVED] Use the screen corners to change the sound volume using the mouse wheel?

[pemartins]

Is there a way I can use the screen corners to change the sound volume using the mouse wheel?

Using Compiz in MATE I was used to having left, right and bottom corners of the screen set to change volume, something like assigning these commands to the buttons when the mouse pointer is at a corner:
pactl set-sink-volume 1 +10% for button 6
pactl set-sink-volume 1 -10% for button 5

Is there a way I can do this in Kubuntu 18.04 (KDE using KWin)?

edit
Solution scripts:
https://www.kubuntuforums.net/showth...l=1#post416295
and
https://www.kubuntuforums.net/showth...l=1#post416652

[GreyGeek]

In System Settings --> Desktop Behavior --> ScreenEdges are six buttons. You can right click on a button and select "Run a command". How you set which command to run is not apparent and I do not know, but maybe Kubical or someone else does.

[vinnywright]

In System Settings --> Desktop Behavior --> ScreenEdges are six buttons. You can right click on a button and select "Run a command". How you set which command to run is not apparent and I do not know, but maybe Kubical or someone else does.

it opens krunner like in "alt +F2"

VINNY

[GreyGeek]

it opens krunner like in "alt +F2"

VINNY

So, if "Application Launcher" is selected does click the corner still open Krunner? If so, there is not really anything that is different since either a command or the name of an app has to be manually entered each time. That's not helpful.

[vinnywright]

So, if "Application Launcher" is selected does click the corner still open Krunner? If so, there is not really anything that is different since either a command or the name of an app has to be manually entered each time. That's not helpful.

yes it opens krunner when you click the corner , and no it's not helpful , the keybord shortcut is just as quick and if the desktop has focus you can just start typing and it opens .

VINNY

[jglen490]

Interesting ... And a cool trick.

Sometimes it's just easier to turn the volume knob - like the Bose Companion 2 speakers next to my monitor. Or left click the speaker icon in the tray and use the mouse wheel there.

[pemartins]

Thank y'all for your help!

Help me out here because I think we're almost there, I found this to be quite useful: https://askubuntu.com/questions/6010.../601209#601209

In example, when I use this command:

xdotool behave_screen_edge top-left exec pactl set-sink-volume 0 +10%

the volume raises 10% as I move the mouse pointer to the top left corner. Now I'm only missing a script so that action is only performed when a mouse button is clicked, in this particular case when the mouse wheel is moved.
I am not capable of making such a script myself.

I already have these commands added to the file ~/.xbindkeysrc so I can use Super key plus mouse wheel to control the volume, they can perhaps be helpful (for some season I used amixer instead of pactl, basically they both do the same volume control action but pactl raises the volume above 100% which is sometimes useful):

"amixer -D pulse -q sset Master 7%+ unmute"
m:0x50 + c:133 + b:4
"amixer -D pulse -q sset Master 7%- unmute"
m:0x50 + c:133 + b:5

edit:
Maybe it's useful, here's the output of xev for button 4 (mouse wheel up) and button 5 (mouse wheel down):

$ xev | grep -A 2 Button
ButtonPress event, serial 40, synthetic NO, window 0x3c00001,
 root 0x4c7, subw 0x0, time 7996725, (84,52), root:(842,594),
 state 0x10, button 4, same_screen YES
--
ButtonRelease event, serial 40, synthetic NO, window 0x3c00001,
 root 0x4c7, subw 0x0, time 7996725, (84,52), root:(842,594),
 state 0x810, button 4, same_screen YES
--
ButtonPress event, serial 40, synthetic NO, window 0x3c00001,
 root 0x4c7, subw 0x0, time 8002228, (79,51), root:(837,593),
 state 0x10, button 5, same_screen YES
--
ButtonRelease event, serial 40, synthetic NO, window 0x3c00001,
 root 0x4c7, subw 0x0, time 8002228, (79,51), root:(837,593),
 state 0x1010, button 5, same_screen YES

[pemartins]

Seems like someone had the same idea not long ago, here's a script that will allow using the mouse wheel to control the volume on the four edges of the screen:
https://github.com/mnural/xlib-pyvolume

Already changed it to work with my sound device and removed the constant printing on the screen of the mouse pointer location:

#!/usr/bin/env python
#-*-coding:utf-8-*-
# mehmet nural altintas <mehmet.nrl@hotmail.com>
# This script is edited version of  "record_demo.py -- demonstrate record extension" that can be found here: [URL]http://python-xlib.svn.sourceforge.net/viewvc/python-xlib/trunk/examples/[/URL]
# python-xlib package must be installed to run this script
# sudo apt-get install python-xlib

import os
from Xlib import X, display
from Xlib.ext import record
from Xlib.protocol import rq

Screen_resolution = (1366,768) # write here your screen resolution

Corner_area = 20 # write here the size of the virtual squares that receive wheel up and down event at the corner of your screen 

# Let's set up the commands
def volume_up():

 os.system("amixer -D pulse -q sset Master 7%+ unmute & pid=$!")
 # write your bash command between "" to volume up

 # use "& pid=$!" end of your command to prevent freezing python script if your command takes long time to process.

def volume_down():

 os.system("amixer -D pulse -q sset Master 7%- unmute & pid=$!")
 # write your bash command between "" to volume down

record_dpy = display.Display()

ctx = record_dpy.record_create_context(
     0,
     [record.AllClients],
     [{
             'core_requests': (0, 0),
             'core_replies': (0, 0),
             'ext_requests': (0, 0, 0, 0),
             'ext_replies': (0, 0, 0, 0),
             'delivered_events': (0, 0),
             'device_events': (X.KeyPress, X.MotionNotify),
             'errors': (0, 0),
             'client_started': False,
             'client_died': False,
     }])

def record_callback(reply):

 data = reply.data
 while len(data):
     event, data = rq.EventField(None).parse_binary_value(data, record_dpy.display, None, None)
     
     if event.type == X.ButtonPress:
         print  event.detail, event.root_x, event.root_y

         # Let's set up right up corner 

         if all( [event.root_x > Screen_resolution[0] - Corner_area, event.root_y < Corner_area] ):

            print "right up corner detected" 

            # event.detail 4 means wheel up event

            if event.detail is 4 : 
               print "volume up!"
               volume_up() 

            # event.detail 5 means wheel down event

            if event.detail is 5 :
               print "volume down!"
               volume_down() 

         # Let's set up left up corner

         if all( [event.root_x < Corner_area , event.root_y < Corner_area] ):

            print "left up corner detected"

            if event.detail is 4 :
               print "volume up!"
               volume_up() 

            if event.detail is 5 :
               print "volume down!"
               volume_down() 

         # Let's set up right down corner

         if all( [event.root_x > Screen_resolution[0] - Corner_area, event.root_y > Screen_resolution[1] - Corner_area] ):

            print "right down corner detected"

            if event.detail is 4 :
               print "volume up!"
               volume_up() 

            if event.detail is 5 :
               print "volume down!"
               volume_down() 

         # Let's set up left down corner 

         if all( [event.root_x < Corner_area , event.root_y > Screen_resolution[1] - Corner_area] ):

            print "left down corner detected"

            if event.detail is 4 :
               print "volume up!" 
               volume_up() 

            if event.detail is 5 :
               print "volume down!" 
               volume_down() 
                                
         
#        elif event.type == X.ButtonRelease:

#            print  event.detail, event.root_x, event.root_y
         
#        elif event.type == X.MotionNotify:

#            print event.root_x, event.root_y
         

record_dpy.record_enable_context(ctx, record_callback)

In this script is there ways of:
1) make it work not just on the top and button edges but all along the sides from top to bottom?
2) I noticed that, when the script is running, python uses from 1 to 4% of the cpu. Is there a way to lower this cpu usage?

[GreyGeek]

How is that better than just hovering your mouse over the sound icon in the system tray and rolling your thumb wheel up or down?

[claydoh]

How is that better than just hovering your mouse over the sound icon in the system tray and rolling your thumb wheel up or down?

If you don't use any panels, you can't do that

Which gives me an idea:
Create an autohide panel with only an audio volume widget, no systray or taskbar etc , shrunk down to only show the widget in the corner desired. Mouse over to that corner and it pops out, then mouse wheel to adjust volume.

Hacky, but genius I say!

Sent from my LG-H931 using Tapatalk

[GreyGeek]

That's a GREAT idea, Claydoh!

[pemartins]

In full screen mode there's no way of using the volume icon on a panel, that's the main reason I'm looking for this. And just moving the mouse to one side and using the wheel is also way faster, you can do it without even looking at the screen (very useful for a wireless mouse).

[claydoh]

I imagine it is possible with kwin scripting, but you'd have to learn that, or find someone to do it.

[jlittle]

No-one has mentioned the dbus or qdbus yet, so I thought I might. There's qdbus commands to query or set the volume. But something taking button events from the windowing system in full screen mode is a part of the requirement... I've no idea.

Regards, John Little

[claydoh]

Well the Plasma/Kwin master sez it is possible, I think
https://forum.kde.org/viewtopic.php?f=67&t=128169
So you invoke qdbus or dbus commands via kwin scripting
https://techbase.kde.org/Development...ipting/API_4.9
All g(r)eek to me tho