Brightness adjustment slider GUI (wxPython or Tk)

brightness_tk.py

"""
A super-simple GUI for setting my laptop backlight.
For some reason Ubuntu Answers couldn't tell me where to change the minimum brightness and step interval.
So I had to make something because my laptop can be MUCH dimmer than Ubuntu's minimum.

Added this version for tk, since it is such a simple GUI.
"""
import os
import subprocess
from Tkinter import *

class BrightnessSlider(object):
    find_max_brightness_cmd = ['cat', '/sys/class/backlight/intel_backlight/max_brightness']
    find_brightness_cmd = ['cat', '/sys/class/backlight/intel_backlight/actual_brightness']

    def __init__(self, master):
        min_brightness = 92
        p1 = subprocess.Popen(self.find_brightness_cmd,
                              stdout=subprocess.PIPE)
        p2 = subprocess.Popen(self.find_max_brightness_cmd,
                              stdout=subprocess.PIPE)
        current_brightness, stderr = p1.communicate()
        max_brightness, stderr = p2.communicate()

        self.slider = Scale(master,
                  from_=int(min_brightness),
                  to=int(max_brightness),
                  orient=HORIZONTAL,
                  command=self.on_slide)
        self.slider.set(current_brightness)
        self.slider.pack()
        self.slider.focus_set()

    def on_slide(self, new_value):
        self.set_brightness(new_value)

    def set_brightness(self, new_val):
        with open('/sys/class/backlight/intel_backlight/brightness', 'w') as f:
            f.write(new_val)


if __name__ == "__main__":
    master = Tk()
    b = BrightnessSlider(master)
    mainloop()

brightness_wxPython.py

import os
import wx
import subprocess

find_max_brightness_cmd = ['cat', '/sys/class/backlight/intel_backlight/max_brightness']
find_brightness_cmd = ['cat', '/sys/class/backlight/intel_backlight/actual_brightness']
def set_brightness(new_val):
    with open('/sys/class/backlight/intel_backlight/brightness', 'w') as f:
        f.write(str(new_val))

min_brightness = 92
p = subprocess.Popen(find_brightness_cmd, stdout=subprocess.PIPE)
current_brightness, stderr = p.communicate()
p = subprocess.Popen(find_max_brightness_cmd, stdout=subprocess.PIPE)
max_brightness, stderr = p.communicate()

class brightness_slider(wx.Frame):
    """
    A super-simple GUI for setting my laptop backlight.
    For some reason Ubuntu Answers couldn't tell me where to change the minimum brightness and step interval.
    So I had to make something because my laptop can be MUCH dimmer than Ubuntu's minimum.

    The GUI can be dragged by right-clicking anywhere on it.
    """
    def __init__(self):
        wx.Frame.__init__(self, parent=None, title="Change Brightness",
                          style=(wx.DEFAULT_FRAME_STYLE &
                                 ~(wx.RESIZE_BORDER | wx.MAXIMIZE_BOX)
                                 )
                          )
        panel = wx.Panel(self, -1)

        self.slider = wx.Slider(panel, value = int(current_brightness), minValue=int(min_brightness), maxValue=int(max_brightness))#, size=())
        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(self.slider, 1, wx.EXPAND)
        panel.SetSizer(sizer)
        #get the slider's height and width
        ss = self.slider.GetBestSize()
        #replace the slider's width with 100
        ss[0] = 100
        self.SetSize(ss)
        self.SetMaxSize(ss)

        self.slider.Bind(wx.EVT_SLIDER, self.on_slide)
        
        #bind all the widgets
        self.Bind(wx.EVT_RIGHT_UP, self.MouseUp)
        panel.Bind(wx.EVT_RIGHT_UP, self.MouseUp)
        self.slider.Bind(wx.EVT_RIGHT_UP, self.MouseUp)
        self.slider.Bind(wx.EVT_RIGHT_DOWN, self.MouseDown)

        self.Bind(wx.EVT_IDLE, self.OnIdle)


    def on_slide(self, event):
        set_brightness(int(event.GetEventObject().GetValue()))

    def MouseDown(self, event):
        wx.Window.CaptureMouse(self.slider)
        #figure out how thick the Title and Frame border are

        #subtract the panel size from the overall frame
        sizeDiff = self.GetSize() -  self.GetClientSize()

        #these get the system specific thicknesses, 
        #since this works I believe Windows is showing a 3D border next to the normal border
        borderAdjust = wx.SystemSettings.GetMetric(wx.SYS_BORDER_Y) + wx.SystemSettings.GetMetric(wx.SYS_EDGE_Y)

        #the left and right side border is identical, so we can divide by 2
        #since the upper border isn't the same as the bottom, adjust only for the top
        sizeDiff = wx.Point(sizeDiff[0]/2, sizeDiff[1]-borderAdjust)

        #use the global mouse position, since event.GetPosition() can come from a widget,
        # and this will give non-Panel referenced coordinates
        self.posInFrame = self.ScreenToClient(wx.GetMousePosition()) + sizeDiff

    def MouseUp(self, event):
        wx.Window.ReleaseMouse(self.slider)

    def OnIdle(self, event):
        if self.slider.HasCapture():
            topLeftInScreen = wx.GetMousePosition()
            topLeftInScreen = topLeftInScreen - self.posInFrame
            self.SetPosition(topLeftInScreen)
        event.Skip()


if __name__ == "__main__":
    app = wx.App(False)
    frame = brightness_slider()
    frame.Show()
    #import wx.lib.inspection
    #wx.lib.inspection.InspectionTool().Show()
    app.MainLoop()