Alap kéne legyen.

Alap kéne legyen.

Originally shared by Aladin Q

SeekBar with a logarithmic scale on Android.

A linear volume slider do not match human perception of sound intensity (Psychoacoustics). Consequently, using a SeekBar to properly control a volume in your application requires little extra code. 

A SeekBar ranging from 1 to 100 returns value from 1 to 100, linearly (y = x):
1 -- 25 -- 50 -- 75 --> 100

A logarithmic SeekBar ranging from 1 to 100 returns value from 0 to 100:
0 --  4 -- 20 -- 52 --> 100

This trivial formula y = (x²/200)*log(x) in the OnSeekBarChangeListener listener will allow us to change the default linear SeekBar into a logarithmic one.

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@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
    int x = progress;
    int y = (int) (((x*x)/200)*Math.log10(x));

    // Use the value "y" to control a volume level
}

#Android   #AndroidDev   #SeekBar  Audioid