Setting up the SeekBar

So we want to use the SeekBar. We want the minimum value to be 10 and the maximum value to be 100, and it should increment by 10.

Thing is, SeekBar by default always starts at 0, and the increment is always an int. It is definitely possible to get what we want, but we need to do some simple math first.

Compute how many increments you will need from your minimum up to your maximum:

numberOfIncrements = maximum - minimum = 90

Then divide it by the amount of each increment we want:

seekBarMaximum = numberOfIncrements / 10 = 9

This means we should set up the SeekBar to have max = 9 and increment = 1. Then in our code, we have to figure out how to get the actual progress that we want.

SeekBar.OnSeekBarChangeListener mSeekbarListener = new OnSeekBarChangeListener() {
			
	@Override
	public void onStopTrackingTouch(SeekBar seekBar) { /* Do nothing*/ }
			
	@Override
	public void onStartTrackingTouch(SeekBar seekBar) { /* Do nothing*/ }
			
	@Override
	public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
		mProgressDisplay.setText("Seekbar is at: " + getProgressToDisplay(progress));
	}
};


private String getProgressToDisplay(int progress) {

        // We are multiplying by 10 since it is our actual increment
	int actualProgress = (progress + 1) * 10;
	return String.valueOf(actualProgress);
}

Another example:

minimum = 1, maximum = 10, increment = 0.5
numberOfIncrements = 9
seekBarMaximum = 18

In this case, the contents of getProgressToDisplay() will change since the increment is not a whole number.

private String getProgressToDisplay(int progress) {
	float actualProgress = (progress + 1) - (progress * 0.5f);
	return String.valueOf(actualProgress);
}

That damn seekbar thumb

If you have ever needed to use a SeekBar, you definitely would have noticed how hard it is to move the slider (aka thumb) when it is set to the minimum or maximum value. The slider tends to be cut in half, and fitting your finger into it to press it becomes a test of patience.

See how small the slider becomes when it reaches the far ends of the SeekBar? Crazy!

Luckily, I found a way (just today!) to move the slider just a little tiny bit to make it easier to press. Apparently, there is a method called setThumbOffset() that allows us to nudge the slider by a number of pixels.

It's pretty easy to use, aside from the fact that it accepts pixels and not dip measurements. Anyway, here's how to do it:

int pixels = convertDipToPixels(8f);
SeekBar mySeekBar = (SeekBar) findViewById(R.id.quiz_settings_seekbar);
mySeekBar.setOnSeekBarChangeListener(mySeekBarListener);
mySeekBar.setThumbOffset(pixels);

I convert dip measurements to pixels to better manage the growing number of resolutions of screen sizes present. Here's the code to do that:

private int convertDipToPixels(float dip) {
     DisplayMetrics metrics = new DisplayMetrics();
     getWindowManager().getDefaultDisplay().getMetrics(metrics);
     float density = metrics.density;
     return (int)(dip * density);
}

Aaaaaaaand this is now how our slider looks:Applause! Confetti! Applause!