[android] How to assign text size in sp value using java code

If I assign an integer value to change a certain text size of a TextView using java code, the value is interpreted as pixel (px).

Now does anyone know how to assign it in sp?

When the accepted answer doesn't work (for example when dealing with Paint) you can use:

float spTextSize = 12;
float textSize = spTextSize * getResources().getDisplayMetrics().scaledDensity;
textPaint.setTextSize(textSize);

You can use a DisplayMetrics object to help convert between pixels and scaled pixels with the scaledDensity attribute.

DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
pixelSize = (int)scaledPixelSize * dm.scaledDensity; 

semeTextView.setTextSize(TypedValue.COMPLEX_UNIT_PX, 
                       context.getResources().getDimension(R.dimen.text_size_in_dp))

This is code for the convert PX to SP format. 100% Works

view.setTextSize(TypedValue.COMPLEX_UNIT_PX, 24);

After trying all the solutions and none giving acceptable results (maybe because I was working on a device with default very large fonts), the following worked for me (COMPLEX_UNIT_DIP = Device Independent Pixels):

textView.setTextSize(TypedValue.COMPLEX_UNIT_DIP, 14);

Thanks @John Leehey and @PeterH:

desiredSp = getResources().getDimension(R.dimen.desired_sp);
density = getResources().getDisplayMetrics().density;
textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, desiredSp / density);

The thing is if you define R.dimen.desired_sp to 25 in your dimen.xml

1. On non-HD Device: desiredSp is still 25, density = 1
2. On HD Device(like Nexus 7 2nd Generation): desiredSp becomes 50 ish, density = 2

From Api level 1, you can use the public void setTextSize (float size) method.

From the documentation:

Set the default text size to the given value, interpreted as "scaled pixel" units. This size is adjusted based on the current density and user font size preference.

Parameters: size -> float: The scaled pixel size.

So you can simple do:

textView.setTextSize(12); // your size in sp

Based on the the source code of setTextSize:

public void setTextSize(int unit, float size) {
    Context c = getContext();
    Resources r;

    if (c == null)
        r = Resources.getSystem();
    else
        r = c.getResources();

    setRawTextSize(TypedValue.applyDimension(
        unit, size, r.getDisplayMetrics()));
}

I build this function for calulating any demension to pixels:

int getPixels(int unit, float size) {
    DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
    return (int)TypedValue.applyDimension(unit, size, metrics);
}

Where unit is something like TypedValue.COMPLEX_UNIT_SP.

Cleaner and more reusable approach is

define text size in dimens.xml file inside res/values/ directory:

</resources>
   <dimen name="text_medium">14sp</dimen>
</resources>

and then apply it to the TextView:

textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, context.getResources().getDimension(R.dimen.text_medium));

By default setTextSize, without units work in SP (scales pixel)

public void setTextSize (float size) 
Added in API level 1
Set the default text size to the given value, interpreted as "scaled pixel" units. This 
size is adjusted based on the current density and user font size preference.