How to assign text size in sp value using java code

Question

http://developer.android.com/reference/android/widget/TextView.html#setTextSize%28int,%20float%29

Example:

textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 65);

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));

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; 

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.

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);

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.