Change font of the floating label EditText and TextInputLayout

Question

Someone tried to change the font of the floating label? I changed the source of EditText but the font of the floating label did not change, I am very grateful to those who h

Answer 1

Unfortunately, you'll have to use reflection to handle this.

The floating label is drawn by CollapsingTextHelper, which is an internal, package-private class and isn't setup to handle spans. So, using something like a custom TypefaceSpan won't work in this case.

Because this uses reflection, it isn't guaranteed to work in the future.

Implementation

final Typeface tf = Typeface.createFromAsset(getAssets(), "your_custom_font.ttf");
final TextInputLayout til = (TextInputLayout) findViewById(R.id.yourTextInputLayout);
til.getEditText().setTypeface(tf);
try {
    // Retrieve the CollapsingTextHelper Field
    final Field cthf = til.getClass().getDeclaredField("mCollapsingTextHelper");
    cthf.setAccessible(true);

    // Retrieve an instance of CollapsingTextHelper and its TextPaint
    final Object cth = cthf.get(til);
    final Field tpf = cth.getClass().getDeclaredField("mTextPaint");
    tpf.setAccessible(true);

    // Apply your Typeface to the CollapsingTextHelper TextPaint
    ((TextPaint) tpf.get(cth)).setTypeface(tf);
} catch (Exception ignored) {
    // Nothing to do
}

Error view

If you needed to change the font of the error, you could do one of two things:

1. Use Reflection grab the error TextView and apply the Typeface much like before
2. Use a custom span. Unlike the floating label, the error view used by TextInputLayout is just a TextView, so it's able to handle spans.

Using reflection

final Field errorField = til.getClass().getDeclaredField("mErrorView");
errorField.setAccessible(true);
((TextView) errorField.get(til)).setTypeface(tf);

Using a custom span

final SpannableString ss = new SpannableString("Error");
ss.setSpan(new FontSpan(tf), 0, ss.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
til.setError(ss);

private static final class FontSpan extends MetricAffectingSpan {

    private final Typeface mNewFont;

    private FontSpan(Typeface newFont) {
        mNewFont = newFont;
    }

    @Override
    public void updateDrawState(TextPaint ds) {
        ds.setTypeface(mNewFont);
    }

    @Override
    public void updateMeasureState(TextPaint paint) {
        paint.setTypeface(mNewFont);
    }

}

Results

The font I'm using is Smoothie Shoppe.