app keeps 'purging from font cache' and eventually crashes due to low memory, android

I'm right at the beginning of building an app (which doesn't even do anything yet, but display some buttons) and when I run开发者_运维知识库 it, I get the error message in logcat: "purding 193K from font cache [23 entries]" over and over, until about a minute later the app crashes due to low memory. My 3 buttons are custom buttons, using a custom font. Problem with the font perhaps?

The problem is calling Typeface.createFromAsset().

I've reduced that creating a font factory, so it calls Typeface.createFromAsset() once per font type.

The font factory holds the typeface in a hashmap and that does the trick.

I found the solution on this link and tweaked a little bit:

http://www.levinotik.com/2011/09/22/custom-fonts-in-android-can-cause-issues-heres-how-to-fix-it/

This is how I've implemented it.

public class FontFactory {
    private static FontFactory instance = new FontFactory();
    private HashMap<String, Typeface> fontMap = new HashMap<String, Typeface>();

    private FontFactory() {
    }

    public static FontFactory getInstance() {
        return instance;
    }

    public Typeface getFont(String font) {
        Typeface typeface = fontMap.get(font);
        if (typeface == null) {
            typeface = Typeface.createFromAsset(MyApplication.getApplicationContext().getResources().getAssets(), "fonts/" + font);
            fontMap.put(font, typeface);
        }
        return typeface;
    }
}

I've been able to drastically reduce this skia message (and eventual low-memory condition) by declaring the Typeface as static within the activity class.

i.e.

public class myActivity extends Activity
{
    //font
    private static Typeface mFontHelvet;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mylayout);

        if (mFontHelvet == null)
        {
            mFontHelvet = Typeface.createFromAsset(this.getAssets(), "Helvetica.TTF");
        }

        myTextView = (TextView) findViewById(R.id.mytextview);
        myTextView.setTypeface(mFontHelvet);
        myTextView.setText("blah blah");
    }
}

this might seem risky, but at least a user can go back and forth between my two activities without entering a low-memory state !