Today I want to share with you custom TextView which allows to set font to be used in xml layout.
First, we need to declare our custom styleable
attrs.xml:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="TypefaceTextView">
<attr name="typeface" format="string"/>
</declare-styleable>
</resources>
Then we need to create subclass of TextView which will use custom attribute.
TypefaceTextView:
public class TypefaceTextView extends TextView {
public TypefaceTextView(Context context) {
this(context, null);
}
public TypefaceTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public TypefaceTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.TypefaceTextView, 0, 0);
try {
String font = ta.getString(R.styleable.TypefaceTextView_typeface);
if (null == font) {
font = context.getString(R.string.default_font_name);
}
Typeface typeface = TypefaceCache.getTypeface(context, font);
if (null != typeface) {
setTypeface(typeface);
}
} finally {
ta.recycle();
}
}
}
Also, above class allows to use default custom font, all is needed is to define its name in strings.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="default_font_name" translatable="false">custom.ttf</string>
</resources>
Due to the bug in Android we have to cache all created typefaces in cache:
TypefaceCache:
public class TypefaceCache {
private static final Map<String, Typeface> CACHE = new HashMap<String, Typeface>();
public static Typeface getTypeface(Context context, String font) {
if (null == font) {
return null;
}
Typeface typeface = CACHE.get(font);
if (null == typeface) {
typeface = Typeface.createFromAsset(context.getAssets(), font);
CACHE.put(font, typeface);
}
return typeface;
}
}
Basically, that’s it. In order to use it is required to put TTF font in the assets folder and reference the font:
Example usage:
<?xml version="1.0" encoding="utf-8"?>
<com.example.android.widget.TypefaceTextView
xmlns:a="http://schemas.android.com/apk/res/android"
xmlns:custom="http://schemas.android.com/apk/res-auto"
a:layout_width="match_parent"
custom:typeface="custom-font.ttf"/>
And the last use case it to set custom font for the actionbar title. In this case we can implement custom android.text.style.CharacterStyle
TypefaceSpan:
public class TypefaceSpan extends MetricAffectingSpan {
private Typeface mTypeface;
/**
* Load the {@link Typeface} and apply to a {@link Spannable}.
*/
public TypefaceSpan(Context context, String typefaceName) {
mTypeface = TypefaceCache.getTypeface(context, typefaceName);
}
@Override
public void updateMeasureState(TextPaint p) {
p.setTypeface(mTypeface);
// Note: This flag is required for proper typeface rendering
p.setFlags(p.getFlags() | Paint.SUBPIXEL_TEXT_FLAG);
}
@Override
public void updateDrawState(TextPaint tp) {
tp.setTypeface(mTypeface);
// Note: This flag is required for proper typeface rendering
tp.setFlags(tp.getFlags() | Paint.SUBPIXEL_TEXT_FLAG);
}
}
Then we can set actionbar title using the following code:
public static void setActionBarTitle(Activity context, CharSequence title) {
SpannableString s = new SpannableString(title);
s.setSpan(new TypefaceSpan(context, context.getString(R.string.default_font_name)), 0, s.length(),
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
context.getActionBar().setTitle(s);
}
}