Io uso un'altra soluzione. Ho impostato l'attività personalizzata su LayoutInflater.Factory. Quindi ho accesso completo alla vista dopo averla creata. Posso installare font personalizzati per ogni TextView senza iterare sulla gerarchia delle viste. Una cosa che dovresti fare per usare caratteri personalizzati in tutte le tue applicazioni è chiamare new Font(...).install() nella tua attività di base. Vedi l'esempio di seguito.
Ecco la mia soluzione con il campione di utilizzo:
import java.util.Map;
import com.google.common.collect.Maps;
import static com.google.common.base.Preconditions.checkNotNull;
import android.R;
import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Typeface;
import android.support.v4.app.FragmentActivity;
import android.util.AttributeSet;
import android.util.Log;
import android.view.InflateException;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.TextView;
/**
* Provides an ability to apply custom font to all {@link TextView} and subclasses.
*
* To install custom font use method {@link #install(Activity)} in {@link Activity#onCreate(android.os.Bundle)}
* <b>before</b> calling super.onCreate(Bundle).
*
* <p/>Example of usage:
* <pre>
* {@code
* public class BaseActivity extends SherlockFragmentActivity {
*
* protected void onCreate(Bundle state) {
* applyCustomFontForPreICS();
* super.onCreate(state);
* }
*
* private void applyCustomFontForPreICS() {
* boolean isPreICS = Build.VERSION.SDK_INT < BUILD_VERSION_CODE_ICE_CREAM_SANDWICH
* if (isPreICS) {
* new Font(
* "font/roboto_regular.ttf",
* "font/roboto_bold.ttf",
* "font/roboto_italic.ttf",
* "font/roboto_bold_italic.ttf"
* ).install(this);
* }
* }
* }
* }
* </pre>
*
* @author Alexey Danilov ([email protected])
*/
public class Font {
private static final Map<String, Typeface> FONTS = Maps.newHashMap();
private String regularFontPath;
private String boldFontPath;
private String italicFontPath;
private String boldItalicFontPath;
/**
* Creates instance to be used for setting particular font.
*
* @param regularPath regular font assets path, must be not {@code null}
* @param boldPath bold font assets path, must be not {@code null}
* @param italicPath italic font assets path, must be not {@code null}
* @param boldItalicPath bold and italic font assets path, must be not {@code null}
*/
public Font(String regularPath, String boldPath, String italicPath, String boldItalicPath) {
this.regularFontPath = checkNotNull(regularPath);
this.boldFontPath = checkNotNull(boldPath);
this.italicFontPath = checkNotNull(italicPath);
this.boldItalicFontPath = checkNotNull(boldItalicPath);
}
/**
* Installs custom font to activity.
*
* @param activity an activity custom font will be installed to, must be not {@code null}.
*/
public void install(Activity activity) {
checkNotNull(activity, "Activity must be not null!");
LayoutInflater layoutInflater = activity.getLayoutInflater();
boolean factoryIsEmpty = layoutInflater.getFactory() == null;
if (!factoryIsEmpty) {
throw new IllegalStateException("Impossible to use this method for this activity: layout factory is set!");
}
layoutInflater.setFactory(new FontLayoutInflaterFactory());
}
private Typeface getFont(int type, Context context) {
switch (type) {
case Typeface.NORMAL:
return getFont(context, regularFontPath);
case Typeface.BOLD:
return getFont(context, boldFontPath);
case Typeface.ITALIC:
return getFont(context, italicFontPath);
case Typeface.BOLD_ITALIC:
return getFont(context, boldItalicFontPath);
default: {
throw new IllegalArgumentException("Undefined font type " + type);
}
}
}
private Typeface getFont(Context context, String path) {
if (FONTS.containsKey(path)) {
return FONTS.get(path);
} else {
Typeface typeface = makeTypeface(context, path);
FONTS.put(path, typeface);
return typeface;
}
}
private Typeface makeTypeface(Context context, String path) {
try {
return Typeface.createFromAsset(context.getAssets(), path);
} catch (Exception e) {
// add user-friendly error message
throw new IllegalArgumentException(String.format("Error creating font from assets path '%s'", path), e);
}
}
private void applyFontToTextView(Context context, TextView textView, AttributeSet attrs) {
int[] fontStyleAttributes = {R.attr.textStyle};
TypedArray typedArray = context.obtainStyledAttributes(attrs, fontStyleAttributes);
boolean isStyleSpecified = typedArray.getIndexCount() != 0;
int type = isStyleSpecified ? typedArray.getInt(0, Typeface.NORMAL) : Typeface.NORMAL;
Typeface font = getFont(type, context);
textView.setTypeface(font, type);
}
private final class FontLayoutInflaterFactory implements LayoutInflater.Factory {
// to improve perfomance the package with the most usable components should be the first.
private final String[] ANDROID_UI_COMPONENT_PACKAGES = {
"android.widget.",
"android.webkit.",
"android.view."
};
@Override
public View onCreateView(String name, Context context, AttributeSet attrs) {
try {
// we install custom LayoutInflater.Factory, so FragmentActivity have no chance set own factory and
// inflate tag <fragment> in method onCreateView. So call it explicitly.
if ("fragment".equals(name) && context instanceof FragmentActivity) {
FragmentActivity fragmentActivity = (FragmentActivity) context;
return fragmentActivity.onCreateView(name, context, attrs);
}
View view = createView(name, attrs, LayoutInflater.from(context));
if (view == null) {
// It's strange! The view is not ours neither android's. May be the package of this view
// is not listed in ANDROID_UI_COMPONENT_PACKAGES. Return null for the default behavior.
Log.d(LOG_TAG, "Cannot create view with name: " + name);
return null;
}
if (view instanceof TextView) {
TextView textView = (TextView) view;
applyFontToTextView(context, textView, attrs);
}
return view;
} catch (InflateException e) {
Log.e(LOG_TAG, "Error inflating view", e);
return null;
} catch (ClassNotFoundException e) {
Log.e(LOG_TAG, "Error inflating view", e);
return null;
}
}
private View createView(String name, AttributeSet attrs, LayoutInflater layoutInflater) throws ClassNotFoundException {
View view = null;
boolean isAndroidComponent = name.indexOf('.') == -1;
if (isAndroidComponent) {
// We don't know package name of the view with the given simple name. Try android ui packages listed in
// ANDROID_UI_COMPONENT_PACKAGES
// The same implementation is in the class PhoneLayoutInflater from internal API
for (String androidPackage : ANDROID_UI_COMPONENT_PACKAGES) {
try {
view = layoutInflater.createView(name, androidPackage, attrs);
if (view != null) {
break;
}
} catch (ClassNotFoundException e) {
// Do nothing, we will try another package
}
}
} else {
view = layoutInflater.createView(name, null, attrs);
}
return view;
}
}
}
Nota ha dipendenza da guava, ma è possibile implementare questa metodi da lui stesso.
Si può mettere in un [stile] (http://developer.android.com/guide/topics/ui/themes.html) forse. Idk se questo funziona con caratteri tipografici da risorse però. – zapl