WeightTypefaceApi26.java
/*
* Copyright 2021 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.core.graphics;
import static androidx.annotation.RestrictTo.Scope.LIBRARY;
import android.annotation.SuppressLint;
import android.graphics.Typeface;
import android.util.Log;
import android.util.SparseArray;
import androidx.annotation.GuardedBy;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import androidx.annotation.RestrictTo;
import androidx.collection.LongSparseArray;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
* Helper for creating {@link Typeface}s with exact weight on API 26-27.
*/
@SuppressLint("SoonBlockedPrivateApi")
@RestrictTo(LIBRARY)
@RequiresApi(26)
final class WeightTypefaceApi26 {
private static final String TAG = "WeightTypeface";
private static final String NATIVE_INSTANCE_FIELD = "native_instance";
private static final String NATIVE_CREATE_FROM_TYPEFACE_WITH_EXACT_STYLE_METHOD =
"nativeCreateFromTypefaceWithExactStyle";
private static final Field sNativeInstance;
private static final Method sNativeCreateFromTypefaceWithExactStyle;
private static final Constructor<Typeface> sConstructor;
static {
Field nativeInstance;
Method nativeCreateFromTypefaceWithExactStyle;
Constructor<Typeface> constructor;
try {
nativeInstance = Typeface.class.getDeclaredField(NATIVE_INSTANCE_FIELD);
nativeCreateFromTypefaceWithExactStyle = Typeface.class
.getDeclaredMethod(NATIVE_CREATE_FROM_TYPEFACE_WITH_EXACT_STYLE_METHOD,
long.class, int.class, boolean.class);
nativeCreateFromTypefaceWithExactStyle.setAccessible(true);
constructor = Typeface.class.getDeclaredConstructor(long.class);
constructor.setAccessible(true);
} catch (NoSuchFieldException | NoSuchMethodException e) {
Log.e(TAG, e.getClass().getName(), e);
nativeInstance = null;
nativeCreateFromTypefaceWithExactStyle = null;
constructor = null;
}
sNativeInstance = nativeInstance;
sNativeCreateFromTypefaceWithExactStyle = nativeCreateFromTypefaceWithExactStyle;
sConstructor = constructor;
}
/**
* Returns true if all the necessary methods were found.
*/
private static boolean isPrivateApiAvailable() {
return sNativeInstance != null;
}
/**
* Cache for Typeface objects for weight variant. Currently max size is 3.
*/
@GuardedBy("sWeightCacheLock")
private static final LongSparseArray<SparseArray<Typeface>> sWeightTypefaceCache =
new LongSparseArray<>(3);
private static final Object sWeightCacheLock = new Object();
/**
* @return Valid typeface, or {@code null} if private API is not available
*/
@Nullable
static Typeface createWeightStyle(@NonNull Typeface base, int weight, boolean italic) {
if (!isPrivateApiAvailable()) {
return null;
}
final int key = (weight << 1) | (italic ? 1 : 0);
Typeface typeface;
synchronized (sWeightCacheLock) {
final long baseNativeInstance = getNativeInstance(base);
SparseArray<Typeface> innerCache = sWeightTypefaceCache.get(baseNativeInstance);
if (innerCache == null) {
innerCache = new SparseArray<>(4);
sWeightTypefaceCache.put(baseNativeInstance, innerCache);
} else {
typeface = innerCache.get(key);
if (typeface != null) {
return typeface;
}
}
typeface = create(
nativeCreateFromTypefaceWithExactStyle(baseNativeInstance, weight, italic));
innerCache.put(key, typeface);
}
return typeface;
}
private static long getNativeInstance(@NonNull Typeface typeface) {
try {
return sNativeInstance.getLong(typeface);
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
}
@SuppressLint("BanUncheckedReflection")
@SuppressWarnings("ConstantConditions")
private static long nativeCreateFromTypefaceWithExactStyle(long nativeInstance, int weight,
boolean italic) {
try {
return (long) sNativeCreateFromTypefaceWithExactStyle.invoke(null, nativeInstance,
weight, italic);
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
} catch (InvocationTargetException e) {
throw new RuntimeException(e);
}
}
@Nullable
private static Typeface create(long nativeInstance) {
try {
return sConstructor.newInstance(nativeInstance);
} catch (IllegalAccessException e) {
return null;
} catch (InstantiationException e) {
return null;
} catch (InvocationTargetException e) {
return null;
}
}
private WeightTypefaceApi26() {
// No instances.
}
}