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      1 /*
      2  * Copyright (C) 2012 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.text.style;
     18 
     19 import com.android.internal.util.Preconditions;
     20 
     21 import android.annotation.NonNull;
     22 import android.annotation.Nullable;
     23 import android.graphics.Paint;
     24 import android.os.LocaleList;
     25 import android.os.Parcel;
     26 import android.text.ParcelableSpan;
     27 import android.text.TextPaint;
     28 import android.text.TextUtils;
     29 
     30 import java.util.Locale;
     31 
     32 /**
     33  * Changes the {@link Locale} of the text to which the span is attached.
     34  */
     35 public class LocaleSpan extends MetricAffectingSpan implements ParcelableSpan {
     36     @NonNull
     37     private final LocaleList mLocales;
     38 
     39     /**
     40      * Creates a {@link LocaleSpan} from a well-formed {@link Locale}.  Note that only
     41      * {@link Locale} objects that can be created by {@link Locale#forLanguageTag(String)} are
     42      * supported.
     43      *
     44      * <p><b>Caveat:</b> Do not specify any {@link Locale} object that cannot be created by
     45      * {@link Locale#forLanguageTag(String)}.  {@code new Locale(" a ", " b c", " d")} is an
     46      * example of such a malformed {@link Locale} object.</p>
     47      *
     48      * @param locale The {@link Locale} of the text to which the span is attached.
     49      *
     50      * @see #LocaleSpan(LocaleList)
     51      */
     52     public LocaleSpan(@Nullable Locale locale) {
     53         mLocales = locale == null ? LocaleList.getEmptyLocaleList() : new LocaleList(locale);
     54     }
     55 
     56     /**
     57      * Creates a {@link LocaleSpan} from {@link LocaleList}.
     58      *
     59      * @param locales The {@link LocaleList} of the text to which the span is attached.
     60      * @throws NullPointerException if {@code locales} is null
     61      */
     62     public LocaleSpan(@NonNull LocaleList locales) {
     63         Preconditions.checkNotNull(locales, "locales cannot be null");
     64         mLocales = locales;
     65     }
     66 
     67     public LocaleSpan(Parcel source) {
     68         mLocales = LocaleList.CREATOR.createFromParcel(source);
     69     }
     70 
     71     @Override
     72     public int getSpanTypeId() {
     73         return getSpanTypeIdInternal();
     74     }
     75 
     76     /** @hide */
     77     public int getSpanTypeIdInternal() {
     78         return TextUtils.LOCALE_SPAN;
     79     }
     80 
     81     @Override
     82     public int describeContents() {
     83         return 0;
     84     }
     85 
     86     @Override
     87     public void writeToParcel(Parcel dest, int flags) {
     88         writeToParcelInternal(dest, flags);
     89     }
     90 
     91     /** @hide */
     92     public void writeToParcelInternal(Parcel dest, int flags) {
     93         mLocales.writeToParcel(dest, flags);
     94     }
     95 
     96     /**
     97      * @return The {@link Locale} for this span.  If multiple locales are associated with this
     98      * span, only the first locale is returned.  {@code null} if no {@link Locale} is specified.
     99      *
    100      * @see LocaleList#get()
    101      * @see #getLocales()
    102      */
    103     @Nullable
    104     public Locale getLocale() {
    105         return mLocales.get(0);
    106     }
    107 
    108     /**
    109      * @return The entire list of locales that are associated with this span.
    110      */
    111     @NonNull
    112     public LocaleList getLocales() {
    113         return mLocales;
    114     }
    115 
    116     @Override
    117     public void updateDrawState(TextPaint ds) {
    118         apply(ds, mLocales);
    119     }
    120 
    121     @Override
    122     public void updateMeasureState(TextPaint paint) {
    123         apply(paint, mLocales);
    124     }
    125 
    126     private static void apply(@NonNull Paint paint, @NonNull LocaleList locales) {
    127         paint.setTextLocales(locales);
    128     }
    129 }
    130