com.reandroid.arsc.item.FixedLengthString Maven / Gradle / Ivy

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/*
 *  Copyright (C) 2022 github.com/REAndroid
 *
 *  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 com.reandroid.arsc.item;

import com.reandroid.arsc.io.BlockReader;
import com.reandroid.utils.StringsUtil;

import java.nio.charset.StandardCharsets;

public class FixedLengthString  extends StringItem{
    private final int bytesLength;
    public FixedLengthString(int bytesLength){
        super(true);
        this.bytesLength=bytesLength;
        setBytesLength(bytesLength);
    }
    @Override
    byte[] encodeString(String str){
        if(str==null){
            return new byte[bytesLength];
        }
        byte[] bts=getUtf16Bytes(str);
        byte[] results=new byte[bytesLength];
        int len=bts.length;
        if(len>bytesLength){
            len=bytesLength;
        }
        System.arraycopy(bts, 0, results, 0, len);
        return results;
    }
    @Override
    String decodeString(){
        return decodeUtf16Bytes(getBytesInternal());
    }
    @Override
    public StyleItem getStyle(){
        return null;
    }
    @Override
    int calculateReadLength(BlockReader reader){
        return bytesLength;
    }
    @Override
    public int compareTo(StringItem stringItem){
        if(stringItem == null){
            return -1;
        }
        return StringsUtil.compareStrings(get(), stringItem.get());
    }
    @Override
    public String toString(){
        return "FIXED-" + bytesLength + " {" + get() + "}";
    }
    private static String decodeUtf16Bytes(byte[] bts){
        if(isNullBytes(bts)){
            return null;
        }
        int len=getEndNullPosition(bts);
        return new String(bts,0, len, StandardCharsets.UTF_16LE);
    }
    private static int getEndNullPosition(byte[] bts){
        int max=bts.length;
        int result=0;
        boolean found=false;
        for(int i=1; i