implement LongItem block

src/main/java/com/reandroid/arsc/item/BlockItem.java

@@ -158,4 +158,29 @@ public abstract class BlockItem extends Block {
         int value = (bytes[byteOffset] & mask) | add;
         bytes[byteOffset] = (byte) value;
     }
+    protected static long getLong(byte[] bytes, int offset){
+        if((offset + 8)>bytes.length){
+            return 0;
+        }
+        long result = 0;
+        int index = offset + 7;
+        while (index>=offset){
+            result = result << 8;
+            result |= (bytes[index] & 0xff);
+            index --;
+        }
+        return result;
+    }
+    protected static void putLong(byte[] bytes, int offset, long value){
+        if((offset + 8) > bytes.length){
+            return;
+        }
+        int index = offset;
+        offset = index + 8;
+        while (index<offset){
+            bytes[index] = (byte) (value & 0xff);
+            value = value >>> 8;
+            index++;
+        }
+    }
 }

src/main/java/com/reandroid/arsc/item/IntegerItem.java

@@ -46,6 +46,9 @@ package com.reandroid.arsc.item;
     public int get(){
         return mCache;
     }
+    public long unsignedLong(){
+        return get() & 0x00000000ffffffffL;
+    }
     public String toHex(){
         return String.format("0x%08x", get());
     }

src/main/java/com/reandroid/arsc/item/LongItem.java

@@ -0,0 +1,45 @@
+ /*
+  *  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;
+
+public class LongItem extends BlockItem{
+    private long mCache;
+    public LongItem() {
+        super(8);
+    }
+    public void set(long value){
+        if(value == mCache){
+            return;
+        }
+        mCache = value;
+        putLong(getBytesInternal(), 0, value);
+    }
+    public long get(){
+        return mCache;
+    }
+    public String toHex(){
+        return String.format("0x%016x", get());
+    }
+
+    @Override
+    protected void onBytesChanged() {
+        mCache = getLong(getBytesInternal(), 0);
+    }
+    @Override
+    public String toString(){
+        return String.valueOf(get());
+    }
+}