content: /*
   * Copyright (C) 2010 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 android.graphics;
  
  import com.android.ide.common.rendering.api.LayoutLog;
  import com.android.layoutlib.bridge.Bridge;
  import com.android.layoutlib.bridge.impl.DelegateManager;
  import com.android.ninepatch.NinePatchChunk;
  import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
  
  import android.graphics.drawable.NinePatchDrawable;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.lang.ref.SoftReference;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Delegate implementing the native methods of android.graphics.NinePatch
   *
   * Through the layoutlib_create tool, the original native methods of NinePatch have been replaced
   * by calls to methods of the same name in this delegate class.
   *
   * Because it's a stateless class to start with, there's no need to keep a {@link DelegateManager}
   * around to map int to instance of the delegate.
   *
   */
  public final class NinePatch_Delegate {
  
      // ---- delegate manager ----
      private static final DelegateManager<NinePatch_Delegate> sManager =
              new DelegateManager<>(NinePatch_Delegate.class);
  
      // ---- delegate helper data ----
      /**
       * Cache map for {@link NinePatchChunk}.
       * When the chunks are created they are serialized into a byte[], and both are put
       * in the cache, using a {@link SoftReference} for the chunk. The default Java classes
       * for {@link NinePatch} and {@link NinePatchDrawable} only reference to the byte[] data, and
       * provide this for drawing.
       * Using the cache map allows us to not have to deserialize the byte[] back into a
       * {@link NinePatchChunk} every time a rendering is done.
       */
      private final static Map<byte[], SoftReference<NinePatchChunk>> sChunkCache = new HashMap<>();
  
      // ---- delegate data ----
      private byte[] chunk;
  
  
      // ---- Public Helper methods ----
  
      /**
       * Serializes the given chunk.
       *
       * @return the serialized data for the chunk.
       */
      public static byte[] serialize(NinePatchChunk chunk) {
          // serialize the chunk to get a byte[]
          ByteArrayOutputStream baos = new ByteArrayOutputStream();
          ObjectOutputStream oos = null;
          try {
              oos = new ObjectOutputStream(baos);
              oos.writeObject(chunk);
          } catch (IOException e) {
              Bridge.getLog().error(null, "Failed to serialize NinePatchChunk.", e, null /*data*/);
              return null;
          } finally {
              if (oos != null) {
                  try {
                      oos.close();
                  } catch (IOException ignored) {
                  }
              }
          }
  
          // get the array and add it to the cache
          byte[] array = baos.toByteArray();
          sChunkCache.put(array, new SoftReference<>(chunk));
          return array;
      }
  
      /**
       * Returns a {@link NinePatchChunk} object for the given serialized representation.
       *
       * If the chunk is present in the cache then the object from the cache is returned, otherwise
       * the array is deserialized into a {@link NinePatchChunk} object.
       *
       * @param array the serialized representation of the chunk.
       * @return the NinePatchChunk or null if deserialization failed.
       */
      public static NinePatchChunk getChunk(byte[] array) {
          SoftReference<NinePatchChunk> chunkRef = sChunkCache.get(array);
          NinePatchChunk chunk = chunkRef == null ? null : chunkRef.get();
          if (chunk == null) {
              ByteArrayInputStream bais = new ByteArrayInputStream(array);
              try (ObjectInputStream ois = new ObjectInputStream(bais)) {
                  chunk = (NinePatchChunk) ois.readObject();
  
                  // put back the chunk in the cache
                  if (chunk != null) {
                      sChunkCache.put(array, new SoftReference<>(chunk));
                  }
              } catch (IOException e) {
                  Bridge.getLog().error(LayoutLog.TAG_BROKEN,
                          "Failed to deserialize NinePatchChunk content.", e, null /*data*/);
                  return null;
              } catch (ClassNotFoundException e) {
                  Bridge.getLog().error(LayoutLog.TAG_BROKEN,
                          "Failed to deserialize NinePatchChunk class.", e, null /*data*/);
                  return null;
              }
          }
  
          return chunk;
      }
  
      // ---- native methods ----
  
      @LayoutlibDelegate
      /*package*/ static boolean isNinePatchChunk(byte[] chunk) {
          NinePatchChunk chunkObject = getChunk(chunk);
          return chunkObject != null;
      }
  
      @LayoutlibDelegate
      /*package*/ static long validateNinePatchChunk(byte[] chunk) {
          // the default JNI implementation only checks that the byte[] has the same
          // size as the C struct it represent. Since we cannot do the same check (serialization
          // will return different size depending on content), we do nothing.
          NinePatch_Delegate newDelegate = new NinePatch_Delegate();
          newDelegate.chunk = chunk;
          return sManager.addNewDelegate(newDelegate);
      }
  
      @LayoutlibDelegate
      /*package*/ static void nativeFinalize(long nativeNinePatch) {
          NinePatch_Delegate delegate = sManager.getDelegate(nativeNinePatch);
          if (delegate != null && delegate.chunk != null) {
              sChunkCache.remove(delegate.chunk);
          }
          sManager.removeJavaReferenceFor(nativeNinePatch);
      }
  
  
      @LayoutlibDelegate
      /*package*/ static long nativeGetTransparentRegion(long bitmapHandle, long chunk,
              Rect location) {
          return 0;
      }
  
      static byte[] getChunk(long nativeNinePatch) {
          NinePatch_Delegate delegate = sManager.getDelegate(nativeNinePatch);
          if (delegate != null) {
              return delegate.chunk;
          }
          return null;
      }
  
      public static void clearCache() {
          sChunkCache.clear();
      }
  }
  