content: /*
   * Copyright (C) 2006 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;
  
  /**
   * LargeBitmap can be used to decode a rectangle region from an image.
   * LargeBimap is particularly useful when an original image is large and
   * you only need parts of the image.
   *
   * To create a LargeBitmap, call BitmapFactory.createLargeBitmap().
   * Given a LargeBitmap, users can call decodeRegion() repeatedly
   * to get a decoded Bitmap of the specified region.
   * @hide
   */
  public final class LargeBitmap {
      private long mNativeLargeBitmap;
      private boolean mRecycled;
  
      /*  Private constructor that must received an already allocated native
          large bitmap int (pointer).
  
          This can be called from JNI code.
      */
      private LargeBitmap(long nativeLbm) {
          mNativeLargeBitmap = nativeLbm;
          mRecycled = false;
      }
  
      /**
       * Decodes a rectangle region in the image specified by rect.
       *
       * @param rect The rectangle that specified the region to be decode.
       * @param opts null-ok; Options that control downsampling.
       *             inPurgeable is not supported.
       * @return The decoded bitmap, or null if the image data could not be
       *         decoded.
       */
      public Bitmap decodeRegion(Rect rect, BitmapFactory.Options options) {
          checkRecycled("decodeRegion called on recycled large bitmap");
          if (rect.left < 0 || rect.top < 0 || rect.right > getWidth() || rect.bottom > getHeight())
              throw new IllegalArgumentException("rectangle is not inside the image");
          return nativeDecodeRegion(mNativeLargeBitmap, rect.left, rect.top,
                  rect.right - rect.left, rect.bottom - rect.top, options);
      }
  
      /** Returns the original image's width */
      public int getWidth() {
          checkRecycled("getWidth called on recycled large bitmap");
          return nativeGetWidth(mNativeLargeBitmap);
      }
  
      /** Returns the original image's height */
      public int getHeight() {
          checkRecycled("getHeight called on recycled large bitmap");
          return nativeGetHeight(mNativeLargeBitmap);
      }
  
      /**
       * Frees up the memory associated with this large bitmap, and mark the
       * large bitmap as "dead", meaning it will throw an exception if decodeRegion(),
       * getWidth() or getHeight() is called.
       * This operation cannot be reversed, so it should only be called if you are
       * sure there are no further uses for the large bitmap. This is an advanced call,
       * and normally need not be called, since the normal GC process will free up this
       * memory when there are no more references to this bitmap.
       */
      public void recycle() {
          if (!mRecycled) {
              nativeClean(mNativeLargeBitmap);
              mRecycled = true;
          }
      }
  
      /**
       * Returns true if this large bitmap has been recycled.
       * If so, then it is an error to try use its method.
       *
       * @return true if the large bitmap has been recycled
       */
      public final boolean isRecycled() {
          return mRecycled;
      }
  
      /**
       * Called by methods that want to throw an exception if the bitmap
       * has already been recycled.
       */
      private void checkRecycled(String errorMessage) {
          if (mRecycled) {
              throw new IllegalStateException(errorMessage);
          }
      }
  
      protected void finalize() {
          recycle();
      }
  
      private static native Bitmap nativeDecodeRegion(long nativeLbm,
              int start_x, int start_y, int width, int height,
              BitmapFactory.Options options);
      private static native int nativeGetWidth(long nativeLbm);
      private static native int nativeGetHeight(long nativeLbm);
      private static native void nativeClean(long nativeLbm);
  }
  