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Frame by Frame アニメーションを作成し、Drawable を URL からダウンロードしたいと考えています。

質問: onPostExecute または imageButton から bitmapDrawable を取得することは可能ですか? もっと簡単な方法は考えられなかった

次のコードは不完全です。 から取得する方法がわかりません。そのため、現在持っているものbitmapDrawableからonPostExecutenull の Drawable を取得します。

プリンシパルフラグメント

public class PrincipalFragment extends Fragment {



    private int mNum;
    private AnimationDrawable mframeAnimation = null;
    private static final int DELAY = 500;




    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mNum = getArguments() != null ? getArguments().getInt("num") : 1;
    }

    /**
     * The Fragment's UI is just a simple text view showing its
     * instance number.
     */
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.scrollview, container, false);




          ImageButton i = (ImageButton)v.findViewById(R.id.imageButton1);
          i.setOnTouchListener(new OnTouchListener() {

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                // TODO Auto-generated method stub
                ImageButton button = (ImageButton)v;
                String principal = "principal";
                if (event.getAction() == MotionEvent.ACTION_DOWN) {
                    button.setColorFilter(0x8066bbdd);
                    return true;
                } else if (event.getAction() == MotionEvent.ACTION_UP) {
                    button.setColorFilter(null);
                    Intent i = new Intent(getActivity(), SubView.class);
                    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    i.putExtra("query", principal);
                    startActivity(i);
                    return true;
                }
                return false;
            }
        });
          ImageButton i2 = (ImageButton)v.findViewById(R.id.imageButton2);
          i2.setOnTouchListener(new OnTouchListener() {

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                // TODO Auto-generated method stub
                ImageButton button = (ImageButton)v;
                String principal2 = "principal2";
                if (event.getAction() == MotionEvent.ACTION_DOWN) {
                    button.setColorFilter(0x8066bbdd);
                    return true;
                } else if (event.getAction() == MotionEvent.ACTION_UP) {
                    button.setColorFilter(null);
                    Intent i = new Intent(getActivity(), SubView.class);
                    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    i.putExtra("query", principal2);
                    startActivity(i);

                    return true;
                }
                return false;
            }
        });



          ImageDownloader.Mode mode = ImageDownloader.Mode.CORRECT;

          ImageDownloader imageDownloader = new ImageDownloader();
          imageDownloader.setMode(mode);          
          BitmapDrawable frame1 = imageDownloader.download(URLnames.URLS[0], i, getResources());
          BitmapDrawable frame2 = imageDownloader.download(URLnames.URLS[1], i2, getResources());




          int reasonableDuration = 2500;
            mframeAnimation = new AnimationDrawable();
            mframeAnimation.setOneShot(false);
            mframeAnimation.addFrame(frame1, reasonableDuration);
            mframeAnimation.addFrame(frame2, reasonableDuration);

            ImageView img = (ImageView) v.findViewById(R.id.img_animated);
            img.setImageDrawable(mframeAnimation);
            mframeAnimation.setVisible(true, true);

            img.post(new Starter());



        return v;
    }

    class Starter implements Runnable {
        public void run() {
            mframeAnimation.start();
        }
}

}

ImageDownloader.class

public class ImageDownloader {
    private static final String LOG_TAG = "ImageDownloader";

    public enum Mode { NO_ASYNC_TASK, NO_DOWNLOADED_DRAWABLE, CORRECT }
    private Mode mode = Mode.NO_ASYNC_TASK;
    private Resources r = null;

    /**
     * Download the specified image from the Internet and binds it to the provided ImageView. The
     * binding is immediate if the image is found in the cache and will be done asynchronously
     * otherwise. A null bitmap will be associated to the ImageView if an error occurs.
     *
     * @param url The URL of the image to download.
     * @param imageView The ImageView to bind the downloaded image to.
     * @param resources 
     */
    public BitmapDrawable download(String url, ImageView imageView, Resources resources) {
        resetPurgeTimer();
        Bitmap bitmap = getBitmapFromCache(url);
        BitmapDrawable bitmapDrawable = new BitmapDrawable(r, bitmap);
        this.r = resources;

        if (bitmap == null) {
            bitmapDrawable = forceDownload(url, imageView);

        } else {
            cancelPotentialDownload(url, imageView);
            imageView.setImageBitmap(bitmap);

        }
        return bitmapDrawable;



    }

    /*
     * Same as download but the image is always downloaded and the cache is not used.
     * Kept private at the moment as its interest is not clear.
       private void forceDownload(String url, ImageView view) {
          forceDownload(url, view, null);
       }
     */

    /**
     * Same as download but the image is always downloaded and the cache is not used.
     * Kept private at the moment as its interest is not clear.
     * @param resources 
     * @return 
     */
    private BitmapDrawable forceDownload(String url, ImageView imageView) {
        // State sanity: url is guaranteed to never be null in DownloadedDrawable and cache keys.
        BitmapDrawable bitmapDrawable;
        if (url == null) {
            imageView.setImageDrawable(null);
            return null;
        }

        if (cancelPotentialDownload(url, imageView)) {
            switch (mode) {
                case NO_ASYNC_TASK:
                    Bitmap bitmap = downloadBitmap(url);
                    addBitmapToCache(url, bitmap);
                    imageView.setImageBitmap(bitmap);
                    break;

                case NO_DOWNLOADED_DRAWABLE:
                    imageView.setMinimumHeight(156);
                    BitmapDownloaderTask task = new BitmapDownloaderTask(imageView);
                    task.execute(url);
                    break;

                case CORRECT:

                    task = new BitmapDownloaderTask(imageView);
                    DownloadedDrawable downloadedDrawable = new DownloadedDrawable(task);
                    imageView.setImageDrawable(downloadedDrawable);
                    imageView.setMinimumHeight(156);
                    task.execute(url);

                    break;
            }
        }
        return null;

    }

    /**
     * Returns true if the current download has been canceled or if there was no download in
     * progress on this image view.
     * Returns false if the download in progress deals with the same url. The download is not
     * stopped in that case.
     */
    private static boolean cancelPotentialDownload(String url, ImageView imageView) {
        BitmapDownloaderTask bitmapDownloaderTask = getBitmapDownloaderTask(imageView);

        if (bitmapDownloaderTask != null) {
            String bitmapUrl = bitmapDownloaderTask.url;
            if ((bitmapUrl == null) || (!bitmapUrl.equals(url))) {
                bitmapDownloaderTask.cancel(true);
            } else {
                // The same URL is already being downloaded.
                return false;
            }
        }
        return true;
    }

    /**
     * @param imageView Any imageView
     * @return Retrieve the currently active download task (if any) associated with this imageView.
     * null if there is no such task.
     */
    private static BitmapDownloaderTask getBitmapDownloaderTask(ImageView imageView) {
        if (imageView != null) {
            Drawable drawable = imageView.getDrawable();
            if (drawable instanceof DownloadedDrawable) {
                DownloadedDrawable downloadedDrawable = (DownloadedDrawable)drawable;
                return downloadedDrawable.getBitmapDownloaderTask();
            }
        }
        return null;
    }

    Bitmap downloadBitmap(String url) {
        final int IO_BUFFER_SIZE = 4 * 1024;

        // AndroidHttpClient is not allowed to be used from the main thread
        final HttpClient client = (mode == Mode.NO_ASYNC_TASK) ? new DefaultHttpClient() :
            AndroidHttpClient.newInstance("Android");
        final HttpGet getRequest = new HttpGet(url);

        try {
            HttpResponse response = client.execute(getRequest);
            final int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode != HttpStatus.SC_OK) {
                Log.w("ImageDownloader", "Error " + statusCode +
                        " while retrieving bitmap from " + url);
                return null;
            }

            final HttpEntity entity = response.getEntity();
            if (entity != null) {
                InputStream inputStream = null;
                try {
                    inputStream = entity.getContent();
                    // return BitmapFactory.decodeStream(inputStream);
                    // Bug on slow connections, fixed in future release.
                    return BitmapFactory.decodeStream(new FlushedInputStream(inputStream));
                } finally {
                    if (inputStream != null) {
                        inputStream.close();
                    }
                    entity.consumeContent();
                }
            }
        } catch (IOException e) {
            getRequest.abort();
            Log.w(LOG_TAG, "I/O error while retrieving bitmap from " + url, e);
        } catch (IllegalStateException e) {
            getRequest.abort();
            Log.w(LOG_TAG, "Incorrect URL: " + url);
        } catch (Exception e) {
            getRequest.abort();
            Log.w(LOG_TAG, "Error while retrieving bitmap from " + url, e);
        } finally {
            if ((client instanceof AndroidHttpClient)) {
                ((AndroidHttpClient) client).close();
            }
        }
        return null;
    }

    /*
     * An InputStream that skips the exact number of bytes provided, unless it reaches EOF.
     */
    static class FlushedInputStream extends FilterInputStream {
        public FlushedInputStream(InputStream inputStream) {
            super(inputStream);
        }

        @Override
        public long skip(long n) throws IOException {
            long totalBytesSkipped = 0L;
            while (totalBytesSkipped < n) {
                long bytesSkipped = in.skip(n - totalBytesSkipped);
                if (bytesSkipped == 0L) {
                    int b = read();
                    if (b < 0) {
                        break;  // we reached EOF
                    } else {
                        bytesSkipped = 1; // we read one byte
                    }
                }
                totalBytesSkipped += bytesSkipped;
            }
            return totalBytesSkipped;
        }
    }

    /**
     * The actual AsyncTask that will asynchronously download the image.
     */
    class BitmapDownloaderTask extends AsyncTask<String, Void, Bitmap> {
        private String url;

        private final WeakReference<ImageView> imageViewReference;

        public BitmapDownloaderTask(ImageView imageView) {
            imageViewReference = new WeakReference<ImageView>(imageView);
        }

        /**
         * Actual download method.
         */
        @Override
        protected Bitmap doInBackground(String... params) {
            url = params[0];
            return downloadBitmap(url);
        }

        /**
         * Once the image is downloaded, associates it to the imageView
         */
        protected void onPostExecute(Bitmap bitmap) {
            if (isCancelled()) {
                bitmap = null;
            }

            addBitmapToCache(url, bitmap);

            if (imageViewReference != null) {
                ImageView imageView = imageViewReference.get();
                BitmapDownloaderTask bitmapDownloaderTask = getBitmapDownloaderTask(imageView);
                // Change bitmap only if this process is still associated with it
                // Or if we don't use any bitmap to task association (NO_DOWNLOADED_DRAWABLE mode)
                if ((this == bitmapDownloaderTask) || (mode != Mode.CORRECT)) {
//                  imageView.setImageBitmap(bitmap);
                    BitmapDrawable bitmapDrawable = new BitmapDrawable(r, bitmap);
                    imageView.setImageDrawable(bitmapDrawable);
                }
            }

        }
    }





    /**
     * A fake Drawable that will be attached to the imageView while the download is in progress.
     *
     * <p>Contains a reference to the actual download task, so that a download task can be stopped
     * if a new binding is required, and makes sure that only the last started download process can
     * bind its result, independently of the download finish order.</p>
     */
    static class DownloadedDrawable extends ColorDrawable {
        private final WeakReference<BitmapDownloaderTask> bitmapDownloaderTaskReference;

        public DownloadedDrawable(BitmapDownloaderTask bitmapDownloaderTask) {
            super(Color.BLACK);
            bitmapDownloaderTaskReference =
                new WeakReference<BitmapDownloaderTask>(bitmapDownloaderTask);
        }

        public BitmapDownloaderTask getBitmapDownloaderTask() {
            return bitmapDownloaderTaskReference.get();
        }
    }

    public void setMode(Mode mode) {
        this.mode = mode;
        clearCache();
    }


    /*
     * Cache-related fields and methods.
     * 
     * We use a hard and a soft cache. A soft reference cache is too aggressively cleared by the
     * Garbage Collector.
     */

    private static final int HARD_CACHE_CAPACITY = 10;
    private static final int DELAY_BEFORE_PURGE = 10 * 1000; // in milliseconds

    // Hard cache, with a fixed maximum capacity and a life duration
    private final HashMap<String, Bitmap> sHardBitmapCache =
        new LinkedHashMap<String, Bitmap>(HARD_CACHE_CAPACITY / 2, 0.75f, true) {
        @Override
        protected boolean removeEldestEntry(LinkedHashMap.Entry<String, Bitmap> eldest) {
            if (size() > HARD_CACHE_CAPACITY) {
                // Entries push-out of hard reference cache are transferred to soft reference cache
                sSoftBitmapCache.put(eldest.getKey(), new SoftReference<Bitmap>(eldest.getValue()));
                return true;
            } else
                return false;
        }
    };

    // Soft cache for bitmaps kicked out of hard cache
    private final static ConcurrentHashMap<String, SoftReference<Bitmap>> sSoftBitmapCache =
        new ConcurrentHashMap<String, SoftReference<Bitmap>>(HARD_CACHE_CAPACITY / 2);

    private final Handler purgeHandler = new Handler();

    private final Runnable purger = new Runnable() {
        public void run() {
            clearCache();
        }
    };

    /**
     * Adds this bitmap to the cache.
     * @param bitmap The newly downloaded bitmap.
     */
    private void addBitmapToCache(String url, Bitmap bitmap) {
        if (bitmap != null) {
            synchronized (sHardBitmapCache) {
                sHardBitmapCache.put(url, bitmap);
            }
        }
    }

    /**
     * @param url The URL of the image that will be retrieved from the cache.
     * @return The cached bitmap or null if it was not found.
     */
    private Bitmap getBitmapFromCache(String url) {
        // First try the hard reference cache
        synchronized (sHardBitmapCache) {
            final Bitmap bitmap = sHardBitmapCache.get(url);
            if (bitmap != null) {
                // Bitmap found in hard cache
                // Move element to first position, so that it is removed last
                sHardBitmapCache.remove(url);
                sHardBitmapCache.put(url, bitmap);
                return bitmap;
            }
        }

        // Then try the soft reference cache
        SoftReference<Bitmap> bitmapReference = sSoftBitmapCache.get(url);
        if (bitmapReference != null) {
            final Bitmap bitmap = bitmapReference.get();
            if (bitmap != null) {
                // Bitmap found in soft cache
                return bitmap;
            } else {
                // Soft reference has been Garbage Collected
                sSoftBitmapCache.remove(url);
            }
        }

        return null;
    }

    /**
     * Clears the image cache used internally to improve performance. Note that for memory
     * efficiency reasons, the cache will automatically be cleared after a certain inactivity delay.
     */
    public void clearCache() {
        sHardBitmapCache.clear();
        sSoftBitmapCache.clear();
    }

    /**
     * Allow a new delay before the automatic cache clear is done.
     */
    private void resetPurgeTimer() {
        purgeHandler.removeCallbacks(purger);
        purgeHandler.postDelayed(purger, DELAY_BEFORE_PURGE);
    }
}
4

1 に答える 1

0

私がそれを機能させる唯一の方法はAsynctask.get();、UIをフリーズさせる可能性があるため正しい方法ではなく、コールバックインターフェイスを使用する必要があると言う人もいますが、長い時間後、コールバックを機能させることができませんでしたAsynctask.get();。動作し、コードは次のとおりです。

public Bitmap download(String url, ImageView imageView, Resources resources) throws InterruptedException, ExecutionException {
        resetPurgeTimer();
        Bitmap bitmap = getBitmapFromCache(url);

        this.r = resources;

        if (bitmap == null) {
            bitmapDrawable = forceDownload(url, imageView);

        } else {
            cancelPotentialDownload(url, imageView);
            imageView.setImageBitmap(bitmap);

        }
        return bitmapDrawable;



    }

    /*
     * Same as download but the image is always downloaded and the cache is not used.
     * Kept private at the moment as its interest is not clear.
       private void forceDownload(String url, ImageView view) {
          forceDownload(url, view, null);
       }
     */

    /**
     * Same as download but the image is always downloaded and the cache is not used.
     * Kept private at the moment as its interest is not clear.
     * @param resources 
     * @return 
     * @throws ExecutionException 
     * @throws InterruptedException 
     */
    private Bitmap forceDownload(String url, ImageView imageView) throws InterruptedException, ExecutionException {
        // State sanity: url is guaranteed to never be null in DownloadedDrawable and cache keys.
        Bitmap bitmap = null;
        if (url == null) {
            imageView.setImageDrawable(null);
            return null;
        }

        if (cancelPotentialDownload(url, imageView)) {
            switch (mode) {
                case NO_ASYNC_TASK:
                    Bitmap bitmap2 = downloadBitmap(url);
                    addBitmapToCache(url, bitmap2);
                    imageView.setImageBitmap(bitmap2);
                    break;

                case NO_DOWNLOADED_DRAWABLE:
                    imageView.setMinimumHeight(156);
                    BitmapDownloaderTask task = new BitmapDownloaderTask(imageView, this);
                    task.execute(url);
                    break;

                case CORRECT:

                    task = new BitmapDownloaderTask(imageView, this);
                    DownloadedDrawable downloadedDrawable = new DownloadedDrawable(task);
                    imageView.setImageDrawable(downloadedDrawable);
                    imageView.setMinimumHeight(156);
                    task.execute(url);
                    bitmap = task.get();
                    break;
            }
        }
        return bitmap;
于 2013-01-13T18:13:22.250 に答える