diff options
Diffstat (limited to 'docs/html/training/displaying-bitmaps/display-bitmap.jd')
| -rw-r--r-- | docs/html/training/displaying-bitmaps/display-bitmap.jd | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/docs/html/training/displaying-bitmaps/display-bitmap.jd b/docs/html/training/displaying-bitmaps/display-bitmap.jd index 5eac04c..4572c42 100644 --- a/docs/html/training/displaying-bitmaps/display-bitmap.jd +++ b/docs/html/training/displaying-bitmaps/display-bitmap.jd @@ -103,7 +103,8 @@ public class ImageDetailActivity extends FragmentActivity { } </pre> -<p>The details {@link android.app.Fragment} holds the {@link android.widget.ImageView} children:</p> +<p>Here is an implementation of the details {@link android.app.Fragment} which holds the {@link android.widget.ImageView} children. This might seem like a perfectly reasonable approach, but can +you see the drawbacks of this implementation? How could it be improved?</p> <pre> public class ImageDetailFragment extends Fragment { @@ -146,11 +147,11 @@ public class ImageDetailFragment extends Fragment { } </pre> -<p>Hopefully you noticed the issue with this implementation; The images are being read from -resources on the UI thread which can lead to an application hanging and being force closed. Using an -{@link android.os.AsyncTask} as described in the <a href="process-bitmap.html">Processing Bitmaps Off -the UI Thread</a> lesson, it’s straightforward to move image loading and processing to a background -thread:</p> +<p>Hopefully you noticed the issue: the images are being read from resources on the UI thread, +which can lead to an application hanging and being force closed. Using an +{@link android.os.AsyncTask} as described in the <a href="process-bitmap.html">Processing Bitmaps +Off the UI Thread</a> lesson, it’s straightforward to move image loading and processing to a +background thread:</p> <pre> public class ImageDetailActivity extends FragmentActivity { @@ -190,7 +191,7 @@ modifications for a memory cache:</p> <pre> public class ImageDetailActivity extends FragmentActivity { ... - private LruCache<String, Bitmap> mMemoryCache; + private LruCache<String, Bitmap> mMemoryCache; @Override public void onCreate(Bundle savedInstanceState) { @@ -229,7 +230,8 @@ UI remains fluid, memory usage remains under control and concurrency is handled the way {@link android.widget.GridView} recycles its children views).</p> <p>To start with, here is a standard {@link android.widget.GridView} implementation with {@link -android.widget.ImageView} children placed inside a {@link android.app.Fragment}:</p> +android.widget.ImageView} children placed inside a {@link android.app.Fragment}. Again, this might +seem like a perfectly reasonable approach, but what would make it better?</p> <pre> public class ImageGridFragment extends Fragment implements AdapterView.OnItemClickListener { @@ -261,7 +263,7 @@ public class ImageGridFragment extends Fragment implements AdapterView.OnItemCli } @Override - public void onItemClick(AdapterView<?> parent, View v, int position, long id) { + public void onItemClick(AdapterView<?> parent, View v, int position, long id) { final Intent i = new Intent(getActivity(), ImageDetailActivity.class); i.putExtra(ImageDetailActivity.EXTRA_IMAGE, position); startActivity(i); @@ -345,13 +347,13 @@ public class ImageGridFragment extends Fragment implements AdapterView.OnItemCli } static class AsyncDrawable extends BitmapDrawable { - private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference; + private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference; public AsyncDrawable(Resources res, Bitmap bitmap, BitmapWorkerTask bitmapWorkerTask) { super(res, bitmap); bitmapWorkerTaskReference = - new WeakReference<BitmapWorkerTask>(bitmapWorkerTask); + new WeakReference<BitmapWorkerTask>(bitmapWorkerTask); } public BitmapWorkerTask getBitmapWorkerTask() { |