BTW, instead of using imageview + textview, you should use the
compound drawable feature of textview. That will save you one view per
row.
On Wed, May 6, 2009 at 1:35 PM, sam <samuel.e.pe...@gmail.com> wrote:
>
> Thanks for the reply! Originally we only had the ImageView icon and
> TextView guts. The only reason we added the BitmapDrawable and Bitmap
> was because we wanted to maintain direct references that we could
> null. Even without those two in our ViewHolder, the same problem
> still exists.
>
> Thing that is perplexing is that we do not have any problems with the
> heap space, yet the load time from quitting the activity that is above
> our list and showing the list is definitely directly proportional to
> how many calls there have been to getView().
> -Sam
>
> On May 6, 4:18 pm, Romain Guy <romain...@google.com> wrote:
>> Why are you putting the Bitmap inside the ViewHolder? That means you
>> are always loading the bitmaps, which is very slow. You could simply
>> use a list of SoftReference<Bitmap> to store them.
>>
>>
>>
>> On Wed, May 6, 2009 at 1:11 PM, sam <samuel.e.pe...@gmail.com> wrote:
>>
>> > Hey guys, I am writing an app that has an activity that is a
>> > ListActivity which implements its own listadapter. Each row is
>> > defined by an xml layout, and the contents of each row is an ImageView
>> > (initially bytes stored in our own database and reconstructed into an
>> > image on getView()) and a TextView (whose text is contact name from
>> > the contact provider database). We are also allowing the user to
>> > launch other activities from our ListActivity by long clicking on a
>> > row and selecting from the context menu "view contact", which will
>> > launch Intent.ACTION_VIEW, which is the activity that displays all of
>> > the information about the relevant contact.
>>
>> > So it seems like we have a problem that gets compounded every time a
>> > call to getView() is made. Basically, when we first start up the list
>> > view, we can start the intent to view a gestures information and
>> > subsequently hit the back button to finish the viewing activity and
>> > return back to our list activity without any real problems. But, the
>> > more you scroll through the list, and the more you view contact
>> > information and come back to the list (inducing more calls to getView
>> > ()), the longer the phone takes to return back to our ListActivity,
>> > eventually prompting the "not responding" screen. The problem almost
>> > certainly has no relevance to the activity that is launched from our
>> > list activity because we have tried opening up random apps rather than
>> > Intent.ACTION_VIEW and returning to our list view and it resulted in
>> > the same behavior. What does seem to be relevant is having the list
>> > activity lose focus and then try to regain it. I have suspicions that
>> > we are leaking drawables when calling getView and trying to recycle,
>> > but it doesn't make all that much sense because I have spent minutes
>> > just scrolling the list with no memory issues. We have tried testing
>> > how much time it took for our program to execute the relevant
>> > functions that are a part of every application's life-cycle (onPause,
>> > onResume, onStop, onRestart, onStart), to see if there is any
>> > significant slow down in any of those calls, but they are all very
>> > fast. The only correlation we have witnessed is the more calls to
>> > getView(), the worse the time gets between finishing the activity on
>> > top of our list activity and putting our list activity back into
>> > focus. We have been stumped for the past few days, our only recourse
>> > up until now has been to try to explicitly null the references to
>> > everything that gets recycled to encourage garbage collection, but
>> > quite honestly I am out of ideas for why this could be happening.
>> > Here is our code for getView():
>>
>> > @Override
>> > public View getView(int position, View convertView,
>> > ViewGroup
>> > parent) {
>>
>> > ViewHolder holder;
>> > if (convertView == null) {
>> > convertView =
>> > mInflater.inflate(R.layout.list_view, null); /*our
>> > view holding a tview and iview*/
>>
>> > // Creates a ViewHolder and store
>> > references to the two children
>> > views
>> > // we want to bind data to.
>> > holder = new ViewHolder();
>> > holder.guts = (TextView)
>> > convertView.findViewById(R.id.text);
>> > holder.icon = (ImageView)
>> > convertView.findViewById(R.id.icon);
>> > holder.icon.setImageBitmap(null);
>> > // init this stuff
>> > holder.bitmapD = null;
>> > holder.bitmap = null;
>>
>> > convertView.setTag(holder);
>> > } else {
>> > // Get the ViewHolder back to get
>> > fast access to the TextView
>> > // and the ImageView.
>> > holder = (ViewHolder)
>> > convertView.getTag();
>> > holder.icon.setImageBitmap(null);
>> > }
>>
>> > // null the old stuff;
>>
>> > holder.bitmapD = null;
>>
>> > if(holder.bitmap != null) {
>> > holder.bitmap.recycle();
>> > holder.bitmap = null;
>> > }
>>
>> > Cursor c1 = (Cursor) getItem(position);
>> >
>> > ContactsListActivity.this.startManagingCursor(c1);
>> > String name =
>> > c1.getString(c1.getColumnIndexOrThrow(People.NAME));
>>
>> > long personID =
>> > c1.getLong(c1.getColumnIndexOrThrow(People._ID));
>> > Uri temp = Uri.withAppendedPath
>> > (ContactGesturesProvider.GESTURES_CONTENT_URI, "contacts");
>> > final Uri personURI =
>> > Uri.withAppendedPath(temp, "" + personID);
>> > Cursor c = mContext.managedQuery(personURI,
>> > null, null, null,
>> > null);
>>
>> > BitmapDrawable bd = null;// = new
>> > BitmapDrawable();
>> > if(c.moveToFirst()) {
>> > byte[] work =
>> > c.getBlob(c.getColumnIndexOrThrow
>> > (ImageProvider.IMAGE_COLUMN));
>> > Bitmap newb =
>> > BitmapFactory.decodeByteArray(work, 0,
>> > work.length);
>> > bd = new BitmapDrawable(newb);
>>
>> > holder.bitmap = newb;
>> > }
>> > c.close();
>> > // Bind the data efficiently with the
>> > holder.
>> > holder.guts.setText(name);
>> > holder.icon.setImageDrawable(bd);
>> > holder.bitmapD = bd;
>>
>> > return convertView;
>> > }
>>
>> > and our holder:
>>
>> > // stuff for views
>> > private static class ViewHolder {
>> > ImageView icon;
>> > TextView guts;
>> > BitmapDrawable bitmapD;
>> > Bitmap bitmap;
>> > }
>>
>> > Thanks ahead of time for anyone who has made it this far, let alone
>> > for posting a reply!
>>
>> > -Sam
>>
>> --
>> Romain Guy
>> Android framework engineer
>> romain...@android.com
>>
>> Note: please don't send private questions to me, as I don't have time
>> to provide private support. All such questions should be posted on
>> public forums, where I and others can see and answer them
> >
>
--
Romain Guy
Android framework engineer
romain...@android.com
Note: please don't send private questions to me, as I don't have time
to provide private support. All such questions should be posted on
public forums, where I and others can see and answer them
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