I have created RecyclerView with list of clients (from 0 till 14). I need maximum down state. For this purpose I am using method RecyclerView.scrollToPosition(14).
When RecyclerView are placing in Activity, I have the good result.
IMAGE: RecyclerView are placing in Activity
And now I am inflating new RecyclerView and put it in Dialog. The Adapter of RecyclerView the same. Method RecyclerView.scrollToPosition(14) give me the bad result (scroll is not set on the 14th position, by the way I can pull it to the down manually):
IMAGE: Bad result in Dialog
Why it happens? I think the problem in parent (Dialog) of RecyclerView. But I don't know what to do.
UPDATED! I think this is a really bug of RecyclerView. Because with ListView is all right (in my case with setSelection(14)).
Because your interaction panel hide the last element. Position your recycler view above the panel.
Related
Basically what the title says. I'm trying to start a ViewPager activity when a user clicks a RecyclerView item. I'm not having problems here, that works fine. The goal is to go from a grid based gallery to viewpager gallery. I'm also trying to send the List<> of data which is loaded over the network. This is where I'm having a lot of trouble. The data is sent through a singleton because it's too large to send through intent and if opened in the new activity too quickly upon app startup, more data is loaded in the original activity (Even if Call is cancelled, using Retrofit2 btw) and I need to notify the adapter, which I have a listener that does.
Another crash that is common is a null pointer when reading an item in viewpager activity, which doesn't make sense to me because the item is not null in the original activity before sending, but if I wait a few seconds it is not null. Some of the code pertaining to my issue can be found here, a question I asked yesterday with a solution I could not successfully implement.
Please point me in the right direction for starting a ViewPager of the same dataset from a RecyclerView, thanks
When you are "sending" feed data to the view pager activity, use a shallow copy of the list instead of directly referencing it as shown below
DataTransferer.get().storeItems(new ArrayList(feed));
This should prevent IllegalStateException raised by feed being updated on your RecyclerView activity.
I have a RecyclerView as the following image presents:
This is the setup code for this RecyclerView:
RecyclerView.LayoutManager layoutManager = new GridLayoutManager(this, 2);
dataRecyclerView.setLayoutManager(layoutManager);
dataRecyclerView.addItemDecoration(new GridSpacingItemDecoration(...);
dataRecyclerView.setItemAnimator(new DefaultItemAnimator());
after starting a new activity where I update the selected item of the RecyclerView, the RecyclerView is re-populated with new data to reflect the new change, but I get the following result:
And when I scroll down, I get this gap:
I tried calling RecyclerView#invalidate(), #invalidateItemDecorations(), #requestLayout() after the refresh but to no avail; & I'm also not calling setHasFixedSize(true) on the RecyclerView.
What is the problem exactly ? How can I resize the child items so as they wrap their content precisely after refreshing?
(P.S: I tried refreshing without making any changes & nothing happened, which proves my theory that the issue arises only when a child item's height changes.)
That's quite late but I have also experienced this problem. This could be helpful for those still having the same bug.
In my case the solution was checking if there are any item decoration for recyclerview:
recyclerView.addItemDecoration(new SpacesItemDecoration(8));
This line was called everytime recyclerview is updated and was make recyclerview items getting smaller. Hope it helps the other.
Happy Coding,
Baki
I have a standard recyclerview with 20 elements in a fragment. Now what I want is to open the view from the fifth element. Please note that I don't want to smoothscrolltoposition. I want it to be open from the fifth element.
UPDATE:
I want it to be opened with this without scroll-
I want a functionality where the user can still scroll up-
And I have already populated my recyclerview.
You can try any of these two methods according to your use case. It won't be a smooth scroll.
If you want to scroll to a specific position but that position is the adapter's position and not the RecyclerView's item position. You can only achieve this through the LayoutManager.
recylerView.getLayoutManager().scrollToPosition(adapterPosition);
If it is RecyclerView's item position:
recylerView.scrollToPosition(itemPosition);
Hope this helps you out.
References: 1 and 2.
NOTE:
Try to call this before onStart callback method. Because by that time, activity/fragment is not visible to the user and thus scroll won't be visible.
Example - If the RecylerView is inside an Activity, call it from onCreate.
I have a ListView that is like an inbox. The information comes from a user,so the ListView displays text and a userPicture.To display userPictures, I display the userPicture if exists or a imageView of a letter of the first name.
when I receive data from WS I launch an asynctask that compare userPicture ids with DB to ask the WS for ones I don't have or one's that have changed.
After the asyncTask finishes I save pictures locally and notify listView that the data set has changed, in order to look for the new pictures.
my problem comes when there is only 1 user on the listview and the picture wasn't found but was downloaded from WS. after calling notifyDataSetChanged, also calling refreshDrawableState and invalidateViews,that acording to documentation "Causes all the views to be rebuilt and redrawn". the image is not changed and imageView still shows the letter ImageView,
neither scrolling through the listView its updated. (I guess is part of the Viewholder that recycle the views that is meant for performance and a good practive acording to ).
on the getView of the adapter I have a the Following statement to processThe Picture
if(mIDataPersistence.userHasPicture(userId)
ViewHolder.userImg.setImageBitmap(mIDataPersistence.getUserPicture(userId));
else
ViewHolder.userImg.setImageBitmap(BitmapUtils.createBitMap(userName);
note: mIDataPersistence is persistence data interface to access all the data locally stored that I'm using here. and BitmapUtils.createBitMap() makes a bitmap from the first letter of the user.
can anyone help me or point me on a way to make listView update images in this particular case.
I have a ListView.
I'm using anArrayAdapter and I'd like to:
when the user clicks any item on the list, its LinearLayout (is just a content for x information) fades out and is substituted by other LinearLayout (with y information) which fades in.
However, I do not know how to apply this on my ArrayAdapter. I've searched for a while but I'm not understanding how can I access a single item from the Adapter and make it's children fade out or fade in.
Any help would be very appreciated. Thank you very much for your time.
In general - adapters do not hold items the role of adapter is to get data model, and to produce item views when i.e. list view needs them.
The main concept of replacing item is to replace data inside the adapter and call notifyDataSetChanged(); - thats all.
I don't like ArrayAdapter as it's aimed for very simple scenarios. Usually I just create my own Adapter class extending BaseAdapter (just 4 methods to implement).
The transitions of items on ListView are described here: Adding animation to a List View in Android