Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Get x/y positions of nth item in RecyclerView

Tags:

I would like to know how to get the X or Y position of nth item in RecyclerView. This is easy to do if the item is currently within the visible range. However, when the view is currently off the screen (e.g., current visible items range on the RecyclerView is 4 to 7, while the item I am interested in is, say, 1 or 10), there seems to be no way to get that value.

Here's what I have tried. I have the following three fields:

private RecyclerView rv;

/* The Layout Manager of rv */
private LinearLayoutManager llm;

/* The data to be shown in the RecyclerView. */
private String[] data = {"0","1","2",...,"9"};

I have the items "2" to "5" shown on the screen, and I want to get the X/Y position of the item "9", which is currently off the screen. So I tried the following:

int index = 9;
View v = rv.getChildAt(index);
View v2 = llm.getChildAt(index);

Unfortunately, both v and v2 are null. The reason for it seems to be that while the size of data is 10, the childCount of rv and llm is whatever the number of views currently visible on the screen, as evidenced by the following:

int count = rv.getChildCount();
int count2 = llm.getChildCount();

Both variables are 4 (the number of views currently visible; i.e., "2" to "5"). Since the size of the recyclerView is 4, and I want to look up the item at index 9, I get null returned above.

like image 938
RestInPeace Avatar asked Jun 24 '16 01:06

RestInPeace


2 Answers

I got perfect x and y of every item in recycler view using following:

int[] originalPos = new int[2];
view.getLocationInWindow(originalPos);
//or view.getLocationOnScreen(originalPos)
int x = originalPos[0];
int y = originalPos[1];
like image 168
pal gajjar Avatar answered Oct 20 '22 01:10

pal gajjar


Pal gajjar's answer is correct... You can not get the coordinates of recycled views by the simple reason they aren't rendered yet, they haven't been created at this point. You have to check if the view exist in the first place using recyclerview.getChildAt(intValueHere)...if it's different from null it means its close to the currently displayed child position and its partially rendered holded in memory...at this point, and only at this point in which views are holded in memory you're able to use the view. You should read how a recyclerview works and how the layout manager recycle the views to understand what's really going on... -> https://developer.android.com/guide/topics/ui/layout/recyclerview

like image 30
Ramiro G.M. Avatar answered Oct 20 '22 01:10

Ramiro G.M.