Develop Reference

Update RecyclerView From Different Tab In Viewpager

I have a ViewPager with 2 tabs. Each tab just holds a Fragment with a RecyclerView. The RecyclerView in the first tab holds a list of all Articles while the RecyclerView in the second tab only holds the list of user's favorite Articles. Each Article in the first tab has a button in the RecyclerView row that allows the user to favorite it. I want new favorites to be displayed automatically (without forcing the user to manually press the refresh button) when the user navigates to the second tab. How can I go about doing this? Essentially I need to add / remove items from the RecyclerView which contains the favorites, but from the first fragment.
Things I have tried
Call adapter.notifyDataSetChanged() in the onRefresh() method of the favorites fragment. This works, but the performance hit is big because notifyDataSetChanged() is not a cheap operation. I would like to avoid this if possible.
Tried following this guide, and implemented some interfaces. The problem is, when I try to reference the adapter in my fragment from the containing activity, the adapter is always null. I can post code if needed to show what I was doing if this is supposed to be possible.
Now I am considering using SQLite DB to store changes (favorite removals/additions) in the onClickListeners, and then checking that table in the onResume() method and processing the changes individually, one by one with notifyItemChanged()
Is there a better way to do this?

For SQlite use CursorLoader to load data from SQlite. You can register to be notified when a data changed in a table. Then your loader will automatically load data again. Check this answer. Also check this Thread.
For getting data from internet you can use
Communicate with 2 fragments via parent Activity. Check this and this answer. This tutorial is good for better understanding.
LocalBroadcastManager to notify from one fragment to another fragment.

"Nested" RecyclerViews

Hi everyone.
I've come up with an idea for an Android App, and I was thinking how to turn my thoughts into something working. I know how to program for Android even though I'm not that advanced as you might see, so I wanted some tips from you guys who I'm sure will be able to help.
Idea
I was thinking about an App to organize stuff, see your objects on a list and be able to add, move or remove them from the list.
Thoughts
I first thought I needed a RecyclerViewto display each item. Then I thought every item itself might be a box, and so be containing other items inside: this brought me to think of a sort of "nested" system of RecyclerViews. Before going too deep into this system I had to clarify each item should have been a Class, each of which should have had a RecyclerView assigned.
Question
I was wondering how I could make this "nested" system of RecyclerViews. I thought about making a RecyclerView an object, because I need each RecyclerView to display, function and be always the same in any screen of any item. But I don't know what the best way is.
Should I make it an object? How do I create a new RecyclerView through a button so the user can first tap an item and then, eventually, tap a button (inside the item details view for instance) to make it a box item and so create and open a RecyclerView when tapped?
P.S.
It may seem like multiple questions but it actually is only one: how to add and display a RecycerView when I tap a button inside a details screen of an item, of course automatically (have a reference to that RecyclerView).

You have to create the RecyclerView that holds your items list, let's call it rv_list, this RecyclerView has an adapter that takes each item and adapts it to an xml layout row_item.xml that you should define. Now to make an item itself display its own recyclerview you should put a recyclerview inside row_item.xml and populate it when adapting that item to rv_list inside the method onBindViewHolder.

Showing pagerSlidingTabStrip on the layout without viewPagerAdapter on Android 5.0+

I would like to develop an android app's UI looks like the Uber's but booking rooms.
I want to implement the function about showing the option's description, from users who are clicking the PagerSlidingTabStrip items which shown on the bottom. The fragment page will be shown when the user click the fragment tab (PagerSlidingTabStrip), also the chosen option will be selected.
I feel puzzled and confused when I am implementing this function, and concern the pagerSlidingTabStrip can trigger events by setOnClickListner or not. Also I don't willing to show the fragment page on the main page once users logged on the page by default.
Thank you.

Its better if you use TabLayout instead of PagerSlidingTabStrip
That will help you to get click of the Tab selected as well as reselected and on that click event you can hide and show your Bottom Views which holding fragments

changing listview item elements

I'm new to Android development.
I need to make a listview with text and icon audio player. The icon has three States, "download", "downloading", "play" and "pause". The idea is that when populating the listview, set the "download" icon if the track is not downloaded and "play" if the track is downloaded". If a person clicks the "download" button the icon should be updated to "downloading" to start the download, then when complete, you should see the icon "play". If the user presses the "play" icon for this element should be updated to "pause".
I can't change the icon . I tried to change them in onItemClickListener and make the onClick in the getView method in adapter, but when scrolling the icons changed to the old. And if you select multiple items in the list, then change all the icons, and I need to change only one, for playing of the track.
I didn't show the code because there is nothing that can be corrected. - all wrong

if you have your own adapter try using a method notifyDataSetChanged();

That is happening due to recycling of views. If you click on an item and you will see multiple items clicked.
Use RecyclerView instead of listView, which will handle recycling by its own and its ViewHolder class takes care of the issue you are having.
And don't forget to notify the recyclerView adapter whenever you make some change in data source (i.e. arraylist)
Check out this example...
Hope it helps
http://hmkcode.com/android-simple-recyclerview-widget-example/

Trigger Textview when clicked on ListView

I'm a noob Android developer. I learned of the basic UI controls and different types of views that I can utilize.
Now my problem is, I need to show list of items using the ListView that is being shown full screen. when I click on an item it should load a TextView full screen. when I click the back button it should go back to ListView again..
Can someone point me where I can learn such stuff?? any support or even external link is greatly appreciated.
Thanks in advance.

Write your text view in a different activity. And when ever you click on a list item start that activity putting your text in the intent. Fetch the text in that text view activity in onCreate() from the intent and set it to text view. Obviously when ever you click back you 'll come back to list view activity.

Check out this website... http://www.xtensivearts.com/topics/tutorials/
He's no longer updating but what you've asked is covered in the video tutorials he did create. It's not answered directly but by watching them, you should have a solid enough understanding to piece it together yourself.
Best of luck!