Develop Reference

What's the name of this Button?

Which is the name of the method/library which collapses/extends a list triggered by the user action?
Please see the image below to understand my use case.

As far I can see you have a List View with one Item, and on press you want to show a sublist. I guess you do not know Android terms and you are thinking from an abstract design point of view.
In more technical terms you need to expand a ListView when the user touches the item.
Here you can find a tutorial to use ExpandibleListVIew
Please consider that nowdays is really used in place of ListView a library called RecyclerView, and here and maybe even better this stack overflow post where you can find a valid method that explain your UX use case, without recurring to external libraries but capitalizing the method onBindViewHolder, as allegedly recommended at a Google I/O official conference.
RecyclerView offers much more functionalities, animations and should be the best option to go if the app increases in complexity, namely a real life scenario.

you can use expandable recyclerview
eg
Expandable recycler view

Building an infinitely scrollable calendar-like view in Android

This is not a code problem, I interpret the guidelines as that being OK.
I've been researching a way of building an infinitely scrolling calendar-like view in Android, but I've reached an impasse.
Right now my dilemma is that most of the similar views available have their children placed relative each other in a recurring style. With this I mean:
item 4 comes after item 3, which comes after item 2, and there is constant padding/margin between all items.
What I need is a way to produce an infinitely long scrollable view that may, or may not, contain items. The items should be placed at variable positions within the view. The best way I can describe a similar looking view is a one-day calendar-like view that is infinitely scrollable.
So far my best two bets are using the new RecyclerView with a custom LayoutManager (this seems very complex and still not perfectly documented by Google though). I like this approach because, among other things, it is optimized for displaying large sets in a limited view.
My other solution would be to build a completely custom View. However, with that solution I loose the adapter unless I build a container view (which is probably more complex than building a layout manager).
How would you go about solving such a problem? Tips are appreciated, I don't need code examples, just ideas which path is the best to solve this problem.
Thanks.
Apologies if I've misunderstood the guidelines
Edit: How I resolved this problem
My first solution to use RecyclerView with a special Decorator seemed promising, but it remained a "hack" so we decided not to go for that solution since we were afraid of the complications that it would create down the line.
To solve the problem I went with a SurfaceView instead of an Adapter, this means having to rewrite all the adapter-functionality for my SurfaceView but it seemed to be the best way of solving this issue of very custom drawing and layout managing for my use-case.
It still would be nice to build a custom Viewgroup that can handle this kind of layout problems.

ListView and ListAdapter are based on a fixed list, so the current infinite-scrollers just keep adding more and more data to the end of the list.
But what you want is scroller similar to Google's Calendar app which has a bi-directional infinite scroller. The problem with using ListView and ListAdapter in this case is that if you add data to the front of the list, the index of any one item changes so that the list jumps.
If you really start thinking about this from the MVC perspective, you realize that ListAdapter does not provide a model that fits this need.
Instead of having absolute indexing (i.e. 1, 2, 3, 4, etc), what you really want is relative indexing, so instead of saying "Give me the item at index 42" you want to say "here's an item, give me the five items before it". Or you have something like a calendar date which is absolute; yet — unlike your device's memory — it has effectively no beginning or end, so what you really want here is a "window" into a section of that data.
A better data model for this would be a kind of double-ended queue that is partly a LRU cache. You place a limit on the number of items in the structure. Then as prior items are loaded (user is scrolling up) the items at back end are pushed off, and when subsequent items are added (user is scrolling down), items at the front are pushed off.
Also, you would have a threshold where if you got within a few items of of one edge of the structure, a "loadNext" or "loadPrevious" event would fire and invoke a callback that you set up to push more data onto the edge of the structure.
So once you've figured out that your model is completely different, you realize that even RecyclerView isn't going to help you here because it's tied to the absolute indexing model. You need some sort of custom ViewGroup subclass that recycles item views like a ListView, but can adapt to the double-ended queue. And when you search code repos for something like this, there's nothing out there.
Sounds like fun. I'll post a link when I get a project started. (Sadly, it won't be done in any timely manner to help you right now, sorry.)
Something that might help you a little sooner: look at Google's Calendar implementation and see how they did it: Google Calendar Git repo

What you may be searching for is a FragmentStatePagerAdapter , where you can implement a swiped view, meaning when the user (for example)swipes to the right, a completely new view is displayed.
Using a FragmentStatePagerAdapter , you can handle a huge amount of views without overflowing the memory, because this specific PagerAdapter only keeps the views' states and is explicitly meant to handle large sets of views.
Keeping your example of a calendar, you can implement swiped navigation between for example weeks and generate the week views on demand while only keeping for example the year and the week's number as identifiers.
There are plenty of online tutorials for Android, maybe you have a look at this one

Create a ListView like view in a ScrollView Android

So I did some research and testing of using a listview in a scrollview, and as a lot of people may know this is supposedly bad to do, since they both scroll. It also means I can't show the complete listview as it will wrap to be smaller.
I have seen places which re change the height of the listview to fix this problem but again most people say that it isn't preferred.
What I would like to know though is what is the preferred way of making a nonscrollable listview like view? Basically I want the exact same as the listview but obviously non scrolled and the height based on its contents. I would prefer to work with the layout in as much XML as possible, and I would like to be able to send my array list to it to view on screen. Unfortunately either my search skills are quite dull, as I haven't been able to find anywhere that really explains the preferred method so I thought I would ask here.
Thanks for your help.
<>Clarification Information
I thought I would put this here in case it will help, first off I basically want to show an image, with a list of comments (each one has an author and a text) below it, the comments themselves are obtained from an array and can change. I want the whole page to be scrollable though so I can either view more comments or go back up to the image.

Using a RecyclerView and an adapter supporting multiple item types you could make a list which shows an image on top and several comments below it. Generally you'd have to check what item corresponds to each position - in your case on position 0 you have an image and in every other position you'd have a comment. Then in your adapter's onCreateViewHolder and onBindViewHolder you would check the item type and handle them differently.
You could take a look at this answer for a short example.
Let me know if you'd need any other details and/ or sample codes to get the idea. :)

Android- Contact details UI layout

I'm building a contacts app and wanted to know what the best way of building something like the image below(Jessica is not too shabby...) in terms of using a list view, scrollview, etc.
Ideally, all of my data is in the sql database so a cursor adapter wouldn't be an issue. Is it better to have a listview with separators, or a scrollview where you add views. Since all contacts won't have exactly the same information, what can we do to make that? Any ideas would be greatly appreciated.

If you plan to have interactive elements inside of the items (e.g. the message button in the screenshot above) I'd recommend a ScrollView. Actually, since you probably don't have that many items I would again recommend a ScrollView. Then it's justa matter of having a set of layouts that you dynamically add depending on the information you have for the contact.

ListItem click and checkbox click at the same time

I've been trying many things with list items and i'm facing some problems. In my previous question, thanks to #nEx.Software i was able to resolve the problem. But I'm still missing some concepts here.
Right now i'm trying to differentiate between an item's click and a checkbox within it. However, I want to do it without extending the array adapter. Is there a way to use both methods: listView.onItemClickListener() AND listView.getCheckedItemPositions(), together!
There should be a way to use an xml file [doesn't matter how complex it gets] along with extending the available Views and this thing should be done.
Putting it simple, open the gmail app, and u'll find all emails listed with checkboxes where u can click on the checkbox to mark it OR the rest of the item to open the email.
Again, I know that it is doable with extending Adapters and adding an Array for the checkboxes, but, is it possible to use the convenient methods: listView.onItemClickListener() AND listView.getCheckedItemPositions()? is CheckedTextView a part of the solution?
One more thing, rather than just answering me [where i become lazy]
Wheather it is possible or not, is there a verry reliable reference for such issues? I would really like to fully understand everything that goes into this matter... if its not possible, i must be able to tell why!
Thank you :)

add custom row into your listview. into your custom row you add one textview and checkbox into linerlayout and get linerlayout click event.