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How can I make recyclerview scroll by only one direction and disable others

I just want to allow only scroll left in horizontal recyclerview for example. Please help me on that

Best way is to remove other directions item from adapter, which are getting hidden one by one. So when user scroll back ward it will not show up any thing.

I would not touch the data in your adapter (what does the data have to do with a UI business rule?). If you want, you could notify your Repository or ViewModel what views have been "scrolled" but that's a lot of events going up, and state coming down for everyone involved.
You have the tools at your disposal in the form of a combination of:
A GestureDetector (See (the documentation.)
A TouchListener (See (the documentation.)
Your favorite search engine to put these things together.
or perhaps benefit from the somewhat modular approach of RecyclerView:
Using OnItemTouchListener and a OnScrollListener to analyze the events and ignore the ones you don't want.
You could also create your own extended RecyclerView but that's more painful because you now need to change it all over the place you want this behavior.
In any case, your search engine of choice is also a good starting point. But think of this as:
You will need to intercept the touches and flings gestures (as well as other motion actions like "Dpads" and other Accessibility Events that may trigger a "scroll", evaluate in which direction this is headed, and determine if you still want that event to happen.

Android move items with acceleration

I cant seem to find the answer to this, mainly because I don't know what it is called.
I am going to expand a few features in my app, currently users can touch and drag to move forward in a list of images. What I want is for the users to "swipe" there finger and then all of these images will move under acceleration and will slowly come to a stop.
Is this a gesture? If so is it the "Fling" gesture?

There are several ways to do so.
Use ListView
Use Gallery
Use ScrollView
Use HorizontalScrollView
Write your custom ViewGroup or View
For the last approach, you have to detect the Fling gesture as you said and handle all the scrolling animations involved.

Android: Next/Previous fling that sticks to the finger similar to Home Screen

I want to give my app a nice touch by allowing users to slide the page left or right instead of just using next/previous buttons (similar to the home screen).
What is the best way to do that? I assume I would have to override one of the Activity.on... methods and that I would also have to put my page's main View in a ViewGroup that allows me to shift pages left and right.

ViewFlipper is your friend!
Here you can see a nice video of the ViewFlipper in action and also a very good tutorial:
http://www.inter-fuser.com/2009/07/android-transistions-slide-in-and-slide.html

The solution is even easier these days with the release of Compatibility Package r3. You can download here: http://developer.android.com/sdk/compatibility-library.html
It includes
ViewPager: A ViewGroup that manages the layout for the child views, which the user can swipe between.
PagerAdapter: An adapter that populates the ViewPager with the views that represent each page.
and Fragment versions of those, if you are that way inclined.
The pager code is compatible back to API version 4 (1.6), and I just implemented a dynamically generated viewPager coming off a dynamically generated ListView in about 2 hours. I'm a novice, so this is definitely the preferred path.
There is an example app here: http://geekyouup.blogspot.com/2011/07/viewpager-example-from-paug.html

If one wants to flip between two activities perhaps one can apply this animated transition:
Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
startActivity(intent);
finish();
//transition using XML view animations
overridePendingTransition(R.anim.slideinfromright, R.anim.slideouttoleft);

Use GestureDetector to detect if the touch event is a scroll.
If the first event to the first call to onScroll is ACTION_DOWN then you should see if it was a dominantly horizontal scroll. If so then your scroll is started and you should shift the absolute position of the view that fills the page.
For non deprecated absolute positioning, see my answer here Android: Alternative to AbsoluteLayout (I really do need absolute positioning)
You will want to be cautions of whether you return true to consume the touch events or not.
GestureDetector does not have a callback for scrolling having stopped. You will have to check if there was an ACTION_UP before you call GestureDetector.onTouchEvent and if there was an action up and you did have an unfinished scroll then you should set the absolute position to the destination location and use a TranslateAnimation to make it look nice moving from current to destination.
Edit:
GestureDetector did not work well at all if the child views also wanted to respond to touch events. I ended up creating a subclass of FrameLayout (one of the most basic layouts and the closest thing to a non intrusive parent view) and overriding dispatchTouchEvent. I just took all the events and did the detection myself.

cant we use Gallery view here?? with the adapter the whole page can be inflated inside gallery view adapter getView() and it will manage the left right scrolling perfectly.

Android: Detect when ScrollView has finished scrolling and bouncing back?

I have a ScrollView which has two hidden images, one at the top and one at the bottom. In between there is a bunch of visible content.
What I need to do is make these images hidden by default but when you scroll all the way up or all the way down you could see them as you're scrolling. But then as soon as you stop scrolling it should bounce back to the visible area so that the hidden images aren't showing.
Basically I'm trying to imitate the bounce scrolling feature of the iphone UIScrollView.
I have my ScrollView all setup and I do a scroll at the beginning so as to hide the top hidden image. Now all I need to do is detect when a scrolling has ended, figure out the Y position, and check whether a hidden image is shown. If it is, I would just programmatically scroll the view back so that the hidden image is hidden.
I hope all that made sense.
So anyways, I know how to programmatically scroll a ScrollView. Now what I need is some sort of callback to tell me when a ScrollView ended scrolling and also a way to get the ScrollView's current 'Y' position. Are there any such methods I could use?
I looked through the ScrollView docs but nothing jumped out at me. I'm still not very familiar with the Android naming schemes so maybe I missed something obvious somewhere.
Anyways, any help would be appreciated here. Cheers.

You can use an OnTouchListener to detect when the user presses/releases the list.
You can also use the onScrollStateChanged method of the OnScrollListener class (most likely in conjunction with a touch listener) to detect changes in the SCROLL_STATE - when the list has stopped scrolling the state will change from a state that is not SCROLL_STATE_IDLE to SCROLL_STATE_IDLE.
Alternatively if you are using 2.3 or above you can use an OverScroller to get the desired effect (see Modifying Android OverScroll for how to change the over scroll effect to an iPhone like one).

ViewFlipper caching issue

The views are not cached in a ViewFlipper. Is there a way wherein we can get an image of the view and show it to user so that he sees the Ui as we see on Home scrren(when we swipe the previous view also moves along and when we lift our finger, only then the next view is shown completely.)
What I want to do is that when the user starts moving his finegr on screen, the view should also move along(create an image of view).
I am not getting to do this, as when we swipe the present view goes and next view comes, we do not get both visible when we r moving our finger on screen.
Please if anyone gets what I am trying to do, do help me.
Thanks,
Farha

It's tricky to get scroll and swipe tracking working on Android, while using ViewAnimator or its subclasses.
They allow you to set in and out animations and start them at a given moment, but they work with discrete, either-this-or-the-other-view animations. They are actually using FrameLayout and after in or out animation is executed, other views' visibility is set to View.GONE to hide them from showing up under/over your current View.
The Launcher and the Gallery application are actually doing the functionality you want, by using a different approach.
They track the user touch input (onTouchEvent()), on MotionEvent.ACTION_MOVE they perform animations manually and on MotionEvent.ACTION_UP snap to the appropriate view, just like in the iPhone.
Unfortunately, this approach is actually more complicated than it looks like.
With the manual handling, you have to ensure that you are taking care of everything related to the touch input. This includes a lot of flag-raising, value-checking, event-delegating, etc.
If you want to get better acquainted with this, take a look at these classes from Gallery3D or Launcher's source code.
One other way to get nice horizontal scrolling is to use HorizontalScrollView.
You have to figure out a way to recycle your views, like you would with a ListView and you have to add the snap-to-view logic, but if you have to take care of a small number of views it could be the easiest approach.
Hope that helps.