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Android Dialog Fragment RecyclerView wrap content but max height based on constraints?

So I'm working on creating a dialog fragment to allow user to choose from some options. I have a pretty simple layout inside a constraint layout. TextView on top, recycler view, then two buttons at the bottom.
The problem is, I want the recyclerview to be wrap content, so that if there aren't a lot of options, the dialog will shrink down. However, if there are a lot of options, i'd like it to expand but then start scrolling so all views are visible on the screen.
I can't seem to get past the situation where either it constantly is large. Or if I just allow wrap content, the dialog will grow so large the bottom buttons are missing.
I'm assuming it has something to do with some particular constraint options, but I can't figure out the combination. Any ideas?
EDIT: I know an easy answer is to set a max height on the recycler view. I'm hoping to do that same thing but with constraints, so its not a fixed hard height.
EDIT2: It looks like the constraints will work nicely with wrap as default if the view model's height is fixed. I really can't deal with a fixed height view model though...
Thanks

Create a customRecyclerView that override onMeasure method.
public class CustomRecyclerView extends RecyclerView{
public CustomRecyclerView (Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomRecyclerView (Context context) {
super(context);
}
public CustomRecyclerView (Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,
MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, expandSpec);
}
}
you can call the recyclerview like this
<com.example.yourpackage.CustomRecyclerView>

Vertical and horizontal RecyclerViews with PagerSnapHelper

I'm trying to figure out what's the best way to implement two lists, where the parent list can be swiped vertically and the children can be swiped horizontally.
Parent list is assumed to be an infinite list, while the children can have at most n pages.
RecyclerView appears to be the best tool for the job and given the addition of PagerSnapHelper, it's really easy to recreate a page swipe behavior (think ViewPager.)
The current problem I'm facing is that when the we horizontally swipe all the way to the end or the beginning, sometimes the vertical recyclerview (parent) takes over and changes page.
This can be recreated even with a single vertical recyclerview, as follows:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView = (RecyclerView) findViewById(R.id.recyclerView);
LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
PagerSnapHelper snapHelper = new PagerSnapHelper();
SearchAdapter searchAdapter = new SearchAdapter();
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setAdapter(searchAdapter);
snapHelper.attachToRecyclerView(mRecyclerView);
}
A top to bottom or bottom to top swipe/fling will change pages as expected. However, if you do a horizontal motion (left to right or right to left) sometimes the vertical swipe kicks in.
It seems like PagerSnapHelper is very sensitive to fast movements. Is there any way to avoid this page changes when a swipe is initiated horizontally instead of vertically? This issue is more noticeable in my case since I have a horizontal pagersnaphelper as well.
Possible solutions:
Extend RecyclerView an control onTouchEvent and OnInterceptTouchEvent. Haven't figured out a way to use this.
Use GestureDetector
I'm happy to provide more context/code if needed.
Having two PagerSnapHelper may not be a current pattern in Android, but even if I take that part away, I wonder why PagerSnapHelper is so sensitive to some gestures.

I figured the issue when having to PagerSnapHelpers where the parent is vertical, was that the vertical parent was confusing some horizontal swipes as vertical. In order to avoid such confusion I intercept event that are detected as horizontal and disallow the parent to consume such events.
Here's a simplified version of what I did:
public class VerticalRecyclerView extends RecyclerView {
private GestureDetector mGestureDetector;
public VerticalRecyclerView(Context context) {
super(context);
init();
}
public VerticalRecyclerView(Context context, #Nullable AttributeSet attrs) {
super(context, attrs);
init();
}
public VerticalRecyclerView(Context context, #Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
LinearLayoutManager layoutManager = new LinearLayoutManager(getContext());
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
setLayoutManager(layoutManager);
mGestureDetector = new GestureDetector(getContext(), new HorizontalScrollDetector());
}
#Override
public boolean onInterceptTouchEvent(MotionEvent e) {
if (mGestureDetector.onTouchEvent(e)) {
return false;
}
return super.onInterceptTouchEvent(e);
}
public class HorizontalScrollDetector extends
GestureDetector.SimpleOnGestureListener {
#Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
return Math.abs(distanceX) > Math.abs(distanceY);
}
}
}
They key is on how to detect if a scroll should be consider horizontal, as in return Math.abs(distanceX) > Math.abs(distanceY);

apSTRK's class in Kotlin:
class VerticalRecyclerView #JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = 0
) : RecyclerView(context, attrs, defStyleAttr) {
private var mGestureDetector = GestureDetector(context, object : SimpleOnGestureListener() {
override fun onScroll(e1: MotionEvent, e2: MotionEvent, distanceX: Float, distanceY: Float)
= abs(distanceX) > abs(distanceY)
})
override fun onInterceptTouchEvent(e: MotionEvent?) = if (mGestureDetector.onTouchEvent(e)) false
else super.onInterceptTouchEvent(e)
}

Android RecyclerView plus ViewPager

I have a ViewPager that utilizes a RecyclerView for each page and shares ViewItem rows across pages. Accordingly I share a single RecyclerViewPool between them. However, the ViewPager loads each RecyclerView whether or not it is the page on screen. Is there a way to indicate to the RecyclerView that all of its items are offscreen and force its views to be returned to the Recycler?
My sense is that subclassing LinearLayoutManager and overriding its onLayoutChildren method is the way to go, but I don't have much experience with LayoutManager and would like some guidance.

So here is a subclass of LinearLayoutManager that operates the way I described:
public class PageVisibleLinearLayoutManager extends LinearLayoutManager {
public PageVisibleLinearLayoutManager(Context context) {
super(context);
}
public PageVisibleLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
super(context, orientation, reverseLayout);
}
public PageVisibleLinearLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
private boolean pageVisible = true;
void setPageVisible(boolean pageVisible) {
boolean change = (this.pageVisible != pageVisible);
this.pageVisible = pageVisible;
if(change) requestLayout();
}
#Override
public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
if(pageVisible) {
super.onLayoutChildren(recycler, state);
} else {
removeAndRecycleAllViews(recycler);
}
}
}
It works nicely and gives up its views if requested. As dsh mentioned, it is important to mark adjacent pages as being on screen (and I really don't know why setOffscreenPageLimit doesn't limit the number of pages loaded as expected). My previous solution was to use ViewStub and inflate a page only when it was on screen or adjacent. The layout manager method is slightly faster upon initial turning to an unloaded page, but ViewStub has the advantage of pages staying in memory once loaded (making subsequent scrolling more smooth), so I decided to stick with that.
Thank you all. Next question...

Android - How to create Excel sheet type layout?

I want to create an Excel type layout where there is infinite scroll vertically. There are fixed number of columns horizontally, but they should be scrollable.
I tried the below code
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<android.support.v7.widget.RecyclerView
android:id="#+id/table_data_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</HorizontalScrollView>
If I used the above code, then I am able to scroll vertically, but the columns are not scrollable.
Even giving fixed height in the xml for HorizontalScrollView and RecyclerView, the columns do not scroll.
Finally, I found an answer here, where it was advised to extend the RecyclerView and calculate the height dynamically.
public class MySmartRecyclerView extends RecyclerView {
public MySmartRecyclerView(Context context) {
super(context);
}
public MySmartRecyclerView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MySmartRecyclerView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
#Override
public boolean canScrollHorizontally(int direction) {
return false;
}
#Override
public int getMinimumWidth() {
return computedWidth;
}
#Override
protected void onMeasure(int widthSpec, int heightSpec) {
super.onMeasure(widthSpec, heightSpec);
setMeasuredDimension(computedWidth, getMeasuredHeight());
}
#Override
protected int getSuggestedMinimumWidth() {
return computedWidth;
}
}
So is this the only way, this can be achieved? Or is there any other way to achieve this. For RecyclerView inside ScrollView there is NestedScrollView, but no such thing for HorizontalScrollView.
Any pointers will be appreciated. TIA.

There is one alternate solution. You can use this library.

You want to do Ehhhh? Like the guy said, use library. You need and have normal easy to use solutions.
EDIT:
Okay my bad.
You want to infinite scroll vertically, not excel. I'm back from excel topic:
at onScroll listener, you should incriment endlessly the totalItemCount, you do it with double recurssion. From within the function of listener, you call to another listner whereas you call it by a function in the middle, which also increments that number before calling to the same listener again. You simply edit the view and re-attach the listener.

Disable Scrolling in child Recyclerview android

I have a layout consists of a Parent RecyclerView with a sub Recyclerview in it
i know that it is not good to put a list inside another list but i have to so that i can use the sub list features like swiping and drag and drop
My issue is that the child Recyclerview gain focus and stops the parent from scrolling if the touch point was on it
simply i want if the touch was vertically on the child Recyclerview
the parent scrolls up and down and if the touch was horizontal or a click then the child Recyclerview list item swipes left and right.
Any help to achieve this?

I finally found a solution.
Create Custom LinearLayoutManager
public class CustomLinearLayoutManager extends LinearLayoutManager {
public CustomLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
super(context, orientation, reverseLayout);
}
// it will always pass false to RecyclerView when calling "canScrollVertically()" method.
#Override
public boolean canScrollVertically() {
return false;
}
}
Then instantiate it like this for vertical scrolling
CustomLinearLayoutManager customLayoutManager = new CustomLinearLayoutManager(getActivity(),LinearLayoutManager.VERTICAL,false);
Finally set the custom layout as layout manager of recycler view
recyclerView.setLayoutManager(customLayoutManager);

android:nestedScrollingEnabled="false" in the child RecyclerView
You can add
android:nestedScrollingEnabled="false"
to your RecyclerView in XML or
childRecyclerView.setNestedScrollingEnabled(false);
to your RecyclerView in Java.
EDIT:-
childRecyclerView.setNestedScrollingEnabled(false); will work only in android_version>21 devices. to work in all devices use the following
ViewCompat.setNestedScrollingEnabled(childRecyclerView, false);

On your ActivityName.java, inside the onCreate() method write:
RecyclerView v = (RecyclerView) findViewById(R.id.your_recycler_view_id);
v.setNestedScrollingEnabled(false);
By any means, if you are using Coordinator Layout, In case you want to simplify things, and you want to disable nested scrolling.
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<android.support.v7.widget.RecyclerView
android:id="#+id/activitiesListRV"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</android.support.v4.widget.NestedScrollView>
And again you apply the same principle:
On your ActivityName.java, inside the onCreate() method write:
RecyclerView v = (RecyclerView) findViewById(R.id.your_recycler_view_id);
v.setNestedScrollingEnabled(false);
So basically in XML, you have to specify the app: layout_behavior
app:layout_behavior="#string/appbar_scrolling_view_behavior">

While it might not be good practice to have embedded recycler views, sometimes you cannot avoid it. Something like this might work:
public class NoScrollRecycler extends RecyclerView {
public NoScrollRecycler(Context context){
super(context);
}
public NoScrollRecycler(Context context, AttributeSet attrs){
super(context, attrs);
}
public NoScrollRecycler(Context context, AttributeSet attrs, int style){
super(context, attrs, style);
}
#Override
public boolean dispatchTouchEvent(MotionEvent ev){
//Ignore scroll events.
if(ev.getAction() == MotionEvent.ACTION_MOVE)
return true;
//Dispatch event for non-scroll actions, namely clicks!
return super.dispatchTouchEvent(ev);
}
}
This will disable the scroll event, but not the click events. Use this class for the "child" RecyclerView. You want the PARENT recyclerview to scroll, but not the child. Well this should do that, since the parent will just be the standard RecyclerView, but the child will be this custom one with no scrolling, but handles clicks. Might need to disable clicking for the parent RecyclerView.. Not sure as I have not tested this, so consider it just an example...
Also, to use this in XML (incase you didn't know) do the following:
<com.yourpackage.location.NoScrollRecycler
...
... >
...
...
</com.yourpackage.location.NoScrollRecycler>

you can use setNestedScrollingEnabled(false); on sub RecyclerView which stops scrolling inside sub RecyclerView.
In my case code was
mInnerRecyclerView.setNestedScrollingEnabled(false); where mInnerRecyclerView being inner RecyclerView.

Ithink I'm too late but here i found the solution if it's still annoying someone:
RecyclerView v = (RecyclerView);
findViewById(R.id.your_recycler_view_id);
v.setNestedScrollingEnabled(false);
sensorsRecyclerView.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
return true;
}
});

I've tried many suggested solutions and couldn't find one that worked in my case. I have more than 1 RecyclerView inside a ScrollView using a GridLayoutManager. The result from the suggestion above resulted in the ScrollView stopping to scroll whenever I lifted my finger (it didn't glide to the top or bottom of the view when my finger was lifted over a RecyclerView)
Looking through the RecyclerView source, inside the onTouchEvent there is a call to the layout manager:
final boolean canScrollHorizontally = mLayout.canScrollHorizontally();
final boolean canScrollVertically = mLayout.canScrollVertically();
If you override these in a custom layout manager, return false and it will stop scrolling. It also fixes the problem where the ScrollView would stop scrolling abruptly.

<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="#+id/rv"
android:layout_marginTop="2dp"
android:layout_marginLeft="2dp"
android:layout_marginBottom="10dp"
android:layout_marginRight="2dp"
android:nestedScrollingEnabled="false"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>
put the code inside LinearLayout...no need to do anything pragmatically

If you don't want make a custom view, another option is to create a same sized layout in front of the RecyclerView, and make it clickable.
EDIT:
But unfortunately it blocks events for list item too.

The Kotlin way:
recyclerView.layoutManager = object: LinearLayoutManager(recyclerView.context) {
override fun canScrollVertically(): Boolean {
return false
}
}