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How to make the holder in if else statements of onClick method work without final in argument Viewholder in arguments of onBindViewHolder method

I am trying to make a text change when a button located along with the text (layoutPasswd) in recycler view and to change it back if the button is again pressed.Like a password hiding button. The values to the adapter is from a static class object as arraylist. The problem occurring now is that the value for all the items (only for layoutPasswd) in recycler view is same.
public void onBindViewHolder(#NonNull final viewHolder holder, int position) {
holder.layoutUName.setText(users.get(position).getUserName());
pos = position;
holder.layoutPasswd.setText("********");
holder.btnViewChanger.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (holder.view1) {
holder.layoutPasswd.setText(users.get(pos).getPasswd());
holder.btnViewChanger.setText("hide");
holder.view1 = false;
} else {
holder.layoutPasswd.setText("********");;
holder.btnViewChanger.setText("Show");
holder.view1 = true;
}
}
});

You cannot rely on the ViewHolders or Views in a RecyclerView to hold any state, because they are recycled. Every time a view scrolls onto the screen, first it calls your onBindViewHolder function to update the contents of that ViewHolder to match the data.
Any configuration you set on the views or the ViewHolder instance in onBindViewHolder cannot be relied on to stay the same if the view scrolls off the screen, because the original ViewHolder might be recycled to be used for some other data, and when it scrolls back on screen, you might be looking at some other view that has been recycled from other data that just scrolled off the screen.
So if your views have configuration that you want to "stick", you have to back it up when you change it, and restore it in onBindViewHolder. The way you accomplish this will depend on how you are managing the data that you pass to the adapter.
If you can modify your User class, you can add a Boolean to it that stores whether it should show the password. Then in your onBindViewHolder, you restore the state based on this Boolean. And you also update this Boolean when the state changes.
I also updated the way the click listener works to simplify it for toggling. I removed the pos = position line, because almost certainly that is not something you should be doing.
public void onBindViewHolder(#NonNull final viewHolder holder, int position) {
final User user = users.get(position)
holder.layoutUName.setText(user.getUserName());
holder.layoutPasswd.setText(user.isShowPassword() ? user.getPasswd() : "********");
holder.btnViewChanger.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
user.setShowPassword(!user.isShowPassword());
holder.layoutPasswd.setText(user.isShowPassword() ? user.getPasswd() : "********");
holder.btnViewChanger.setText(user.isShowPassword() ? "hide" : "show");
}
});
// ...
}
If you cannot modify the User class, this is more complicated. Then the adapter should have its own ArrayList<Boolean> to store the state by position index, but you need to keep this list at least as long as the data that is bound, and reset everything to false if the whole list of data is refreshed.

On hold event trigger the on click event

I have a ListView displayed on my screen.
When I click on an item (using setOnItemClickListener), you can rename it.
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick() {}
When I hold on an item (using setOnItemLongClickListener), you can delete it.
listview.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick() {}
However, when i hold on an item, it displays the "rename" window and the "delete" window, as if both were triggered.
Any idea on how to prevent this?
Thanks a lot

Try this
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view,
int position, long id) {
return true; //<-- this should be TRUE, not FALSE
}

Input Events This returns a boolean to indicate whether you have consumed the event and it should not be carried further.
If it return true to indicate that you have handled the event and it should stop here.
If it return false if you have not handled it and the event should continue to any other on-click listeners.

You can use setTimeout and .bind to fix your problem with the shortest amount of logic:
var timeoutId = 0;
$('#myElement').mousedown(function() {
timeoutId = setTimeout(myFunction, 1000);
}).bind('mouseup mouseleave', function() {
clearTimeout(timeoutId);
});

Items of RecyclerView are not showing correctly

In my onBindViewHolder of my RecyclerView.Adapter<SearchAdapter.ViewHolder> when user clicks on cardview a button becomes visible. But when I'm scrolling recyclerview some other items buttons are shown as visible too. Why is this happening?
this is my code:
#Override
public void onBindViewHolder(final ViewHolder viewHolder, final int position) {
viewHolder.card.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (viewHolder.content_layout.getVisibility() == View.VISIBLE) {
viewHolder.content_layout.setVisibility(View.GONE);
viewHolder.address.setMaxLines(2);
viewHolder.attribute.setMaxLines(2);
} else {
viewHolder.content_layout.setVisibility(View.VISIBLE);
viewHolder.address.setMaxLines(8);
viewHolder.attribute.setMaxLines(8);
}
}
});
...
}

Once you start scrolling down the list your views get recycled. This means a previously inflated ViewHolder (some that gets created in onCreateViewHolder) is reused.
So what you have to do is to remember the clicked positions (e.g. via a SparseBooleanArray) and check in onBindViewHolder whether the view should be visible (previously clicked) or not.
You can find a basic usage example of the SparseBooleanArray in this StackOverflow post

The 'other' visible items buttons are the ones using the same viewholder that was modified in the callback. So because viewholders (and views) are recycled :
They should only store information that can be retrieved each time the viewholder is bound to a position.
Anything that may be changed in the views state should be refreshed in onBindViewHolder()
In your case you should store the 'is selected' somewhere else and reset the visibility and maxlines in onBindViewHolder() (not only in the callback)

Good idea is to make a class object with all data you need for one item in recycler view, also add there one boolean isItemWasClicked and inside onBindViewHolder() check this boolean and make buttons visible or not.
For example:
public class OneItemOfList{
int priceToDisplay;
String name;
String date;
boolean wasClicked;
}
public class YourAdapter extends RecyclerView.Adapter<OneItemOfList.ViewHolder> {
ArrayList<OneItemOfList> items;
...
#Override
public void onBindViewHolder(ViewHolder viewHolder, final int position) {
viewHolder.view.setText(items.get(position).name);
if (items.get(position).wasClicked)
viewHolder.button.setVisible(View.VISIBLE);
else
viewHolder.button.setVisible(View.GONE);
viewHolder.view2.setOnClickListener(...
OnClick(...){
items.get(position).wasClicked = !items.get(position).wasClicked;
});
}
...
}

create an array for example Boolean array, and when each position clicked, set true in same position of array. and in onBindViewHolder check if that array[position] is true set that item visible if.

Prevent Click-through of Android ImageVIew?

I have an ImageView overlay inside of a RelativeLayout and want to prevent any clicks from going through the ImageView to the Buttons etc that are behind it (thus in effect disabling the entire RelativeLayout).
Is the a simpler way of doing this then iterating the RelativeLayout views and setting them to disabled as I currently am doing using this code:
RelativeLayout rlTest = (RelativeLayout ) findViewById(R.id.rlTest);
for (int i = 0; i < rlTest.getChildCount(); i++) {
View view = rlTest.getChildAt(i);
view.setEnabled(true);
}

you can set the image to be
android:clickable="true"

Simply call rlTest.setClickable(false). This will prevent the click to be propagate to the children

There is a much cleaner way
You can use:
android:onClick="preventClicks"
in XML and in your Activity
public void preventClicks(View view) {}
This works with fragments.
Example inside this Activity has multiple fragments overlapping one another, just by adding the XML attribute in the background of your fragment it will still call the Activity.preventClicks and will prevent touches on fragments behind it

The following solution works in the general case:
_container.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
// NOTE: This prevents the touches from propagating through the view and incorrectly invoking the button behind it
return true;
}
});
It basically blocks any touches from propagating through the view by marking the touch event as handled.
This works on both UI controls and layout containers (ie: LinearLayout, FrameLayout etc.).
The solution to set "clickable" as false did not work for me for layout containers either in code or in the view XML.

I assume that you are using onClickListeners.
How about using onTouchListener instead of onClickListeners. By doing this you will have a control over how deep down in your hierarchy the touch even can be visible. For example, if you have toch listeners on a relative-layout(RL) and a image-view(IV)(contained in RL), and you assign touchListeners to both. Now if you return true from IV's touch event, the lower down member RL will not receive the touch event. However if you return false from from IV's touch event, the lower down member RL will receive the touch event.
Hope this helps!

Just add these two listeners:
// Set an OnTouchListener to always return true for onTouch events so that a touch
// sequence cannot pass through the item to the item below.
view.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
v.onTouchEvent(event);
return true;
}
});
// Set an OnHoverListener to always return true for onHover events so that focus cannot
// pass through the item to the item below.
view.setOnHoverListener(new OnHoverListener() {
#Override
public boolean onHover(View v, MotionEvent event) {
v.onHoverEvent(event);
return true;
}
});

You could use databindings and consume the clicks like this:
android:onClick="#{() -> true}"

In C#, I use an empty delegate:
objectName.Click += delegate {};
I haven't encountered any problems with it but it does prevent clicks from filtering through to underlying controls.

you can also se the root click listener to null:
// Do not process clicks on other areas of this fragment
binding.root.setOnClickListener(null)
This works 100%.
It doesnt affect other listeners that are already set on the fragment's views.

Android: HorizontalScrollView inside ScrollView

I have multiple HorizontalScrollViews inside a ScrollView. Horizontal scroll isn't smooth at all. I have to scroll almost perfectly horizontally for scrolling to work. Is there a simple fix to tweak this ??? Thanks!

You can use Recycler view with Staggered layout manager
StaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(4, StaggeredGridLayoutManager.HORIZONTAL);
RecyclerViewAdapter recyclerViewAdapter = newRecyclerViewAdapter(this);
recyclerView.setAdapter(recyclerViewAdapter); //Don't miss to initialize your adapter

This class creates a ScrollView containing a HorizontalScrollView combined into one class. You can put stuff inside it using the AddChild() method. The dispatchTouchEvent overide keeps the scrolling smooth so you can pan around with a single slide of the finger.
(I recently used this to wrap a programmatically created TextView)
class MultiScrollView extends ScrollView
{
public HorizontalScrollView hscroll;
public MultiScrollView ( Context context )
{
super( context );
}
public void AddChild( View child )
{
hscroll.addView( child );
}
#Override
public boolean dispatchTouchEvent( MotionEvent event )
{
hscroll.dispatchTouchEvent(event);
onTouchEvent(event);
return true;
}
}

If you are using the horizontal scroll view solution from (http://www.dev-smart.com/archives/34) the solution for the cross focus problem between the scroll view and the list view is blocking the focus to the scroll view once you have focus on the list view.
From a technical point of view you should add the following line to the onScroll function inside the HorizontalListView class.
getParent().requestDisallowInterceptTouchEvent(true);
Hope this helps.

I've found the solution and still can't believe that this is what you have to do to make this work normal! Just added blank onClickListener to the each item in the HorizontalScrollView:
item.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
After this slide is really smooth, both upwards and downwards.

In general, you shouldn't be using nested ScrollViews in Android at all, the behaviour of scrolling in this way is unnatural too.
You may want to rethink your layout design, is it anything that couldn't be achieved with an expandable list?

While David's answer works, it has a downside. It passes ScrollView's MotionEvent object directly to HorizontalScrollView.onTouchEvent(), so if HorizontalScrollView or its children try to get the event coordinates, they will get the wrong coordinates which based on ScrollView.
My solution:
public class CustomScrollView extends ScrollView{
/*************skip initialization*************/
#Override
public boolean onInterceptTouchEvent(MotionEvent e){
//returning false means ScrollView is not interested at any events,
//so ScrollView's onTouchEvent() won't be called,
//and all of the events will be passed to ScrollView's child
return false;
}
#Override
public boolean dispatchTouchEvent(MotionEvent ev) {
//manually call ScrollView's onTouchEvent(),
//the vertical scrolling happens there.
onTouchEvent(ev);
//dispatch the event,
//ScrollView's child will have every event.
return super.dispatchTouchEvent(ev);
}
}
Just wrap this CustomScrollView around the HorizontalScrollView in your layout file.