CounterView | simple Android counter view for showing edittext character | RecyclerView library

I have a counter view which should update as user touch minus and plus buttons.

I'm trying to update counter within ViewPager's adapter instantiateItem method, but it doesn't make any effect.

I can update it's value only in instantiateItem. Is there any way to setText() outside of instantiateItem? Sorry for dumb question, i'm a newbie in Android.

In my example when I click button I have error "dispatch is not a function". Please tell my why? How correct set dispatch in props? Do I need always use useContext for that?

source (codesandbox)

App.tsx

I am trying to change the value of one ViewController by clicking a button inside a second ViewController with delegation. But so far it only prints a message, but doesn't change the value.

I have this class where I defined a view:

I would appreciate a practical advice how to handle this problem, because I'm completely lost.

I have a Contentview presenting a task for user and three button with options for answer. Choosing any of the options user gets immediate response whether the answer right or wrong and a new task immediately presented. As well as, there are three counter that counts general number of answered tasks per session, and respectively number of right and wrong answers per session.

Also I have a toggle that is responsible to fix one of condition for following tasks.

The problem is, that once I click this toggle it accepts a new value, but it is reflected on new task only after user answers old task. Simply speaking it works only with the next task, though I would like the view updated to new task with this fixed condition immediately and task presented before toggling wouldn't be counted as an answer.

ContentView.swift

In this example, when I drag across the screen why does LabelViewRepresentable get re-initialized before every "updateUIView" call? If I make the counter a @State property instead of an @EnvironmentObject property, it only initializes once like I would expect.

I am looking into MVP architecture Implementation in a flutter. and I have implemented one.

View Model:

I call adapter.notifyItemRangeChanged(), but see (via log statements) that positions outside the specified range are being re-bound. What could cause this?

My application contains a RecyclerView with a huge number of items. I have a counter that updates every second, and I want to modify only the visible views in my RecyclerView whenever the counter is updated. I do not want to call notifyDataSetChanged() or otherwise ask the adapter to completely reset the view.

To accomplish this, I use adapter.notifyItemRangeChanged(). I use the overload of this method that accepts a payload object so that I can do an "efficient partial update" (i.e. only update the counter view instead of re-binding the entire ViewHolder).

However, I see in the logs that the RecyclerView is binding ViewHolders that I haven't told it to. For example, if positions 5 through 14 are visible on screen, I get an efficient partial update for 5-14 (as expected), but I also get a full re-bind of positions 17-24.

Additionally, when the RecyclerView does the full re-bind of these other positions, it sometimes calls onCreateViewHolder(). It seems that the RecyclerView wants to bind these other views, but the cache size is smaller than the range it wants to re-bind, so it has to create ViewHolders (which then get immediately thrown away).

Is there any explanation for why these other positions are being re-bound? Again, these positions are outside of the range I notified the adapter for.

If the RecyclerView only ever called onBindViewHolder(), I could live with the performance penalty. But since it sometimes also calls onCreateViewHolder(), flinging the view causes dropped frames. This is not acceptable.

This problem is reproducible with the following app:

MainActivity.java

This is my first question.

I am trying to increment a variable value in a textbox when a button is clicked using primefaces.

But through debug I found out that whenever I click the p:commandButton, EL bean function call, tries to increment the bean class variable "counter", whenever this happens the value of counter is always 0, so it gets incremented to 1 and that is shown in my webpage. It never reaches 2, 3, 4...

Below is the code: