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It's a field of ViewHolder and you return that.
# android
p
It's a field of ViewHolder and you return that.
l
I don't have the itemView at the creation of the Delegate, if you check the code it's created and passed on the bind method which is invoked by a viewholder class after its creation. So if I call itemView.myView the compiler will still produce a findViewById inside this Bind method where I want to use the cached version
p
What is 
BaseDelegateAdapter
?
l
it's a basic recyclerView adapter implementation
p
Then write an 
ExtensionsViewHolder
which extends 
ViewHolder
and implements 
LayoutContainer
and return that subclass there.
l
But instead of doing the binding logic there I register these delegated adapters and I delegate to then, something very similar to `groupie`/`epoxy` library do
Yeah I was thinking that after looking at the groupie implementaion https://github.com/lisawray/groupie/blob/master/example/src/main/java/com/xwray/groupie/example/item/CardItem.kt But one thing I didn't understand is see how the CardItem here extends 
Item
which is basically what you said? I looked at the byte code and it stills this
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Intrinsics.checkParameterIsNotNull(viewHolder, "viewHolder");
      TextView var10000 = (TextView)((LayoutContainer)viewHolder).getContainerView().findViewById(id.tvHeadline);
I'm not sure if the calling 
getContainerView().findViewById
is the same thing as calling 
_$_findCachedViewById
even extending ViewHolder and making it implements 
LayoutContainer
internally the kotlin synthetic doesn't know about the delegated class and don´t generate the 
findCacheViewById
I could be wrong but it seems to me that it's the same thing as not using 
LayoutContainer
p
Maybe you are using an outdated version?
I just tested:
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class ExtensionViewHolder(view: View) : RecyclerView.ViewHolder(view), LayoutContainer {
  override val containerView: View = itemView
}

fun bind(holder: ExtensionViewHolder) {
  holder.title.text = "hello"
}
And the bytecode for that is:
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LINENUMBER 13 L1
    ALOAD 0
    GETSTATIC com/yazio/android/coach/R$id.title : I
    INVOKEVIRTUAL com/yazio/android/coach/data/ExtensionViewHolder._$_findCachedViewById (I)Landroid/view/View;
    CHECKCAST android/widget/TextView
    DUP
    LDC "holder.title"
    INVOKESTATIC kotlin/jvm/internal/Intrinsics.checkExpressionValueIsNotNull (Ljava/lang/Object;Ljava/lang/String;)V
    LDC "hello"
    CHECKCAST java/lang/CharSequence
    INVOKEVIRTUAL android/widget/TextView.setText (Ljava/lang/CharSequence;)V
   L2
l
yes if you do the way you did it works fine, but let's say you have something like this (groupie or my baseadapter)
p
What is "something like this"?
What's different?
l
typing sorry 😛
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inner class ViewHolder(
        parent: ViewGroup,
        @LayoutRes layoutRes: Int
    ) : RecyclerView.ViewHolder(parent.inflate(layoutRes)) {
       //This will delegate to another class
        fun bind(item: BaseViewType) = delegateAdapters[item.getViewType()]?.bindView(itemView, item, this)
    }

`
p
That doesn't implement LayoutContainer
l
even if I make this ViewHolder extends Layout container the other class that is actually making the binding similar to the one I sent you from groupie, doesn't know anything about LayoutContainer
p
the one I sent you from groupie, doesn't know anything about LayoutContainer
Yes it does
It takes a ViewHolder which implements LayoutContainer
Post a minimal self-contained example which demonstrates your issue please
l
I will do it then
p
And btw it only works explicitly
So the original line:
override fun bindView(itemView: View, item: BaseViewType, viewHolder: RecyclerView.ViewHolder) {
That 
viewHolder: RecyclerView.ViewHolder
must be 
viewHolder: ExtensionViewHolder
l
I'm gonna try it here on a self-contained project
Thanks for the attention https://gitlab.com/leobrujah/kotlin-synthetic-test/blob/master/app/src/main/java/com/test/kotlinsyntheticssample/MainActivity.kt here it is two adapters on a self-contained project, one using the library groupie and other one using my own basic implementation
both of them not using cache
p
Here you are not using LayoutContainer at all
Here you are not using the ViewHolder at all
It should be 
viewHolder.textView...
, not 
<http://containerView.xyz|containerView.xyz>
.
l
internally is the result different? because the bytecode is the same
just tested
p
What did you test?
l
either 
viewHolder.textView
or 
<http://containerView.xyz|containerView.xyz>
or 
<http://itemView.xyz|itemView.xyz>
or 
<http://viewHolder.containerView.xyz|viewHolder.containerView.xyz>
produces the same exactly bythe code which is 
findViewById
p
t should be 
viewHolder.textView...
, not 
<http://containerView.xyz|containerView.xyz>
.
VIEWHOLDER.textView
not viewHolder.CONTAINERVIEW.textView
l
have you read what I said? 😄
I don't think you understand the fact the viewHolder is being passed trought the 
bind
method so the container class doesn't have a clue about 
LayoutContainer
this way kotlin compiler can't generate 
findViewByCache
if you run the project and decompile by yourself I think you can see what I´m saying
implementing LayoutContainer by itself doesn´t do any caching magic ... it´s just so the compiler can generate the cache bytecode to it´s containing class and since the delegates RECEIVE an instance of the VIEWHOLDER it doesn´t matter how the heck I call it, the compiler can't generate the cached code
p
Gimme a sec, I'll make a PR
l
thanks for the patience 😛
@Paul Woitaschek I've just updated with the change I mention calling 
viewHolder.textView
as you mention, just so you can see that I tried
p
Gradle is building for 15 minutes now 😄
l
so the code looks like this
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override fun bind(viewHolder: ViewHolder, position: Int) {
        viewHolder.textView.text = content
    }
and the generated bytecode
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TextView var10000 = (TextView)((LayoutContainer)viewHolder).getContainerView().findViewById(id.textView);
p
Ehm
You didn't enable experimental extensions 😛
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androidExtensions {
  experimental = true
}
Read the readme of groupie
l
I just commit with that change
p
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// IMPORTANT!  Enables view caching in viewholders.
   // See: <https://github.com/Kotlin/KEEP/blob/master/proposals/android-extensions-entity-caching.md>
    androidExtensions {
        experimental = true
    }
l
I also commited now at the bottom a version where the cache does work (but does not suits my purposes)
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class CachedViewHolder(override val containerView: View) : RecyclerView.ViewHolder(containerView), LayoutContainer {
    fun bind(model: DummyModel) {
        textView.text = model.content
    }
}
so you can decompile and see the difference between my implementation / groupie / and the normal one with the bind directly on the viewHolder and not delegated
p
This line
should have 
ExtensionsViewHolder
as it's signature
l
changed and stills 
TextView var10000 = (TextView)itemView.findViewById(id.textView);
p
Don't use itemView.textView but viewHolder.textView
l
I'm not anymore 🤣
p
I don't know what's wrong with groupie but for your own class it works like this:
l
when you decompile can you show me a print of your bytecode please?
of the 
DummyModel
specifically
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