Develop Reference

View won't update in dialog after creation

Surely a simple question to ask but I've tried for hours and I can't seem to get the problem !
I have a DialogFragment which contains a
<com.google.android.material.textfield.TextInputLayout
android:id="#+id/interval_input_layout"
style="#style/Widget.MaterialComponents.TextInputLayout.FilledBox.ExposedDropdownMenu"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:boxStrokeWidth="0dp">
<AutoCompleteTextView
android:id="#+id/time_interval_input"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="none"
tools:ignore="LabelFor" />
</com.google.android.material.textfield.TextInputLayout>
This is the listener set on this AutoCompleteView
binding.untilInput.onItemClickListener =
AdapterView.OnItemClickListener { parent, view, position, id ->
when (position) {
0 -> {
binding.numberLayout.visibility = View.GONE
}
1 -> {
binding.numberLayout.visibility = View.GONE
}
2 -> {
binding.numberLayout.visibility = View.VISIBLE
}
}
}
While number layout is just a linear layout like this
<androidx.appcompat.widget.LinearLayoutCompat
android:id="#+id/number_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:orientation="horizontal"
android:padding="16dp">
<com.google.android.material.textview.MaterialTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="For number of events"
android:textColor="?android:textColorSecondary" />
</androidx.appcompat.widget.LinearLayoutCompat>
At first the listener wasn't being called so I set it like this instead of directly calling the function setOnItemClickListener (don't know why that wasn't working) , Now the listener is being called , I even put a breakpoint and debugged it and its setting visibility but its not taking any effect and it does not cause any error so I can't seem to get the problem here

Using a DialogFragment I inflated the view layout with the use of databinding in the method OnCreateView & then in OnViewCreated I worked with my view and caused changes to UI and set listeners to it and again cause changes to UI
in OnCreateDialog I called both of these methods onCreateView (to get the view and set it to dialog) and onViewCreated to setup the view
I tried to find the view using findViewById just to ensure if the databinding was working fine and it was working fine but visibility still won't change and the view won't update !
I still have't gotten to the root of the problem but it seems you have to store the view inside a variable so you don't lose a reference to it when onClickListener is called and in my opinion just when the onClickListener is called getting the view from the binding becomes invalid and it should but the small problem is that I am not calling onDestroy to make the binding null because the binding was invalid at that time !
Now I am just storing a refrence to binding like this
val myvar = binding.monthLayout
and I am capturing the value of myvar inside the onClickListener rather than using the binding

Android BindAdapter with custom attribute with custom values (similar to visible attribute)

I've successfully made my first bind adapter and I wish to know a bit more about it.
I want to know how to make an attribute that can get only specific strings for a different state for my view.
For example every view has the visibility attribute that it can be"gone", "visible", "invisible"
<TextView
android:id="#+id/loading_tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="#id/inventory_items_recycler"
app:layout_constraintEnd_toEndOf="#+id/inventory_items_recycler"
app:layout_constraintStart_toStartOf="#id/inventory_items_recycler"
app:layout_constraintBottom_toBottomOf="#id/inventory_items_recycler"
android:textSize="18sp"
android:visibility="gone"
app:item_id="#{ItemID.BLACK_GLOVES.ordinal()}"
/>
I've made a custom attribute called item_id that get a number that represent enum value. And in my binding utils I have this code:
#BindingAdapter("item_id")
public static void setItemName(TextView tv, int itemId) {
tv.setText(ItemData.get(ItemID.values()[itemId]).getName());
}
I prefer to have something similar to the visibility attribute that it value can be either "visible", "invisible" or "gone"
Bonus::
I wish android studio can auto-complete me for the possibilities that I can use.

You could pass directly the enum to your binding adapter, instead of converting it first to an int and than back to enum.
#BindingAdapter("item_id")
public static void setItemName(TextView tv, ItemID itemId) {
..
}
Then you could pass directly the enum in your xml:
app:item_id="#{ItemID.BLACK_GLOVES}"
This way you'll have a limited number of possibilities to enter and will be less likely to accidentally enter a meaningless integer.
However, binding adapters and custom attibutes are different. With a binding adapter, you still need to use the syntax of binding expression, ie: "#{ }".
android:visibility , on the other hand, is an attribute. You can also define custom attributes for your custom views and get something similar (have a limited number of input options and IDE shows you your options etc). But you shouldn't confuse that with binding adapters. These are two different concepts.

Try this:
#BindingAdapter("isGone")
#JvmStatic
fun View.setVisibility(isGone: Boolean) {
if (isGone) this.visibility = View.GONE else View.VISIBLE
}
Inside your xml:
<com.google.android.material.checkbox.MaterialCheckBox
android:id="#+id/cb_class"
style="#style/TextStyleNormal.White"
android:layout_marginStart="#dimen/margin_large"
isGone="#{isSharedDailyActivity}"// it take boolean value
app:buttonTint="#color/white"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:useMaterialThemeColors="true" />

Which is more recommendable in kotlin?

if i have this button:
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button" />
which is more advisable in kotlin when it comes to calling views?
this:
val buttonVar: Button = findById(R.id.buuton)
buttonVar.setOnClickListener{
//my code
}
or:
button.setOnClickListener{
//my code
}

When it comes to performance in Kotlin , this is more advisable
button.setOnClickListener{
//my code
}
Because calling views by their ID directly will generate a local view cache.
So the when the view is called the first time kotlin plugin will execute findViewById just a single time, and the next time the view gets called, it will get recovered from the cache . So accesing that view will be faster.
You can refer to this link for more informations enter link description here
I hope this will help you, don't forget to accept the answer if it helps you.

First one is recommended now. The reason is because if you do it the second way, you would be using kotlinx synthetic which is no longer a recommended practice. Source

MutableLiveData doesn't work, ObservableField does - why?

I have a very simple code in XML:
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPassword"
android:text="#={viewModel.password}"
android:enabled="#{viewModel.inputEnabled}">
Now when viewModel.inputEnabled is a MutableLiveData<Boolean> underneath, it simply doesn't work, edit is always enabled, regardless of value of inputEnabled. However, it takes only to change inputEnabled to an ObservableField<Boolean> (and switch setValue to set) such that it immediately starts working.
Why is that so? How can I make MutableLiveData work correctly?
Note, that this field is used in three places (to enable/disable form during processing).

I ran in to same issue....make sure to call following in your activity/fragment:
binding.setLifecycleOwner(this)

Espresso AutoCompleteTextView click

So I recently started messing around with Espresso in one of my existing Android projects.
Everything went pretty decently, until I came to find AutoCompleteTextView in my program. I don't seem to understand how to properly click the first thing in the autocomplete list. I'm actually not even sure which to use, onView() or onData() in this instance.

By some reasons which I don't know, AStupidNoob's solution doesn't work. So I found another one:
onView(withText("Spinner Item"))
.inRoot(RootMatchers.isPlatformPopup())
.perform(click());
The AutoCompleteTextView itself
<com.google.android.material.textfield.TextInputLayout
android:id="#+id/textInputLayout2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="12dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
app:layout_constraintEnd_toStartOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<AutoCompleteTextView
android:id="#+id/product"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:completionThreshold="1"
android:hint="#string/product"
android:singleLine="true"
android:textSize="16sp" />
</com.google.android.material.textfield.TextInputLayout>

I think I found a bit of a cleaner method than the accepted answer!
onData(equalTo("ITEM")).inRoot(RootMatchers.isPlatformPopup()).perform(click());
The breakdown:
onData(x) This will find the view rendering the data object matching x in the drop down. The data is provided by the Adaptor given to the AutoCompleteTextView, so it can be an object of any type that Adaptor provides, it probably won't be a View. You'll want to use the standard hamcrest core matchers for this (equalTo, instanceOf, etc...) rather than (withText, withId, etc...). It might be a pain to try and find what object this is and how to match it, but there isn't a neater way: with a lot of items in your adapter some of the views won't even be in the hierarchy yet, so onView can't work! onData will make sure to load the views that match your data. Checkout here (this what onData returns) and here (this loads the matching data)
inRoot(RootMatchers.isPlatformPopup()) So it turns out the dropdown menu is on another window than the default window your activity runs in. So we have to specify that we want to search that window. The accepted answer uses RootMatchers.withDecorView(not(is(mActivityRule.getActivity().getWindow().getDecorView()))) which seems to match any window that is not the default one.
Anyways HTH someone else.

For anyone still running into this issue, despite trying out the accepted solution above, I managed to get it working with help from a github issue I uncovered. For reference, I am using Robolectric 4.6, which I believe may be the reason why I am requiring a different solution from non-instrumented tests.
The solution I came up with (to verify an item is appearing in an AutoCompleteTextView popup is:
fun testAutoCompleteTextViewEntry() {
onView(withId(R.id.editText_search))
.perform(typeTextIntoFocusedView("x"), showDropDown())
onView(withText("xyz"))
.inRoot(RootMatchers.isPlatformPopup())
.check(matches(isDisplayed()))
}
// Somewhere else in your code
fun showDropDown(): ViewAction =
object : ViewAction {
override fun getDescription(): String = "Shows the dropdown menu of an AutoCompleteTextView"
override fun getConstraints(): Matcher<View> = allOf(
isEnabled(), isAssignableFrom(AutoCompleteTextView::class.java)
)
override fun perform(uiController: UiController, view: View) {
val autoCompleteTextView = view as AutoCompleteTextView
autoCompleteTextView.showDropDown()
uiController.loopMainThreadUntilIdle()
}
}

So i finally figured it out, thanks to this previous question:
Testing autocomplete textview using espresso tool
Ill just post my version of it for people who might use it in future.
onData(instanceOf("Whatever your arrayadapter contains".class)).inRoot(RootMatchers.withDecorView(not(is(mActivityRule.getActivity().getWindow().getDecorView())))).perform(ViewActions.click());

Following on from the answer from AStupidNoob on 28 July 2017...
To click on a specific row number of the drop-down list, you can use this:
onData(anything())
.atPosition(2)
.inRoot(RootMatchers.isPlatformPopup())
.perform(click());
To click on a specific item in a specific row number of the drop-down list, you can use this:
onData(anything())
.atPosition(2)
.inRoot(RootMatchers.isPlatformPopup())
.onChildView(withId(R.id.button_on_layout))
.perform(click());

Since the place predictions are inside a recyclerview, after typing the name of the placement, if you want to click on the first option in the predicted list, you can go with one of the RecyclerViewActions methods (actionOnItemAtPosition).
The key is to find out the id of the autocompleted places. It is set up by Google Place SDK but not yourself so might not be that straightforward to find out.
This works for my project, see if it can help:
onView(ViewMatchers.withId(com.google.android.libraries.places.R.id.places_autocomplete_list)).perform(RecyclerViewActions.actionOnItemAtPosition(0,click()));