1. Introduction
Compose and the View system can work together side by side.
In this codelab, you'll be migrating parts of the Sunflower's plant details screen to Compose. We created a copy of the project for you to try out migrating a realistic app to Compose.
By the end of the codelab, you'll be able to continue with the migration and convert the rest of Sunflower's screens if you wish.
For more support as you're walking through this codelab, check out the following code-along:
What you will learn
In this codelab, you will learn:
- The different migration paths you can follow
- How to incrementally migrate an app to Compose
- How to add Compose to an existing screen built using Views
- How to use a View from inside Compose
- How you can create a theme in Compose
- How to test a mixed screen written in both Views and Compose
Prerequisites
- Experience with Kotlin syntax, including lambdas
- Knowing the basics of Compose
What you will need
2. Migration strategy
Jetpack Compose was designed with View interoperability right from the start. To migrate to Compose, we recommend an incremental migration where Compose and View co-exist in your codebase until your app is fully in Compose.
The recommended migration strategy is this:
- Build new screens with Compose
- As you're building features, identify reusable elements and start to create a library of common UI components
- Replace existing features one screen at a time
Build new screens with Compose
Using Compose to build new features that encompass an entire screen is the best way to drive your adoption of Compose. With this strategy, you can add features and take advantage of the benefits of Compose while still catering to your company's business needs
A new feature might encompass an entire screen, in which case the entire screen would be in Compose. If you are using Fragment-based navigation, that means you would create a new Fragment and have its contents in Compose.
You can also introduce new features in an existing screen. In this case, Views and Compose will coexist on the same screen. For example, say the feature you are adding is a new view type in a RecyclerView. In that case, the new view type would be in Compose while keeping the other items the same.
Build a library of common UI components
As you're building features with Compose, you'll quickly realize that you end up building a library of components. You'll want to identify reusable components to promote reuse across your app so that shared components have a single source of truth. New features you build can then depend on this library.
Replace existing features with Compose
In addition to building new features, you'll want to gradually migrate existing features in your app to Compose. How you approach this is up to you, but here are a few good candidates:
- Simple screens - simple screens in your app with few UI elements and dynamicity such as a welcome screen, a confirmation screen, or a settings screen. These are good candidates for migrating to Compose as it can be done with few lines of code.
- Mixed View and Compose screens - screens that already contain a bit of Compose code are another good candidate as you can continue to migrate elements in that screen piece-by-piece. If you have a screen with only a subtree in Compose, you can continue migrating other parts of the tree until the entire UI is in Compose. This is called the bottom-up approach of migration.
The approach in this Codelab
In this codelab, you'll be doing an incremental migration to Compose of the Sunflower's plant details screen having Compose and Views working together. After that, you'll know enough to continue with the migration if you wish.
3. Getting set up
Get the code
Get the codelab code from GitHub:
$ git clone https://github.com/android/codelab-android-compose
Alternatively you can download the repository as a Zip file:
Running the sample app
The code you just downloaded contains code for all Compose codelabs available. To complete this codelab, open the MigrationCodelab
project inside Android Studio.
In this codelab, you're going to migrate Sunflower's plant details screen to Compose. You can open the plant details screen by tapping in one of the plants available in the plant list screen.
Project setup
The project is built in multiple git branches:
- The
main
branch is the codelab's starting point. - The
end
contains the solution to this codelab.
We recommend that you start with the code in the main
branch and follow the codelab step-by-step at your own pace.
During the codelab, you'll be presented with snippets of code that you'll need to add to the project. In some places, you'll also need to remove code that is explicitly mentioned in comments on the code snippets.
To get the end
branch using git, cd
into the directory of the MigrationCodelab
project followed by using the command:
$ git checkout end
Or download the solution code from here:
Frequently asked questions
4. Compose in Sunflower
Compose is already added to the code you downloaded from the main
branch. However, let's take a look at what's required to have it working.
If you open the app-level build.gradle
file, see how it imports the Compose dependencies and enables Android Studio to work with Compose by using the buildFeatures { compose true }
flag.
app/build.gradle
android {
//...
kotlinOptions {
jvmTarget = '1.8'
}
buildFeatures {
//...
compose true
}
composeOptions {
kotlinCompilerExtensionVersion '1.3.2'
}
}
dependencies {
//...
// Compose
def composeBom = platform('androidx.compose:compose-bom:2024.09.02')
implementation(composeBom)
androidTestImplementation(composeBom)
implementation "androidx.compose.runtime:runtime"
implementation "androidx.compose.ui:ui"
implementation "androidx.compose.foundation:foundation"
implementation "androidx.compose.foundation:foundation-layout"
implementation "androidx.compose.material3:material3"
implementation "androidx.compose.runtime:runtime-livedata"
implementation "androidx.compose.ui:ui-tooling"
//...
}
The version of those dependencies are defined in the project-level build.gradle
file.
5. Hello Compose!
In the plant details screen, we'll migrate the description of the plant to Compose while leaving the overall structure of the screen intact.
Compose needs a host Activity or Fragment in order to render UI. In Sunflower, as all screens use fragments, you'll be using ComposeView
: an Android View that can host Compose UI content using its setContent
method.
Removing XML code
Let's start with the migration! Open fragment_plant_detail.xml
and do the following:
- Switch to the Code view
- Remove the
ConstraintLayout
code and 4 nestedTextView
s inside theNestedScrollView
(the codelab will compare and reference the XML code when migrating individual items, having the code commented out will be useful) - Add a
ComposeView
that will host Compose code instead withcompose_view
as view id
fragment_plant_detail.xml
<androidx.core.widget.NestedScrollView
android:id="@+id/plant_detail_scrollview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
android:paddingBottom="@dimen/fab_bottom_padding"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
<!-- Step 2) Comment out ConstraintLayout and its children –->
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="@dimen/margin_normal">
<TextView
android:id="@+id/plant_detail_name"
...
</androidx.constraintlayout.widget.ConstraintLayout>
<!-- End Step 2) Comment out until here –->
<!-- Step 3) Add a ComposeView to host Compose code –->
<androidx.compose.ui.platform.ComposeView
android:id="@+id/compose_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</androidx.core.widget.NestedScrollView>
Adding Compose code
At this point, you are ready to start migrating the plant details screen to Compose!
Throughout the codelab, you'll be adding Compose code to the PlantDetailDescription.kt
file under the plantdetail
folder. Open it and see how we have a placeholder "Hello Compose"
text already available in the project.
PlantDetailDescription.kt
@Composable
fun PlantDetailDescription() {
Surface {
Text("Hello Compose")
}
}
Let's display this on the screen by calling this composable from the ComposeView
we added in the previous step. Open PlantDetailFragment.kt
.
As the screen is using data binding, you can directly access the composeView
and call setContent
to display Compose code on the screen. Call the PlantDetailDescription
composable inside MaterialTheme
as Sunflower uses material design.
PlantDetailFragment.kt
class PlantDetailFragment : Fragment() {
// ...
override fun onCreateView(...): View? {
val binding = DataBindingUtil.inflate<FragmentPlantDetailBinding>(
inflater, R.layout.fragment_plant_detail, container, false
).apply {
// ...
composeView.setContent {
// You're in Compose world!
MaterialTheme {
PlantDetailDescription()
}
}
}
// ...
}
}
If you run the app, you can see "Hello Compose
" displayed on the screen.
6. Creating a Composable out of XML
Let's start by migrating the name of the plant. More exactly, the TextView
with id @+id/plant_detail_name
you removed in fragment_plant_detail.xml
. Here's the XML code:
<TextView
android:id="@+id/plant_detail_name"
...
android:layout_marginStart="@dimen/margin_small"
android:layout_marginEnd="@dimen/margin_small"
android:gravity="center_horizontal"
android:text="@{viewModel.plant.name}"
android:textAppearance="?attr/textAppearanceHeadline5"
... />
See how it has a textAppearanceHeadline5
style, has a horizontal margin of 8.dp
and it's centered horizontally on the screen. However, the title to be displayed is observed from a LiveData
exposed by PlantDetailViewModel
that comes from the repository layer.
As observing a LiveData
is covered later, let's assume we have the name available and is passed as a parameter to a new PlantName
composable that we create in the PlantDetailDescription.kt
file. This composable will be called from the PlantDetailDescription
composable later.
PlantDetailDescription.kt
@Composable
private fun PlantName(name: String) {
Text(
text = name,
style = MaterialTheme.typography.headlineSmall,
modifier = Modifier
.fillMaxWidth()
.padding(horizontal = dimensionResource(R.dimen.margin_small))
.wrapContentWidth(Alignment.CenterHorizontally)
)
}
@Preview
@Composable
private fun PlantNamePreview() {
MaterialTheme {
PlantName("Apple")
}
}
With preview:
Where:
Text
's style isMaterialTheme.typography.headlineSmall
which is similar totextAppearanceHeadline5
from the XML code.- The modifiers decorate the Text to make it look like the XML version:
- The
fillMaxWidth
modifier is used so that it occupies the maximum amount of width available. This modifier corresponds to thematch_parent
value of thelayout_width
attribute in XML code. - The
padding
modifier is used so that a horizontal padding value ofmargin_small
is applied. This corresponds to themarginStart
andmarginEnd
declaration in XML. Themargin_small
value is also the existing dimension resource which is fetched using thedimensionResource
helper function. - The
wrapContentWidth
modifier is used to align the text so that it is centered horizontally. This is similar to having agravity
ofcenter_horizontal
in XML.
7. ViewModels and LiveData
Now, let's wire up the title to the screen. To do that, you'll need to load the data using the PlantDetailViewModel
. For that, Compose comes with integrations for ViewModel and LiveData.
ViewModels
As an instance of the PlantDetailViewModel
is used in the Fragment, we could pass it as a parameter to PlantDetailDescription
and that'd be it.
Open the PlantDetailDescription.kt
file and add the PlantDetailViewModel
parameter to PlantDetailDescription
:
PlantDetailDescription.kt
@Composable
fun PlantDetailDescription(plantDetailViewModel: PlantDetailViewModel) {
//...
}
Now, pass the instance of the ViewModel when calling this composable from the fragment:
PlantDetailFragment.kt
class PlantDetailFragment : Fragment() {
...
override fun onCreateView(...): View? {
...
composeView.setContent {
MaterialTheme {
PlantDetailDescription(plantDetailViewModel)
}
}
}
}
LiveData
With this, you already have access to the PlantDetailViewModel
's LiveData<Plant>
field to get the plant's name.
To observe LiveData from a composable, use the LiveData.observeAsState()
function.
As values emitted by the LiveData can be null
, you'd need to wrap its usage in a null
check. Because of that, and for reusability, it's best to split the LiveData consumption and listening in different composables. So let's create a new composable called PlantDetailContent
that will display Plant
information.
With these updates, the PlantDetailDescription.kt
file should now look like this:
PlantDetailDescription.kt
@Composable
fun PlantDetailDescription(plantDetailViewModel: PlantDetailViewModel) {
// Observes values coming from the VM's LiveData<Plant> field
val plant by plantDetailViewModel.plant.observeAsState()
// If plant is not null, display the content
plant?.let {
PlantDetailContent(it)
}
}
@Composable
fun PlantDetailContent(plant: Plant) {
PlantName(plant.name)
}
@Preview
@Composable
private fun PlantDetailContentPreview() {
val plant = Plant("id", "Apple", "description", 3, 30, "")
MaterialTheme {
PlantDetailContent(plant)
}
}
PlantNamePreview
should reflect our change without having to update it directly since PlantDetailContent
just calls PlantName
:
Now, you've wired up the ViewModel so that a plant name is displayed in Compose. In the next few sections, you'll build the rest of the composables and wire them up to the ViewModel in a similar way.
8. More XML code migration
Now, it's easier to complete what's missing in our UI: the watering info and plant description. Following a similar approach as before, you can already migrate the rest of the screen.
The watering info XML code you removed before from fragment_plant_detail.xml
consists of two TextViews with ids plant_watering_header
and plant_watering
.
<TextView
android:id="@+id/plant_watering_header"
...
android:layout_marginStart="@dimen/margin_small"
android:layout_marginTop="@dimen/margin_normal"
android:layout_marginEnd="@dimen/margin_small"
android:gravity="center_horizontal"
android:text="@string/watering_needs_prefix"
android:textColor="?attr/colorAccent"
android:textStyle="bold"
... />
<TextView
android:id="@+id/plant_watering"
...
android:layout_marginStart="@dimen/margin_small"
android:layout_marginEnd="@dimen/margin_small"
android:gravity="center_horizontal"
app:wateringText="@{viewModel.plant.wateringInterval}"
.../>
Similar to what you did before, create a new composable called PlantWatering
and add Text
composables to display the watering information on the screen:
PlantDetailDescription.kt
@OptIn(ExperimentalComposeUiApi::class)
@Composable
private fun PlantWatering(wateringInterval: Int) {
Column(Modifier.fillMaxWidth()) {
// Same modifier used by both Texts
val centerWithPaddingModifier = Modifier
.padding(horizontal = dimensionResource(R.dimen.margin_small))
.align(Alignment.CenterHorizontally)
val normalPadding = dimensionResource(R.dimen.margin_normal)
Text(
text = stringResource(R.string.watering_needs_prefix),
color = MaterialTheme.colorScheme.primaryContainer,
fontWeight = FontWeight.Bold,
modifier = centerWithPaddingModifier.padding(top = normalPadding)
)
val wateringIntervalText = pluralStringResource(
R.plurals.watering_needs_suffix, wateringInterval, wateringInterval
)
Text(
text = wateringIntervalText,
modifier = centerWithPaddingModifier.padding(bottom = normalPadding)
)
}
}
@Preview
@Composable
private fun PlantWateringPreview() {
MaterialTheme {
PlantWatering(7)
}
}
With preview:
Some things to notice:
- As the horizontal padding and align decoration is shared by the
Text
composables, you can reuse the Modifier by assigning it to a local variable (i.e.centerWithPaddingModifier
). Since modifiers are regular Kotlin objects, you can do that. - Compose's
MaterialTheme
doesn't have an exact match to thecolorAccent
used inplant_watering_header
. For now, let's useMaterialTheme.colorScheme.primaryContainer
that you'll improve in the interop theming section. - In Compose 1. 2.1, using
pluralStringResource
requires opting in toExperimentalComposeUiApi
. In a future version of Compose this may no longer be needed.
Let's connect all the pieces together and call PlantWatering
from the PlantDetailContent
as well. The ConstraintLayout XML code we removed at the beginning had a margin of 16.dp
that we need to include in our Compose code.
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="@dimen/margin_normal">
In PlantDetailContent
, create a Column
to display the name and watering info together and have that as padding. Also, so that the background color and the text colors used are appropriate, add a Surface
that will handle that.
PlantDetailDescription.kt
@Composable
fun PlantDetailContent(plant: Plant) {
Surface {
Column(Modifier.padding(dimensionResource(R.dimen.margin_normal))) {
PlantName(plant.name)
PlantWatering(plant.wateringInterval)
}
}
}
If you refresh the preview, you'll see this:
9. Views in Compose code
Now, let's migrate the plant description. The code in fragment_plant_detail.xml
had a TextView
with app:renderHtml="@{viewModel.plant.description}"
to tell the XML what text to display on the screen. renderHtml
is a binding adapter that you can find in the PlantDetailBindingAdapters.kt
file. The implementation uses HtmlCompat.fromHtml
to set the text on the TextView
!
However, Compose doesn't have support for Spanned
classes nor displaying HTML formatted text at the moment. Thus, we need to use a TextView
from the View system in the Compose code to bypass this limitation.
As Compose is not able to render HTML code yet, you'll create a TextView
programmatically to do exactly that using the AndroidView
API.
AndroidView
allows you to construct a View
in its factory
lambda. It also provides an update
lambda which gets invoked when the View has been inflated and on subsequent recompositions.
Let's do this by creating a new PlantDescription
composable. This composable calls AndroidView
which constructs a TextView
in its factory
lambda. In the factory
lambda, initialize a TextView
that displays HTML formatted text followed by setting the movementMethod
to an instance of LinkMovementMethod
. Finally, in the update
lambda set the text of the TextView
to be htmlDescription
.
PlantDetailDescription.kt
@Composable
private fun PlantDescription(description: String) {
// Remembers the HTML formatted description. Re-executes on a new description
val htmlDescription = remember(description) {
HtmlCompat.fromHtml(description, HtmlCompat.FROM_HTML_MODE_COMPACT)
}
// Displays the TextView on the screen and updates with the HTML description when inflated
// Updates to htmlDescription will make AndroidView recompose and update the text
AndroidView(
factory = { context ->
TextView(context).apply {
movementMethod = LinkMovementMethod.getInstance()
}
},
update = {
it.text = htmlDescription
}
)
}
@Preview
@Composable
private fun PlantDescriptionPreview() {
MaterialTheme {
PlantDescription("HTML<br><br>description")
}
}
Preview:
Notice that htmlDescription
remembers the HTML description for a given description
passed as a parameter. If the description
parameter changes, the htmlDescription
code inside remember
will execute again.
As a result, the AndroidView
update callback will recompose if htmlDescription
changes. Any state read inside the update
lambda causes a recomposition.
Let's add PlantDescription
to the PlantDetailContent
composable and change preview code to display a HTML description too:
PlantDetailDescription.kt
@Composable
fun PlantDetailContent(plant: Plant) {
Surface {
Column(Modifier.padding(dimensionResource(R.dimen.margin_normal))) {
PlantName(plant.name)
PlantWatering(plant.wateringInterval)
PlantDescription(plant.description)
}
}
}
@Preview
@Composable
private fun PlantDetailContentPreview() {
val plant = Plant("id", "Apple", "HTML<br><br>description", 3, 30, "")
MaterialTheme {
PlantDetailContent(plant)
}
}
With preview:
At this point, you've migrated all the content inside the original ConstraintLayout
to Compose. You can run the app to check that it's working as expected.
10. ViewCompositionStrategy
Compose disposes of the Composition whenever the ComposeView
becomes detached from a window. This is undesirable when ComposeView
is used in fragments for 2 reasons:
- The Composition must follow the fragment's view lifecycle for Compose UI
View
types to save state. - When transitions happen, the underlying
ComposeView
will be at a detached state. However, Compose UI elements will still be visible during these transitions.
To modify this behavior, call setViewCompositionStrategy
with the appropriate ViewCompositionStrategy
so it follows the fragment's view lifecycle instead. Specifically, you'll want to use the DisposeOnViewTreeLifecycleDestroyed
strategy to dispose of the Composition when the LifecycleOwner
of the fragment is destroyed.
As PlantDetailFragment
has enter and exit transitions (check nav_garden.xml
for more info), and we'll use View
types inside Compose later, we need to make sure the ComposeView
uses the DisposeOnViewTreeLifecycleDestroyed
strategy. Nonetheless, it's best practice to always set this strategy when using ComposeView
in fragments.
PlantDetailFragment.kt
import androidx.compose.ui.platform.ViewCompositionStrategy
...
class PlantDetailFragment : Fragment() {
...
override fun onCreateView(...): View? {
val binding = DataBindingUtil.inflate<FragmentPlantDetailBinding>(
inflater, R.layout.fragment_plant_detail, container, false
).apply {
...
composeView.apply {
// Dispose the Composition when the view's LifecycleOwner
// is destroyed
setViewCompositionStrategy(
ViewCompositionStrategy.DisposeOnViewTreeLifecycleDestroyed
)
setContent {
MaterialTheme {
PlantDetailDescription(plantDetailViewModel)
}
}
}
}
...
}
}
11. Material theming
We have the text content of plant details migrated to Compose. However, you might have noticed that Compose is not using the right theme colors. It's using purple in the plant name when it should be using green.
To use the correct theme colors, you'll need to customize the MaterialTheme
by defining your own theme and providing your theme's colors.
Customizing MaterialTheme
To create your own theme, open the Theme.kt
file under the theme
package. Theme.kt
defines a composable called SunflowerTheme
which accepts a content lambda and passes it down to a MaterialTheme
.
It doesn't do anything interesting yet—you'll customize that next.
Theme.kt
import androidx.compose.material3.MaterialTheme
import androidx.compose.runtime.Composable
@Composable
fun SunflowerTheme(
content: @Composable () -> Unit
) {
MaterialTheme(content = content)
}
MaterialTheme
allows you to customize its colors, typography and shapes. For now, go ahead and customize the colors by providing the same colors in the Sunflower View's theme. The SunflowerTheme
can also accept a boolean parameter called darkTheme
which will default to true
if the system is in dark mode, otherwise, false
. Using this parameter, we can pass the right color values to MaterialTheme
to match the currently set system theme.
Theme.kt
@Composable
fun SunflowerTheme(
darkTheme: Boolean = isSystemInDarkTheme(),
content: @Composable () -> Unit
) {
val lightColors = lightColorScheme(
primary = colorResource(id = R.color.sunflower_green_500),
primaryContainer = colorResource(id = R.color.sunflower_green_700),
secondary = colorResource(id = R.color.sunflower_yellow_500),
background = colorResource(id = R.color.sunflower_green_500),
onPrimary = colorResource(id = R.color.sunflower_black),
onSecondary = colorResource(id = R.color.sunflower_black),
)
val darkColors = darkColorScheme(
primary = colorResource(id = R.color.sunflower_green_100),
primaryContainer = colorResource(id = R.color.sunflower_green_200),
secondary = colorResource(id = R.color.sunflower_yellow_300),
onPrimary = colorResource(id = R.color.sunflower_black),
onSecondary = colorResource(id = R.color.sunflower_black),
onBackground = colorResource(id = R.color.sunflower_black),
surface = colorResource(id = R.color.sunflower_green_100_8pc_over_surface),
onSurface = colorResource(id = R.color.sunflower_white),
)
val colors = if (darkTheme) darkColors else lightColors
MaterialTheme(
colorScheme = colors,
content = content
)
}
To use this, replace MaterialTheme
uses for SunflowerTheme
. For example, in PlantDetailFragment
:
PlantDetailFragment.kt
class PlantDetailFragment : Fragment() {
...
composeView.apply {
...
setContent {
SunflowerTheme {
PlantDetailDescription(plantDetailViewModel)
}
}
}
}
And all the preview composables in the PlantDetailDescription.kt
file:
PlantDetailDescription.kt
@Preview
@Composable
private fun PlantDetailContentPreview() {
val plant = Plant("id", "Apple", "HTML<br><br>description", 3, 30, "")
SunflowerTheme {
PlantDetailContent(plant)
}
}
@Preview
@Composable
private fun PlantNamePreview() {
SunflowerTheme {
PlantName("Apple")
}
}
@Preview
@Composable
private fun PlantWateringPreview() {
SunflowerTheme {
PlantWatering(7)
}
}
@Preview
@Composable
private fun PlantDescriptionPreview() {
SunflowerTheme {
PlantDescription("HTML<br><br>description")
}
}
As you can see in the preview, the colors should now match the Sunflower theme's colors.
You can also preview the UI in dark theme by creating a new function and passing Configuration.UI_MODE_NIGHT_YES
to the uiMode
of the preview:
import android.content.res.Configuration
...
@Preview(uiMode = Configuration.UI_MODE_NIGHT_YES)
@Composable
private fun PlantDetailContentDarkPreview() {
val plant = Plant("id", "Apple", "HTML<br><br>description", 3, 30, "")
SunflowerTheme {
PlantDetailContent(plant)
}
}
With preview:
If you run the app, it behaves exactly the same as before the migration in both light and dark theme:
12. Testing
After migrating parts of the plant detail screen to Compose, testing is critical to make sure you haven't broken anything.
In Sunflower, PlantDetailFragmentTest
located in the androidTest
folder tests some functionality of the app. Open the file and take a look at the current code:
testPlantName
checks for the name of the plant on the screentestShareTextIntent
checks that the right intent is triggered after tapping on the share button
When an activity or fragment uses compose, instead of using ActivityScenarioRule
, you need to use createAndroidComposeRule
that integrates ActivityScenarioRule
with a ComposeTestRule
that lets you test Compose code.
In PlantDetailFragmentTest
, replace the usage ActivityScenarioRule
with createAndroidComposeRule
. When the activity rule is needed to configure the test, use the activityRule
attribute from createAndroidComposeRule
as follows:
@RunWith(AndroidJUnit4::class)
class PlantDetailFragmentTest {
@Rule
@JvmField
val composeTestRule = createAndroidComposeRule<GardenActivity>()
...
@Before
fun jumpToPlantDetailFragment() {
populateDatabase()
composeTestRule.activityRule.scenario.onActivity { gardenActivity ->
activity = gardenActivity
val bundle = Bundle().apply { putString("plantId", "malus-pumila") }
findNavController(activity, R.id.nav_host).navigate(R.id.plant_detail_fragment, bundle)
}
}
...
}
If you run the tests, testPlantName
will fail! testPlantName
checks for a TextView to be on the screen. However, you migrated that part of the UI to Compose. Thus, you need to use Compose assertions instead:
@Test
fun testPlantName() {
composeTestRule.onNodeWithText("Apple").assertIsDisplayed()
}
If you run the tests, you'll see all of them pass.
13. Congratulations
Congratulations, you've successfully completed this codelab!
The compose
branch of the original Sunflower github project completely migrates the plant details screen to Compose. Apart from what you've done in this codelab, it also simulates the behavior of the CollapsingToolbarLayout. This involves:
- Loading images with Compose
- Animations
- Better dimensions handling
- And more!
What's next?
Check out the other codelabs on the Compose pathway:
Further reading
- Jetpack Compose migration code-along
- Migrate existing View-based apps documentation page