TestScreenManager

Added in 1.1.0

Kotlin |Java

class TestScreenManager : ScreenManager

kotlin.Any
↳	androidx.car.app.ScreenManager
	↳	androidx.car.app.testing.TestScreenManager

The ScreenManager that is used for testing.

This class will track the following usages of the ScreenManager throughout your test:

All the Screens pushed via push, or pushForResult.
All the Screens removed via, pop, popTo, or remove.

Summary

Public functions
`(Mutable)List<Screen!>`	`getScreensPushed()` Returns all the `Screen`s pushed via `push`, and `pushForResult`.
`(Mutable)List<Screen!>`	`getScreensRemoved()` Returns all the `Screen`s removed via `pop`, `popTo`, and `remove`.
`Boolean`	`hasScreens()` Returns `true` if the `Screen` stack has any screens in it.
`Unit`	`pop()` Pops the top `Screen` from the stack.
`Unit`	`popTo(marker: String)` Removes screens from the top of the stack until a `Screen` which has the given `marker` is found, or the root has been reached.
`Unit`	`popToRoot()` Removes all screens from the stack until the root has been reached.
`Unit`	`push(screen: Screen)` Pushes the `screen` to the stack.
`Unit`	`pushForResult( screen: Screen, onScreenResultListener: OnScreenResultListener )` Pushes a `Screen`, for which you would like a result from, onto the stack.
`Unit`	`remove(screen: Screen)` Removes the `screen` from the stack.
`Unit`	`reset()` Resets the values tracked by this `TestScreenManager` and the `Screen` stack.

Inherited functions

From androidx.car.app.ScreenManager

`(Mutable)Collection<Screen!>`	`getScreenStack()` Returns the copy of the current screen stack as a type `Collection`
`Int`	`getStackSize()` Returns the current stack size.
`Screen`	`getTop()` Returns the `Screen` that is at the top of the stack.

Public functions

getScreensPushed

Added in 1.1.0

fun getScreensPushed(): (Mutable)List<Screen!>

Returns all the Screens pushed via push, and pushForResult.

The screens are stored in the order in which they were pushed, where the first screen in the list is the first screen that was pushed.

The screens will be stored until reset is called.

getScreensRemoved

Added in 1.1.0

fun getScreensRemoved(): (Mutable)List<Screen!>

Returns all the Screens removed via pop, popTo, and remove.

The screens are stored in the order in which they were removed, where the first screen in the list, is the first screen that was removed.

The screens will be stored until reset is called.

hasScreens

Added in 1.1.0

fun hasScreens(): Boolean

Returns true if the Screen stack has any screens in it.

pop

fun pop(): Unit

Pops the top Screen from the stack.

If the top Screen is the only Screen in the stack, it will not be removed.

If the app's lifecycle is already in the DESTROYED state, this operation is a no-op.

Throws
`java.lang.IllegalStateException`	if the current thread is not the main thread

popTo

fun popTo(marker: String): Unit

Removes screens from the top of the stack until a Screen which has the given marker is found, or the root has been reached.

The root Screen will not be popped.

If the app's lifecycle is already in the DESTROYED state, this operation is a no-op.

Throws
`java.lang.NullPointerException`	if `marker` is `null`
`java.lang.IllegalStateException`	if the current thread is not the main thread

See also
`setMarker`

popToRoot

fun popToRoot(): Unit

Removes all screens from the stack until the root has been reached.

If the app's lifecycle is already in the DESTROYED state, this operation is a no-op.

Throws
`java.lang.IllegalStateException`	if the current thread is not the main thread

push

fun push(screen: Screen): Unit

Pushes the screen to the stack.

If the screen pushed is already in the stack it will be moved to the top of the stack.

If the app's lifecycle is already in the DESTROYED state, this operation is a no-op.

Throws
`java.lang.NullPointerException`	if `screen` is `null`
`java.lang.IllegalStateException`	if the current thread is not the main thread

pushForResult

fun pushForResult(
    screen: Screen,
    onScreenResultListener: OnScreenResultListener
): Unit

Pushes a Screen, for which you would like a result from, onto the stack.

When the given screen finishes, the onScreenResultCallback will receive a callback to onScreenResult with the result that the pushed screen set via setResult.

If the app's lifecycle is already in the DESTROYED state, this operation is a no-op.

Parameters
`screen: Screen`	the `Screen` to push on top of the stack
`onScreenResultListener: OnScreenResultListener`	the listener that will be executed with the result pushed by the `screen` through `setResult`. This callback will be executed on the main thread

Throws
`java.lang.NullPointerException`	if either the `screen` or the `onScreenResultCallback` are `null`
`java.lang.IllegalStateException`	if the current thread is not the main thread

remove

fun remove(screen: Screen): Unit

Removes the screen from the stack.

If the screen is the only Screen in the stack, it will not be removed.

If the app's lifecycle is already in the DESTROYED state, this operation is a no-op.

Throws
`java.lang.NullPointerException`	if `screen` is `null`
`java.lang.IllegalStateException`	if the current thread is not the main thread

reset

Added in 1.1.0

fun reset(): Unit

Resets the values tracked by this TestScreenManager and the Screen stack.